WorldWideScience

Sample records for planetary gear trains

  1. Planetary gear train ring gear and support structure investigation

    Science.gov (United States)

    Valco, Mark J.

    1992-01-01

    Most helicopter transmissions utilize a planetary gear train as the final speed reduction stage. Due to weight constraints these transmissions have high power-to-weight ratios and relatively flexible structures. This investigation addresses the analysis of planetary gear trains with the ring gear mounted on a flexible support structure. The approach utilizes recent advances in automated contact methods for nonlinear finite element analysis. Rather than using a line of action spring to model gear pair mesh stiffness, finite element models of complete gears are developed, and the elastic gear members are engaged and rolled through mesh. The procedure includes detailed gear tooth geometry with profile modifications. A nonlinear approach is required due to large displacements associated with gear rotation and nonlinear boundary conditions associated with the gear tooth surface contact. The updated Lagrangian formulation and the MARC K-4.1 automated contact features are applied in the analysis. The ring gear support structure is modeled by an elastic foundation linking the ring gear to a rigid support. Calculation of gear pair deflections, stresses, transmission error, and mesh stiffness through the gear meshing cycle are demonstrated for external and internal spur gear pairs and a planetary gear train. Issues relating to the accuracy of the nonlinear finite element contact method, gear mesh stiffness, transmission error, and the planetary gear train elastic support structure are discussed.

  2. DESIGN FOR A BI-PLANETARY GEAR TRAIN

    OpenAIRE

    Józef DREWNIAK; Paulina GARLICKA; Aleksandra KOLBER

    2016-01-01

    The article presents the design for a bi-planetary gear train. The project description is supplemented with calculations of kinematics, statics and meshing efficiency of the gear wheels included in the gear train. Excluded are calculations of strength and geometry of gears, shaft and rolling bearing, since they are similar to classical calculations for planetary gears. An assembly drawing in 2D and assembly drawings in 3D of the designed bi-planetary gear train are also shown. This gear train...

  3. Dynamics of early planetary gear trains

    Science.gov (United States)

    August, R.; Kasuba, R.; Frater, J. L.; Pintz, A.

    1984-01-01

    A method to analyze the static and dynamic loads in a planetary gear train was developed. A variable-variable mesh stiffness (VVMS) model was used to simulate the external and internal spur gear mesh behavior, and an equivalent conventional gear train concept was adapted for the dynamic studies. The analysis can be applied either involute or noninvolute spur gearing. By utilizing the equivalent gear train concept, the developed method may be extended for use for all types of epicyclic gearing. The method is incorporated into a computer program so that the static and dynamic behavior of individual components can be examined. Items considered in the analysis are: (1) static and dynamic load sharing among the planets; (2) floating or fixed Sun gear; (3) actual tooth geometry, including errors and modifications; (4) positioning errors of the planet gears; (5) torque variations due to noninvolute gear action. A mathematical model comprised of power source, load, and planetary transmission is used to determine the instantaneous loads to which the components are subjected. It considers fluctuating output torque, elastic behavior in the system, and loss of contact between gear teeth. The dynamic model has nine degrees of freedom resulting in a set of simultaneous second order differential equations with time varying coefficients, which are solved numerically. The computer program was used to determine the effect of manufacturing errors, damping and component stiffness, and transmitted load on dynamic behavior. It is indicated that this methodology offers the designer/analyst a comprehensive tool with which planetary drives may be quickly and effectively evaluated.

  4. Global Analysis of a Planetary Gear Train

    OpenAIRE

    Tongjie Li; Rupeng Zhu

    2014-01-01

    By using the Poincaré-like cell-to-cell mapping method and shooting method, the global characteristics of a planetary gear train are studied based on the torsional vibration model with errors of transmission, time-varying meshing stiffness, and multiple gear backlashes. The study results reveal that the planetary with a certain set of parameters has four coexisting periodic orbits, which are P-1, P-2, P-4, and P-8, respectively. P-1 and P-2 motions are not of long-term stability, P-8 motion ...

  5. DESIGN FOR A BI-PLANETARY GEAR TRAIN

    Directory of Open Access Journals (Sweden)

    Józef DREWNIAK

    2016-06-01

    Full Text Available The article presents the design for a bi-planetary gear train. The project description is supplemented with calculations of kinematics, statics and meshing efficiency of the gear wheels included in the gear train. Excluded are calculations of strength and geometry of gears, shaft and rolling bearing, since they are similar to classical calculations for planetary gears. An assembly drawing in 2D and assembly drawings in 3D of the designed bi-planetary gear train are also shown. This gear train will form the main element of the research in hand.

  6. Global Analysis of a Planetary Gear Train

    Directory of Open Access Journals (Sweden)

    Tongjie Li

    2014-01-01

    Full Text Available By using the Poincaré-like cell-to-cell mapping method and shooting method, the global characteristics of a planetary gear train are studied based on the torsional vibration model with errors of transmission, time-varying meshing stiffness, and multiple gear backlashes. The study results reveal that the planetary with a certain set of parameters has four coexisting periodic orbits, which are P-1, P-2, P-4, and P-8, respectively. P-1 and P-2 motions are not of long-term stability, P-8 motion is of local stability, and P-4 motion is of global stability. Shooting method does not have the capacity of searching coexisting periodic orbits in a global scope, and it is easy to omit some periodic orbits which are far away from the main gropes of periodic orbits.

  7. Efficiency Formulas for the 2K-H Type Planetary Gear Train (A II Type Planetary Gear Train with an Idie Planet Pinion)

    OpenAIRE

    岸, 佐年; 両角, 宗晴

    1989-01-01

    A new 2K-H type planetary gear train with an idle planet pinion is devised. This planetary gear train consists of only spur gears. The function of this planetary gear train is equal to those of the internal 2K-H type planetary gear train and the bevel gear type planetary gear train. The efficiency formulas of this planetary gear train are derived from the theoretical analysis and tabulated. The formulas tabulated can be utilized safely without any understanding of the underlying theory.

  8. Modeling of the process of gear shifting in planetary gear trains of motor vehicles

    OpenAIRE

    Aleksandar R. Grkić; Čedomir V. Duboka; Milan M. Krsmanović

    2011-01-01

    Gear boxes, i. e. the realization of their functions, especially gear shift, have a big impact on vehicle operation quality through their effects on the performance of vehicles and their comfort. This paper shows a method of modeling the transition process during gear shifting in planetary gear trains. The simulation model is developed with in order to provide virtual research of planetary gear trains, which would positively decrease the number of real prototypes, thus considerably saving tim...

  9. Performances of a balanced hydraulic motor with planetary gear train

    Science.gov (United States)

    Yu, Hongying; Luo, Changjie; Wang, Huimin

    2012-07-01

    The current research of a balanced hydraulic motor focuses on the characteristics of the motor with three planet gears. References of a balanced hydraulic motor with more than three planet gears are hardly found. In order to study the characteristics of a balanced hydraulic motor with planetary gear train that includes more than three planet gears, on the basis of analysis of the structure and working principle of a balanced hydraulic motor with planetary gear train, formulas are deduced for calculating the hydraulic motor's primary performance indexes such as displacement, unit volume displacement, flowrate fluctuation ratio, etc. Influences of the gears' tooth number on displacement and flowrate characteristics are analyzed. In order to guarantee the reliability of sealing capability, the necessary conditions that tooth number of the sun gear and the planet gears should satisfy are discussed. Selecting large unit volume displacement and small displacement fluctuation ratio as designing objectives, a balanced hydraulic motor with three planet gears and a common gear motor are designed under the conditions of same displacement, tooth addendum coefficien and clearance coefficient. By comparing the unit volume displacement and fluctuation ratio of the two motors, it can be seen that the balanced hydraulic motor with planetary gear train has the advantages of smaller fluctuation ratio and larger unit volume displacement. The results provide theoretical basis for choosing gear tooth-number of this kind of hydraulic motor.

  10. Modeling of the process of gear shifting in planetary gear trains of motor vehicles

    Directory of Open Access Journals (Sweden)

    Aleksandar R. Grkić

    2011-04-01

    Full Text Available Gear boxes, i. e. the realization of their functions, especially gear shift, have a big impact on vehicle operation quality through their effects on the performance of vehicles and their comfort. This paper shows a method of modeling the transition process during gear shifting in planetary gear trains. The simulation model is developed with in order to provide virtual research of planetary gear trains, which would positively decrease the number of real prototypes, thus considerably saving time and contributing to the quality improvement of the final product (planetary gear train and vehicles in general. Introduction Modeling of gear shift processes has been carried out on the planetary gear type Ravigneaux used in planetary gear trains of motor vehicles. The model was developed modularly, so that more simulation models can be added to the whole. At the same time each subsystem is a model for itself and can be used independently from the main model. Simplified engine model Bearing in mind that, for the simulation of the planetary gear which is the subject of this paper, the necessary input parameters are in the form of engine torque Mm, angular velocity and motor ωm moment of inertia of rotating engine components reduced to the input shaft gear, a simplified model of an internal combustion engine has been formed. Model of external load External load resistance is in the form of the torque Mt occurring on the drive wheel of the vehicle. On the other hand, this load is defined by the moment of inertia of rotating elements from the planetary gear to the drive wheel, reduced to the output shaft. Model of friction transmission simulation Transmission power control in planetary gears is achieved through friction components. The output size of this subsystem is the moment of carrying the friction assembly. Simulation model of the planetary gear train The model simulation of the planetary gear type Ravigneaux was formed in accordance with the kinematic

  11. Teaching Planetary Gear Trains with the Aid of Nomographs

    Directory of Open Access Journals (Sweden)

    Essam Lauibi Esmail

    2013-01-01

    Full Text Available Planetary gear trains (PGTs are introduced to undergraduate mechanical engineering students in the course of Theory of Machines. The complexity of the traditional methods for analyzing PGTs has kept many from becoming familiar with the capability of PGTs in mechanisms and machine design. In this paper a unified general formulation for simultaneously visualizing velocities, torques, and power flow through a train is presented on a single nomograph. Therefore, the increasing complex mechanical systems, such as automotive transmissions, are much easier to understand. Nomographs of Fundamental Gear Entities (FGEs are constructed based on the nomographs of their fundamental circuits, without specifying the exact gear dimensions. They are then unified in one system nomograph. Nomographs are promising to provide designers with an efficient tool for the design of geared mechanisms.

  12. New Design and Improvement of Planetary Gear Trains

    Science.gov (United States)

    Handschuh, Robert (Technical Monitor); Litvin, Faydor L.; Fuentes, Alfonso; Vecchiato, Daniele; Gonzalez-Perez, Ignacio

    2004-01-01

    The development of new types of planetary and planetary face-gear drives is proposed. The new designs are based on regulating backlash between the gears and modifying the tooth surfaces to improve the design. The goal of this work is to obtain a nearly uniform distribution of load between the planet gears. In addition, a new type of planetary face-gear drive was developed in this project.

  13. Dynamic load sharing characteristics and sun gear radial orbits of double-row planetary gear train

    Institute of Scientific and Technical Information of China (English)

    盛冬平; 朱如鹏; 靳广虎; 陆凤霞; 鲍和云

    2015-01-01

    A new non-linear bending-torsional coupled model for double-row planetary gear set was proposed, and planet’s eccentricity error, static transmission error, and time-varying meshing stiffness were taken into consideration. The solution of differential governing equation of motion is determined by applying the Fourier series method. The behaviors of dynamic load sharing characteristics affected by the system parameters including gear eccentricities error, ring gear’s supporting stiffness, planet’s bearing stiffness, torsional stiffness of first stage carrier and input rotation rate were investigated qualitatively and systematically, and sun gear radial orbits at first and second stage were explored as well. Some theoretical results are summarized as guidelines for further research and design of double-row planetary gear train at last.

  14. Nonlinear dynamic modeling of a helicopter planetary gear train for carrier plate crack fault diagnosis

    OpenAIRE

    Fan Lei; Wang Shaoping; Wang Xingjian; Han Feng; Lyu Huawei

    2016-01-01

    Planetary gear train plays a significant role in a helicopter operation and its health is of great importance for the flight safety of the helicopter. This paper investigates the effects of a planet carrier plate crack on the dynamic characteristics of a planetary gear train, and thus finds an effective method to diagnose crack fault. A dynamic model is developed to analyze the torsional vibration of a planetary gear train with a cracked planet carrier plate. The model takes into consideratio...

  15. Aspects of geometric calculation of the planetary gear train with intermediate rollers. Part 1

    Science.gov (United States)

    I-Kan, An; Il'In, A. S.; Lazurkevich, A. V.

    2016-04-01

    The paper presents the geometric calculation of the planetary gear train with intermediate rollers, where the number of intermediate rollers is greater or less than that of the teeth in the annular gear by one, the profile surface of the annular gear teeth being the same. The gear ratio is changed by both a value and a sign.

  16. Aspects of geometric calculation of the planetary gear train with intermediate rollers. Part 1

    OpenAIRE

    An I-Kan; Ilin, A. S.; Lazurkevich, A. V.

    2016-01-01

    The paper presents the geometric calculation of the planetary gear train with intermediate rollers, where the number of intermediate rollers is greater or less than that of the teeth in the annular gear by one, the profile surface of the annular gear teeth being the same. The gear ratio is changed by both a value and a sign.

  17. Kinematic Operating Modes of Two-Speed Two-Carrier Planetary Gear Trains with Four External Shafts

    OpenAIRE

    Troha, Sanjin; Žigulić, Roberto; Karaivanov, Dimitar

    2014-01-01

    Two-speed planetary gear trains with four external shafts, composed of two simple planetary gear trains, are considered in this paper. The labelling system of these trains is defined and all possible variants are determined. Planetary gear trains are divided into three different design groups, and characteristics of trains of each group are given. Possible power flows through the train at both gears for every group are described. An example of determining the function of transmission ratios o...

  18. Symmetry and its Effects on Structures of Planetary Gear Trains

    Science.gov (United States)

    Rajasri, I.; Gupta, A. V. S. S. K. S.; Rao, Y. V. D.

    2014-01-01

    A Planetary Gear Train (PGT) can be represented by a graph and this graph in turn is converted to a link to link adjacency symmetric matrix. Identifying isomorphism in structural synthesis of PGT is very important. Several methods have been adopted by various researchers to test for isomorphism in PGTs and out of these isomorphic PGTs one PGT is selected at random. There is no definite basis for selecting a particular PGT out of these isomorphic PGTs for further generation process. Structural aspects and rating of the PGTs are useful in selecting one such PGT for further generation process. Symmetry in PGTs is one such aspect. Hamming matrix is used to measure the structural aspect of symmetry in PGTs. Symmetry in PGT results in more number of structural arrangements i.e. more symmetry in EGTs results in higher number of structural arrangements as compared to EGTs with no or less symmetry.

  19. Innovative Design of Cam-Controlled Planetary Gear Trains

    Directory of Open Access Journals (Sweden)

    Wen-Hsiang Hsieh

    2011-10-01

    Full Text Available The objective of this paper is to perform the innovation design for the new structures of cam-controlled planetary gear trains (CCPGTs, based on the creative mechanism design methodology. Firstly, the design requirements and design constraints are summarized according to the kinematics characteristics of existing CCPGTs. Then, the (4, 5 and (5, 7 graphs are generated by the theory of number synthesis. After that, the atlas of feasible specialized graphs is obtained. Finally, the atlas of new designs is obtained through the particularization process. In addition, an illustrated example is given, and the feasibility of the design is verified by computer simulation using ADAMS software. The result indicates that new design can produce a more wide range of non-uniform motion than the existing design. Therefore, they are better alternatives for driving a variable speed input mechanism.

  20. HOW TO STEER THE TRANSMISSION RATIO OF PLANETARY CONTINUOUSLY ADJUSTABLE GEAR TRAIN

    Directory of Open Access Journals (Sweden)

    A. M. Dankov

    2016-01-01

    Full Text Available The known attempts to create a continuously-adjustable gear train with solid gears have led to development of some so-called adaptive gears. The most structurally simple version of continuously- adjustable gear train is a two-wheel planetary gear. It is an obvious fact that an active regulation of gear ratio for the gear should be based on the presence of con- trolled elements (parameters and a mechanism for their control. In respect of the mentioned gear one of the controlled elements that is a compound central toothed gear has such controlled parameter as a nominal pitch diameter. In this case it can rotate or remain motionless. Other controlled element which is a planetary carrier has its own radius as a controlled parameter and makes a rotary motion with a great speed of a leading element. The purpose of the control mechanism is to ensure radial displacement of central toothed gear and planet gear sectors in the working gear. The paper describes the mechanism modifications and considers two variants for transfer of control action from its source to an object to be controlled. The transfer is ensured by mechanical gears (two variants and hydraulics.

  1. Analysis of dynamic behavior of multiple-stage planetary gear train used in wind driven generator.

    Science.gov (United States)

    Wang, Jungang; Wang, Yong; Huo, Zhipu

    2014-01-01

    A dynamic model of multiple-stage planetary gear train composed of a two-stage planetary gear train and a one-stage parallel axis gear is proposed to be used in wind driven generator to analyze the influence of revolution speed and mesh error on dynamic load sharing characteristic based on the lumped parameter theory. Dynamic equation of the model is solved using numerical method to analyze the uniform load distribution of the system. It is shown that the load sharing property of the system is significantly affected by mesh error and rotational speed; load sharing coefficient and change rate of internal and external meshing of the system are of obvious difference from each other. The study provides useful theoretical guideline for the design of the multiple-stage planetary gear train of wind driven generator.

  2. Analysis of Dynamic Behavior of Multiple-Stage Planetary Gear Train Used in Wind Driven Generator

    Directory of Open Access Journals (Sweden)

    Jungang Wang

    2014-01-01

    Full Text Available A dynamic model of multiple-stage planetary gear train composed of a two-stage planetary gear train and a one-stage parallel axis gear is proposed to be used in wind driven generator to analyze the influence of revolution speed and mesh error on dynamic load sharing characteristic based on the lumped parameter theory. Dynamic equation of the model is solved using numerical method to analyze the uniform load distribution of the system. It is shown that the load sharing property of the system is significantly affected by mesh error and rotational speed; load sharing coefficient and change rate of internal and external meshing of the system are of obvious difference from each other. The study provides useful theoretical guideline for the design of the multiple-stage planetary gear train of wind driven generator.

  3. Strukturna analiza složenih planetarnih prenosnika snage / Structural analysis of compound planetary gear trains

    Directory of Open Access Journals (Sweden)

    Slavko Muždeka

    2005-03-01

    Full Text Available Određivanje osnovnih kinematičkih i dinamičkih karakteristika složenih planetarnih prenosnika je složen proces za koji je razvijeno više analitičkih, grafičkih i grafoanalitičkih metoda. U radu je prikazan način određivanja prenosnog odnosa, opterećenja elemenata i tokova snage za planetarni red sa spoljašnjim i unutrašnjim ozubljenjem preko polužne analogije i primene strukturnog (Wolfovog simbola. Polužna analogija definisana je i za planetarni red sa spoljašnjim ozubljenjem, za koji je, takođe, definisan strukturni simbol. Definisani strukturni simboli iskorišćeni su za definisanje strukture prenosnika tipa Ravigneaux. Primena strukturne šeme za analizu karakteristika složenih planetarnih prenosnika ilustrovana je kroz analizu određenih funkcionalnih stanja planetarnih menjačkih prenosnika. Posebno je definisana mogućnost analize blokiranih stanja planetarnih menjačkih prenosnika. / Determination of basic cinematic and dynamic characteristics of compound planetary gear trains is complex process. Therefore there are many analytical, graphical and graphic-analytical methods. This paper presents method of determination gear ratios, loads and power flows for planetary gear set with the sun and ring gear by lever analogy with the application of Wolfs structural symbol. The lever analogy and structural symbols are also defined for the planetary gear set with two sun gears. Defined structural symbols are employed for definition of Ravigneaux gear structure. Application of structural schemes for an analysis of compound planetary gear trains is illustrated through analysis of certain planetary gearboxes functional state. The possibility of analysis of blocked compound planetary gear train is defined too.

  4. Nonlinear dynamic modeling of a helicopter planetary gear train for carrier plate crack fault diagnosis

    Institute of Scientific and Technical Information of China (English)

    Fan Lei; Wang Shaoping; Wang Xingjian; Han Feng; Lyu Huawei

    2016-01-01

    Planetary gear train plays a significant role in a helicopter operation and its health is of great importance for the flight safety of the helicopter. This paper investigates the effects of a planet carrier plate crack on the dynamic characteristics of a planetary gear train, and thus finds an effec-tive method to diagnose crack fault. A dynamic model is developed to analyze the torsional vibra-tion of a planetary gear train with a cracked planet carrier plate. The model takes into consideration nonlinear factors such as the time-varying meshing stiffness, gear backlash and viscous damping. Investigation of the deformation of the cracked carrier plate under static stress is performed in order to simulate the dynamic effects of the planet carrier crack on the angular displacement of car-rier posts. Validation shows good accuracy of the developed dynamic model in predicting dynamic characteristics of a planetary gear train. Fault features extracted from predictions of the model reveal the correspondence between vibration characteristic and the conditions (length and position) of a planet carrier crack clearly.

  5. Nonlinear dynamic modeling of a helicopter planetary gear train for carrier plate crack fault diagnosis

    Directory of Open Access Journals (Sweden)

    Fan Lei

    2016-06-01

    Full Text Available Planetary gear train plays a significant role in a helicopter operation and its health is of great importance for the flight safety of the helicopter. This paper investigates the effects of a planet carrier plate crack on the dynamic characteristics of a planetary gear train, and thus finds an effective method to diagnose crack fault. A dynamic model is developed to analyze the torsional vibration of a planetary gear train with a cracked planet carrier plate. The model takes into consideration nonlinear factors such as the time-varying meshing stiffness, gear backlash and viscous damping. Investigation of the deformation of the cracked carrier plate under static stress is performed in order to simulate the dynamic effects of the planet carrier crack on the angular displacement of carrier posts. Validation shows good accuracy of the developed dynamic model in predicting dynamic characteristics of a planetary gear train. Fault features extracted from predictions of the model reveal the correspondence between vibration characteristic and the conditions (length and position of a planet carrier crack clearly.

  6. Dynamic load sharing behavior of transverse-torsional coupled planetary gear train with multiple clearances

    Institute of Scientific and Technical Information of China (English)

    盛冬平; 朱如鹏; 靳广虎; 陆凤霞; 鲍和云

    2015-01-01

    A new nonlinear transverse-torsional coupled model with backlash and bearing clearance was proposed for planetary gear set. Meanwhile, sun gear and planet’s eccentricity errors, static transmission error, and time-varying meshing stiffness were taken into consideration. The differential governing equations of motion were solved by employing variable step-size Rung-Kutta numerical integration method. The behavior of dynamic load sharing characteristics affected by the system parameters including input rate, sun gear’s supporting stiffness and eccentricity error, planet’s eccentricity error, sun gear’s bearing clearance, backlashes of sun-planet and planet-ring meshes were investigated qualitatively and systematically. Some theoretical results are summarized at last which extend the current understanding of the dynamic load sharing behavior of planet gear train, enrich the related literature and provide references for the design of planetary gear train.

  7. Another test for isomorphism in planetary gear trains

    Energy Technology Data Exchange (ETDEWEB)

    Narayanappa, P.; Rao, Y.V.D. [BITS-Pilani. Dept. of Mechanical Engineering, Hyderabad (India)

    2012-07-01

    Wind turbines need overdrives that amplify the speed of turbine shaft and provide high speed at generator shaft. Epicyclic gear trains being compact, convenient to build and operate are most suitable for over drives. Graph theory is used in synthesis of the Epicyclic Gear Trains (EGT) to identify various possible design alternatives. Recursive method is used for generation of EGTs. Test for Isomorphism is essential to remove redundancy in the synthesis of EGTs. A test for isomorphism of EGTs using connectivity count matrix (CCM) is explained. The test is applied to unleveled graphs of EGT with up to seven links. The non-isomorphic graphs were identified by comparing CCMs of the graphs which are generated by adding one link to each of the non-isomorphic graphs of previous stage graphs. This method does not consider the connectivity relations between vertices and levels of the links. The results were compared with previously published results to check the validity of the method explained. (Author)

  8. A novel configuration for a brushless DC motor with an integrated planetary gear train

    Science.gov (United States)

    Yan, Hong-Sen; Wu, Yi-Chang

    2006-06-01

    This paper presents a novel configuration of a brushless DC (BLDC) motor with an integrated planetary gear train, which provides further functional and structural integrations to overcome inherent drawbacks of traditional designs. The effects of gear teeth on the magnetic field and performance of the BLDC motor are investigated. Two standard gear profile systems integrated on the stator with feasible numbers of gear teeth are introduced to reduce the cogging torque. An equivalent magnetic circuit model and an air-gap permeance model are applied to analytically analyze the magnetic field, while the validity is verified by 2-D finite-element method (FEM). Furthermore, the motor performance is discussed and compared with an existing design. The results show that the present design has the characteristics of lower cogging torque and torque ripple than the conventional design, which is of benefit to the widely applications on accurate motion and position control for BLDC motors.

  9. Some structural aspects that are relevant for synthesis of planetary gear trains

    Energy Technology Data Exchange (ETDEWEB)

    Rajasri, I. [Pathfinder Engineering College, Hanamkonda (India); Gupta, A.V.S.S.K.S. [JNTU, Hyderabad (India); Rao, Y.V.D. [BITS-Pilani. Dept. of Mechanical Engineering, Hyderabad (India)

    2012-07-01

    Gear Trains are typically used in various mechanisms including wind turbines and robots to transmit specified motion and/or torque between two or more shafts and wind turbines need drives and overdrives that amplify the speed of turbine shaft and provide high speed at generator shaft. Planetary gear trains (PGT) are compact, easy to build and operate. Therefore PGTs are most suitable for such drives including over drives. Graph theory used in synthesis of the PGTs is also useful to identify various possible structural aspects of the PGTs. Generation of PGTs is followed by the test for isomorphism in PGTs generated. In this context various structural aspects relevant for the synthesis of PGTs is described. (Author)

  10. Random Vibration and Dynamic Analysis of a Planetary Gear Train in a Wind Turbine

    Directory of Open Access Journals (Sweden)

    Jianming Yang

    2016-01-01

    Full Text Available Premature failure of gearboxes is a big challenge facing the wind power industry. It highly depends on fully understanding the embedded dynamics to solve this problem. To this end, this paper investigates the random vibration and dynamics of planetary gear trains (PGTs in wind turbines under the excitation of wind turbulence. The turbulence is represented by the Von Karmon spectrum and implemented by passing white noise through a 2nd-order shaping filter. Then, extra equations are formed and added to the original governing equations of motion. With this augmented equation set, a recursive numerical algorithm based on stochastic Newmark scheme is applied to solve for the statistics of the responses starting from initial conditions. After simulation, the variances of the vibration responses and the dynamic meshing forces at gear meshes are obtained.

  11. 齿轮参数对行星轮系模态的影响%Influence of Gear Parameters on Planetary Gear Train Moding

    Institute of Scientific and Technical Information of China (English)

    王天利; 张键

    2014-01-01

    使用Catia对行星轮系进行实体建模,通过有限元分析软件Workbench的高效率模型导入功能实现了Catia和Workbench 的联合仿真,对行星轮系模型进行动力学模态分析,提取了前9阶固有频率和主振型。在其他参数不变情况下,先对行星轮系中所有齿轮的模数进行改变并对行星轮系进行模态分析,结果表明固有频率随模数增大而减小;在其他参数不变情况下,再对行星轮系中所有齿轮的压力角进行改变并对行星轮系进行模态分析,结果表明固有频率随压力角增大而增大。%This paper builds the model of the planetary gears train, using Catia, simulates it with Catia and Workbench, does its dy-namic analysis and obfains the first nine frequences and mode shapes. The modulus of al gears in planetary gear train are changed and its modal analysis is done without the change of the other parameters. The results show that the natural frequency decreases with the increase of modulus. On the same condition, through changing the pressure angle of al gears in planetary gear train and making its modal analysis, the results show that the natural frequency increases with the increase of the pressure angle .

  12. Finite Element Residual Stress Analysis of Planetary Gear Tooth

    Directory of Open Access Journals (Sweden)

    Jungang Wang

    2013-01-01

    Full Text Available A method to simulate residual stress field of planetary gear is proposed. In this method, the finite element model of planetary gear is established and divided to tooth zone and profile zone, whose different temperature field is set. The gear's residual stress simulation is realized by the thermal compression stress generated by the temperature difference. Based on the simulation, the finite element model of planetary gear train is established, the dynamic meshing process is simulated, and influence of residual stress on equivalent stress of addendum, pitch circle, and dedendum of internal and external meshing planetary gear tooth profile is analyzed, according to non-linear contact theory, thermodynamic theory, and finite element theory. The results show that the equivalent stresses of planetary gear at both meshing and nonmeshing surface are significantly and differently reduced by residual stress. The study benefits fatigue cracking analysis and dynamic optimization design of planetary gear train.

  13. 复杂行星轮系传动比计算的简化法%Simplification Calculation Method of Transmission Ratio of the Complex Planetary Gear Train

    Institute of Scientific and Technical Information of China (English)

    冯仲; 陈甲虎; 张华平

    2012-01-01

    行星传动在齿轮传动中有很多的优点,复杂行星轮系的传动比计算比较复杂,从最简单的行星轮系计算公式中得到启示,将行星架假想成有齿数的内齿轮.并得到了简化公式,举例说明了公式的运用,简化了复杂的行星轮系传动比计算.%Planetary gear transmission has many advantages in gear transmission. It is difficult to calculate the transmission ratio of complex planetary gear train is obtained. An idea from the calculation formula of the simplest planetary gear train is got, a formula to calculate the transmission ratio is proposed, there is supposition that the planetary carrier is an inner gear with teeth. The use of the formula is illustrated and the transmission ratio calculation of the complex planetary gear train is simplified.

  14. 行星轮系侧隙分析理论探讨%Theoretical Discussion on Backlash in Planetary Gear Trains

    Institute of Scientific and Technical Information of China (English)

    王文; 曹罚君; 张跃春; 陈磊

    2015-01-01

    Based on the theory of the backlash for fixed axis gear trains and the motion characteristics of the planetary gear trains ,the floating displacement of the sun gear/annulus was calculated by using the theory of load sharing .The limit deviation of the center distance was substituted by the sum of the floating displacement of the sun gear/annulus and the position errors of the planet gear , an analytical theory of the backlash which was available for the planetary gear trains was presented with the help of aforementioned improvement of the theory of the backlash for fixed axis gear trains .%在充分研究固定中心距齿轮副侧隙分析理论的基础上,结合行星轮系的运动特性,依据均载分析理论测算出太阳轮、齿圈的浮动量,用浮动量及行星轮位置度误差之和代替中心距极限偏差,在原有的侧隙分析理论的基础上进行必要的改进后,建立了一套适用于行星轮系侧隙的分析理论。

  15. The singular point transition concept: A novel continuously variable transmission comprising planetary gear trains and a variator

    Science.gov (United States)

    Gomà Ayats, J. R.; Diego-Ayala, U.; Artes, F. Fenollosa

    2012-01-01

    The singular point transition concept relates a novel type of continuously variable transmission. This transmission comprises a pair of planetary gear trains and a couple of electric motors, used to control the overall speed ratio. Its singularity lies in the topology of operation, with less than 10% of nominal power circulating through the electric path. This low power level is achieved by segmenting the range of operation of the transmission. To validate this technology, a test bed was built. The transmission presented here is able to provide any output/input speed ratio within the interval of 0:1.55, meaning that it also offers the function of an infinite variable transmission. Description of the system and results of experimental tests are presented. The results showed that the transmission is able to function in the whole range of operation. They also showed that under load conditions the fraction of power transmitted through the electric path is maintained around the design value.

  16. Vibration characteristic of basic building block floating planetary gear train%基本构件浮动式行星轮系的振动特性

    Institute of Scientific and Technical Information of China (English)

    尹华魁; 蒋玲莉; 张锐; 李学军

    2014-01-01

    基本构件浮动是解决行星轮系均载问题的有效方法,基本构件浮动会改变整个行星轮系的模态,此类轮系设计过程中,需首先开展其固有特性研究,以规避共振区。研究了圆盘行星架浮动、太阳轮浮动、太阳轮与圆盘行星架同时浮动以及无构件浮动4种情况下行星轮系的振动特性,利用CATIA对行星轮系进行了参数化实体三维建模与干涉分析,通过有限元软件WORKBENCH进行了模态分析,分别提取了前10阶固有频率与振型,并对结果进行了分析和对比。论文研究可为基本构件浮动式行星轮系设计时共振区的规避提供参考和依据。%Floating of the basic building blocks is the effective method to solve the problem that planetary gear train is uneven load,but it change the mode of planetary gear train.Firstly,it is necessary for this kind of gear train to research their inherent characteristics in design process.So the resonance region will be avoided. Therefore,vibration characteristics of planetary gear train in four conditions were researched,which included the disc planet carrier floating,the sun wheel floating,the sun wheel and disc of planet carrier floating and without floating.The three -dimensional modeling software CATIA was used to establish the parametric three -dimensional solid model of the planetary gear train.Then interference was analysed.Through the finite element software WORKBENCH,the modal analysis was carried on that of planetary gear train in four conditions,and respectively to extract the first ten steps natural frequency and vibration mode of this four conditions,and the results was analyzed and compared.The reference and basis was provided for avoiding resonance region of the basic building blocks floating planetary gear train in the design phase.

  17. Dynamics Analysis of Planetary Gear Trains Based on Topological Transformation%基于拓扑变换的行星轮系动力学分析

    Institute of Scientific and Technical Information of China (English)

    汪友明; 薛隆泉

    2013-01-01

    Planetary gear train mechanism analysis and synthesis method is proposed for the type and dimension synthesis.The topological transformation is used to convert the topology diagram into actual gear train system.The transformation ofgear,tied,shaft as well as special auxiliary member changes is proposed.The kinematics and dynamics analysis methods of planetary gear trains are presented based on topology diagram and signal flow diagram and the generation condition of cycle power for planetary gear trains is also discussed.%提出了用于型综合和尺度综合的行星轮系机构分析与综合方法.采用拓扑变换解决由轮系拓扑图与实际轮系机构的转换问题,根据齿轮、系杆、转轴变换以及辅助构件的特殊变换,论述了基于信号流图和拓扑图的行星轮系运动学和动力学分析方法,讨论了行星轮系的循环功率产生条件.

  18. High-Ratio Gear Train

    Science.gov (United States)

    Lefever, A. E.

    1982-01-01

    Proposed arrangement of two connected planetary differentials results in gear ratio many times that obtainable in conventional series gear assembly of comparable size. Ratios of several thousand would present no special problems. Selection of many different ratios is available with substantially similar gear diameters. Very high gear ratios would be obtained from small mechanism.

  19. 一种新型行星轮系机构的研究%Research on a New Planetary Gear Train Mechanism

    Institute of Scientific and Technical Information of China (English)

    俞高红; 俞腾飞; 叶秉良; 贾德宝; 王林伟; 胡海军

    2013-01-01

    分析现有行星轮系机构,提出一种新型的基于偏心圆-不完全非圆齿轮间歇传动行星轮系机构,在一个工作周期内,实现行星轮相对行星架作非匀速间歇转动.介绍该机构的工作原理和运动学特性,建立行星轮系机构模型.开发该行星轮系机构的计算机辅助分析软件,通过人机交互方式得出一组满足非匀速间歇传动的结构参数.基于该参数对该行星轮系机构进行设计及试验,并将该行星轮系机构成功应用于穴盘苗取苗机构的创新设计,并进行取苗试验,从而验证了该行星轮系机构理论模型的正确性和可行性.%A new intermittent drive transfer mechanism of planetary gear train with eccentric circle and incomplete non-circular gear is designed on the basis of the analysis of recent advances.In one work period,non-uniform intermittent rotation of planet gear relative to planet carrier is achieved.Work principle and structural feature of the mechanism are introduced,kinematics model is established.The software of computer-aided analysis for this intermittent drive transfer mechanism of planetary gear train is developed.By human-computer conversation,structural parameters are carried out,which can meet the demand of driving.Based on these parameters,design and test of this intermittent drive transfer mechanism of planetary gear train are carried out.The mechanism has been successfully used in creation design of vegetable plug seedling pick-up mechanism,and experimented with transplanting seedling.The correct and feasible of theoretical model of planetary gear train mechanism are verified.

  20. A Method of Velocity Analysis for Planetary Gear Train%一种行星轮系速度分析方法

    Institute of Scientific and Technical Information of China (English)

    刘东亚; 姚金声

    2012-01-01

    The model of linear pure rolling is established through the theory of pure rolling. And then the model is transferred to planetary gear train, then the relationship expression is given among the linear velocity. Combining the basic knowledge of gear,the relationship among rotation velocity of the sun gear, gear ring and the planet carrier are given. From the model, the relationship of rotation velocity of the planetary pinion is also got.%从纯滚动原理出发,在直线纯滚运动模型的基础上,通过逐步分析,将直线运动模型转化为行星轮系,推出构件间线速度关系式,然后结合齿轮基本知识,进一步导出常用的行星轮系中太阳轮、齿圈及行星架之间的转速关系式以及行星轮转速关系式.

  1. 行星轮系渐开线变位齿轮时变啮合刚度数值计算%Numerical Calculation of Planetary Gear Train Involute Modified Gear Time-Varying Meshing Stiffness

    Institute of Scientific and Technical Information of China (English)

    岳喜铮; 丁问司; 丁康; 曾智杰

    2016-01-01

    齿轮啮合刚度的时变性是齿轮产生振动的主要原因,对齿轮时变刚度进行求解计算具有重要的意义。基于正变位行星轮系外齿轮齿形几何参数的计算方法,根据内外齿轮齿形的不同,推导出内齿轮齿形几何参数计算过程。利用石川公式中轮齿变形计算公式和刚度求解公式,通过 Matlab 编程求得正变位行星轮系内外啮合时变啮合刚度曲线,并与 Weber 能量法计算结果进行对比,结果表明:静态刚度最大误差为3.7%,不考虑幅值为很小值时的动态刚度,前4阶谐波幅值最大误差约为9.1%,精度满足要求,可以为行星轮系运动微分方程提供较为准确的啮合刚度。%The time-varying gear meshing stiffness is the main cause of gear vibration.To caculate the time-varying meshing stiffness has vital significance.Based on geometric parameters calculation method of external gear tooth profile in positive modified planetary gear train,according to the differences between external and internal gear tooth profiles,the geometric parameters calculation method of internal gear tooth profile was deduced in detail.Using Ishikawa tooth deformation calculation formula and stiffness calculation formula,positive modified planetary gear train internal and external time-varying meshing stiffness curves can be got by Matlab programming.Compared with the calculation result of Weber energy method,maximum static stiffness error is 3.7% and the first four order harmonic amplitude maximum error is 9.1% without considering the small amplitude value of the dynamic stiffness.Calculation accuracy meets the requirements.It can provide relatively accurate meshing stiffness for motion differential equation of the planetary gear train.

  2. A Method to Determine the Mesh Phasing in Planetary Gear Train%行星传动啮合相位计算方法研究

    Institute of Scientific and Technical Information of China (English)

    史志伟

    2011-01-01

    The mesh phasing was a key factor which influences the dynamics of planetary gear train and vibration could be suppressed by adjusting the mesh phasing. A method to determine the mesh phasing in planetary gear train was proposed and the calculating process to figure out the mesh phasing between external and internal gear pair at any planet was discussed in detail. Finally, an example is given to validate the method proposed. The mesh phasing results can be used to determine more accurate mesh stiffness and error excitation.%行星传动啮合相位是影响系统动态特性的一种重要因素,调节啮合相位可以实现系统的振动抑制.建立了一种计算行星轮间啮合相位的计算方法.详细讨论了任一行星轮处外啮合与内啮合相位差的计算过程.计算实例验证了方法的有效性,并可根据计算结果确定每个行星轮处更为精确的刚度及误差激励.

  3. On the Meshing Efficiency of 2K-2H Type Planetary Gear Reducer

    Directory of Open Access Journals (Sweden)

    Long-Chang Hsieh

    2013-01-01

    Full Text Available This paper proposes 2K–2H type planetary gear reducer and analyzes its meshing efficiency. First, according to the concept of train value equation, the kinematic design of 2K–2H type planetary gear reducers is carried out. Three 2K–2H type planetary gear reducers are designed to illustrate the design algorithm. Then, based on the latent power theorem, the meshing efficiency equation of 2K–2H type planetary gear reducer is derived. According to the meshing efficiency equation, the meshing efficiencies of 2K–2H type planetary gear reducers are analyzed. The 2K–2H type planetary gear reducer has the following characteristics. (1 There is a power circulation in 2K–2H type planetary gear reducer. (2 Larger reduction ratio makes less meshing efficiency. (3 For the same reduction ratio, larger value ξ42 (ξα will get better meshing efficiency. (4 For 2K–2H type planetary gear reducer, the quality of gears is an important factor. (5 The efficiency of gears manufactured by grinding is only improved by 1.5%; however, meshing efficiency of 2K–2H type planetary gear reducer is improved by 28%~44.8%.

  4. 一种新型自动变速器行星轮系的设计与分析%Design and Analysis of A New Automatic Transmission Planetary Gear Train

    Institute of Scientific and Technical Information of China (English)

    夏鹏飞; 汪韶杰; 李旗号

    2015-01-01

    The planetary gear train is designed on the basis of the structural characteristics of parallel planetary gear train automation transmission .The model of planetary gear train is built by Pro/E software ,the modal analysis is conducted by finite element analysis software ANSYS ,and the natural frequencies and mode shapes of planetary gear train are obtained .This method provides the impor‐tant modal parameters for parallel planetary gear train automation transmission performance optimization ,and lays the theoretical ba‐sis for further improvement on its structure design .%针对并联行星轮系自动变速器的结构特点设计出行星轮系,利用三维建模软件Pro/E建立行星轮系模型,并用有限元分析软件ANSYS对所设计的行星齿轮系进行模态有限元分析,从而可以得出行星轮系的固有频率以及振型,为并联行星轮系自动变速器传动性能的优化提供重要的模态参数,同时也为结构的改进设计提供了理论依据。

  5. Analysis on Calculation Errors for Transmission Ratio of Planetary Gear Train%行星轮系传动比计算误区分析

    Institute of Scientific and Technical Information of China (English)

    庞正刚

    2014-01-01

    行星轮系传动比的计算是机械设计基础中的难点,通过分析容易出错的内容,找准错误所在,加深对传动比计算的理解。%The calculation of planetary gear train transmission ratio is a difficulty in the mechanical design basis.lo-cating errors through analysis on the error-prone contents is to deepen an understanding of transmission ratio calcula-tions.

  6. On the Meshing Efficiency of 2K-2H Type Planetary Gear Reducer

    OpenAIRE

    Long-Chang Hsieh; Hsiu-Chen Tang

    2013-01-01

    This paper proposes 2K-2H type planetary gear reducer and analyzes its meshing efficiency. First, according to the concept of train value equation, the kinematic design of 2K-2H type planetary gear reducers is carried out. Three 2K-2H type planetary gear reducers are designed to illustrate the design algorithm. Then, based on the latent power theorem, the meshing efficiency equation of 2K-2H type planetary gear reducer is derived. According to the meshing efficiency equation, the meshing effi...

  7. Određivanje krutosti planetarnog prenosnika / Determination of gear mesh stiffness in planetary gearing

    Directory of Open Access Journals (Sweden)

    Vojislav Batinić

    2008-04-01

    Full Text Available Kontaktna krutost zubaca jedan je od glavnih generatora unutrašnjih dinamičkih sila u spregama zupčanika planetarnih prenosnika. Neophodan je pri opisivanju dinamičkog ponašanja planetarnih prenosnika, tj. pri postavljanju jednačina dinamičke ravnoteže. U radu je prikazan metodološki pristup analitičkom i eksperimentalnom određivanju krutosti posmatranog planetarnog prenosnika. / Gear mesh stiffness in planetary gearing is one of the main generators of internal dynamic forces. It is necessary in describing dynamic behavior of planetary trains, i.e. in defining their equations of dynamic balance. This paper presents a methodological approach to experimental and analytical calculation of stiffness in planetary gearing.

  8. 基于拓扑学的行星轮系综合与研究%Synthesis and Research of Planetary Gear Train based on Topological Theory

    Institute of Scientific and Technical Information of China (English)

    俞庆; 毛旭东

    2012-01-01

    应用拓扑图对行星轮系进行综合与研究是寻找新行星轮系的一种最有效方法.利用拓扑学探讨了拓扑图基本构成和行星轮系的基本单元,通过对行星轮系演化和反演规律的深入研究得到了行星轮系图库建立的方法与基础,为行星轮系的创新设计提供了一种简单而又可行的途径.%Application of topological graphs to analyze and synthesize planetary gear trains is an effective approach in searching for innovative planetary gear trains. Topological graphs of basic structure and fundamental units of PGTs are discussed as the basis of topological theory. According to the further research of the law of PGTs diversification and inversion, the basic and method of PGTs graph library establishment is obtained. Thus graph library based on variation law is presented as a simple and practical way to create a great number of new PGTs.

  9. Research on Simulation of Contact Force of Fault Planetary Gear Train%故障行星轮系接触力仿真研究∗

    Institute of Scientific and Technical Information of China (English)

    向玲; 陈涛

    2015-01-01

    In order to obtain the changing pattern of contact force of fault planetary gear train, pro/E and ADAMS were used to build the modal of fault planetary gear train and the computation method for contact force based on Hertz theory was also introduced, with the dynamic modal, the contact force and the frequen-cy spectrum of gear meshing were simulated. The simulation results show that the contact force of fault plan-etary gear train contains significant cyclical impact in time domain graph and obvious modulation phenome-non. In frequency domain, not only the failure frequency is found, but also fault characteristic that failure frequency stands for side band in meshing frequency and the frequency doubling is appeared. At the same time, As also can be seen from the frequency domain:the carrier wave is meshing frequency and the modu-lation wave is revolution frequency of the planet wheel.%为获得故障行星轮系啮合传动时接触力的变化规律,运用pro/E与ADAMS建立故障行星轮系的动力学模型,结合Hertz接触理论的接触力计算方法,对故障行星轮系啮合传动时的接触力的变化规律及其频谱特征进行仿真研究。仿真结果表明:故障行星轮系的接触力在时域上具有显著的周期性冲击和明显的调制现象。在频域上,不仅出现了故障频率,而且在啮合频率及其倍频处出现了以故障频率为边频带的故障特征。同时,从频域中还可以看出:载波频率为啮合频率,调制频率为行星轮的公转频率。

  10. Dynamic Meshing Characteristic Analysis of Wind Power Planetary Gear Train%风电行星轮系动态啮合特性分析

    Institute of Scientific and Technical Information of China (English)

    杨海湾; 穆塔里夫·阿赫迈德; 赵阳

    2015-01-01

    The dynamic meshing study is essential for the wind turbine which works in a harsh condition,especially,the gear train will be destructed by the time-varying load.Taking a wind turbine helical planetary gear train as study object,considering the influence of a variety of clearance and friction on meshing,a FEM model is built.By using the nonlinear dynamics method,the variation law of the gear tooth root bending stresses in the processing of the planet gear meshing with the sun gear or the internal gear is studied,the influence of the rotating speed on the meshing impact stresses is analyzed.Though the analyzing,with the speed increasing,the meshing stresses curve could get ahead,the impact stress of gear box and drive shaft will increase,while the curve of the impact stress are overall forward.However,the impact stress can't always increase with the impact speed increasing.%时变风载是风电增速齿轮系破坏的重要原因之一,因此对处于极端恶劣工况风电增速齿轮系动态啮合研究非常重要.以风电斜齿行星轮系为对象,考虑齿侧间隙、轴承游隙及摩擦对啮合的影响,建立了风电斜齿行星齿轮系有限元模型.采用非线性动力学方法,研究了行星齿轮与太阳轮、内齿轮啮合过程中其齿根弯曲应力的变化规律,分析了转速对其啮合冲击应力的影响.通过分析计算得出:转速增加能使齿根弯曲应力曲线提前,行星轮的冲击应力不一定会随着转速的提升而变大;齿轮箱和传动轴受到的冲击应力会随着转速的提升而变大,同时冲力应力曲线整体前移.

  11. Simulation of dynamic characteristics of compound planetary gear trains%复合行星齿轮系动态特性仿真分析

    Institute of Scientific and Technical Information of China (English)

    李国彦; 李方义; 朱兆聚

    2015-01-01

    为了研究复合行星齿轮系振动信号频谱特征,以SD16再制造变速箱复合行星齿轮系为研究对象,建立系统动力学模型。通过系统转速特性、啮合频率以及啮合力计算分析,给出理想啮合力曲线。利用ADAMS仿真平台,对复合齿轮系动力学模型进行验证,并对双排行星架太阳轮与行星轮啮合力在系统绝对坐标系中x轴分量和y轴分量的时域和频域特性进行仿真分析,为再制造变速箱现场故障诊断频谱分析提供参考依据。仿真结果表明:啮合齿轮副啮合力时域波形与理想啮合力曲线基本一致,具有明显的波动性与周期性。在频谱分析中,齿轮副啮合频率的1倍频与2倍频为主要频率,存在明显的幅值调制现象。%In order to study the vibration spectrum of compound planetary gear train, a SD16 remanufacturing gear box was considered, and the dynamic model was established. Through the calculation and analysis of the speed characteristic, meshing frequency and meshing force of the system, the ideal meshing curve was proposed. By using ADAMS platform, the model was verified and the time domain and frequency domain characteristics of meshing force between sun gear and planet gear of the double row planetary gear in absolute coordinate were simulated to provide reference for the fault diagnosis of remanufactured gear box. The simulation results show that the waveform of meshing force in time domain can match up with the ideal meshing curve, which has notable volatility and periodic property. In the frequency domain, the frequency multiplication of 1 and 2 of meshing frequency are the main frequency, which have explicit amplitude modulating characteristic.

  12. 斜齿交错-非圆锥齿轮行星系水稻宽窄行分插机构设计与优化%Design and optimization of transplanting mechanism with planetary gear train composed of helical gears and noncircular bevel gears

    Institute of Scientific and Technical Information of China (English)

    祝建彬; 孙良; 刘晓龙; 武传宇; 张斌

    2014-01-01

    为获取一般性的空间行星轮系传动比,以达到直取秧和小穴口的插秧要求,在斜齿交错椭圆锥行星轮系分插机构的基础上,引入非圆锥齿轮,得到一种斜齿交错-非圆锥行星轮系分插机构,并应用于高速宽窄行插秧机当中。建立了非圆锥齿轮副节曲线的数学表达式和机构的运动学模型;基于Matlab开发平台开发了机构参数优化软件,利用该软件分析了节曲线形状、行星架初始安装角、斜齿轮螺旋角和非圆锥齿轮锥距对理想轨迹姿态、直取秧特征和穴口大小的影响,并以理想轨迹姿态、直取秧、小穴口等要求为目标,通过人机交互方式优选机构参数;与斜齿交错-椭圆锥行星轮系分插机构形成的总传动比及其轨迹进行对比,并得出了斜齿交错-非圆锥行星轮系分插机构轨迹在改进直取秧姿态、降低伤苗率等方面作业性能更优的结论。利用仿真软件Adams进行了机构的运动学仿真,加工分插机构实物,利用通用分插机构试验台完成机构插秧轨迹测试,得出斜齿交错-非圆锥行星轮系分插机构可以更好的满足水稻宽窄行插秧的要求,从而验证了非圆锥齿轮在宽窄行分插机构中应用的优越性。%In order to obtain high-quality wide-narrow distance planting trajectory that can solve the problems such as large horizontal offset of picking seeding trajectory in inclined and shaping wider plant hole, a wide-narrow distance transplanting mechanism with spatial planetary gear train composed of non-circular bevel gears and crossed cylindrical gears was put forward based on spatial planetary gear train composed of elliptical bevel gears and crossed cylindrical gears. Non-circular bevel gears were better than traditional gears, such as circular gears and elliptical gears. In addition, the pitch curve of the non-circular bevel gear was general so that this mechanism could achieve more

  13. Unequal assembly method and Pro/E modeling simulation of NGW planetary gear train%NGW型行星轮系的不等分装配及其Pro/E建模仿真研究

    Institute of Scientific and Technical Information of China (English)

    叶福民; 高杰; 姜卫

    2012-01-01

    The general formula of planetary gear train assembly is explored under uniform and non-uniform condi tions through the research of assembly condition of the planetary gear transmission, and an assembly angle calcu lation method is obtained under non-uniform condition, thus extending the scope of the number of teeth in plane tary gear train assembly. Interface input of design parameters of planetary gear train is realized and the assembly angle of the planetary gear in unequal assembly condition is accurately calculated using MATLAB. The model of planetary gear train is parameterized with Pro/E and the planetary gear transmission is simulated through motion simulation function. The gears' interference condition is also analyzed and the planetary gear train motion is veri fied by observation of three-dimensional modeling design and through motion simulation.%通过对行星轮系装配条件的探讨,给出了其在均布及不均布情况下的通用公式,得出了行星轮不均布情况下的装配角度计算方法,扩大了行星传动的齿数选择范围.运用MATLAB软件,将装配条件相关要求进行程序化,实现设计参数的界面输入,计算出行星轮不等分情况下所需要的装配角度,减少设计人员计算量,提高设计校核效率.同时,对设计出的行星轮系进行Pro/E参数化建模及运动仿真,验证设计的行星轮系运动情况并分析其运动是否干涉,从而为工程实践中的生产加工提供参考.

  14. Kinematic precision of gear trains

    Science.gov (United States)

    Litvin, F. L.; Goldrich, R. N.; Coy, J. J.; Zaretsky, E. V.

    1982-01-01

    Kinematic precision is affected by errors which are the result of either intentional adjustments or accidental defects in manufacturing and assembly of gear trains. A method for the determination of kinematic precision of gear trains is described. The method is based on the exact kinematic relations for the contact point motions of the gear tooth surfaces under the influence of errors. An approximate method is also explained. Example applications of the general approximate methods are demonstrated for gear trains consisting of involute (spur and helical) gears, circular arc (Wildhaber-Novikov) gears, and spiral bevel gears. Gear noise measurements from a helicopter transmission are presented and discussed with relation to the kinematic precision theory.

  15. Kinematic precision of gear trains

    Science.gov (United States)

    Litvin, F. L.; Goldrich, R. N.; Coy, J. J.; Zaretsky, E. V.

    1983-01-01

    Kinematic precision is affected by errors which are the result of either intentional adjustments or accidental defects in manufacturing and assembly of gear trains. A method for the determination of kinematic precision of gear trains is described. The method is based on the exact kinematic relations for the contact point motions of the gear tooth surfaces under the influence of errors. An approximate method is also explained. Example applications of the general approximate methods are demonstrated for gear trains consisting of involute (spur and helical) gears, circular arc (Wildhaber-Novikov) gears, and spiral bevel gears. Gear noise measurements from a helicopter transmission are presented and discussed with relation to the kinematic precision theory. Previously announced in STAR as N82-32733

  16. Vibration characteristics of single-stage planetary gear transmissions

    OpenAIRE

    Molina Vicuña,Cristián

    2014-01-01

    Condition monitoring based on vibration measurement and analysis of planetary gear transmissions has not provided the same good results observed in conventional fixed-shaft gear transmissions. One of the causes being the improper interpretation of the vibration spectrum. The structure of the lines present in the spectrum of the vibrations measured on a non-faulty planetary gear transmission, with a sensor mounted on the outer part of the ring gear, is strictly related to the geometry of the t...

  17. Impacts of Sliding Friction on Planetary Gear Train Nonlinear Vibration%齿间滑动摩擦对行星轮系非线性振动的影响

    Institute of Scientific and Technical Information of China (English)

    卫一多; 刘凯; 崔亚辉; 赵常青

    2011-01-01

    考虑齿间互动摩擦和时变刚度非线性因素,建立扭转行星轮系动力学模型.根据齿间摩擦的特点,将啮合周期划分为三个阶段.用解析和数值计算相结合的方法,研究行星轮系齿间滑动摩擦、齿间载荷分配系数、相位差等参数对行星轮系非线性振动和稳定性的影响.发现在考虑齿间滑动摩擦力时,行星轮系非线性动力学存在如下特点:摩擦因子对行星轮系各构件的摩擦振幅有重要影响,特别对太阳轮的影响最为明显;相位差的存在改善了行星轮系啮合刚度的分布,对减小各构件的摩擦振幅和提高系统的参数稳定性有重要影响.研究结果表明,齿间滑动摩擦对行星轮系非线性振动动力学的影响不容忽视,尤其是在低速、重载的工况下.%In considering the interactive friction among gear teeth and the nonlinear factors of time fluctuation stiffness, dynamic model of rotational planetary gear train is established. Based on the features among gear friction, mesh period can be divided into three segments. Impact of sliding friction, load distribution among gear teeth coefficient, phase of planetary gear train are studied by analytical method and numerical calculation. When the sliding friction is considered, the nonlinear dynamics of planetary gear train has following characteristics:the friction of amplitude is significantly effected by friction factor,the amplitude of sun is more sensitive than others. The existence of phase of planetary gear train can improve mesh stiffness distribution, the phase has an important influence on friction of amplitude and improves the stability of system. Research shows that sliding friction impact of nonlinear dynamics on planetary gear train can not be ignored espically in the case of low speed and heavy load.

  18. 非等模数非等压力角行星齿轮系的动力学均载特性%Dynamic Load-Sharing Behaviors of Planetary Gear Train System with Unequal Moduli and Pressure Angles

    Institute of Scientific and Technical Information of China (English)

    叶福民; 朱如鹏; 鲍和云; 靳广虎

    2011-01-01

    考虑由各齿轮的偏心误差和齿频误差引起的内部激励,建立了非等模数非等压力角NGW型行星齿轮系的动力学微分方程,应用Fourier级数法求解方程,并给出了动载系数的表达式.在此基础上,将其与等模数等压力角齿轮系的均载效果进行比较,并讨论了太阳轮分度圆压力角、齿轮误差、太阳轮转速对该系统均载特性的影响.计算结果表明:设计非等模数非等压力角行星齿轮系时,通过确定合适的齿轮压力角,能够使系统具有较好的均载特性;太阳轮浮动支承机构可以改善系统的均载性能;转速对系统的均载有较大的影响,相同转速下的非等模数非等压力角设计有着较好的均载效果.%In this paper, first, a dynamic differential equation of the NGW planetary gear train system with unequal moduli and pressure angles is established by taking into consideration the internal excitation caused by the eccentric error and tooth-frequency error of each gear. Next, the equation is solved by means of Fourier series method.Then, the dynamic load coefficients are formulated and are compared with those of the normal gear train. Finally,the load-sharing behaviors of the gear train, which are affected by the sun-gear pressure angles in pitch circle, the gear error and the rotating speed of the sun gear, are analyzed. Calculated results indicate that the planetary gear train with suitable pressure angles is of excellent load-sharing behaviors, that the floating sun gear improves the load-sharing behaviors and the rotating speed also greatly influences the load-sharing, and that, at the same rotating speed, the loading-sharing effect of the planetary gear train with unequal moduli and pressure angles is better than that of the normal one.

  19. 一种共轴输出封闭差动行星轮系分析%Analysis of a Coaxial Output Encased Differential Planetary Gear Train

    Institute of Scientific and Technical Information of China (English)

    余震; 朱自冰; 聂慧阳

    2016-01-01

    针对直升机共轴输出的要求,提出了一种实现共轴输出的封闭差动行星传动机构,该构型由定轴轮系和差动行星轮系构成,同时给出了该构型传动比条件、同心条件、邻接条件、装配条件等齿数匹配约束条件;研究了该构型的各个主要部件的受力情况。采用Romax软件和AGMA标准对构型的设计进行了仿真和强度验证。研究结果表明,该构型能够在较小的尺寸下,传递较大的功率,实现共轴输出的要求。%According to the requirements of coaxial output of helicopters, a transmission configuration of coaxial output encased dif-ferential planetary is presented. This configuration is composed of ordinary gear train and differential gear train. The constraint condi-tions of tooth number matching such as the transmission ratio condition, concentricity condition, adjacency condition and assembly condition are also presented. Attention is paid to the load on the main component of the configuration. Simulation and strength verifi-cation of scheme are conducted by Romax and AGMA standard, which shows that the scheme with smal er size can offer larger transmission power and meet the requirements of the coaxial output.

  20. 行星轮系的机架变换与传动比变化规律的研究%Research on the variation law of transmission ratio and frame alternation of planetary gear train

    Institute of Scientific and Technical Information of China (English)

    程爱明; 赵自强; 张春林

    2009-01-01

    The frame alternation method is an important meth-od of mechanism innovation; it has significant application prospects in the innovative design of gear train. Taking the simplest gear train as the innovative base, this paper probed into the transmission ratio relationship between the new gear train after the alternation of frame and the original gear train, thus an important conclusion was educed that the sum of the transmission ratio that takes the gear train link-ing bar as the output component and the transmission ratio of the mechanism when the linking bar was fixed equals to one. And then a certification was carried out on this conclusion. By means of car-tying out the calculations of transmission ratios on the typical plane-tary gear train, the fewer teeth differenced transmission, the transla-tional gear transmission and the frame alternation of complex hybrid gear train, the correctness of this conclusion was verified. Finally the important role of this conclusion in the calculation of transmis-sion ratio of the complex planetary gear train was clarified.%转换机架法是机构创新的重要方法,在轮系的创新设计中有重要应用前景.文中以最简单的轮系为创新基础,探讨机架变换后的新轮系与原轮系的传动比关系,得出重要结论:以轮系系杆为输出构件时的传动比与系杆固定时机构的传动比之和为1.然后对该结论进行证明,再通过典型的行星轮系、少齿差传动、平动齿轮传动和复杂的混合轮系的机架变换进行传动比的计算,验证了该结论的正确性.最后阐明了该结论在复杂行星轮系传动比计算中的重要作用.

  1. Optimization and Verification of HMT Planetary Gear Train in High-speed Transplanter%高速插秧机 HMT 行星轮系机构的优化设计

    Institute of Scientific and Technical Information of China (English)

    李革; 李明杰; 俞高红

    2014-01-01

    This paper discussed the problem:The key to solve the hardness of the design of hydraulic mechanical trans-mission ( HMT) planetary gear train in High speed transplanter .The paper wrote with the design goal of the minimum volume of planetary gear train from some aspects , which is to meet the transmission requirements , reduce the weight , en-sure the tooth root bending fatigue strength and gear surface contact fatigue strength .With the establishment of objective function and constraint function , an optimum design math-model has been set up .By fmincon function for solving con-strained nonlinear programming problems in MATLAB optimization toolbox , the optimization problem was solved .At the same time , the specific steps of optimization of planetary gear system are given .Such as a real example calculation and a-nalysis of HMT planetary gear train , compared the optimization design results with the conventional design method re-sults, the volume and weight of HMT planetary gear train decreases by 24%, the space of assembly is reduce , what’ s more, the strength of the gear transmission is within the allowable range .%针对高速插秧机液压机械无级变速器( HMT )行星齿轮系设计困难的问题,从满足传动要求,保证齿轮弯曲疲劳强度、齿面接触疲劳强度及减轻质量的角度出发,以行星齿轮系体积最小或质量最轻为优化目标,确立目标函数与约束条件,建立最优设计的数学模型,选用 MATLAB 优化工具箱中求解约束非线性规划问题的 fmin-con函数进行优化问题的求解。通过对一种高速插秧机HMT行星齿轮系的实例设计,优化设计与常规设计方法得出的结果相比,优化设计后HMT行星齿轮系齿轮的体积减小了22.4%,质量减轻明显。

  2. Application of planetary gear train with eccentric gears and non-circular gear in backward rotary transplanting mechanism%偏心齿轮-非圆齿轮行星轮系在后插旋转式分插机构中的应用

    Institute of Scientific and Technical Information of China (English)

    俞高红; 张玮炜; 孙良; 赵匀

    2011-01-01

    针对步行式水稻插秧机的工作要求,将偏心齿轮-非圆齿轮行星轮系应用于水稻插秧机后插式分插机构的设计中,研制出偏心齿轮-非圆齿轮后插旋转式分插机构.分析了偏心齿轮-非圆齿轮行星轮系的运动学特性,建立运动学模型,并自主开发了分插机构辅助分析与优化软件,通过人机交互优化方式对该分插机构进行参数优化,完成了该分插机构的二维和三维设计,并进行了虚拟样机试验,试验结果表明:该分插机构可以形成"海豚形"插秧静轨迹,满足步行式水稻插秧机的工作要求.%According to work requirements of walking-type rice transplanter, backward rotary transplanting mechanism with eccentric gears and non-circular gear was developed, in which planetary gear train with eccentric gears and non-circular gear were used. In this paper, the kinematic characteristics of planetary gear train with eccentric gears and non-circular gear were analyzed and kinematic models of the transplanting mechanism were established. Based on the optimization software, which was developed by the authors, parameters of the transplanting mechanism were optimized and the one which met the work requirements of walking-type rice transplanter was given by the method of man-machine conversation. Virtual prototype test was performed after finishing the 2D and 3D design of the transplanting mechanism,and the results showed that the transplanting mechanism can create static locus which looks like a ‘dolphin' in shape and meet the work requirements of walking-type rice transplanter.

  3. Modal properties for bevel planetary gear trains%锥齿行星齿轮传动模态特性分析

    Institute of Scientific and Technical Information of China (English)

    王世宇; 王建; 曹树谦; 张策; 刘建平; 朱雷威

    2011-01-01

    根据相对质心的动量矩定理,建立了锥齿行星齿轮传动的多维动力学模型,采用归纳方法研究了模态特性.结果表明:该传动系统的模态可归结为4种典型振动模式,即:轴向平移—扭转、径向平移—扭摆、行星轮及轴向平移振动模式.在轴向平移-扭转振动模式下,中心构件呈现沿轴线方向的平移振动及绕该轴的扭转振动;在径向平移—扭摆振动模式下,中心构件呈现沿径向的平移振动及绕该方向的扭摆振动;在行星轮振动模式下,中心构件均不振动,仅行星轮在振动;在轴向平移振动模式下,中心构件仅呈现沿轴线方向的平移振动,其他方向不存在振动.与上述4种典型振动模式对应的固有频率的重数分别为1,2,N-3及N-2.该研究为锥齿行星传动的动态特性优化奠定了理论基础.%Based on the theory of angular momentum relative to mass center, an analytical model of bevel planetary gear trains is developed including the gyroscopic effect to investigate the dynamic characteristics of the gear system. According to the inductive method, the free vibration properties of the system are studied. And the results show that the vibration modes can be classified into four groups: axial translational and rotational modes in which the center components exhibit translation motion in the direction of the axis and the rotational motion around it, the radial translational and torsional modes in which the center components exhibit translation motion in the radial direction and the torsional motion around it, planet modes in which the center components have no motion and only the planets deflect, and axial translational modes in which the center members only exhibit translation motion in the direction of the axis. The multiplicity of the associated natural frequencies for the four vibration modes is 1, 1 or 2, N-3 and N-2. This work lays a foundation for the optimization of the dynamic properties for

  4. Gears and gear drives

    CERN Document Server

    Jelaska, Damir T

    2012-01-01

    Understanding how gears are formed and how they interact or 'mesh' with each other is essential when designing equipment that uses gears or gear trains. The way in which gear teeth are formed and how they mesh is determined by their geometry and kinematics, which is the topic of this book.  Gears and Gear Drives provides the reader with comprehensive coverage of gears and gear drives. Spur, helical, bevel, worm and planetary gears are all covered, with consideration given to their classification, geometry, kinematics, accuracy control, load capacity and manufacturing. Cylindric

  5. Dynamic simulation of planetary gear set with flexible spur ring gear

    Science.gov (United States)

    Chen, Zaigang; Shao, Yimin; Su, Daizhong

    2013-12-01

    Ring gear is a key element for vibration transmission and noise radiation in the planetary gear system which has been widely employed in different areas, such as wind turbine transmissions. Its flexibility has a great influence on the mesh stiffness of internal gear pair and the dynamic response of the planetary gear system, especially for the thin ring cases. In this paper, the flexibility of the internal ring gear is considered based on the uniformly curved Timoshenko beam theory. The ring deformation is coupled into the mesh stiffness model, which enables the investigation on the effects of the ring flexibility on the mesh stiffness and the dynamic responses of the planetary gear. A method about how to synthesize the total mesh stiffness of the internal gear pairs in multi-tooth region together with the ring deformation and the tooth errors is proposed. Numerical results demonstrate that the ring thickness has a great impact on the shape and magnitude of the mesh stiffness of the internal gear pair. It is noted that the dynamic responses of the planetary gear set with equally spaced supports for the ring gear are modulated due to the cyclic variation of the mesh stiffness resulted from the presence of the supports, which adds more complexity in the frequency structure.

  6. Resarch on Static Load Sharing Character of Series Planetary Gear Train%串联型行星齿轮传动系统均载特性分析

    Institute of Scientific and Technical Information of China (English)

    刘文彬; 刘更; 李阳

    2012-01-01

    依据串联型行星轮系统均载机理,综合考虑齿轮制造误差和安装误差、啮合刚度以及间隙浮动等因素的影响,建立了系统均载分析模型,通过计算得到了输入级与输出级的不均载系数.分析了不同齿轮精度对两级行星轮系统均载性能的影响,得出输入级对齿轮精度等级的反应比较敏感的结论,就啮合刚度及联轴器润滑条件对系统均载性能的影响做出了讨论.%According to the load sharing mechanism of the series planetary gear train and consideration the ef-fects of manufacturing errors, assembly errors, mesh stiffness and the clearance floating coefficient,the analysis model is set up. The load sharing coefficients of the input stage and output stage are obtained through the calculation. The effect of the gear accuracy grade on the load sharing coefficient is analyzed. The results illustrate that the input stage is much more sensitive of the gear accuracy grade than the output stage. Then the effects of gear mesh stiffness and lubri-cation of toothed coupling on load sharing coefficient are discussed. The study provides useful theoretical guideline to the design of planetary gear train.

  7. Design of stimulation optimized planetary gears; Entwurf anregungsoptimierter Planetengetriebe

    Energy Technology Data Exchange (ETDEWEB)

    Paples, Jennifer; Vill, Dietmar [Bochum Univ. (Germany). Lehrstuhl fuer Industrie- und Fahrzeugantriebstechnik

    2013-06-01

    Planetary gears are characterized by their high power density combined with their compactness. To take full advantage of these benefits a uniform distribution of the load on the individual planet gears has to be achieved. In planetary gears the chronology of the meshing of the teeth involved depends only on the macro-geometry of the gears, namely the number of teeth and the angular pitch of the planet carrier. The interaction between these meshing teeth provides an additional parameter for excitation because of their phase delayed stiffnesses, which counteracts this uniform distribution. With the aid of the variation of toothing parameters, such as tooth height or shift factors, which are influenced by the design engineer, the stiffnesses in the meshing between sun and planet and between planet and ring gear can be balanced at its best to provide low vibration. (orig.)

  8. 行星差动轮系功率分流和传动比的内在规律及速算法%Inherent Laws and Fast Calculation Method of Power Dividing and Transmission Ratio of Planetary Differential Gear Train

    Institute of Scientific and Technical Information of China (English)

    冯仲

    2012-01-01

    以履带式行走机构的三级行星差动轮系为例,用解析法分别推导该机构功率分流、传动比通式,并揭示差动行星机构功率分流与传动比的内在规律及速算法,通过进一步说明,提出差动行星机构的串、并联关系,将差动行星轮系简化成一般行星轮系.%Taking the three planetary differential gear train of crawler walking mechanism as an example, the mechanism power dividing and transmission ratio formula are derived by analytical method,the inherent laws and fast calculation method of planetary differential gear train power dividing and transmission ratio are revealed. By further explanation , the serial connection and parallel connection of planetary differential gear train is proposed, planetary differential gear train to general planetary gear train is simplified.

  9. EFFICIENCY ANALYSIS OF DOUBLE CRANK RING-PLATE-TYPE PIN-CYCLOIDAL GEAR PLANETARY DRIVE

    Institute of Scientific and Technical Information of China (English)

    Li Xin; He Weidong; Linda Schmidt; Li Lixing

    2003-01-01

    From the general formula for calculating the efficiency of planetary gear trains, the efficiency of the double crank ring-plate-type pin-cycloidal gear planetary drive is derived. To prove the theory, an experimental study has been conducted. The tested value of the efficiency of a sample set of the new-type drive in the experiment agrees with the calculated one. It shows that the new-type drive is of not merely high bearing capacity, but also quite high efficiency.

  10. 斜齿行星传动多体动力学建模与分析%Multibody dynamic modeling and analysis for a helical planetary gear train

    Institute of Scientific and Technical Information of China (English)

    张俊; 刘先增

    2014-01-01

    A multibody dynamic model for a helical planetary gear train (HPGT)was proposed and the dynamic performance of the HPGT system was analyzed.Its free vibration characteristics,steady-state dynamic responses and the effects of design parameters on the system dynamic behavior were investigated with numerical simulations.The free vibration of the HGPT was classified into 3 categories according to modal properties,such as,eigenvalue multiplies, modal coordinates of central components and coordinate ratios of planets.The classified vibration modes were axial translational and torsional mode (AT mode ),radial translational and rotational mode (RR mode )and planet mode (P mode).The characteristics of each category were presented.The simulation results agreed well with those using the previous discretized model neglecting the component flexibilities to validate the correctness of the proposed multibody dynamic model.The steady-state dynamic responses indicated that the dynamic meshing forces fluctuate about the average static values and the time-varying meshing stiffness is the major excitation of the system.The parametric sensitivity analysis showed that the floating sun gear and the reduction of circumferential assembly error of planets are effective to suppress the vibration of the HGPT.%建立了斜齿行星传动的多体动力学模型,对其进行了动态特性仿真,获知了该类系统的自由振动特性、稳态动力响应以及部分设计参数对系统动态特性的影响规律。根据系统特征值的重根数、中心构件的振型坐标及各行星轮间振型坐标的比例,将斜齿行星轮系的自由振动归结为3类典型振动模式,即:轴向平移-扭转振动模式、径向平移-扭摆振动模式和行星轮振动模式,并进一步给出了各类模式的特点。当不考虑构件自身柔性时,基于多体动力学模型的自由振动特性与前人的集中参数模型的仿真结果完全一致,表明了本文

  11. Modal properties of three-dimensional helical planetary gears

    Science.gov (United States)

    Eritenel, Tugan; Parker, Robert G.

    2009-08-01

    The structured modal properties of single-stage helical planetary gears with equally spaced planets are categorized and mathematically proved. Compared to prior two-dimensional analyses of spur gears, this study examines the three-dimensional motion of the helical gears and shafts. A lumped-parameter model is formulated to obtain the equations of motion. The gear-shaft bodies are modeled as rigid bodies with compliant bearings at arbitrary axial locations on the shafts. A translational and a tilting stiffness account for the force and moment transmission at the gear mesh interface. The derived modal properties generalize those of two-dimensional spur planetary gears; there are twice as many degrees of freedom and natural frequencies due to the added tilting and axial motion. All vibration modes are categorized as rotational-axial, translational-tilting, and planet modes. The modal properties are shown to hold even for configurations that are not symmetric about the gear plane, due to, for example, shaft bearings not being equidistant from the gear plane.

  12. Nonlinear Vibroimpact Characteristics of a Planetary Gear Transmission System

    Directory of Open Access Journals (Sweden)

    Jianxing Zhou

    2016-01-01

    Full Text Available In order to research the vibroimpact characteristics of a planetary gear transmission system under high speed and lightly loaded conditions, a new modeling method is proposed. In the modeling process, linear spring was used to simulate gear mesh elasticity under heavy load cases, and Hertz contact theory was used to calculate the contact force of gear pair under light load cases. Then, effects of the working conditions on the system vibroimpact characteristics are analyzed. The results show that, with input speed growing, the mesh force produced obvious fluctuations on the resonance frequencies of the sun gear and carrier torsion vibration, ring gear’s transverse vibration under the heavy load. Under light load condition, the collision vibration occurs in the gear pair; the changing trend of the contact force shows strongly nonlinear characteristics. The time of mesh-apart in gears pair decreases gradually as the load is increased; until it reaches collision vibration threshold value, the gear pair is no longer mesh-apart. With increasing of the input speed, the time of mesh-apart is decreased gradually; the fluctuation amplitude of contact force shows a linearly increasing trend. The study provides useful theoretical guideline for planetary gear transmission low-noise design.

  13. Method of bond graph for distinguishing power flow of closed planetary gear train%封闭式行星轮系功率流判别的键合图法

    Institute of Scientific and Technical Information of China (English)

    李庆凯; 唐德威; 姜生元; 邓宗全

    2012-01-01

    为更简单清晰地对封闭式行星轮系的功率流情况进行判别,利用键合图能量守恒和功率流动的特点,将键合图理论应用于该类轮系的功率流分析中.以功率汇流型、回流型2种形式的封闭式行星轮系为例,根据轮系的传动关系,利用绝对速度法建立轮系的键合图模型,根据提出的功率流向判别依据对轮系进行功率流向判别,得到整个轮系及其转换机构的功率流情况,为轮系的效率计算提供了基础.该方法适用于其它复杂轮系的功率流判别中,比传统方法更具直观性、系统性.%In order to distinguish the power flow of the closed planetary gear train more simply and clearly,the theory of bond graph was applied for the analysis of power flow of the gear train utilizing the characteristic of conversation of energy and power fluxion of bond graph.Taking the power regurgitant and confluence style of the gear trains for examples,the bond graph model of the gear trains was established according to the transmission relationships and the method of absolute speed.And then the power flow of the gear trains,as well as the conversion mechanism,was got after distinguishing the power flow basing on the discriminant,which provides the foundation for the efficiency computing.This method which is more intuitionistic and systematic than the traditional methods could be applied in the power flow judgement of other complex gear trains.

  14. 非等模数非等压力角NGW型行星齿轮系静力学均载行为%Static load sharing behavior in NGW planetary gear train with unequal modulus and pressure angles

    Institute of Scientific and Technical Information of China (English)

    叶福民; 朱如鹏; 鲍和云

    2011-01-01

    建立非等模数非等压力角NGW型行星齿轮系的计算模型,针对各齿轮的偏心误差和齿频误差,运用当量啮合误差原理和浮动构件的静力平衡关系,推导出该系统的静力学方程;对方程进行求解并与等模数等压力角系统的均载特性进行比较,同时还讨论太阳轮(或内齿轮)压力角、齿轮误差、啮合刚度与支撑刚度对该系统均载特性的影响.研究结果表明:非等模数非等压力角行星齿轮系有着较好的均载效果,其均载特性不会随着压力角改变而产生大的波动;太阳轮浮动支撑机构对系统的均载特性有很大的改善;选择误差相同的行星齿轮、减小太阳轮和行星轮的支撑刚度均有利于系统均载.%An analytical model for NGW planetary gear train with unequal modulus and pressure angles was presented, and in consideration of the eccentric error and tooth-frequency error of parts, a static equation of the NGW planetary system was developed based on the theory of equivalent mesh error and the principle of static equilibrium. After equation was solved, the load sharing characteristics were compared with the normal gear transmission. Also the load sharing behavior of each planet was analyzed and compared by the sun and the ring pressure angle, the difference of the gear error, the variety of mesh stiffness and support stiffness. The analysis results show that planetary gear train with unequal modulus and pressure angles has better load sharing behavior, which does not change significantly with the different pressure angles, the floating sun gear has improved the load sharing behavior substantially, and the planets fixed with the same production batch and the lower support stiffness of the sun and the planets benefit the load sharing behavior.

  15. Bifurcation characteristics of a nonlinear planetary gear train changing with power%传递功率对行星齿轮传动系分岔特性的影响规律

    Institute of Scientific and Technical Information of China (English)

    李同杰; 靳广虎; 鲍和云; 朱如鹏

    2016-01-01

    As the motion state of a planetary gear reducer is easy to bifurcate when the transmitted power changes,a study on the bifurcation characteristics of a planetary gear train changing with the transmitted power is explored in this paper.The local bifurcation characteristics were studied with CPNF(continuous Poincaré-Newton-Floquet) method on the basis of the nonlinear torsional vibration model of 2K-H planetary gear train.As a comparison,the global bifurcation diagram changing with power was calculated by using the method of numerical integration.The comparison results reveal that a nonlinear planetary gear train with certain parameters may have several coexisting periodic trajectories,some of them may be stable and some may be unstable.As the power gradually increases in the range of 196~220 kW,the stable asymptotic stable periodic traj ectory may change into chaos in the way of inverse period doubling bifurcation.And chaos is easy to appear when the planetary gear train is under light load condition.%针对行星齿轮减速器工作过程中传递功率的频繁变化容易导致其运动状态发生突变的问题,探讨行星齿轮传动系统随传递功率的分岔特性。基于2K-H 型行星齿轮传动系统纯扭转非线性动力学模型,采用CPNF(continuous Poincaré-Newton-Floquet)方法研究了传递功率对行星齿轮传动系统周期运动稳定性的局部精细分岔规律,运用直接数值积分的方法绘制了系统随功率的全局分岔图,并对两种仿真结果进行了对比。结果发现,在某些参数组合下,行星齿轮传动系统会共存几个稳定或不稳定的周期轨道;当功率在196~220 kW范围内,随着功率值的逐渐增大,行星齿轮传动系统的各种形态的周期轨道均是通过倍周期倒分岔的途径在相应功率分岔点处发生稳定性突变的;在轻载工况下(传递小功率),行星齿轮非线性系统容易呈现混沌运动状态。

  16. AUTOMOTIVE DIESEL MAINTENANCE 2. UNIT VI, AUTOMATIC TRANSMISSIONS--PLANETARY GEARING.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 25-MODULE COURSE IS DESIGNED TO ACQUAINT THE TRAINEE WITH THE OPERATION OF PLANETARY GEARS IN AUTOMATIC TRANSMISSIONS USED ON DIESEL POWERED VEHICLES. TOPICS ARE (1) PURPOSE OF PLANETARY GEARING, (2) POWER TRANSMISSION THROUGH A PLANETARY SYSTEM, (3) HYDRAMATIC TRANSMISSION, (4) HYDRAULIC SYSTEM, AND (5) GEAR FAILURE AND…

  17. Double Helical Gear Performance Results in High Speed Gear Trains

    Science.gov (United States)

    Handschuh, Robert F.; Ehinger, Ryan; Sinusas, Eric; Kilmain, Charles

    2010-01-01

    The operation of high speed gearing systems in the transmissions of tiltrotor aircraft has an effect on overall propulsion system efficiency. Recent work has focused on many aspects of high-speed helical gear trains as would be used in tiltrotor aircraft such as operational characteristics, comparison of analytical predictions to experimental data and the affect of superfinishing on transmission performance. Baseline tests of an aerospace quality system have been conducted in the NASA Glenn High-Speed Helical Gear Train Test Facility and have been described in earlier studies. These earlier tests had utilized single helical gears. The results that will be described in this study are those attained using double helical gears. This type of gear mesh can be configured in this facility to either pump the air-oil environment from the center gap between the meshing gears to the outside of tooth ends or in the reverse direction. Tests were conducted with both inward and outward air-oil pumping directions. Results are compared to the earlier baseline results of single helical gears.

  18. 一种行星齿轮式防滑差速器的研究%Study on a Kind of Anti-skid Differential Gear of Planetary Gear

    Institute of Scientific and Technical Information of China (English)

    海争平

    2011-01-01

    设计了一种采用行星齿轮组作为自动锁止机构的防滑差速器.在普通差速器壳体中增加行星齿轮组(行星轮、转臂、中心轮)和控制机构(离合器1、离合器2),根据左右半轴的速度信号来自动控制差速器的锁止动作.%By using planetary gear train as the automatic locking mechanism, a kind of anti-skid differential gear is designed. Adding planetary gear train (planetary gear, planet carrier, center gear) and controlling mechanism (clutch 1, clutch 2) to the common differential gear case and according to the speed signal of the half-shaft, the locking of the differential gear is automatically controlled.

  19. Topological and parametric optimization of gear trains

    Science.gov (United States)

    Swantner, Albert; Campbell, Matthew I.

    2012-11-01

    A method for automating the design of gear trains comprised of simple, compound, bevel and worm is described. The search process combines topological changes, discrete variable choices and continuous variable optimization. By combing best-first search, implicit enumeration, automated optimization invocation and gradient-based optimization, a near guarantee of the optimal solution can be made. While the combination of methods is specific to gear trains, there are aspects of the work that make it amenable to other engineering design problems. In addition, the topological and discrete modifications to the candidate solutions are specific to gear trains, but the graph grammar methodology that is adopted has been tailored to other problems. This article presents details on the rules that generate feasible gear trains, the evaluation routines used in determining the objective functions and constraints, and the interaction among the three search methods. Resulting gear trains are presented for a variety of gear problems.

  20. Inherent Characteristics of 3K-Ⅱ Spur Planetary Gear Trains%3K-Ⅱ型直齿行星齿轮传动的固有特性

    Institute of Scientific and Technical Information of China (English)

    宋轶民; 张俊; 张君; 王世宇; 刘建平

    2009-01-01

    A translational-rotational coupling model of 3K-Ⅱ spur planetary gear trains is developed to investigate the natural frequencies and corresponding vibration modes. The model admits three planar degrees of freedom for each of the sun, rings, carrier and planets and includes some key factors affecting planetary gears vibration such as component bearing stiffness, time-varying mesh stiffness and gyroscopic effect. By deriving the displacement relationships between gears and carrier, the governing differential equations are obtained. The solution of associated eigenvalue problem leads to natural frequencies and vibration modes of the transmission. The vibration modes are classified into three types, i.e., rotational modes, translational modes, and planetary gear modes based on their unique properties.%为揭示3K-Ⅱ型直齿行星齿轮传动的固有特性,建立该类传动系统在系杆随动参考坐标系下的平移-扭转耦合动力学模型.模型设定系统中每个构件均拥有3自由度,并计入各构件的支承刚度、轮齿时变啮合刚度和陀螺效应等影响因素.通过分析各构件间的相对位移关系,推导出系统的运动微分方程,进而求解其特征值问题即可获知系统的固有频率和相应振型.固有特性分析表明,3K-Ⅱ型行星齿轮传动具有与2K-H行星齿轮传动类似的三种典型振动模式,即扭转振动模式、平移振动模式和行星轮振动模式.列出三种典型振动模式下传动系统的运动特征.

  1. Analysis of dynamic floating displacement of center gear for encased differential planetary train%封闭差动行星传动系统中心轮动力学浮动量分析

    Institute of Scientific and Technical Information of China (English)

    朱增宝; 朱如鹏; 鲍和云; 靳广虎

    2012-01-01

    Based on the vibration theory of the concentrated parameter, a dynamics model which adopted the floating frame of the center gears for the encased differential planetary train was set up. The elastic deformation of the bearings, the time-varying meshing stiffness and the gear errors were considered in the model. The center gears' floating displacements of the two stages were calculated and some curves of the relationships between the errors (the bearing stiffness) and the center gears' floating displacements were obtained. The impacts of the errors and bearing stiffness on the center gears' floating displacements were analyzed. The results show that the center gears' floating displacements of the two stages change largely with the increase of the errors. The center gear's floating displacements of the differential stage are much bigger than those of the encased stage. In differential stages, the floating displacements caused by the meshing-frequency error are far greater than those by the run-out errors, and the floating displacements are more sensitive to the meshing-frequency errors man the run-out errors. The center gears' bearing stiffness of the two stages can be decreased moderately to increase the center gears' floating displacements. In order to realize the larger floating displacements of the center gears of the differential stage, the center gears' bearing stiffness of the differential stage should be smaller.%基于集中参数振动理论,建立采用中心轮浮动的封闭差动行星传动系统动力学模型.考虑支撑的弹性变形、啮合齿轮副的时变啮合刚度激励和齿轮误差激励.计算系统两级中心轮的浮动量,获得齿轮误差、支撑刚度与系统两级中心轮浮动量间的关系曲线,分析误差、支撑刚度对系统两级中心轮浮动量的影响.研究结果表明:系统两级中心轮浮动量随误差增大而增大;差动级中心轮的浮动量远比封闭级的浮动量大;差动级齿频误差

  2. Research on Virtual Prototype Simulation of Compound Planetary Gear Train Sets%复合行星齿轮传动系统虚拟样机仿真研究

    Institute of Scientific and Technical Information of China (English)

    刘振皓; 巫世晶; 潜波; 王晓笋

    2012-01-01

    Based on the typical structure of Ravigneaux compound planetary gear train sets, the transmission ratio and meshing frequency of the system were analyzed. In order to obtain the changing patterns of contact force of Ravigneaux compound planetary gear train sets, a 3-D solid model of the sets was established by SolidWorks software and the virtual prototype of the system was built based on ADAMS software. The computation method for contact force of gear meshing was introduced based on Hertz theory. The transmission ratio of the system was verified. The changing pattern and the spectrum characteristics of the synthetic contact force between small sun gear and short planet gear, that of x direction and y direction were simulated. The simulation results show that the ampltude of contact force fluctuated obviously, which had notable periodic property. The contact force of x direction and y direction has the same frequency spectrum and phase difference of 90°. The rotational frequency and frequency multiplication of 1 to 7 of meshing frequency are in the frequency spectrum of contact force,which have explict modulating characteristics. The virtual prototype researches of Ravigneaux compound planetary gear train sets can provide some references to improve the system dynamic characteristics and achieve dynamic design.%根据Ravigneaux式复合行星齿轮传动系统的典型结构,分析了系统的传动比与啮合频率.为获得Ravigneaux式复合行星齿轮传动系统轮齿接触力的变化规律,运用三维CAD软件SolidWorks建立了系统的三维实体模型,以ADAMS软件为平台建立了系统的虚拟样机模型.给出基于Hertz接触理论的齿轮啮合传动时轮齿接触力的计算方法,验证了系统传动比,对小太阳轮与短行星轮啮合的综合接触力、x方向接触力和y方向接触力的变化规律及其频谱特性进行仿真研究.仿真结果表明,接触力的幅值波动显著,具有明显的周期性.x方向接触力

  3. Design of Cam-planetary Gear Train Combined Mechanism with Trajectory Requirement%实现轨迹的凸轮-行星轮系组合机构设计

    Institute of Scientific and Technical Information of China (English)

    马文静; 葛正浩; 马志平; 梁金生

    2012-01-01

    针对现有的实现轨迹的组合机构存在的局限性,设计了一种由行星轮系、凸轮机构和差动轮系组成的新型组合机构.该组合机构在做往复直线运动的同时实施摆动以产生避让动作,可用于高速连续自动送料场合.对该组合机构的原理及设计思路进行了详细阐述,确定了关键参数.最后通过一个设计实例,对组合机构进行建模及仿真,验证了执行端的轨迹满足设计要求.%As many combined mechanisms for trajectory realizing have some limitations, a new type of combined mechanism composed by planetary gear train, cam mechanism and differential gear train is designed. The combined mechanism can move reciprocate in a straight line while sway to avoid other materials, which can be applied to continuous automatic feeding in high - speed situation. The principle and design ideas of the combined mechanism are described in details, and the key parameters are determined. Finally, the trajectory of the implementation is verified through a design example.

  4. Gear Defect Modeling of a Multiple-Stage Gear Train

    Directory of Open Access Journals (Sweden)

    Andrew Sommer

    2011-01-01

    Full Text Available This study demonstrates the transient and steady state dynamic loading on teeth within a two-stage gear transmission arising from backlash and geometric manufacturing errors by utilizing a nonlinear multibody dynamics software model. Backlash between gear teeth which is essential to provide better lubrication on tooth surfaces and to eliminate interference is included as a defect and a necessary part of transmission design. Torsional vibration is shown to cause teeth separation and double-sided impacts in unloaded and lightly loaded gearing drives. Vibration and impact force distinctions between backlash and combinations of transmission errors are demonstrated under different initial velocities and load conditions. The backlash and manufacturing errors in the first stage of the gear train are distinct from those of the second stage. By analyzing the signal at a location between the two stages, the mutually affected impact forces are observed from different gear pairs, a phenomenon not observed from single pair of gears. Frequency analysis shows the appearance of side band modulations as well as harmonics of the gear mesh frequency. A joint time-frequency response analysis during startup illustrates the manner in which contact forces increase during acceleration.

  5. Planetary Gear Profile Modification Design Based on Load Sharing Modelling

    Institute of Scientific and Technical Information of China (English)

    IGLESIAS Miguel; FERNÁNDEZ DEL RINCÓN Alfonso; DE-JUAN Ana Magdalena; GARCIA Pablo; DIEZ Alberto; VIADERO Fernando

    2015-01-01

    In order to satisfy the increasing demand on high performance planetary transmissions, an important line of research is focused on the understanding of some of the underlying phenomena involved in this mechanical system. Through the development of models capable of reproduce the system behavior, research in this area contributes to improve gear transmission insight, helping developing better maintenance practices and more efficient design processes. A planetary gear model used for the design of profile modifications ratio based on the levelling of the load sharing ratio is presented. The gear profile geometry definition, following a vectorial approach that mimics the real cutting process of gears, is thoroughly described. Teeth undercutting and hypotrochoid definition are implicitly considered, and a procedure for the incorporation of a rounding arc at the tooth tip in order to deal with corner contacts is described. A procedure for the modeling of profile deviations is presented, which can be used for the introduction of both manufacturing errors and designed profile modifications. An easy and flexible implementation of the profile deviation within the planetary model is accomplished based on the geometric overlapping. The contact force calculation and dynamic implementation used in the model are also introduced, and parameters from a real transmission for agricultural applications are presented for the application example. A set of reliefs is designed based on the levelling of the load sharing ratio for the example transmission, and finally some other important dynamic factors of the transmission are analyzed to assess the changes in the dynamic behavior with respect to the non-modified case. Thus, the main innovative aspect of the proposed planetary transmission model is the capacity of providing a simulated load sharing ratio which serves as design variable for the calculation of the tooth profile modifications.

  6. Engineering analysis and test results of the pre-stage planetary gear trains for wrist rotation and pitch assembly and azimuth and elevation assembly of the extendable stiff arm manipulator kit assembly

    Science.gov (United States)

    Morris, R. N.

    1973-01-01

    In order to improve the performance capability of the Extendable Stiff Arm Manipulator (ESAM) it was necessary to increase the overall gear ratio by a factor of approximately four. This is accomplished with minimum effect to existing hardware by the interposition of a planetary gear transmission between the respective drive motors and the harmonic drive transmissions. The engineering analysis in support of this design approach and the subsequent no-load test results are reported.

  7. Reverse Design and Kinematic Analysis of Non-circular Planetary Gear Trains Weft Insertion Mechanism%非圆齿轮行星轮系引纬机构的反求设计与运动学分析

    Institute of Scientific and Technical Information of China (English)

    陈建能; 王英; 任根勇; 赵雄; 雷昌毅

    2012-01-01

    In order to analyze the kinematic characteristics of non-circular planetary gear trains weft insertion mechanism and then obtain a group of preferable parameters, a kinematic model of this mechanism was established. Besides, the aided analytical and kinematic simulation software was compiled based on Visual Basic 6. 0. The influences of several important parameters on the shape of pitch curves of the non-circular gears in this mechanism were analyzed, and a group of preferable structural parameters were obtained. The movement simulation analysis was conducted under this group of parameters. Under the condition of same reed width and rotary speed of loom spindle, this novel mechanism was compared with the weft insertion mechanism applied on the TT96 rapier loom. The conclusion shows that non-circular planetary gear trains weft insertion mechanism has smaller maximum value of velocity and acceleration, and it can meet the requirments of weft insertion.%为了分析非圆齿轮行星轮系引纬机构的运动学特性并获得一组较优的参数,建立了该机构的运动学分析模型,基于Visual Basic 6.0平台编写了该机构的辅助分析与运动仿真软件,分析了几个重要参数对机构中非圆齿轮节曲线的影响,得到了一组较优的机构参数.对该组参数下的引纬机构进行运动仿真分析,在相同筘幅和织机主轴转速条件下,对非圆齿轮行星轮系引纬机构和TT96剑杆织机引纬机构的运动学特性进行了比较,结果表明非圆齿轮行星轮系引纬机构具有较小的最大速度值和最大加速度值,能够满足引纬要求.

  8. 复合行星齿轮传动系统分岔与混沌特性研究%Bifurcation and chaotic characteristics of compound planetary gear train sets

    Institute of Scientific and Technical Information of China (English)

    巫世晶; 刘振皓; 潜波; 王晓笋

    2012-01-01

    建立了含中心件平移振动的拉威娜式复合行星齿轮传动系统非线性动力学模型,推导了构件间相对位移并建立了系统的运动微分方程组.采用数值积分法对方程组进行求解,得到了系统的非线性动态响应结果.综合运用分岔图、时间历程曲线、相空间轨线、庞加莱截面与功率谱分析了激励频率对系统分岔与混沌特性的影响.结果表明:齿侧间隙与时变啮合刚度等非线性因素的耦合使得复合行星齿轮传动系统内部具有丰富的非线性动力学行为;增大系统啮合阻尼比可以使系统逐渐摆脱混沌状态,进入稳定的周期运动.%A nonlinear dynamic model of Ravingneaux compound planetary gear train sets was devel- oped, which included the translational vibration of the center component. The governing differential equations were obtained by analyzing the displacement relationships between the components. Themethod of numerical integration was used to solve the equations, from which the result of the nonlin- ear dynamic response was obtained. The influences of excitation frequency on the bifurcation and cha- otic characteristics were analyzed by using bifurcation diagram, time history curve, phase trajectory, Poncdre section and power spectrum synthetically. The study shows that the coupling of gear back-lashes and time-varying meshing stiffness make the compound planetary gear train sets have various inner nonlinear dynamic behaviors. Increasing the meshing ratio of damping could make the system get rid of the chaos condition and come into stable periodic motion.

  9. The study about planetary gearbox virtual prototyping with nonlinear gear contact characteristics

    Science.gov (United States)

    Yin, Huabing; Zhou, Guangming

    2010-06-01

    The virtual prototypes of gear transmission system built in most multi-body dynamic software have difficulties in describing the gear mesh characteristics. The gear mesh contact is modelled as rigid contact and this is not accurate for the gear mesh contact, which is elastic or flexible. The gear contact formula used in the multi-body dynamic software does not reveal the gear contact nonlinear stiffness characteristic. The model built with gear meshing contact is difficult to solve because of its time-consuming algorithm. In the paper a new method is put forward to build the virtual prototype of planetary gearbox system according to the nonlinear mesh stiffness and mesh phase obtained through FEM models. This new FEM method of gear mesh stiffness calculation is much more accurate than the common formulas. The gear mesh nonlinear stiffness of sun gear- pinion and pinion-ring gear of all the planetary gear sets in gearbox are obtained through MATALB code, which is used to read and plot the analyzing result data. The gear mesh phase differences between different pinions with suns or rings of different planetary gear set can be also obtained. With all these data modelled in simulink (or other software) and integrated with the multi-body dynamic planetary gearbox model and the gear meshing contact problem in multi-body gear models is solved easily and accurately. The interfaces for gear mesh stiffness and mesh phases are designed for multi-body dynamic model and simulink. The nonlinear planetary gear set prototyping models are integrated to become the whole planetary gear box model and the whole vehicle system model built in multi-body dynamic software can be integrated to simulate different duty conditions. At last high speed input is put into the nonlinear planetary transmission model and the different duty cases are simulated. The dynamic characteristics of different parts are obtained. The dynamic characteristic comparison between nonlinear and linear models is made

  10. 滑动轴承支承人字齿轮行星传动固有特性分析%Natural Characteristics Analysis on Herringbone Planetary Gear Trains with Slide Bearing Support

    Institute of Scientific and Technical Information of China (English)

    卜忠红; 刘更; 吴立言

    2011-01-01

    考虑滑动轴承支承刚度不对称和耦合特性,建立计入内齿轮轴向振动的人字齿轮行星传动动力学模型.利用4个刚度系数描述行星轮滑动轴承支承油膜刚度.分析系统的自由振动特性,发现系统存在5种振动模式:中心轮扭转-轴向振动模式、内齿轮扭转-轴向振动模式、中心轮横向振动模式、内齿轮横向振动模式和行星轮振动模式.根据每种振动模式的振型特征,推导出5种模式同有特性的低阶计算公式.系统固有频率的分布范围比直齿、斜齿行星传动系统小.结果表明,油膜刚度不对称不会对振型特征产生影响,但是刚度耦合不对称时中心轮横向振动模式会发现显著变化:对应的二重固有频率变成两个不同的单蕈频率,振型呈现新特征.%A dynamic model of herringbone planetary gear trains is developed considering the axial vibration of two rings and asymmetry and interaction of oil film stiffness.Four stiffness coefficients are used to describe the oil film stiffness of slide bearings for planets' support.The free vibration characteristic is analyzed and the vibration modes are divided into five groups: rotational-axial vibration mode of center gears, rotational-axial vibration mode of rings, translational vibration mode of center gears, translational vibration mode of rings and planets vibration mode.For each class of mode, the reduced-order inherent characteristics formulas are derived according to the properties of each vibration mode.The distribution range of natural frequencies is smaller than those of spur and helical planetary gear trains.It reveals that although the asymmetry ofoil film stiffness has little influence on the vibration modes properties, the significant changes of translational vibration mode of center gears will happen if there is asymmetry interaction of oil film stiffness: the corresponding twofold natural frequencies will turn into two different frequencies and new

  11. 行星齿轮系扭转非线性振动建模与运动分岔特性研究%Nonlinear Torsional Vibration Modeling and Bifurcation Characteristic Study of a Planetary Gear Train

    Institute of Scientific and Technical Information of China (English)

    李同杰; 朱如鹏; 鲍和云; 项昌乐; 刘辉

    2011-01-01

    建立行星齿轮系扭转非线性振动模型,模型中考虑了行星齿轮系各齿轮副间的时变啮合刚度、齿侧间隙以及综合传递误差等非线性因素;推导出系统的量纲一振动微分方程,采用数值积分方法研究行星齿轮的运动特性随转速以及齿侧间隙等参数的分岔特性,结合Poincaré图形分析,研究转速、啮合阻尼以及齿侧间隙等参数对系统分岔特性的影响.结果发现,随着转速的逐渐增大,系统会通过激变途径进入到混沌运动,而随着齿侧间隙的逐渐增大,系统会通过倍周期分岔途径进入到混沌.阻尼过小将会导致行星齿轮系统的稳态运动由短周期运动向复杂运动转变.齿侧间隙是影响系统运动分岔特性的重要因素,但是影响范围主要限于量纲一齿侧间隙大于3.5的大间隙区段.%A nonlinear torsional vibration model of a planetary gear train with errors of transmission, time varying meshing stiffness and gear backlashes is established and dimensionless equations of the system are derived. The solution of the equations is carried out by using the method of numerical integration. By comparing with Poincare maps and bifurcation diagrams, the bifurcation properties of the system are studied. The influences of some bifurcation parameters such as rotational speed, damping coefficient and gear backlashes on the bifurcation properties of the system are assessed. The study results reveal that the system's motion state will change into chaos in the way of crisis as speed increase and period doubling bifurcation is the way to chaos as backlashes increase. A smaller damping coefficient will make the system's periodic motion state change into complex state. Gear backlashes have a strong impact on the system's bifurcation characteristic when dimensionless the backlashes is bigger than 3.5.

  12. Fiber Optic Strain Sensor for Planetary Gear Diagnostics

    Science.gov (United States)

    Kiddy, Jason S.; Lewicki, David G.; LaBerge, Kelsen E.; Ehinger, Ryan T.; Fetty, Jason

    2011-01-01

    This paper presents a new sensing approach for helicopter damage detection in the planetary stage of a helicopter transmission based on a fiber optic strain sensor array. Complete helicopter transmission damage detection has proven itself a difficult task due to the complex geometry of the planetary reduction stage. The crowded and complex nature of the gearbox interior does not allow for attachment of sensors within the rotating frame. Hence, traditional vibration-based diagnostics are instead based on measurements from externally mounted sensors, typically accelerometers, fixed to the gearbox exterior. However, this type of sensor is susceptible to a number of external disturbances that can corrupt the data, leading to false positives or missed detection of potentially catastrophic faults. Fiber optic strain sensors represent an appealing alternative to the accelerometer. Their small size and multiplexibility allows for potentially greater sensing resolution and accuracy, as well as redundancy, when employed as an array of sensors. The work presented in this paper is focused on the detection of gear damage in the planetary stage of a helicopter transmission using a fiber optic strain sensor band. The sensor band includes an array of 13 strain sensors, and is mounted on the ring gear of a Bell Helicopter OH-58C transmission. Data collected from the sensor array is compared to accelerometer data, and the damage detection results are presented

  13. Natural Frequencies and Vibrating Modes for a Magnetic Planetary Gear Drive

    Directory of Open Access Journals (Sweden)

    Lizhong Xu

    2012-01-01

    Full Text Available In this paper, a dynamic model for a magnetic planetary gear drive is proposed. Based on the model, the dynamic equations for the magnetic planetary gear drive are given. From the magnetic meshing forces and torques between the elements for the drive system, the tangent and radial magnetic meshing stiffness is obtained. Using these equations, the natural frequencies and the modes of the magnetic planetary gear drive are investigated. The sensitivity of the natural frequencies to the system parameters is discussed. Results show that the pole pair number and the air gap have obvious effects on the natural frequencies. For the planetary gear number larger than two, the vibrations of the drive system include the torsion mode of the center elements, the translation mode of the center elements, and the planet modes. For the planetary gear number equal to two, the planet mode does not occur, the crown mode and the sun gear mode occur.

  14. Reverse design of transplanting mechanism with spatial planetary gear train based on spherical curve%基于球面曲线的空间非匀速行星轮系分插机构逆向设计

    Institute of Scientific and Technical Information of China (English)

    孙良; 祝建彬; 陈建能; 赵匀; 武传宇

    2014-01-01

    The transplanting mechanism is an end manipulator which picks seedlings from a seedling box and pushes them into a rice field. A wide-narrow distance mechanism is a kernel part of the rice transplanter to place seedlings in a wide row and narrow row alternation. Because of the spatial movement property of a bevel gear pair, and the requirement of variable speed transmission, a noncircular bevel gear was widely used in a wide-narrow transplanting mechanism design. On the condition of a determinate transmission scheme, how to obtain a sound planting trajectory and proper picking posture which is important for the wide-narrow distance transplanting mechanism to achieve upstanding and fewer damaged seedlings in planting work becomes a key issue. In general, putting forward a new mechanism, building a calculate model, and compiling a parameters optimization program are the three main steps for transplanting mechanism design. But there is some uncertainty of parameters-choosing and parameters effecting design goals in the design of the trajectory and planting paw posture in the traditional way. Furthermore, the special noncircular gear such as elliptical (or bevel) gears, eccentric-noncircular (or bevel) gears whose pitch curve are accessible to expression are often used in the transmission scheme design, which limits the formation of trajectory shape and planting paw posture. A new way to design a spatial planetary noncircular gear train by using reverse design methods was put forward based on the spherical curve. An ideal plane curve which is smooth, continuous, and closed was expressed by a free spline curve, and then a spherical curve was obtained by mapping the ideal plane curve onto the spherical surface with a preserved geodesic curvature. A two bar mechanism with three degrees of freedom was used to describe the spherical curve. According to the spatial geometric relationship between the two bars and the center of sphere, the transmission ratio model was

  15. Nonlinear Dynamic Characteristics of Compound Planetary Gear Train Sets Based on Harmonic Balance Method%基于谐波平衡法的复合行星齿轮传动系统非线性动态特性

    Institute of Scientific and Technical Information of China (English)

    巫世晶; 刘振皓; 王晓笋; 朱恩涌

    2011-01-01

    为揭示多问隙作用下Ravigneaux型复合行星齿轮传动系统的非线性动力学行为,建立考虑时变啮合刚度、齿侧间隙与综合啮合误差的系统纯扭转强非线性动力学模型.将齿侧问隙非线性函数表达为描述函数的形式,运用谐波平衡法(Harmonic balance method,HBM)将方程组转化为非线性代数方程组,使用逆Broyden秩1法进行迭代求解,得到系统的基频稳态响应.通过改变时变啮合刚度、齿侧间隙与综合啮合误差的大小,分析参数变化对系统非线性动态特性的影响.研究发现,由于齿侧间隙的影响,系统动态特性曲线出现幅值跳跃与多值解等典型非线性特征,系统出现复杂的冲击现象;齿侧间隙、啮合刚度波动与误差波动的耦合使系统的非线性程度得以强化.基于描述函数的HBM法可用于求解更加复杂模型的基频稳态响应,为深入研究复合行星齿轮系统的动态特性提供了一种方法.%A purely rotational model of Ravigneaux compound planetary gear train sets including time-varying mesh stiffness,synthetic mesh errors and gear backlashes is developed to show the nonlinear dynamic behavior of the system with the action of multi-clearances. The gap function is expressed as describing function and harmonic balance method (HBM) is used to convert the differential equations to nonlinear algebraic equations, which is solved iteratively by single rank inverse Broyden method. The steady state response of fundamental frequency is obtained. The influences of gear backlashes, time-varying mesh stiffness and synthetic mesh errors are analyzed by changing the value of the parameter. It is showed from the research that multiple value and amplitude jump discontinuities are presented on the dynamic curves, there the impact phenomenon is reflected. Meanwhile the nonlinearity degree of the system is increased by the coupling of stiffness fluctuation, mesh errors and backlashes. The HBM based on

  16. Nonlinear dynamics of planetary gears using analytical and finite element models

    Science.gov (United States)

    Ambarisha, Vijaya Kumar; Parker, Robert G.

    2007-05-01

    Vibration-induced gear noise and dynamic loads remain key concerns in many transmission applications that use planetary gears. Tooth separations at large vibrations introduce nonlinearity in geared systems. The present work examines the complex, nonlinear dynamic behavior of spur planetary gears using two models: (i) a lumped-parameter model, and (ii) a finite element model. The two-dimensional (2D) lumped-parameter model represents the gears as lumped inertias, the gear meshes as nonlinear springs with tooth contact loss and periodically varying stiffness due to changing tooth contact conditions, and the supports as linear springs. The 2D finite element model is developed from a unique finite element-contact analysis solver specialized for gear dynamics. Mesh stiffness variation excitation, corner contact, and gear tooth contact loss are all intrinsically considered in the finite element analysis. The dynamics of planetary gears show a rich spectrum of nonlinear phenomena. Nonlinear jumps, chaotic motions, and period-doubling bifurcations occur when the mesh frequency or any of its higher harmonics are near a natural frequency of the system. Responses from the dynamic analysis using analytical and finite element models are successfully compared qualitatively and quantitatively. These comparisons validate the effectiveness of the lumped-parameter model to simulate the dynamics of planetary gears. Mesh phasing rules to suppress rotational and translational vibrations in planetary gears are valid even when nonlinearity from tooth contact loss occurs. These mesh phasing rules, however, are not valid in the chaotic and period-doubling regions.

  17. Journal Bearing Analysis Suite Released for Planetary Gear System Evaluation

    Science.gov (United States)

    Brewe, David E.; Clark, David A.

    2005-01-01

    Planetary gear systems are an efficient means of achieving high reduction ratios with minimum space and weight. They are used in helicopter, aerospace, automobile, and many industrial applications. High-speed planetary gear systems will have significant dynamic loading and high heat generation. Hence, they need jet lubrication and associated cooling systems. For units operating in critical applications that necessitate high reliability and long life, that have very large torque loading, and that have downtime costs that are significantly greater than the initial cost, hydrodynamic journal bearings are a must. Computational and analytical tools are needed for sufficiently accurate modeling to facilitate optimal design of these systems. Sufficient physics is needed in the model to facilitate parametric studies of design conditions that enable optimal designs. The first transient journal bearing code to implement the Jacobsson-Floberg-Olsson boundary conditions, using a mass-conserving algorithm devised by Professor Emeritus Harold Elrod of Columbia University, was written by David E. Brewe of the U.S. Army at the NASA Lewis Research Center1 in 1983. Since then, new features and improved modifications have been built into the code by several contributors supported through Army and NASA funding via cooperative agreements with the University of Toledo (Professor Ted Keith, Jr., and Dr. Desikakary Vijayaraghavan) and National Research Council Programs (Dr. Vijayaraghavan). All this was conducted with the close consultation of Professor Elrod and the project management of David Brewe.

  18. 基于MATLAB仿真的非规则齿轮行星系扎穴机构的优化设计%Optimization design of non-circular planetary gear trains pricking hole mechanism based on MATLAB

    Institute of Scientific and Technical Information of China (English)

    王金武; 张春凤; 周文琪; 潘振伟; 唐汉; 多天宇

    2016-01-01

    In recent years, as China government policies in agriculture are focused on improving agriculture machinery, deep-fertilization liquid fertilizer applicator with high efficiency, low price, easy operation and environment protection attracts more and more concerns. Deep fertilization for liquid fertilizer is a technology that liquid fertilizer is application accurately in 120-150 mm depth soil, which decreases fertilizer volatilization, increases crop’s nutrient absorbance in fertilizer, decreases environmental pollution brought by fertilizer, and increases crop yield and quality. Deep fertilization for liquid fertilizer is to make the liquid fertilizer into the soil. Northeast Agricultural University developed all elliptic planetary gears for pricking hole mechanism of 1YJ-140 type deep-fertilization liquid fertilizer applicator.Although the mechanism was obtained via using design method for obverse operation, there were a certain blindness in the process of seeking the optimal parameters and a long process of seeking parameters. The transmission part of pricking hole mechanism adopted all elliptic planetary gears so its transmission ratio was fixed. It was difficult to find a perfect path curve. So the non-circular planetary gear trains for pricking hole mechanism was proposed. Several date points on the motion trace of fertilizer-spraying needle tip were selected, and then the curve fitting technique of cubic non-uniform B-spline was applied to control and ascertain the whole trace curve. The inverse kinematics model of the pricking hole mechanism was established on this basis. Then, other parameters could be reversed easily. To meet agronomic requirements of verticality and hole mouth size for deep-fertilization liquid fertilizer machine’ fertilizer-spraying needle when it came in and went out of the soil, the simulation software of reverse design and kinematics analysis was compiled, which was for pricking hole mechanism of the non-circular gear planetary

  19. Analytical/Computational Investigation of Planetary Gear Dynamics in Rotorcraft Transmissions

    Science.gov (United States)

    2008-08-28

    spectrum are at the planetary gear mesh frequency (number of teeth that pass through mesh per second) and integer multiples of this mesh frequency...high torque -weight ratios and division of load between multiple load paths. We completed a full mathematical model of compound planetary gears of...it is evident that large stress occurs at the ring gear teeth even when the strain gaged tooth is far from a tooth mesh of the rotating planets

  20. 复合行星齿轮固有特性分析%Inherent Characteristic Analysis of Compound Planetary Gear

    Institute of Scientific and Technical Information of China (English)

    陈占锋; 程刚; 陈曦晖

    2015-01-01

    A compound planetary gear is considered, which is a part of the rocker driving system. With the lumped parameter method, the dynamics equation is established based on its structure and movement characteristic. According to the parameters of the compound planetary gear, inherent characteristics is analyzed. The vibration mode of compound planetary gear train is summed up, including the planet vibration mode and the overall vibration mode. At the same time, the ADAMS is applied to analyse inherent characteristics of the compound planetary gear. Results show that the conclusion of theoretical analysis is essentially in agreement with simulation. Compared with single-stage planetary gear, the vibration of the compound planetary gear is more complicated.%以摇臂传动系统复合行星齿轮为研究对象,依据其结构和运动特点,应用集中参数法,建立其动力学方程。根据复合行星齿轮的参数,对其固有特性进行分析,归纳了复合行星轮系的振动模式,包括行星轮振动模式和整体振动模式。同时应用ADAMS进行复合行星轮系的固有频率分析,结果表明:理论分析和系统仿真的结论相近。与单级行星齿轮相比,复合行星齿轮的振动情况更加复杂。

  1. A New Model of the Fractional Order Dynamics of the Planetary Gears

    Directory of Open Access Journals (Sweden)

    Vera Nikolic-Stanojevic

    2013-01-01

    Full Text Available A theoretical model of planetary gears dynamics is presented. Planetary gears are parametrically excited by the time-varying mesh stiffness that fluctuates as the number of gear tooth pairs in contact changes during gear rotation. In the paper, it has been indicated that even the small disturbance in design realizations of this gear cause nonlinear properties of dynamics which are the source of vibrations and noise in the gear transmission. Dynamic model of the planetary gears with four degrees of freedom is used. Applying the basic principles of analytical mechanics and taking the initial and boundary conditions into consideration, it is possible to obtain the system of equations representing physical meshing process between the two or more gears. This investigation was focused to a new model of the fractional order dynamics of the planetary gear. For this model analytical expressions for the corresponding fractional order modes like one frequency eigen vibrational modes are obtained. For one planetary gear, eigen fractional modes are obtained, and a visualization is presented. By using MathCAD the solution is obtained.

  2. 曲柄摇杆行星系取苗机构参数匹配与优化%Parameters matching and optimization of seedling pick-up mechanism with crank-rocker planetary gear train

    Institute of Scientific and Technical Information of China (English)

    尚涛; 袁瑞强; 田聪; 王昕

    2016-01-01

    为满足水稻种植农艺的要求,将秧夹式插植臂应用在高速水稻插秧机行星系旋转机构中,设计一种新型曲柄摇杆行星系取苗机构。阐述高速水稻插秧机曲柄摇杆行星系取苗机构的结构特点和工作原理,建立取苗机构的数学模型,通过MATLAB编程对取苗机构的静轨迹进行了分析与优化,对影响秧夹轨迹运动特性的4个主要参数分别选取不同的数值进行优化,得到适合该机构并满足农艺要求的一组最优参数:取苗机构初始位置角a5=−6.05e−2(°),行星轮半径R=78 mm,插植臂长度lc=112.51 mm,插植臂的初始位置角a6=22.73e−2(°)。根据优化结果建立取苗机构的三维虚拟样机模型。通过RecurDyn动力学仿真对理论分析进行验证并试制样机进行试验。研究结果表明,该取苗机构动力学特性良好。%In order to fulfill the agronomic demand of rice planting,the transplanting arms with grippers were applied to the planetary rotation mechanism of high-speed rice transplanter, and a new seedling pick-up mechanism with crank-rocker planetary gear train was designed. The structural features and working principle of seedling pick-up mechanism with crank-rocker planetary gear train was discussed, and the mathematical model of the seedling pick-up mechanism was established. The static trajectory of seedling pick-up mechanism was analyzed and optimized through MATLAB programming, four main parameters influencing the trajectory characteristics of seedling pick-up arms were optimized by choosing different numbers, and a series of optimal structural parameters fulfilling the agronomic demand of rice planting were obtained. The initial position angle of seedling pick-up mechanism (a5) was−6.05e−2(°), the radius of the planet wheel (R) was 78 mm, the length of seedling pick-up arms (lc) was 112.51mm, and the initial position angle of seedling pick-up arms (a6) was 22.73e−2(°). The virtual

  3. Reduction of belt CVT gear noise by gear train modification. Optimize vibration characteristics of gear train; Belt CVT no gear noise teigen gijutsu. Gear train shindo tokusei no saitekika

    Energy Technology Data Exchange (ETDEWEB)

    Arimatsu, M.; Kawakami, T. [Nissan Motor Co. Ltd., Tokyo (Japan)

    1997-10-01

    With the reduction of vehicle noise, the requirements for an efficient method to reduce transmission gear noise have become stronger yearly. So far efforts to reduce gear noise have generally focused on ways of improving the gears themselves. In addition to these traditional methods, it proved very beneficial to us to optimize the gear train structure. Nissan has just released the new Belt CVT for 2.0L Front wheel drive vehicles. We have been analyzing vibration of the gear train by using a finite element model since the early development stage, and we could achieve the quiet gears effectively. 2 refs., 9 figs.

  4. MODELING 3D CAD AND RAPID PROTOTYPING THE PRESENTER PLANETARY GEAR

    Directory of Open Access Journals (Sweden)

    Tadeusz MARKOWSKI

    2014-06-01

    Full Text Available This paper presents a methodology for modeling and prototyping presentation of the planetary gear. Shown is the way of modeling hybrid transmission gear teeth. The first step is to develop a hybrid modeling the geometry of the teeth profiles. In the second stage, solid modeling has been done other elements of the geometry of the gear. In the following, using modeling as a team made the other elements of the planetary gear. The resulting band before performing a physical model has been verified in CAD software. Solid models were used to perform a physical prototype. The prototype was prepared using FDM rapid prototyping methods.

  5. 基于变形协调的行星轮系均载特性研究%Study on load sharing behavior of planetary gear train based on deformation compatibility

    Institute of Scientific and Technical Information of China (English)

    杜进辅; 方宗德; 王宝宾; 董皓

    2012-01-01

    The deformation compatibility equations and the torque balance equations were found of the 2K-H-type planetary transmission system based on the characteristic that the system composed a closed-loop of power flow.In consideration of the manufacturing error,assembly error and float of the parts,the load sharing coefficient of each planetary gear was calculated by using the theory of equivalent mesh error and equivalent mesh stiffness.The effects of the errors on load sharing were studied.The study provides useful theoretical guideline for the design of planetary gear systems.%以2K-H行星齿轮传动系统为研究对象,根据整个系统构成功率流动闭环的特点,建立了系统的力矩平衡条件和变形协调条件,并运用当量啮合误差理论,计算了各个行星轮以及系统的均载系数.从静力学角度分析了各构件的制造误差、安装误差以及浮动对行星传动均载性能的影响.提出了一种新的算法,以供工程应用参考.

  6. Dynamic Analysis of Wind Turbine Planetary Gears Using an Extended Harmonic Balance Approach: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Y.; Keller, J.; Parker, R. G.

    2012-06-01

    The dynamics of wind turbine planetary gears with gravity effects are investigated using an extended harmonic balance method that extends established harmonic balance formulations to include simultaneous internal and external excitations. The extended harmonic balance method with arc-length continuation and Floquet theory is applied to a lumped-parameter planetary gear model including gravity, fluctuating mesh stiffness, bearing clearance, and nonlinear tooth contact to obtain the planetary gear dynamic response. The calculated responses compare well with time domain integrated mathematical models and experimental results. Gravity is a fundamental vibration source in wind turbine planetary gears and plays an important role in system dynamics, causing hardening effects induced by tooth wedging and bearing-raceway contacts. Bearing clearance significantly reduces the lowest resonant frequencies of translational modes. Gravity and bearing clearance together lowers the speed at which tooth wedging occurs lower than the resonant frequency.

  7. 联合收割机割刀驱动行星轮系多目标优化设计%Sickle Mechanism of Combined Harvesters of Drive Planetary Gear Train Multi-objective Optimization

    Institute of Scientific and Technical Information of China (English)

    郝志勇; 刘伟; 闫闯; 夏玮

    2011-01-01

    Aiming at the working characteristics of sickle mechanism of combined harvesters,the working principle of sickle mechanism was analyzed using mainly 2K-H type planetary gear mechanism.Through establishing optimization design model of 2K-H type planetary gear mechanism,applying NSGA-2 algorithm for the multi-objective optimization design of 2K-H type planetary gear mechanism,thinking the smallest size and highest carrying capacity as the optimization design goal,through developing the MATLAB program,Pareto frontier was got and then obtained the optimal solution,compared with the past multi-objective design,the design has been very good improvement.%针对联合收割机割刀机构的工作特点,采用2K-H型行星齿轮机构,分析了割刀机构工作原理。通过建立2K-H型行星轮系的优化设计模型,应用NSGA-2算法对2K-H型行星齿轮机构进行多目标优化设计。以最小体积和最大承载力为优化设计目标,通过编制MATLAB程序得到Pareto前沿,进而得到最优解,与以往多目标优化设计比较,设计得到了很好的改善。

  8. Advanced model for the calculation of meshing forces in spur gear planetary transmissions

    OpenAIRE

    Iglesias Santamaría, Miguel; Fernández del Rincón, Alfonso; Juan de Luna, Ana Magdalena de; Díez Ibarbia, Alberto; García Fernández, Pablo; Viadero Rueda, Fernando

    2015-01-01

    This paper presents a planar spur gear planetary transmission model, describing in great detail aspects such as the geometric definition of geometric overlaps and the contact forces calculation, thus facilitating the reproducibility of results by fellow researchers. The planetary model is based on a mesh model already used by the authors in the study of external gear ordinary transmissions. The model has been improved and extended to allow for the internal meshing simulation, taking into cons...

  9. A theoretical and experimental investigation of modulation sidebands of planetary gear sets

    Science.gov (United States)

    Inalpolat, M.; Kahraman, A.

    2009-06-01

    In this paper, a simplified mathematical model is proposed to describe the mechanisms leading to modulation sidebands of planetary gear sets. The model includes key system parameters such as number of planets, planet position angles, and planet phasing relationships defined by the position angles and the number of teeth of the gears. The model is used to simulate a wide range of gear sets to show that they can be classified in five distinct groups based on their sideband behavior in terms of their frequencies and amplitudes. A special experimental planetary gear set-up is developed and planetary gear sets from of three of these five groups are procured. A methodology is developed to demonstrate modulation sidebands from the ring (internal) gear radial acceleration measurements. For each case, sets of ring gear acceleration measurements at various speed and torque conditions are presented to demonstrate rich sideband activity that agrees well with the model predictions. At the end, based on results of the parametric studies and experiments, general rules on modulation sidebands of planetary gear sets are proposed.

  10. Lifetimes and Reliabilities of Bevel-Gear Drive Trains

    Science.gov (United States)

    Lewicki, D.; Cox, J.; Savage, M.; Brikmanis, C.

    1986-01-01

    Statistical methods used to predict system lifetimes from component lifetimes. Report shows how to use information to determine system life of drive train, using methods of probability and statistics. Presents life and reliability model for bevel-gear drive trains. Bevel-gear and support-bearing lives analyzed for each gear and bearing in drive train, with results statistically combined to produce system life for entire drive train. Numerical example included.

  11. A windowing and mapping strategy for gear tooth fault detection of a planetary gearbox

    Science.gov (United States)

    Liang, Xihui; Zuo, Ming J.; Liu, Libin

    2016-12-01

    When there is a single cracked tooth in a planet gear, the cracked tooth is enmeshed for very short time duration in comparison to the total time of a full revolution of the planet gear. The fault symptom generated by the single cracked tooth may be very weak. This study aims to develop a windowing and mapping strategy to interpret the vibration signal of a planetary gear at the tooth level. The fault symptoms generated by a single cracked tooth of the planet gear of interest can be extracted. The health condition of the planet gear can be assessed by comparing the differences among the signals of all teeth of the planet gear. The proposed windowing and mapping strategy is tested with both simulated vibration signals and experimental vibration signals. The tooth signals can be successfully decomposed and a single tooth fault on a planet gear can be effectively detected.

  12. Modeling, Modal Properties, and Mesh Stiffness Variation Instabilities of Planetary Gears

    Science.gov (United States)

    Parker, Robert G.; Lin, Jian; Krantz, Timothy L. (Technical Monitor)

    2001-01-01

    Planetary gear noise and vibration are primary concerns in their applications in helicopters, automobiles, aircraft engines, heavy machinery and marine vehicles. Dynamic analysis is essential to the noise and vibration reduction. This work analytically investigates some critical issues and advances the understanding of planetary gear dynamics. A lumped-parameter model is built for the dynamic analysis of general planetary gears. The unique properties of the natural frequency spectra and vibration modes are rigorously characterized. These special structures apply for general planetary gears with cyclic symmetry and, in practically important case, systems with diametrically opposed planets. The special vibration properties are useful for subsequent research. Taking advantage of the derived modal properties, the natural frequency and vibration mode sensitivities to design parameters are investigated. The key parameters include mesh stiffnesses, support/bearing stiffnesses, component masses, moments of inertia, and operating speed. The eigen-sensitivities are expressed in simple, closed-form formulae associated with modal strain and kinetic energies. As disorders (e.g., mesh stiffness variation. manufacturing and assembling errors) disturb the cyclic symmetry of planetary gears, their effects on the free vibration properties are quantitatively examined. Well-defined veering rules are derived to identify dramatic changes of natural frequencies and vibration modes under parameter variations. The knowledge of free vibration properties, eigen-sensitivities, and veering rules provide important information to effectively tune the natural frequencies and optimize structural design to minimize noise and vibration. Parametric instabilities excited by mesh stiffness variations are analytically studied for multi-mesh gear systems. The discrepancies of previous studies on parametric instability of two-stage gear chains are clarified using perturbation and numerical methods. The

  13. Detection and Localization of Tooth Breakage Fault on Wind Turbine Planetary Gear System considering Gear Manufacturing Errors

    Directory of Open Access Journals (Sweden)

    Y. Gui

    2014-01-01

    Full Text Available Sidebands of vibration spectrum are sensitive to the fault degree and have been proved to be useful for tooth fault detection and localization. However, the amplitude and frequency modulation due to manufacturing errors (which are inevitable in actual planetary gear system lead to much more complex sidebands. Thus, in the paper, a lumped parameter model for a typical planetary gear system with various types of errors is established. In the model, the influences of tooth faults on time-varying mesh stiffness and tooth impact force are derived analytically. Numerical methods are then utilized to obtain the response spectra of the system with tooth faults with and without errors. Three system components (including sun, planet, and ring gears with tooth faults are considered in the discussion, respectively. Through detailed comparisons of spectral sidebands, fault characteristic frequencies of the system are acquired. Dynamic experiments on a planetary gear-box test rig are carried out to verify the simulation results and these results are of great significances for the detection and localization of tooth faults in wind turbines.

  14. A Survey on the Models of Rotor-bearing System Based on the Wind Gearbox Planetary Gear Train%基于风电增速箱行星轮系的转子-轴承系统模型概述

    Institute of Scientific and Technical Information of China (English)

    宋辰超; 王立勇; 马超; 许宝杰; 王志

    2015-01-01

    Based on the 2K-H planetary gear train of the wind gearbox and the translational-rotational model, this paper establishes the model of rotor-bearing system which considered the input shaft and output shaft of the transmission system. In the model of rotor-bearing system, we take into account the gear pair clearance, time-varying meshing stiffness and phase difference, meshing damping, integrated meshing phase, the bearing stiffness, the input shaft and output shaft stiffness. The dynamic coordinate system is established, each of coordinate system has three degrees of freedom. The method of integrated mass is applied to establish the model, and the motion differential equation is solved by the Lagrange equation. In this paper, it is summarized and compared the method of establishment about planetary train mode at home and abroad in recent years and the dynamic characteristic of the planetary gear train in practical engineering of wind power is researched. On this basis, the model of rotor-bearing system of planter gear train is established based on the wind gearbox.%基于风电增速箱2K-H直齿行星轮系,在行星轮系平移-扭转振动模型的基础上,结合传动系统的输入轴和输出轴,建立了转子-轴承系统模型。模型中考虑了齿轮副间隙,时变啮合刚度及其相位差,啮合阻尼,综合啮合误差及输入轴和输出轴两端轴承的刚度,输入轴和输出轴的刚度。建立了动坐标系,每个坐标系均有3个自由度。采用集中质量法,建立此模型,并利用拉格朗日方程法解运动微分方程。文中对近几年国内外有关行星轮系模型建立的方法进行了比较和总结,对工程实际中风力发电的行星齿轮传动系特性进行了研究。以此为基础,建立了基于风电增速箱行星轮系的转子-轴承系统的模型。

  15. Load sharing characteristics of a planetary gear train system with non-equivalent modulus and pressure angle considering backlashes%考虑齿侧间隙的非等模数非等压力角行星齿轮系统的均载特性研究

    Institute of Scientific and Technical Information of China (English)

    叶福民; 朱如鹏; 靳广虎; 鲍和云; 李发家

    2015-01-01

    针对非等模数非等压力角行星齿轮传动系统,建立了多自由度平移-扭转振动的非线性动力学模型。考虑到齿轮副齿侧间隙、系统综合误差和齿轮副模数与压力角的不相等,计算了系统的均载系数并对由它们所引起的系统不均载特性进行了动力学分析。获得了误差一定且齿侧间隙改变时,啮合副的动载荷曲线与均载系数间的变化关系。讨论了齿轮副模数和压力角分别不同时,系统均载系数的变化幅度。研究表明:随着齿轮副压力角选择范围的扩大,系统均载系数有着较大幅度的变化;齿侧间隙使系统的啮合副处于不同冲击状态,不同冲击状态对系统的均载性能有着重要的影响。%A translation-torsion coupled nonlinear dynamic model with multi-DOF was established for a planetary gear train system with non-equivalent modulus and pressure angle.Considering backlashes,system's comprehensive errors and non-equivalent modulus and pressure angle of gear pair,the load sharing coefficient of the system was calculated.The dynamic characteristics of load sharing caused by the factors mentioned above were analyzed.Some relations between the dynamic load curve of gear pair and the load sharing coefficient were obtained due to certain errors and changes of backlash.The change range of the system load sharing coefficient was discussed with the variation of gear modulus and pressure angle.The results showed that the load sharing coefficient has a larger variation with increase in selecting range of pressure angle of gear pair,and the different impacts of meshing pair caused by backlashes have important influences on the load sharing characteristics of the planetary gear train system.

  16. On the identification of the angular position of gears for the diagnostics of planetary gearboxes

    Science.gov (United States)

    D'Elia, G.; Mucchi, E.; Cocconcelli, M.

    2017-01-01

    Generally, in planetary gearbox diagnostics, vibration transducers are placed on the gearbox case near the ring gear. The relative angular position of the planet gears with respect to the transducer is a useful information for the evaluation of vibration signals related to planet/sun gears. This angular position is usually unknown, or it is known with a large tolerance causing serious difficulties in both gears and bearing diagnostics. In fact, noise and spurious component from healthy planets could overhang the informative content about incipient faults. The present work seeks to propose two alternative methods for the identification of the angular position of the planet gears with respect to the transducer. The first one is based on the study of how the power flows inside the Time Synchronous Average of the ring gear, whilst the second method is based on a modified statistical parameter such as the Crest Factor. The effectiveness of these methods is assessed on the basis of actual vibration signals acquired from a faulty planetary gearbox. The knowledge of the exact angular position of the planet gears allows the diagnostics of both gears and bearings, as proven by extensive experimental activities reported in the paper.

  17. Experimental Investigations of Noise Control in Planetary Gear Set by Phasing

    Directory of Open Access Journals (Sweden)

    S. H. Gawande

    2014-01-01

    Full Text Available Now a days reduction of gear noise and resulting vibrations has received much attention of the researchers. The internal excitation caused by the variation in tooth mesh stiffness is a key factor in causing vibration. Therefore to reduce gear noise and vibrations several techniques have been proposed in recent years. In this research the experimental work is carried out to study the effect of planet phasing on noise and subsequent resulting vibrations of Nylon-6 planetary gear drive. For this purpose experimental set-up was built and trials were conducted for two different arrangements (i.e., with phasing and without phasing and it is observed that the noise level and resulting vibrations were reduced by planet phasing arrangement. So from the experimental results it is observed that by applying the meshing phase difference one can reduce planetary gear set noise and vibrations.

  18. Static load sharing behavior of double-row planetary gear train%双排行星齿轮系统的静态均载特性行为

    Institute of Scientific and Technical Information of China (English)

    盛冬平; 朱如鹏; 靳广虎; 陆凤霞; 鲍和云

    2015-01-01

    建立双排行星齿轮传动系统的计算模型,并针对其进行静态均载特性行为的理论研究。模型中考虑各级行星齿轮的偏心误差,静态传递误差,时变啮合刚度等参数,并利用傅里叶级数法求解系统载荷平衡方程。定性地研究行星轮的偏心误差,齿圈的支撑刚度,行星轮的支撑刚度以及一级行星架的扭转刚度等参数对系统静态均载特性行为的影响,并据此得到一些理论分析结果。该研究延伸和扩展了对双排行星轮系均载特性行为的认识,并为进一步进行动力学均载行为的理论和实验研究形成一定的基础,同时也为双排行星轮系的设计提供一定的参考。%A new model for analyzing the static load sharing characteristics of double-row planetary gear set was proposed, and planet’s eccentricity error, static transmission error, and time-varying meshing stiffness were taken into consideration. The equilibrium equations were determined by the method of Fourier series, and the behavior of static load sharing characteristics affected by the system parameters including gear eccentricity error, ring gear’s supporting stiffness, planet’s bearing stiffness and torsional stiffness of first stage carrier were investigated quantitatively. Theoretical analysis extends our current understanding of behavior of static load sharing characteristics, forms the basis of further theoretical and experimental research, and provides guidelines for the designing of the double-row planetary gear transmission system.

  19. Helicopter transmission arrangements with split-torque gear trains

    Science.gov (United States)

    White, G.

    1983-01-01

    As an alternative to component development, the case for improved drive-train configuration is argued. In particular, the use of torque-splitting gear trains is proposed as a practicable means of improving the effectiveness of helicopter main gearboxes.

  20. Finishing aeronautical planetary herringbone gear wheels in container vibrating smoothing machine

    Directory of Open Access Journals (Sweden)

    Jacek MICHALSKI

    2015-12-01

    Full Text Available The paper presents the technological process of abrasive-chemical machining wheel bearing surface of the cylindrical herringbone gears planetary gear in vibrating container smoothing machine according to Isotropic Finishing ISF® technology of the REM Chemicals Inc. company. Gear wheels are made of stainless Pyrowear 53 and subjected to carburizing, hardening, cold working and low tempering. The change in value of deviation indicators for the kinematic accuracy, smoothness and geometric structure of the machined surfaces of the gear teeth after smoothing compared with the contoured grinding were analyzed. The findings are different a characteristic performance on the surface of the tooth side along the outline, especially with a higher value at the head of the tooths. This creates a need for appropriate modification of the lateral surface of the teeth in the process of contoured grinding. The results of the mechanical strength of the samples gear wheel after the smoothing process and evaluating the hydrogen embrittlement are presented.

  1. Statistical Modification Analysis of Helical Planetary Gears based on Response Surface Method and Monte Carlo Simulation

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun; GUO Fan

    2015-01-01

    Tooth modification technique is widely used in gear industry to improve the meshing performance of gearings. However, few of the present studies on tooth modification considers the influence of inevitable random errors on gear modification effects. In order to investigate the uncertainties of tooth modification amount variations on system’s dynamic behaviors of a helical planetary gears, an analytical dynamic model including tooth modification parameters is proposed to carry out a deterministic analysis on the dynamics of a helical planetary gear. The dynamic meshing forces as well as the dynamic transmission errors of the sun-planet 1 gear pair with and without tooth modifications are computed and compared to show the effectiveness of tooth modifications on gear dynamics enhancement. By using response surface method, a fitted regression model for the dynamic transmission error(DTE) fluctuations is established to quantify the relationship between modification amounts and DTE fluctuations. By shifting the inevitable random errors arousing from manufacturing and installing process to tooth modification amount variations, a statistical tooth modification model is developed and a methodology combining Monte Carlo simulation and response surface method is presented for uncertainty analysis of tooth modifications. The uncertainly analysis reveals that the system’s dynamic behaviors do not obey the normal distribution rule even though the design variables are normally distributed. In addition, a deterministic modification amount will not definitely achieve an optimal result for both static and dynamic transmission error fluctuation reduction simultaneously.

  2. Dynamic Response of a Planetary Gear System Using a Finite Element/Contact Mechanics Model

    Science.gov (United States)

    Parker, Robert G.; Agashe, Vinayak; Vijayakar, Sandeep M.

    2000-01-01

    The dynamic response of a helicopter planetary gear system is examined over a wide range of operating speeds and torques. The analysis tool is a unique, semianalytical finite element formulation that admits precise representation of the tooth geometry and contact forces that are crucial in gear dynamics. Importantly, no a priori specification of static transmission error excitation or mesh frequency variation is required; the dynamic contact forces are evaluated internally at each time step. The calculated response shows classical resonances when a harmonic of mesh frequency coincides with a natural frequency. However, peculiar behavior occurs where resonances expected to be excited at a given speed are absent. This absence of particular modes is explained by analytical relationships that depend on the planetary configuration and mesh frequency harmonic. The torque sensitivity of the dynamic response is examined and compared to static analyses. Rotation mode response is shown to be more sensitive to input torque than translational mode response.

  3. Meta Modeling of Transmission Error for Spur, Helical and Planetary Gears for Wind Turbine Application

    OpenAIRE

    Irfan, Muhammad

    2013-01-01

    Detailed analysis of drive train dynamics requires accounting for the transmission error that arises in gears. However, the direct computation of the transmission error requires a 3-dimensional contact analysis with correct gear geometry, which is impractically computationally intense. Therefore, a simplified representation of the transmission error is desired, a so-called meta-model, is developed. The model is based on response surface method, and the coefficients of the angle-dependent tran...

  4. Transmission Ratio Analysis of 8-Speed Automatic Transmission With Planetary Gear%基于行星轮的8速自动变速器传动比计算

    Institute of Scientific and Technical Information of China (English)

    贾振华; 郏国中; 吴心平

    2011-01-01

    Motion analysis based on planetary gear, essence reflects the planetary gear train transmission combined with common planetary gear, and an 8-speed automatic transmission gearing for analysis, all retaining transmission ratio calculation. Based on the methods of analysis for planetary gear, for the study of complex planetary gear set transmission problems and design of the automatic transmission provides specific solutions.%基于行星齿轮运动分析,本质反映了共用行星轮组合式行星齿轮变速机构的传动特性,并对某8速自动变速器的传动原理进行分析,提供了各挡传动比的计算方法。基于行星轮的分析方法,为研究复杂行星齿轮机构传动问题和设计汽车自动变速器提供了具体的解决途径。

  5. TOLERANCE ANALYSIS OF A PLANETARY GEAR REDUCER UNDER CAD CIRCUMSTANCE

    Institute of Scientific and Technical Information of China (English)

    Zhu Fumin; Li Wanli; Maropoulos P G

    2005-01-01

    Tolerance analysis of a planetary reducer is conducted. By focusing the serially-arranged parts in the central line and setting an appropriate dimension as a "gap", worst-case tolerance analysis method and statistical (RSS) tolerance analysis are used, and then a tolerance-analyzing tool CE/TOL is introduced. The acceptable value range of the "gap" is from 1.5 mm to 3.5 mm. While worst-case analysis rejects the design, RSS accepts it by a more realistic result with the law of probability accounted. With the help of CE/TOL and CAD software Pro/E, all components' dimensions and tolerances are assigned and modified, and more detailed and more comprehensible results are gives out.

  6. Detecting Tooth Damage in Geared Drive Trains

    Science.gov (United States)

    Nachtsheim, Philip R.

    1997-01-01

    This paper describes a method that was developed to detect gear tooth damage that does not require a priori knowledge of the frequency characteristic of the fault. The basic idea of the method is that a few damaged teeth will cause transient load fluctuations unlike the normal tooth load fluctuations. The method attempts to measure the energy in the lower side bands of the modulated signal caused by the transient load fluctuations. The method monitors the energy in the frequency interval which excludes the frequency of the lowest dominant normal tooth load fluctuation and all frequencies above it. The method reacted significantly to the tooth fracture damage results documented in the Lewis data sets which were obtained from tests of the OH-58A transmission and tests of high contact ratio spiral bevel gears. The method detected gear tooth fractures in all four of the high contact ratio spiral bevel gear runs. Published results indicate other detection methods were only able to detect faults for three out of four runs.

  7. A Study on Torsional Vibrations in an Encased Differential Gear Train%封闭行星齿轮传动系统的扭振特性研究

    Institute of Scientific and Technical Information of China (English)

    孙智民; 沈允文; 李素有

    2001-01-01

    本文建立了封闭行星齿轮传动系统的扭振计算模型,模型中考虑了行星轮和星轮的啮合相位,行星架的弹性变形和负载惯性。用数值解法获得了在受周期性变化的齿轮啮合刚度和齿频综合误差激励下的齿轮啮合动载荷和在不同的输入转速下的动载荷系数。分析了在星形轮系和行星轮系动力耦合情况下齿轮系统的动态特性,得出了对封闭行星齿轮传动设计有意义的结论。%A torsional vibration model formulated by time-varying mesh stiffness and composite gear errors was established to predict the dynamic characteristics of the encased differential gear train.The mesh-phases of the planet and star gears,elastic deformation and load inertia of planet carrier were also taken into account.A numerical method was applied to solving the large parametrically excited dynamic system.From the numerical results it was concluded that the gear meshing forces of the planetary gear train mainly fluctuated in meshing frequency of the planetary gear train;but the gear meshing forces of the star gear train fluctuated not only at the meshing frequency of the planetary gear train but also at that of the star gear train.A maximal dynamic load occurred at the high-frequency resonance.The dynamic load factor of the planetary gear train was larger than that of the star gear train in the work speed area.

  8. Structure design and motion simulation of the pin-cycloid gear planetary reducer with ring-plate-type

    Science.gov (United States)

    Duan, Hongjie; Li, Lijun; Tao, Junyi

    2017-06-01

    The pin-cycloid gear planetary reducer with ring-plate-type is a new type of reducers. It has high transmission ratio range and high efficiency. In this paper the working principle of pin-cycloid gear planetary reducer is discussed, and the structure of the reducer is designed. Especially for the complexity and the difficulty in modelling of the cycloid gear tooth profile, the parametric design module of cycloid gear is developed to solve the cycloid gear modelling problem through the second development of Solid Works. At last, the speed schemes of the input shaft and output shaft of the reducer are obtained by the motion simulation. Through the analysis of the simulation curves, the rationality of the structure design is proved, which provides a theoretical basis for the design and manufacture of the reducer.

  9. Dynamic Modeling and Analysis of Power Coupling System with Two-stage Planetary Gear Trains for Hybrid System%混合动力两级行星机构动力耦合系统动力学建模及分析

    Institute of Scientific and Technical Information of China (English)

    罗玉涛; 陈营生

    2012-01-01

    以基于双转子电机的混合动力传动系统的两级行星齿轮机构动力耦合系统为研究对象,考虑前后两级行星齿轮机构的齿轮副啮合刚度、中心构件的扭转支撑刚度、连接部分的扭转耦合刚度、各构件惯性等基本因素,详细推导并建立两级行星齿轮耦合系统的纯扭转动力学模型.利用两级行星齿轮机构的有关参数进行特征值问题求解,得到系统整体模型的固有特性,按照振型特点把系统的振动形式划分为三种模式:整体扭转振动模式、前排行星轮振动模式和后排行星轮振动模式.在整体模式下固有频率为单根,系统各构件均以一定幅度做扭转振动;前、后排行星轮模式下固有频率均为二重根,且除了其自身外,其他构件均无振动.归纳分析得到的各振动模式特征与前人有关结论相吻合.同时指出连接部分的耦合刚度对系统振动特性的影响,并作了初步分析.%A power coupling system with two-stage planetary gear trains is considered, which is a part of a novel hybrid power train system based on a double-rotor motor. Many fundamental factors are taken into account, such as mesh stiffness of gear pairs of the two-stage planetary gears, torsional stiffness of the central parts, torsional coupling stiffness of the connecting section, inertia of the system, etc. Purely torsional dynamic model of the coupling system is developed. The reduced-order eigenvalue problems are derived by using the related parameters of the system, and the natural characteristics of the system is shown. The vibration modes of the system are classified into three categories: overall rotational mode, front row planet mode, rear row planet mode. In overall mode, the natural frequency is a simple root and each part of the system has torsional vibration to some extent. However, the natural frequency is a double root in the other two modes and no part of system vibrates except the planet gears

  10. Fault diagnosis for wind turbine planetary ring gear via a meshing resonance based filtering algorithm.

    Science.gov (United States)

    Wang, Tianyang; Chu, Fulei; Han, Qinkai

    2017-03-01

    Identifying the differences between the spectra or envelope spectra of a faulty signal and a healthy baseline signal is an efficient planetary gearbox local fault detection strategy. However, causes other than local faults can also generate the characteristic frequency of a ring gear fault; this may further affect the detection of a local fault. To address this issue, a new filtering algorithm based on the meshing resonance phenomenon is proposed. In detail, the raw signal is first decomposed into different frequency bands and levels. Then, a new meshing index and an MRgram are constructed to determine which bands belong to the meshing resonance frequency band. Furthermore, an optimal filter band is selected from this MRgram. Finally, the ring gear fault can be detected according to the envelope spectrum of the band-pass filtering result.

  11. The optimization design of experiment platform by gear train design%轮系设计实验台优化设计

    Institute of Scientific and Technical Information of China (English)

    孙孟琴; 李水清; 武向鹏; 许云成

    2014-01-01

    T his paper presents a new type of detachable gear train experimental platform .It can connect many types of gear train (the fixed axis gear train ,the differential gear train ,the planetary gear train ,the mixed gear train ,the gear transmission and so on) ,clears showing its structure .The Design and algorithm of gear parameters have been optimized ,so the experimental platform has meet the requirements of good stability and reliability .It improves the students'practical ability ,observing and analytical ability ,satisfied the strengthening of teaching experiment practices in university .%设计一种新型可拆装轮系实验台,能搭接多种类型的结构(定轴轮系、差动轮系、行星轮系、混合轮系、齿轮传动等),清楚地展示了其内部结构。优化了齿轮等参数的设计与计算,使实验台达到可靠性与稳定性良好的要求。提高学生动手与观察分析能力,满足现在加强高校实验实践教学的要求。

  12. Effect of Symmetry on Structures of Epicyclic Gear Trains

    Directory of Open Access Journals (Sweden)

    Rajasri Reddy

    2014-04-01

    Full Text Available An epicyclic gear train (EGT can be denoted by a graph and this graph in turn represented by an adjaceny matrix. Hamming matrix is used to detect isomorphism and measure the structural aspect of symmetry in EGTs. More symmetry in EGTs results in higher number of structural arrangements as compared to EGTs with no or less symmetry.

  13. Meshing Stiffness Variation Instabilities in Encased Differential Planetary Gear Train%封闭差动行星齿轮传动系统啮合刚度振动不稳定性

    Institute of Scientific and Technical Information of China (English)

    朱增宝; 朱如鹏

    2016-01-01

    No considering the damping and external forces the pure torsional freedom vibration equation of encased differential planetary train is established and this equation is converted to regular modal equation. The multi-scale method is applied to derive the stability conditions of summation resonance frequencies caused by the meshing stiffness fluctuations for this train and the dynamic stability is analyzed. The research results show that the bigger the absolute value of the coefficient matrix element of the first harmonic of the meshing stiffness fluctuations for this regular modal equation, the greater the vibration frequency instability interval caused by the corresponding combination resonance frequency or second harmonic of this coefficient matrix element. The instability is bigger with the increase of the meshing stiffness volatility while the meshing frequency is close to the resonance combination frequency and twice harmonic frequency. The resonance points of the combination resonance frequency and second harmonic frequency of this train caused by the mesh frequency of the encased stage is far more than that of the differential stage. The point in the undulating surface of the unstable three-dimensional map to the integer of internal and external mesh overlap is the bottom and it has a high stability.%不考虑阻尼和外力,建立封闭差动行星传动系统纯扭转自由振动方程并将该方程转换为正则模态方程;利用多尺度法推导出传动系统的啮合刚度波动引起的和型共振频率的稳定性条件并进行动力稳定性分析。研究结果表明:传动系统正则模态方程的啮合刚度波动的一次谐波项的系数矩阵元素绝对值越大,对应该系数矩阵元素的组合共振频率或2倍频引起的振动频率不稳定区间越大;啮合频率接近共振组合频率和2倍频时,不稳定性随啮合刚度波动率的增加而增大;传动系统受封闭级啮合频率激励

  14. 复杂轮系在镗孔车端面装置中的应用%The Application of Complicated Gear train in The Device of Boring Holes and Turning End Face

    Institute of Scientific and Technical Information of China (English)

    刘萍

    2014-01-01

    Researchthe application of complicated gear train in the device of boring holes and turning end face.Analysis the parallel compound gear train consisting of planetary gear train and differential gear train,and the series hybrid gear train consisting of planetary gear train,fixed axis gear train and the parallel compound gear train.The feed movement and the feed amount of the device is discussed,at the stage of rough and finish machining,quick returning.And the application principle of the boring holes and turning end face is clarified.%本文研究复杂轮系在镗孔车端面装置中应用,分析行星轮系与差动轮系构成的并联复合轮系,行星轮系和定轴轮系组成的串联混合轮系,探讨了孔车端面装置在粗、精加工及快退时进给运动和进给量等,阐明镗孔车端面装置的应用原理。

  15. Analysis and Optimization of Wide-Narrow Distance Transplanting Mechanism with Spatial Planetary Gear Train of Variable Speed Transmission%非匀速空间行星轮系宽窄行分插机构分析与优化

    Institute of Scientific and Technical Information of China (English)

    孙良; 赵匀; 姚佳明; 郑建; 俞高红; 祝宇

    2012-01-01

    In order to solve the problems such as grasping seedling obliquely and shaping wider plant hole, a wide - narrow distance transplanting mechanism with spatial planetary gear train composed of elliptical bevel gears and crossed cylindrical gears was put forward. Kinematical model was established based on the transmission characteristics. Furthermore, the proposed mechanism was proved capable of taking the advantages, which known as grasping seedling more vertically and shaping narrower plant hole, by the analysis on relation among the lateral offsets,, lateral plant hole of spatial planting trajectory and shaft angle. A optimization program about wide - narrow distance transplanting mechanism was written to research on the kinematics, and a set of optimal parameters meeting the working requirements of wide -narrow distance rice transplanter was obtained by the method of human - computer conversation afterward. Then configuration of elliptical bevel gear was achieved and virtual prototype test was performed by the software named ADAMS. Finally, a model machining of the transplanting mechanism as well as its testing was made, and concluding that the structural design and its parameters was suited to the requirements of wide - narrow distance rice transplanter.%针对现有宽窄行分插机构存在斜取秧和大穴口问题,提出一种由椭圆锥齿轮-交错圆柱齿轮混合传动的空间行星轮系宽窄行分插机构.分析了椭圆锥齿轮的传动特性,建立了机构的运动学模型.通过分析插秧轨迹的横向线位移、横向插秧穴口边长与传动齿轮交错角的关系,得出椭圆锥齿轮-交错圆柱齿轮混合传动方式可以兼顾斜置式和齿轮交错传动式的小穴口、直取秧的优点.开发了宽窄行分插机构参数优化软件,进行了机构的运动特征分析,并通过人机交互方式优化了一组满足宽窄行插秧机的机构参数.利用仿真软件ADAMS实现了椭圆锥齿轮齿廓的设计,并

  16. 2K-H 行星轮系的平移扭转模型建立与非线性动态特性分析%Establishment of translational and torsional model and nonlinear dynamic characteristic analysis for 2K-H planetary gear trains

    Institute of Scientific and Technical Information of China (English)

    周璐; 巫世晶; 李景; 王晓笋; 朱伟林; 李小勇

    2016-01-01

    To study the nonlinear dynamic characteristics of a 2K-H planetary gear train,a translation-torsion coupling dynamic model is established,taking the nonlinear factors like time-varying mesh stiffness,synthetic meshing error and gear backlash into account.The dimensionless kinematic differential equations of 18 degrees of freedom for the system are then derived.The influences of meshing frequency,damping and backlash on the system's bifurcation and chaos characteristics are analyzed through the phase trajectory,Poincare graph and time history plot.The results show that the system will come into a chaotic state through a catastrophic way with the increase of the meshing frequency.The system can get rid of chaotic movement into a periodic motion state by increasing the damping.The dynamic response of the system is sensitive to backlash at high speeds and with a light load while the response is only a change of amplitude not a dynamic behavior in certain backlash ranges.%为探讨2K-H 行星轮系的非线性动态特性,建立了考虑时变啮合刚度、综合啮合误差和齿侧间隙等强非线性因素的平移-扭转耦合动力学模型,并推导了系统的无量纲化18自由度运动学微分方程组。通过相轨线、Poincare图和时间历程曲线分析了啮合频率、啮合阻尼和齿侧间隙对系统分岔与混沌特性的影响。结果表明:随着啮合频率的增大,系统由激变途径进入混沌状态;增大啮合阻尼可以使系统摆脱混沌运动进入周期运动状态;在高速轻载时,系统的动态响应对间隙非常敏感,而在某些间隙范围内,响应只有幅值的改变,动力学行为不发生变化。

  17. Offset Compound Gear Drive

    Science.gov (United States)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  18. Research on the gear root dynamic stress of the planetary gear transmission%行星齿轮传动齿根动应力计算

    Institute of Scientific and Technical Information of China (English)

    蒋立冬; 李应生; 朱振荣; 陈营利

    2012-01-01

    The workload is big to calculate the gear root stress of the planetary gear transmission because of the big contact ratio, so the gear root dynamic stress was studied in the paper. At the same time, the sun gear in the differential stage of the power dividing planetary transmission was taken an example, the finite element model, meshing and loading method were analyzed in detail. File of load was formed by use of APDL language on Ansys software. It was used for controlling loading on locations of several contact lines in a meshing cycle. Method of calculation in the paper can obtain the gear root dynamic stress on a tooth meshing process precisely and quickly.%针对功率分流行星齿轮传动齿轮重合度大,齿根应力计算工作量大的问题,对齿根动应力的计算问题进行了详细的研究.并以功率分流差动级太阳轮为例,对模型的建立方法、网格的划分方法、载荷的施加方法进行了详细的分析.利用Ansys中的APDL语言形成载荷文件,来控制在1个啮合周期内若干对接触线位置上载荷的施加.本文的计算方法可以精确、快速地得到1个齿在啮合过程中齿根的动应力.

  19. Design and research of belt-differential planetary gear continuously variable transmission%带式差动行星齿轮无级变速器的设计与研究

    Institute of Scientific and Technical Information of China (English)

    吴斌; 孙付春; 段钦华

    2009-01-01

    The belt-differential planetary gear continuously variable transmission is a closed planetary gear train the speed of which is adjustable. The way of designing this kind of gear train has been introduced in this paper based on the study of speed regulation range and differential gears. Meanwhile, a new method for analysis of gear train power flow and calculation for meshing efficiency has been also put forward in the paper though an example. As a result, with this method the belt-differential planetary gear continuously variable transmission with speed Conveniently, high carrying capacity and efficient, large speed range can be designed.%带式差动行星齿轮无级变速器是一种可进行无级调速的封闭式行星轮系,实际上是带式无级变速器和行星轮系的组合.在对带式无级变速调速范围和差动轮系研究的基础上,给出了设计带式差动行星齿轮无级变速器的方法.并通过实例,给出了研究此类无级变速器功率流分析和啮合效率计算的新方法.结果表明,应用此方法可设计出调速方便、承载能力强、效率高、调速范围大的带式差动行星齿轮无级变速器.

  20. Dynamic Characteristics of Two Stages Planetary Gear of a Reducer%减速机二级行星轮系的动力学特性研究

    Institute of Scientific and Technical Information of China (English)

    黄继雄; 尹敏; 刘虎; 李清清; 余本钢

    2015-01-01

    In order to research the vibration and noise of EBZ 132 roadheader cutting reducer , the kinematics and dynamics parameters of two stage planetary gear transmission system of a reducer were theoretically calculated .And the dynamic analysis of the gear system was conduced with the application of the virtual prototype analysis software ADAMS .The characteristic curve of the gear pair meshing force with time and frequency change was obtained .The simulation results agree well with analytical re-sults.The study results have certain guiding significance for the vibration characteristics , reliability and life research of the plane-tary gear train .%为了研究EBZ132型悬臂式掘进机截割部减速机的振动与噪声问题,对该减速机的二级行星齿轮传动系统进行了运动学和动力学参数的理论计算,并应用虚拟样机分析软件ADAMS对该齿轮传动系统进行了动力学分析,得出了各级啮合齿轮对的啮合力随时间和频率变化的特性曲线图。其仿真结果与理论计算结果相吻合,对行星轮系的振动特性、可靠性,以及寿命等研究具有一定的指导意义。

  1. Gear Design Effects on the Performance of High Speed Helical Gear Trains as Used in Aerospace Drive Systems

    Science.gov (United States)

    Handschuh, R.; Kilmain, C.; Ehinger, R.; Sinusas, E.

    2013-01-01

    The performance of high-speed helical gear trains is of particular importance for tiltrotor aircraft drive systems. These drive systems are used to provide speed reduction / torque multiplication from the gas turbine output shaft and provide the necessary offset between these parallel shafts in the aircraft. Four different design configurations have been tested in the NASA Glenn Research Center, High Speed Helical Gear Train Test Facility. The design configurations included the current aircraft design, current design with isotropic superfinished gear surfaces, double helical design (inward and outward pumping), increased pitch (finer teeth), and an increased helix angle. All designs were tested at multiple input shaft speeds (up to 15,000 rpm) and applied power (up to 5,000 hp). Also two lubrication, system-related, variables were tested: oil inlet temperature (160 to 250 degF) and lubricating jet pressure (60 to 80 psig). Experimental data recorded from these tests included power loss of the helical system under study, the temperature increase of the lubricant from inlet to outlet of the drive system and fling off temperatures (radially and axially). Also, all gear systems were tested with and without shrouds around the gears. The empirical data resulting from this study will be useful to the design of future helical gear train systems anticipated for next generation rotorcraft drive systems.

  2. Scientific field training for human planetary exploration

    Science.gov (United States)

    Lim, D. S. S.; Warman, G. L.; Gernhardt, M. L.; McKay, C. P.; Fong, T.; Marinova, M. M.; Davila, A. F.; Andersen, D.; Brady, A. L.; Cardman, Z.; Cowie, B.; Delaney, M. D.; Fairén, A. G.; Forrest, A. L.; Heaton, J.; Laval, B. E.; Arnold, R.; Nuytten, P.; Osinski, G.; Reay, M.; Reid, D.; Schulze-Makuch, D.; Shepard, R.; Slater, G. F.; Williams, D.

    2010-05-01

    Forthcoming human planetary exploration will require increased scientific return (both in real time and post-mission), longer surface stays, greater geographical coverage, longer and more frequent EVAs, and more operational complexities than during the Apollo missions. As such, there is a need to shift the nature of astronauts' scientific capabilities to something akin to an experienced terrestrial field scientist. To achieve this aim, the authors present a case that astronaut training should include an Apollo-style curriculum based on traditional field school experiences, as well as full immersion in field science programs. Herein we propose four Learning Design Principles (LDPs) focused on optimizing astronaut learning in field science settings. The LDPs are as follows: LDP#1: Provide multiple experiences: varied field science activities will hone astronauts' abilities to adapt to novel scientific opportunities LDP#2: Focus on the learner: fostering intrinsic motivation will orient astronauts towards continuous informal learning and a quest for mastery LDP#3: Provide a relevant experience - the field site: field sites that share features with future planetary missions will increase the likelihood that astronauts will successfully transfer learning LDP#4: Provide a social learning experience - the field science team and their activities: ensuring the field team includes members of varying levels of experience engaged in opportunities for discourse and joint problem solving will facilitate astronauts' abilities to think and perform like a field scientist. The proposed training program focuses on the intellectual and technical aspects of field science, as well as the cognitive manner in which field scientists experience, observe and synthesize their environment. The goal of the latter is to help astronauts develop the thought patterns and mechanics of an effective field scientist, thereby providing a broader base of experience and expertise than could be achieved

  3. Torque Ripple Suppression in an External-Meshed Magnetic Gear Train

    OpenAIRE

    Yi-Chang Wu; Wan-Tsun Tseng; Yueh-Tung Chen

    2013-01-01

    Magnetic gear trains transmit torque through noncontact magnetic couplings rather than conjugate gear teeth; they have the unique advantages of reduced maintenance and improved reliability, inherent overload protection, high efficiency, precise peak torque transmission, and tolerance for misalignment. Smooth and steadily transmitted torque is an important characteristic for a magnetic gear train. It is necessary for the reduction of possible mechanical vibration, position inaccuracy, and acou...

  4. Torque Ripple Suppression in an External-Meshed Magnetic Gear Train

    OpenAIRE

    Yi-Chang Wu; Wan-Tsun Tseng; Yueh-Tung Chen

    2013-01-01

    Magnetic gear trains transmit torque through noncontact magnetic couplings rather than conjugate gear teeth; they have the unique advantages of reduced maintenance and improved reliability, inherent overload protection, high efficiency, precise peak torque transmission, and tolerance for misalignment. Smooth and steadily transmitted torque is an important characteristic for a magnetic gear train. It is necessary for the reduction of possible mechanical vibration, position inaccuracy, and acou...

  5. Spiral-bevel geometry and gear train precision

    Science.gov (United States)

    Litvin, F. L.; Coy, J. J.

    1983-01-01

    A new aproach to the solution of determination of surface principal curvatures and directions is proposed. Direct relationships between the principal curvatures and directions of the tool surface and those of the principal curvatures and directions of generated gear surface are obtained. The principal curvatures and directions of geartooth surface are obtained without using the complicated equations of these surfaces. A general theory of the train kinematical errors exerted by manufacturing and assembly errors is discussed. Two methods for the determination of the train kinematical errors can be worked out: (1) with aid of a computer, and (2) with a approximate method. Results from noise and vibration measurement conducted on a helicopter transmission are used to illustrate the principals contained in the theory of kinematic errors.

  6. 3-D finite element cyclic symmetric and contact stress analysis for a complete gear train

    Science.gov (United States)

    Yin, Zeyong; Xu, Youliang; Gao, Xiangqun; Wei, Gang

    1992-10-01

    A complete gear train of a reduction gearbox is the object of finite element stress analysis. One of the basic segments of the complete gear train is taken as the computational model in the light of the cyclic symmetry of the gear train; meanwhile, the contact transmission forces between the corresponding meshed teeth are considered in the analysis of the model. For simplicity, the corresponding meshed lines are used instead of the actual contact surfaces. Both torque and centrifugal loads are involved in the analysis. The stresses in all the parts of a complete gear train can be determined by one analysis. The computed results show that the contact force on a meshed tooth is correlative not only to the length of the meshed line, but also to its position. It is shown that the neglect of the stress resulted from centrifugal load is inappropriate to a high speed gear train.

  7. 轮系运动分析的构件元法%Kinematic Analysis of Gear Trains Based on Link Units

    Institute of Scientific and Technical Information of China (English)

    王成志; 许志龙

    2011-01-01

    By applying the notion of link units to the gear trains, the link units, especially the Jacobian units, the gear and planet carrier was gotten. The closed loops about gear train also were analyzed, and three kinds of basic closed loop were summed up. By using the effect factors and according to the basic closed loops, the units could be easily combined together to build Jacobian matrix, that was a linear equations, of whole gear train. After solved the linear equations, the angular velocities of each gears and planet carriers were yielded. It did not need to divide the compound planetary train into basic epicylic and fixed axis gear trains and also did not need to draw the arrows to determine the rotations of each links in the planar trains. It was easy to model the equations with manual hands or automatically model with computer for its modular property. The method could be used for any complex planar gear trains.%用构件元的概念推导了轮系中齿轮与系杆的构件元,特别是推导出用齿数表示的雅可比元,分析了轮系中的封闭环,总结出3种轮系基本封闭环.通过引入有效因子,可用雅可比元按基本封闭环建立整个轮系的雅可比矩阵,求解线性方程组,就得出各构件的角速度.提出的方法无需区分基本轮系,无需绘制箭头,具有极强的模块性,手工计算和计算机自动求解都非常方便,适用于各类复杂轮系.

  8. Torque Ripple Suppression in an External-Meshed Magnetic Gear Train

    Directory of Open Access Journals (Sweden)

    Yi-Chang Wu

    2013-01-01

    Full Text Available Magnetic gear trains transmit torque through noncontact magnetic couplings rather than conjugate gear teeth; they have the unique advantages of reduced maintenance and improved reliability, inherent overload protection, high efficiency, precise peak torque transmission, and tolerance for misalignment. Smooth and steadily transmitted torque is an important characteristic for a magnetic gear train. It is necessary for the reduction of possible mechanical vibration, position inaccuracy, and acoustic noise. This paper investigates the transmitted torque characteristics, especially torque ripple reduction, of an external-meshed magnetic gear train using finite-element analysis (FEA. The topological structure and working principles of a simple magnetic gear train with parallel axes are introduced. With the aid of a commercial FEA package, the transmitted torque waveform of a magnetic gear train is numerically calculated. The effects of geometrical parameters on the maximum transmitted torque and torque ripple are further discussed in terms of obtaining a magnetic gear train with high transmitted torque or low torque ripple. This examination offers insights beneficial to future magnetic gear mechanism design.

  9. 行星齿轮变速机构传动效率计算的矩阵方法%The Matrix Method of Planetary Gear Transmission Efficiency

    Institute of Scientific and Technical Information of China (English)

    贾振华; 李友才; 吴心平

    2016-01-01

    Here presents a method for the analysis of the planetary gear transmission efficiency. After the transmission ratio and torque of all gears in the planetary gear system are analyzed by using MATLAB,the efficiency calculated conveniently. Through the analysis of an example, illustrate the method is generally applicable to the complex planetary gear transmission efficiency calculation.%利用计算多排复杂行星齿轮机构的传动比和转矩的矩阵方法,进一步求解行星齿轮变速机构的传动效率,并且步骤简单清晰,利于计算机编程。通过 MATLAB 编程实例分析,说明方法普遍适用于复杂行星齿轮变速机构的效率计算。

  10. 履带车辆双排行星齿轮传动系统非线性动力学模型与方程%Nonlinear dynamic modeling of two row planetary gear set of crawler

    Institute of Scientific and Technical Information of China (English)

    李同杰; 朱如鹏; 鲍和云; 项昌乐; 刘辉

    2013-01-01

    By taking the double row planetary gear set in the transmission system of crawler as research subject, and by taking the The nonlinear factors as time-varying mesh stiffness, backlash and meshing error with various gear pairs in planetary gears into consideration, a nonlinear dynamic model of a two-row planetary gear set is established. Based on the operating principle of two row planetary gear set of crawler, the paper simplifies the original system into single row star train and single row planetary train so as to deduce the motion differential equation under the conditions that the first row planetary carrier is fixed and the inner rim of second planetary row is fixed, and the dimensionless of the equation is carried out to ease the subsequent value calculation. Finally, the simulation and study the load sharing behavior is carried out.%以履带车辆传动系统中的双排行星齿轮机构为研究对象,综合考虑行星齿轮中各齿轮副的时变啮合刚度、齿侧间隙及综合啮合误差等非线性因素,建立双排行星齿轮传动系的非线性动力学模型.根据履带车辆双排行星齿轮机构的工作原理,文中模型在第一行星排行星架固定和第二行星排内齿圈固定两种工况下分别将原系统简化为单排行星齿轮系统和单排行星轮系来处理,推导了两种工况下系统的运动微分方程,并对方程进行了量纲一化以方便后续的数值计算,最后对系统在某组参数下的动载、均载特性进行了仿真研究.

  11. Combined Effects of Gravity, Bending Moment, Bearing Clearance, and Input Torque on Wind Turbine Planetary Gear Load Sharing: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Y.; Keller, J.; LaCava, W.

    2012-09-01

    This computational work investigates planetary gear load sharing of three-mount suspension wind turbine gearboxes. A three dimensional multibody dynamic model is established, including gravity, bending moments, fluctuating mesh stiffness, nonlinear tooth contact, and bearing clearance. A flexible main shaft, planetary carrier, housing, and gear shafts are modeled using reduced degrees-of-freedom through modal compensation. This drivetrain model is validated against the experimental data of Gearbox Reliability Collaborative for gearbox internal loads. Planet load sharing is a combined effect of gravity, bending moment, bearing clearance, and input torque. Influences of each of these parameters and their combined effects on the resulting planet load sharing are investigated. Bending moments and gravity induce fundamental excitations in the rotating carrier frame, which can increase gearbox internal loads and disturb load sharing. Clearance in carrier bearings reduces the bearing load carrying capacity and thus the bending moment from the rotor can be transmitted into gear meshes. With bearing clearance, the bending moment can cause tooth micropitting and can induce planet bearing fatigue, leading to reduced gearbox life. Planet bearings are susceptible to skidding at low input torque.

  12. A 23.2:1 ratio, 300-watt, 26 N-m output torque, planetary roller-gear robotic transmission: Design and evaluation

    Science.gov (United States)

    Newman, Wyatt S.; Anderson, William J.; Shipitalo, William; Rohn, Douglas

    1992-01-01

    The design philosophy and measurements performed on a new roller-gear transmission prototype for a robotic manipulator are described. The design incorporates smooth rollers in a planetary configuration integrated with conventional toothed gears. The rollers were designed to handle low torque with low backlash and friction while the complementary gears support higher torques and prevent accumulated creep or slip of the rollers. The introduction of gears with finite numbers of teeth to function in parallel with the rollers imposes severe limits on available designs. Solutions for two-planet row designs are discussed. A two-planet row, four-planet design was conceived, fabricated, and tested. Detailed calculations of cluster geometry, gear stresses, and gear geometry are given. Measurement data reported here include transmission linearity, static and dynamic friction, inertia, backlash, stiffness, and forward and reverse efficiency. Initial test results are reported describing performance of the transmission in a servomechanism with torque feedback.

  13. 带有圆锥齿轮的复合行星传动功率流与传动效率分析%Power Flow and Efficiency Analysis of Compound Planetary Gears Transmission with Bevel Gears

    Institute of Scientific and Technical Information of China (English)

    胡青春; 李剑英; 段福海

    2015-01-01

    The motion of compound planetary gears transmission with bevel gears is analyzed. On this basis the power flows of compound planetary gears transmission with bevel gears are analyzed under two situations which are considered the power losses and without considering them by virtual power theory, the expression of compound planetary gears transmission efficiency is obtained under the defined speed ratio and torque ratio. Further, the influence rule of speed ratio, torque ratio, meshing power losses coefficient and geometrical parameter ratio on compound planetary gears transmission efficiency is studied and the relevant verified experiments are also carried out. Theoretical analysis show that with the increasing of torque ratio, the transmission efficiency of compound planetary gears transmission increases under its meshing power losses coefficient and geometrical parameter ratio are determined, but this influence tendency of speed ratio on its transmission efficiency declines firstly and then increases; there are differences that the compound planetary gears transmission efficiencies are affected by each gear pairs meshing power losses coefficient under its speed ratio, torque ratio and geometrical parameter ratio are determined; with the increasing of geometrical parameter ratio, the compound planetary gears transmission efficiency increases under the determined speed ratio, torque ratio and each gear pairs meshing power losses coefficient. Transmission efficiency tests show that the compound planetary gears transmission efficiency can be improved by using the high accuracy grade bevel gear, increasing the transmission mechanism's torque ratio and pitch radius of planetary gear.%对带有圆锥齿轮的复合行星传动进行运动分析,在此基础上采用虚功率理论分析该复合行星传动在不考虑啮合功率损失和考虑啮合功率损失时的功率流,在定义速比与转矩比的情况下,获得复合行星传动效率表达式,进一步研

  14. CONTROL STRATEGY OF A PARALLEL HYBRID CAR WITH A METAL BELT-PLANETARY GEAR CONTINUOUSLY VARIABLE TRANSMISSION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The most remarkable characteristic of a metal belt-planetary gear continuously variable transmission is a wider ratio range and a bigger torque capacity than a conventional metal pushing belt continuously variable transmission. A parallel hybrid car with this transmission system not only can reduce fuel consumption and pollutant emission at a ECE city cycle, but also can keep the motor working in the most efficiency area and can be started by a lower power motor by oneself. At the same time, the continuously variable transmission system can realize the smooth switch between the motor and the engine.

  15. 差速器行星齿轮轴的断裂分析%Broken Analysis of Planetary Gear Shaft for Bevel Gear Differential

    Institute of Scientific and Technical Information of China (English)

    刘胜勇

    2011-01-01

    The planetary gear shaft for bevel gear differential is assumed to be three parts,which include hollow hoop with internal spline、cross stepped shaft and involute spline,on the basis of cross-section stress' model of the hollow circular shaft deformed when%借鉴空心圆轴扭转变形时的横截面应力模型和十字轴万向节危险断面的分析,把差速器行星齿轮轴假想为三部分——内花键空心箍、十字阶梯轴和渐开线花键,并关联分析其抗扭强度和十字轴轴颈根部抗弯能力;通过对行星齿轮轴扭矩传递影响因素的分析,提出并证明了解决行星齿轮轴断裂的可行性方法。

  16. 考虑制造误差的人字齿行星传动均载特性%Load sharing performances of herringbone planetary gears considering manufacturing errors

    Institute of Scientific and Technical Information of China (English)

    任菲; 秦大同; 吴晓铃

    2016-01-01

    Based on the theory of gear system dynamics and Newton's laws of motion, considering the actual structure of herringbone gears, a lateral-torsional-axial coupling dynamic model of a herringbone planetary gear train (HPGT) was set up by the lumped-parameter method. Manufacturing eccentric errors, tooth profile errors, time-varying mesh stiffness, bearing stiffness, gyroscopic effect, and so on were considered in the presented model. By calculating the system load sharing coefficients with different floating forms, the relationship curves between the sun gear eccentric error as well as the tooth profile error and the system load sharing coefficients were obtained and the effects of manufacturing errors on the HPGT load sharing characteristics were analysed with different floating forms; meanwhile, sun gear radial floating capacities between two situations of sun gear float and non-float were compared. The results show that manufacturing error and the float of the component significantly affect the HPGT load sharing characteristics, the float of the component can obviously improve the system load sharing performance, and as manufacturing errors go up, the system load sharing factor increases; compared with non-floating, the sun gear radial displacement is larger, when the sun gear floats, thus improving the sun gear floating capacity.%以人字齿行星齿轮传动系统为研究对象,基于齿轮系统动力学理论和牛顿运动定律,考虑各构件制造偏心误差和齿廓误差、时变啮合刚度、轴承支承刚度以及陀螺效应等因素,运用集中参数法建立考虑人字齿轮实际结构特点的该型传动弯−扭−轴耦合动力学模型;通过计算在不同浮动方式下的系统均载系数,获得太阳轮偏心误差以及齿廓误差与系统均载系数关系曲线,进而分析在不同浮动方式下制造误差对人字齿行星传动均载特性的影响;同时对比分析在有太阳轮浮动和非浮动情况

  17. Nonlinear dynamics and load sharing of double-mesh helical gear train

    OpenAIRE

    Fuchun Yang; Zhenxing Shi; Jianfeng Meng

    2013-01-01

    Dynamic behaviours and load sharing of double-mesh helical gear trains have been studied in this paper. A nonlinear dynamic model of double-mesh helical gear train was established, including torsional vibration, axial vibration, timevarying mesh stiffness and backlashes. The governing equations were solved by Runge-Kutta method. Frequency responses and influences of main parameters to frequency responses were analyzed to determine the vibration characteristics of the system. The d...

  18. Operational Influence on Thermal Behavior of High-Speed Helical Gear Trains

    Science.gov (United States)

    Handschuh, Robert F.; Kilmain, Charles J.

    2006-01-01

    An experimental effort has been conducted on an aerospace-quality helical gear train to investigate the thermal behavior of the gear system as many important operational conditions were varied. Drive system performance measurements were made at varying speeds and loads (to 5,000 hp and 15,000 rpm). Also, an analytical effort was undertaken for comparison to the measured results. The influence of the various loss mechanisms from the analysis for this high speed helical gear train gearbox will be presented and compared to the experimental results.

  19. Application of spectral kurtosis for detection of a tooth crack in the planetary gear of a wind turbine

    Science.gov (United States)

    Barszcz, Tomasz; Randall, Robert B.

    2009-05-01

    This paper presents the application of the spectral kurtosis technique for detection of a tooth crack in the planetary gear of a wind turbine. The work originated from a real case of catastrophic gear failure on a wind turbine, which was not detected by currently applied methods. Nevertheless, several sets of complete vibration data were recorded and analyzed. The authors explored a number of methods commonly applied in online vibration monitoring and diagnostic systems. Those methods did not react to the failure until a few minutes before the failure. Then the method of time domain averaging of the meshing vibration is investigated. In this case, however, averaging does not detect any trace of the tooth crack, primarily because of the extreme frequency range (>four decades) of the fault symptoms. The application of the method is shown, and then the limitations of the averaging in such a case are presented and discussed. Finally, the authors propose a method based on spectral kurtosis, which yields good results. This method was able to detect the existence of the tooth crack several weeks before the gear failure.

  20. Preliminary Investigation of the Thermal Behavior of High-Speed Helical Gear Trains

    Science.gov (United States)

    Handschuh, Robert F.; Kilmain, Charles J.

    2002-01-01

    A preliminary experimental investigation of the thermal behavior of high-speed helical gears will be presented. A full-scale torque regenerative test stand has been built to test a representative helical gear train as that used in tiltrotor aircraft. Power loss and temperature data from a wide range of operating conditions were measured. Loop power ranged up to 3730 kW (5000 hp). Drive system components representative of flight quality hardware were used in the test program. The results attained in this initial study indicated that windage losses due to the high rotational speeds that were tested were far more important than the losses due to the gear meshing losses.

  1. Analysis of Transformation Mechanism and Gear Ratio on Overlap-Connect Combinational Gear Train%迭连组合轮系的转化机构及传动比分析

    Institute of Scientific and Technical Information of China (English)

    张冬梅

    2013-01-01

    迭连组合轮系是将附加的行星式轮系或组合轮系以迭连方式装置在基础轮系上,构成迭连组合轮系。本文分析以2KH-WN型行星轮系为基础轮系,分别以单一周转轮系、并联轮系、反馈轮系作为迭连子轮系组成迭连组合轮系。其转化机构有串联式、并联式、反馈式,组合轮系的传动比以行星轮系为基础计算。%The Overlap-Connect combinational gear train is fixed on the base gear train, which connect attached Epicylic Gear Train or combined each other. In this paper,the base gear train is 2KH-WN Epicylic Gear Train. This Overlap-Connect combinational gear train take single turenover gear train or parallel gear train or feedback gear train as son gear train. The form of transformation mechanism is series, parallel or feedback. The calculation of combinational gear ratio is based on Epicylic Gear Train.

  2. Influence of compressive gear on powerlifting performance: role of blood flow restriction training.

    Science.gov (United States)

    Godawa, Travis M; Credeur, Daniel P; Welsch, Michael A

    2012-05-01

    This study investigated the effects of powerlifting gear on training volume and performance, defined by the squat, bench press, and deadlift. Eighteen powerlifters (18-26 years) were randomized into either a group that trained and competed using compressive gear (CG) or without the gear (NON). Training volume, volume progression, and powerlifting performance were assessed before and after 10 weeks of training. Training volume increased in the first 4 weeks for both groups. Volume lifted for squat and the totals were greater in the CG. There was an increase in squat (19.05 ± 30.97 lb, p = 0.02), deadlift (19.05 ± 21.17 lb, p = 0.001), and the total score (44.00 ± 60.44 lb, p = 0.005) for both the groups. The improvements in squat (CG = 33.85 vs. NON = 5.74, p = 0.07) and totals (CG = 66.59 vs. NON = 23.67, p = 0.15) were greater in the CG. Both groups showed a significant and similar increase in the Wilks scores (+13.54 points, p = 0.03). There was a trend toward greater volume progression in those wearing CG during the initial stages of training. Both the groups significantly improved performance for the squat, and deadlift, and had higher totals, and Wilks scores, indicating significant strength gains. The greater magnitude of improvements in the squat and totals for the CG lifters suggests an ergogenic potential of training with powerlifting gear.

  3. Nonlinear dynamics and load sharing of double-mesh helical gear train

    Directory of Open Access Journals (Sweden)

    Fuchun Yang

    2013-07-01

    Full Text Available Dynamic behaviours and load sharing of double-mesh helical gear trains have been studied in this paper. A nonlinear dynamic model of double-mesh helical gear train was established, including torsional vibration, axial vibration, timevarying mesh stiffness and backlashes. The governing equations were solved by Runge-Kutta method. Frequency responses and influences of main parameters to frequency responses were analyzed to determine the vibration characteristics of the system. The dynamic factor and load sharing in two mesh pairs were studied in two configuration cases and the result shows that case II has better dynamic response and load sharing.

  4. Design of aircraft turbine fan drive gear transmission system

    Science.gov (United States)

    Dent, E.; Hirsch, R. A.; Peterson, V. W.

    1970-01-01

    The following basic types of gear reduction concepts were studied as being feasible power train systems for a low-bypass-ratio, single-spool, geared turbofan engine for general aircraft use: (1) single-stage external-internal reduction, (2) gears (offset shafting), (3) multiple compound idler gear system (concentric shafting), and (4) star gear planetary system with internal ring gear final output member (concentric shafting-counterrotation). In addition, studies were made of taking the accessories drive power off both the high-speed and low-speed shafting, using either face gears or spiral bevel gears. Both antifriction and sleeve-type bearings were considered for the external-internal and star-planet reduction concepts.

  5. Design of a wearable cable-driven upper limb exoskeleton based on epicyclic gear trains structure.

    Science.gov (United States)

    Xiao, Feiyun; Gao, Yongsheng; Wang, Yong; Zhu, Yanhe; Zhao, Jie

    2017-07-20

    Many countries, including Japan, Italy, and China are experiencing demographic shifts as their populations age. Some basic activities of daily living (ADLs) are difficult for elderly people to complete independently due to declines in motor function. In this paper, a 6-DOF wearable cable-driven upper limb exoskeleton (CABexo) based on epicyclic gear trains structure is proposed. The main structure of the exoskeleton system is composed of three epicyclic gear train sections. This new exoskeleton has a parallel mechanical structure to the traditional serial structure, but is stiffer and has a stronger carrying capacity. The traditional gear transmission structure is replaced with a cable transmission system, which is quieter, and has higher accuracy and smoother transmission. The static workspace of the exoskeleton is large enough to meet the demand of assisting aged and disabled individuals in completing most of their activities of daily living (ADLs).

  6. Experimental Study of the Influence of Speed and Load on Thermal Behavior of High-Speed Helical Gear Trains

    Science.gov (United States)

    Handschuh, R.; Kilmain, C.

    2005-01-01

    An experimental effort has been conducted on an aerospace-quality helical gear train to investigate the thermal behavior of the gear system as speed, load, and lubricant flow rate were varied. Temperature test data from a helical gear train at varying speeds and loads (to 5000 hp and 15000 rpm) was collected using thermocouple rakes and axial arrays. The instrumentation was able to capture the radial and axial expelled lubricant-air environment (fling-off lubricant) that is expelled during the gear meshing process. Effects of operational characteristics are presented.

  7. 行星齿轮机械式自动变速器换挡控制策略的研究%A Study on the Gear Shifting Strategy for AMT with Planetary Gear

    Institute of Scientific and Technical Information of China (English)

    杜常清; 颜伏伍; 李夏楠; 侯献军

    2011-01-01

    A gear shifting control strategy by adjusting electric motor speed for automatic mechanical transmission with planetary gear is proposed to meet the requirements of efficient transmission and automatic shifting in a hybrid electric vehicle. A gear shifting control model is built with MATLAB/Simulink and a simulation is conducted. The results verify the feasibility of gear shifting scheme and its control strategy, which can effectively reduce the torque fluctuation of transmission during gear shifting.%针对混合电动汽车高效传动和自动换挡的需要,提出了运用电机辅助调速实现带行星齿轮机构的机械式自动变速器换挡的控制策略.采用MATLAB/Simulink建立了换挡过程控制的模型,并进行了仿真.结果表明该控制策略能有效减小变速器换挡过程中输出转矩的波动,验证了所提出的变速方案及其控制策略的可行性.

  8. Finite Element Analysis of the Planetary Gear Bending Strength of Differential%差速器行星齿轮弯曲强度有限元分析

    Institute of Scientific and Technical Information of China (English)

    姚春华; 林凤涛

    2012-01-01

    Taking the differential of a type of 400CC all梩errain vehicle as an example,the differential planetary gear of the three-dimensional entity modeling methods and the determination process of highest single tooth meshing point is discitssed.The method of using Pro/ENGINEER to build the three-dimensional modeling of differential planetary gear has been studied, and the solid modeling of planetary gear has been completed.Then the method of determining the highest meshing point of single tooth has been analyzed, and mechanical property of planetary gear has been analyzed by using the nonlinear finite element software ABAQUS.At last is the comparison of the result with traditional method.The theory basis is provided for the lightweight design of gear and fatigue life analysis.The results showed that,the bending strength of planetary gear satisfies the strength requirement, and the traditional calculation method results are relatively conservative.%以某型400CC全地形车差速器为例,对差速器行星齿轮的三维实体建模方法以及单齿最高啮合点的确定过程进行了阐述,探讨了利用Pro/ENGINEER对差速器行星齿轮三维造型的方法并进行了实体建模,分析了确定单齿最高啮合点的方法,通过非线性有限元软件ABAQUS对行星齿轮单齿的力学性能进行了计算分析,最后与齿轮弯曲强度传统计算方法进行了比较.并能够为齿轮的轻量化设计及疲劳寿命分析提供理论依据.结果表明:行星齿轮弯曲强度满足强度要求,传统计算方法计算结果相对保守.

  9. 行星齿轮式离合器可行性研究%Research on Feasibility of Planetary Gear Type Clutch

    Institute of Scientific and Technical Information of China (English)

    海争平; 杨志红

    2011-01-01

    Clutch is mainly to realize disengagement and engagement of driving force. The characteristics of planetary gear set: if one of components (sun gear, planet carrier and gear ring) is fixed, transmission of power is fixed; if three components are all released, driving force can not be transmitted.The above is the process of disengagement and engagement of driving force. This paper analyzes the feasibility of planetary gear set as clutch from the perspective of design.%离合器主要的功能是实现动力的分离和结合.行星齿轮组的特性是:如果将行星齿轮的三元件(太阳轮、行星架和齿圈)中某一个固定,动力传递固定;将三元件全部松开,动力不能传递,也就是动力分离和结合的过程.本文从设计角度分析采用行星齿轮组作为离合器机构的可行性.

  10. Thermal Behavior of High-Speed Helical Gear Trains Investigated

    Science.gov (United States)

    Handschuh, Robert F.

    2003-01-01

    High-speed and heavily loaded gearing are commonplace in the rotorcraft systems employed in helicopter and tiltrotor transmissions. The components are expected to deliver high power from the gas turbine engines to the high-torque, low-speed rotor, reducing the shaft rotational speed in the range of 25:1 to 100:1. These components are designed for high power-to-weight ratios, thus the components are fabricated as light as possible with the best materials and processing to transmit the required torque and carry the resultant loads without compromising the reliability of the drive system. This is a difficult task that is meticulously analyzed and thoroughly tested experimentally prior to being applied on a new or redesigned aircraft.

  11. Adjusting the Passing Scores for Gearing up for Safety: Production Agriculture Safety Training for Youth Curriculum Test Instruments

    Science.gov (United States)

    Hoover, William Brian; French, Brian F.; Field, William E.; Tormoehlen, Roger L.

    2012-01-01

    Minimum passing scores for the Gearing Up for Safety: Production Agriculture Safety Training for Youth curriculum (Gearing Up for Safety) were set in 2006 with widely used and established procedures by efforts of subject matter experts (French, Breidenbach et al., 2007; French, Field, and Tormoehlen, 2006, 2007). While providing a research-based…

  12. Method and Device for Speed Change by the Epicyclic Gear Train with Stepped-Planet Gear Set

    Directory of Open Access Journals (Sweden)

    Malashchenko Volodymyr

    2016-08-01

    Full Text Available The article describes new method and device for continuously variable speed change management via compound epicyclic gearing with composite planet gears and closed circuit hydrosystem, when the speed control element is either outer ring gear (annulus or the carrier or sun gear. In each case, the control element connected to closed circuit hydrosystem and can be in motion or immovable depending on the bandwidth of hydrosystem’s regulating throttle. We had held theoretical research and received graphic dependences between velocities of driving, control and driven elements by means of computer programing.

  13. 移栽机取苗机构行星轮系设计与动力学研究%Dynamic Simulation Research of the Planetary Gear of the Seeding Transplanting Mechanism

    Institute of Scientific and Technical Information of China (English)

    赵宏政; 曹卫彬; 唐海洋; 杨萌; 王崧浩

    2017-01-01

    This paper took planetary gear of the seeding transplanting mechanism as the research object. Firstly, a three-dimensional model of the planetary gear transmission system was built by solid works software,and the model was imported to automatic dynamic analysis of mechanical system,or ADAMS software for simulation,which was used to analyze the change regularity and spectrum characteristics of mesh forces in x direction and y direction when gear drove. After analy-zing the basic consistency of the simulation results and the test results showed the improved design is correct and reasona-ble. Virtual prototype technology is beneficial to improving the design level of planetary gear train of pick-up mechanism, and providing technical support for the optimal design of the transmission system.%以移栽机取苗机构的行星齿轮为研究对象,基于三维造型设计软件 SolidWorks 设计了取苗机构行星齿轮传动系统的实体模型,并将其导入机械系统动力学仿真软件 ADAMS 中,设定工作参数后进行刚体动力学分析,分析行星齿轮传动时的齿轮x 方向接触力和y 方向接触力的变化规律及其频谱特征。经分析,仿真结果与理论值相吻合,验证了仿真的正确性。采用虚拟样机技术可提高取苗机构行星轮系的设计水平,也为后续的传动系统的优化设计提供了一种解决方案。

  14. MODELING OF MANUFACTURING ERRORS FOR PIN-GEAR ELEMENTS OF PLANETARY GEARBOX

    Directory of Open Access Journals (Sweden)

    Ivan M. Egorov

    2014-11-01

    Full Text Available Theoretical background for calculation of k-h-v type cycloid reducers was developed relatively long ago. However, recently the matters of cycloid reducer design again attracted heightened attention. The reason for that is that such devices are used in many complex engineering systems, particularly, in mechatronic and robotics systems. The development of advanced technological capabilities for manufacturing of such reducers today gives the possibility for implementation of essential features of such devices: high efficiency, high gear ratio, kinematic accuracy and smooth motion. The presence of an adequate mathematical model gives the possibility for adjusting kinematic accuracy of the reducer by rational selection of manufacturing tolerances for its parts. This makes it possible to automate the design process for cycloid reducers with account of various factors including technological ones. A mathematical model and mathematical technique have been developed giving the possibility for modeling the kinematic error of the reducer with account of multiple factors, including manufacturing errors. The errors are considered in the way convenient for prediction of kinematic accuracy early at the manufacturing stage according to the results of reducer parts measurement on coordinate measuring machines. During the modeling, the wheel manufacturing errors are determined by the eccentricity and radius deviation of the pin tooth centers circle, and the deviation between the pin tooth axes positions and the centers circle. The satellite manufacturing errors are determined by the satellite eccentricity deviation and the satellite rim eccentricity. Due to the collinearity, the pin tooth and pin tooth hole diameter errors and the satellite tooth profile errors for a designated contact point are integrated into one deviation. Software implementation of the model makes it possible to estimate the pointed errors influence on satellite rotation angle error and

  15. Teaching Exploration of Ordinary Gear Train%定轴轮系教学探微

    Institute of Scientific and Technical Information of China (English)

    罗蓉

    2016-01-01

    定轴轮系广泛应用于各种机械设备中,要让学生深入理解和掌握定轴轮系的相关知识,教师必须精心组织教学,正确处理教材,优化教学方法,以调动学生的学习热情、启发学生的思维,进而取得良好的教学效果。%Ordinary gear train is widely used in various kinds of mechanical equipment. In order to let students understand and master the relevant knowledge of ordinary gear train, teachers must carefully organize teaching, correctly handle teaching materials and optimize teaching methods.

  16. 基于啮合相位分析的盾构机减速器多级行星齿轮传动动力学特性%Dynamic Characteristics of Multi-stage Planetary Gears of Shield Tunnelling Machine Based on Planet Mesh Phasing Analysis

    Institute of Scientific and Technical Information of China (English)

    秦大同; 肖正明; 王建宏

    2011-01-01

    Based on gearing theory and Lagrange equation, the torsional dynamic model for multi-stages planetary gears train is developed by lumped-parameter method. Trapezoid waves are used to express the time-varying mesh stiffness, and the mesh phasing relations among planetary gears are analyzed. For the 3-stages planetary gears of shield tunnelling machine, the torsional vibration frequencies are calculated at the different mesh position of sun and planet gears. According to the characteristics of the gears mesh errors, the harmonic waves composited with shaft frequencies and mesh frequencies are presented to describe the transmission errors of die planetary gears. Considering the time-varying mesh stiffness with different mesh phases of planet gears, the inner excitations of 3-stages planetary gears are analyzed systematically. The dynamic responses of the 3-stages planetary gears are simulated under the inner and external excitation got from a statistical load, and the spectrum properties of gears vibration are also analyzed. The dynamic response of system components are calculated under different speeds for the reducer, and the relationship between gears vibration and the rotational speed of the reducer is studied, which provides the base for choosing the suitable operating condition of driving system of the shield tunnelling machine.%基于齿轮啮合理论和Lagrange方程,运用集中参数法建立多级行星齿轮系统的扭转动力学模型.采用梯形波表示啮合刚度的时变特性,分析行星齿轮啮合过程中的相位关系,计算盾构机减速器三级行星齿轮不同啮合位置的扭转振动结构频率.针对齿轮啮合误差特点,采用轴频和齿频叠加的谐波函数表示行星齿轮传动误差,考虑受啮合相位关系影响的行星齿轮系统时变刚度,系统分析多级行星齿轮传动的内部激励特征.基于某施工标段的统计负载,考虑内外激励,求解三级行星齿轮系统的动态响应,并对齿

  17. A systematic design approach for two planetary gear split hybrid vehicles

    Science.gov (United States)

    Liu, Jinming; Peng, Huei

    2010-11-01

    Multiple power sources in a hybrid vehicle allow for flexible vehicle power-train operations, but also impose kinematic constraints due to component characteristics. This paper presents a design process that enables systematic search and screening through all three major dimensions of hybrid vehicle designs - system configuration, component sizing and control, to achieve optimal performance while satisfying the imposed constraints. An automated dynamic modelling method is first developed which enables the construction of hybrid vehicle model efficiently. A screening process then narrows down to configurations that satisfy drivability and operation constraints. Finally, a design and control optimisation strategy is carried out to obtain the best execution of each configuration. A case study for the design of a power-split hybrid vehicle with optimal fuel economy is used to demonstrate this overall hybrid vehicle design process.

  18. SECTIONAL AREA CALCULATION OF MATERIAL REMOVED FROM BLANK WHILE FORMING SPACE BETWEEN TWO TEETH OF SATELLITE GEAR OF PLANETARY PIN TOOTH REDUCER

    Directory of Open Access Journals (Sweden)

    N. G. Yankevich

    2009-01-01

    Full Text Available One of the most important values while forming gear wheels is a material section area Sс which is to be removed by a tool in the process of forming a space between two teeth in one pass. Cutting resistance which is proportional  to section area of  the layer to be cut and, correspondingly, a thermodynamic intensity in the polishing zone depend on Sс value.The paper proposes relations for calculation of a material section area Sс which is to be removed from a blank while forming a space between two teeth of a satellite gear of a planetary pin tooth reducer.Measurements being made in the AutoCAD packet have shown that any corrections of the profile do not make a significant influence on a section area Sс.

  19. 考虑随机制造误差的风力机行星齿轮系统动力学特性%Dynamic Characteristics of Planetary Gear Transmission System of Wind Turbine with Random Manufacturing Error

    Institute of Scientific and Technical Information of China (English)

    陈会涛; 秦大同; 吴晓铃; 周志刚; 杨军

    2012-01-01

    为研究综合传递误差的随机波动对风力发电机齿轮传动系统动力学特性的影响,考虑齿轮时变啮合刚度、综合传递误差等因素,建立风力发电机行星齿轮传动系统纯扭转动力学模型.以随机风速引起的齿轮系统转矩波动作为行星齿轮系统的外部激励,对某1.5 MW风力发电机行星齿轮传动系统的动力学特性进行仿真分析,得到系统各响应量时域内的统计特征和齿轮副间的动态啮合力统计特征.分析表明:行星架、行星轮和太阳轮在扭转方向上的振动特性与外部载荷相关,其振动位移与外部载荷波动有相似变化的趋势;综合传递误差随机分量的离散程度对行星齿轮系统的动态特性和齿轮副间的动态啮合力有较大影响.随着综合传递误差随机分量离散程度的增加,行星架、太阳轮和行星轮在扭转方向上的振动幅值明显增加;综合传递误差随机分量的随机性使齿轮副间动态啮合力产生随机波动,随机分量离散程度越大,动态啮合力波动越明显;当随机分量的离散程度达到某一值时,齿轮啮合过程发生脱离,引发啮合冲击.%A purely rotational nonlinear dynamic model of planetary gear transmission system including time-varying mesh stiffness and synthetic mesh errors is developed to research the dynamic behavior of the wind turbine with the random fluctuation of synthetic mesh errors. Numerical method is used to simulate the planetary gear system of 1.5 MW wind turbine with the consideration of the torque fluctuation of gear transmission system caused by wind speed and transmission error random variable caused by manufacture and assembly. The statistical characteristics of responses of the planetary gear system and dynamic mesh force of gear pairs are obtained. The statistic analysis show that: the vibration features of the planetary carrier, the sun gear and the planetary gear are closely related to the external

  20. STUDY ON CONTROL STRATEGY OF CLUTCH STARTING FOR CAR WITH A METAL PUSHING BELT-PLANETARY GEAR CONTINUOUSLY VARIABLE TRANSMISSION SYSTEM

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The automatic control of clutch starting in car with a metal pushing belt-planetary gear continuously variable transmission (CVT) is a complex problem. A suited control strategy is required to realize quick and smooth start. A simulation state space equation is established on clutch starting control of a car with CVT by bond graph theory. According to the fuzzy control method with the expert system, a fuzzy control system of car starting process to weaken the jerk motion is introduced. The simulation results indicate that the jerk motion of clutch starting is below 10 m/s3.

  1. 一种基于啮合点的复杂轮系传动比计算方法%A Calculation Method of Transmission Ratio for Complex Gear Trains Based on Gear Meshing Point

    Institute of Scientific and Technical Information of China (English)

    赵玉剑; 乔雪涛

    2011-01-01

    提出了一种基于啮合点的复杂轮系传动比快速计算方法.将复杂轮系分解为若干个轮系单元,根据“转化机构”法的基本原理,列出每个轮系单元的啮合方程,从而通过求解联立方程组计算出轮系传动比.分别讨论了定轴轮系、3K型周转轮系、2K-H型周转轮系及复杂轮系传动比的计算,并得出了定轴轮系和周转轮系之间的关系,把定轴轮系和周转轮系传动比的计算统一起来.啮合点法为求解复杂轮系传动比提供了一种方便、高效、通用的方法.%A fast calculation method of transmission ratio for complex gear trains based on gear meshing point is put forward. The complex gear trains solved are decomposed into several simple gear train units. According to the basic principle of transforming mechanism, meshing equation of each gear train unit is established, and transmission ratio of gear train can be calculated by solving the simultaneous formulas. The calculation methods of transmission ratio of the fixed axis gear trains, 3K type epicyclic gear trains, 2K - H type epicyclic gear trains, complex gear trains are discussed respectively. The relationship between the fixed axis gear trains and the epicyclic gear trains is deduced, which could unify calculating transmission ratio of them organically. In a word, the gear meshing point method adopted to solve the transmission ratio of complex gear trains has advantages of general, convenient operation, high efficient calculation, and so on.

  2. Influencia del movimiento tridimensional sobre mecanismos planetarios en aerogeneradores (1ª Parte // Influence of Tridimensional movement in planetary gears used in wind generators. (First part

    Directory of Open Access Journals (Sweden)

    J. Wellesley-Bourke Funcasta

    2000-03-01

    Full Text Available En el trabajo se desarrolla el basamento matemático para establecer el análisis del efecto nocivo que se produce sobre losrodamientos de los mecanismos planetarios empleados en los aerogeneradores, dado esto por las condiciones variables delviento en cuanto a su velocidad y dirección.Palabras claves: Efecto giroscópico, engranajes planetarios, cargas dinámicas, energía eólica.________________________________________________________________________________AbstractIn this paper is presented the mathematical base that allow to establish the analysis that deals with the noxious effect that isproduced on the bearings of the planetary mechanisms in the wind energy corversor systems, given by the variable conditionsof the velocity and direction of the wind.Key words: Gyroscopic effect, planetary gears, dynamic loads, eolic energy.

  3. The study of double flank micro gear roll testing

    Science.gov (United States)

    Liu, Yen-Chih; An, Nai-Chun; Yang, Shu-Han; Yan, Sheng-Zhan; Chen, Shih-Lu

    2011-12-01

    The recent fast development of multifunctional portable electronic devices results in the obvious requirement of micro mechanical components. Due to the popular application of the micro actuators and the micro gearboxes, micro gears become the frequently used micro mechanical component in a small device such as small intelligent robots or dental surgical devices. Metal Industries Research & Development Centre (MIRDC) has successfully developed a small speed reducer that comprises several micro planetary gear trains. The module of this micro planetary gear train is 0.12mm. Since all gears are small, no commercial instrument is available for inspection. How to evaluate the manufacturing quality of micro gears becomes an important issue. This study focuses on the double flank gear rolling test and a specialized apparatus is built referring to the testing requirements in the international standards. The center distance variation during the rolling test is recorded and two indices, the total radial composite deviation and the maximum tooth-to-tooth radial composite deviation, are calculated to evaluate the accuracy grade of the micro gears. Experimental results show that the accuracy of the micro gear made by the cold forging process conforms to grade 7 defined in the ISO 1328-2 while grade 2 is achieved if the JGMA 116-02 is specified.

  4. Robotic surgery training: construct validity of Global Evaluative Assessment of Robotic Skills (GEARS).

    Science.gov (United States)

    Sánchez, Renata; Rodríguez, Omaira; Rosciano, José; Vegas, Liumariel; Bond, Verónica; Rojas, Aram; Sanchez-Ismayel, Alexis

    2016-09-01

    The objective of this study is to determine the ability of the GEARS scale (Global Evaluative Assessment of Robotic Skills) to differentiate individuals with different levels of experience in robotic surgery, as a fundamental validation. This is a cross-sectional study that included three groups of individuals with different levels of experience in robotic surgery (expert, intermediate, novice) their performance were assessed by GEARS applied by two reviewers. The difference between groups was determined by Mann-Whitney test and the consistency between the reviewers was studied by Kendall W coefficient. The agreement between the reviewers of the scale GEARS was 0.96. The score was 29.8 ± 0.4 to experts, 24 ± 2.8 to intermediates and 16 ± 3 to novices, with a statistically significant difference between all of them (p robotic surgery and, therefore, is a validated and useful tool to evaluate surgeons in training.

  5. 行星传动原理在NGW型减速器中应用%Research on the application of planetary gear transmission technology in the NGW model reducer

    Institute of Scientific and Technical Information of China (English)

    王斌

    2011-01-01

    Since the involute gear planetary transmission features with transmission load by several gears at the same time to divide power. It is widely used in the fields like metallurgy,aviation,shipbuilding,engineering machinery,machine tools and other industries for the gear assembly of reduction gear,overdrive gear or variable gear,which is playing more important role. In order to further enhance the accuracy of involute gear planetary transmission and to expand the applications of involute gear planetary gear,a new method on the plane tary transmission technology is presented it for completing the velocity complex,in which structural design,the stress analysis as well as power allocation and installation methods are also introduced in detail which feasibility and reliability are verified by experiments.%由于渐开线齿轮行星传动具有几个齿轮同时传递载荷,使功率分流的特点,所以在冶金、航空、船舶、工程机械、机床等行业作减速、增速或变速齿轮传动装置,发挥较为重要作用.为了进一步提高渐开线齿轮行星传动的精度,扩大渐开线齿轮行星传动的应用范围,提出了一种采用行星传动技术来完成速度合成的新方法,并对其结构设计、受力分析、功率分配以及安装方法等进行了详细的介绍,并通过实验验证了该方法的简便易行,可靠性要求.

  6. Calculation on the Planetary Transmission Ratio and Efficiency of Spiral Bevel Gears%弧齿锥齿轮行星机构的传动比与效率的计算

    Institute of Scientific and Technical Information of China (English)

    常巧红; 魏冰阳; 刘华伟; 尚怀国; 武浩

    2012-01-01

    高功率密度一直是齿轮箱设计追求重要目标之一.发明了一种弧齿锥齿轮行星传动机构,兼具孤齿锥齿轮与行星齿轮传动的优点,结构紧凑简约.介绍了该孤齿锥齿轮行星机构的传动原理,推导了传动比与传动效率的计算公式,进行了初步的齿轮箱传动试验.为高性能传动齿轮箱的设计提供了可能性.%The high power density is always one of important goals of the gear box. The invented planetary transmission mechanism of spiral bevel gears has the advantages of the spiral bevel gears transmission and the planetary gear transmission, compact structure, high power density. The driving principles of the planetary transmission mechanism are introduced. The calculation formulas derivations of the transmission ratio and transmission efficiency are done. The primal driving tests of the gear box are carried out. The results provide a possibility for the design of the high performance gear box.

  7. Optimization Design for Planetary Gear Reducer of EBZ -135 Excavator%EBZ -135型掘进机行星减速器优化研究

    Institute of Scientific and Technical Information of China (English)

    张利军

    2014-01-01

    EBZ -135 is a kind of longitudinal axis boomed excavator,which used to driving the coal and semi -coal rock.The torque and power of the cutting head are transmitted by the motor through planetary reducer.The planetary reducer,whose performance,structural and size is an important mechanism of the EBZ -135.The paper found the planetary reducer of the EBZ -135 with high security factor,but the gear module is larger,it is necessary to optimize its structure.Compared with the original structure,the optimized structure has the following characters:decreasing gear module from 8 to 5.5,reducing radial dimension by 5%,decreasing transmission impact,convenient to manufacture.%EBZ -135是适用于煤及半煤岩巷的悬臂式掘进机,其截割头的转矩和功率是通过行星减速器传递的,因此受行星减速器性能、体积等各方面的影响。本文通过分析发现其行星减速器安全系数比较大,所选模数偏大,可以进行优化。EBZ -135原齿轮模数为8,计算后分析后改为5.5,径向尺寸缩小了5%,冲动冲击也可以大大减小,提高平稳性的同时方便安装和维修。

  8. 高重合度行星齿轮传动系统动态特性分析%Dynamic Characteristics Analysis of High Contact Ratio Planetary Gear Transmission

    Institute of Scientific and Technical Information of China (English)

    渠珍珍; 鲍和云; 朱如鹏; 李发家

    2012-01-01

    针对行星齿轮传动系统,采用集中质量法建立太阳轮浮动的动力学模型,考虑时变啮合刚度和综合啮合误差的影响,推导得出系统的动力学微分方程。采用变步长Runge-Kutta数值积分方法求解动力学微分方程。对比研究了高重合度行星齿轮传动系统和普通行星齿轮传动系统的动态时域响应,动载特性和均载特性。分析结果表明:高重合度行星齿轮传动振动幅值较低,动载荷较小,均载特性较好,因此传动更加平稳,噪声减小,传动性能更好。%By using lumped-mass method, the dynamic model of planetary gear transmission with floating sun-gear was established; the time-variant stiffness and meshing error were considered in the model. The motion differential equation of the model was presented and solved by Runge-Kutta numerical integration method with variable steps. Dynamic time-domain responses, dynamic loads and load sharing characteristics of the high contact ratio planetary gear transmission and general planetary gear transmission were both investigated for comparison. The results indica- ted that the high contact ratio planetary gear transmission had lower vibration amplitude, smaller dynamic load and dynamic load-sharing coefficient. So the high contact ratio planetary gear drive had better performance with smoot- her transmission, lower noise, and its load distribution is more uniform.

  9. Dynamic analysis of flexible gear trains/transmissions - An automated approach

    Science.gov (United States)

    Amirouche, F. M. L.; Shareef, N. H.; Xie, M.

    1992-01-01

    In this paper an automated algorithmic method is presented for the dynamic analysis of geared trains/transmissions. These are treated as a system of interconnected flexible bodies. The procedure developed explains the switching of constraints with time as a result of the change in the contacting areas at the gear teeth. The elastic behavior of the system is studied through the employment of three-dimensional isoparametric elements having six degrees-of-freedom at each node. The contact between the bodies is assumed at the various nodes, which could be either a line or a plane. The kinematical expressions, together with the equations of motion using Kane's method, strain energy concepts, are presented in a matrix form suitable for computer implementation. The constraint Jacobian matrices are generated automatically based on the contact information between the bodies. The concepts of the relative velocity at the contacting points at the tooth pairs and the subsequent use of the transmission ratios in the analysis is presented.

  10. Real-Time Condition Monitoring and Fault Diagnosis of Gear Train Systems Using Instantaneous Angular Speed (IAS) Analysis

    Science.gov (United States)

    Sait, Abdulrahman S.

    This dissertation presents a reliable technique for monitoring the condition of rotating machinery by applying instantaneous angular speed (IAS) analysis. A new analysis of the effects of changes in the orientation of the line of action and the pressure angle of the resultant force acting on gear tooth profile of spur gear under different levels of tooth damage is utilized. The analysis and experimental work discussed in this dissertation provide a clear understating of the effects of damage on the IAS by analyzing the digital signals output of rotary incremental optical encoder. A comprehensive literature review of state of the knowledge in condition monitoring and fault diagnostics of rotating machinery, including gearbox system is presented. Progress and new developments over the past 30 years in failure detection techniques of rotating machinery including engines, bearings and gearboxes are thoroughly reviewed. This work is limited to the analysis of a gear train system with gear tooth surface faults utilizing angular motion analysis technique. Angular motion data were acquired using an incremental optical encoder. Results are compared to a vibration-based technique. The vibration data were acquired using an accelerometer. The signals were obtained and analyzed in the phase domains using signal averaging to determine the existence and position of faults on the gear train system. Forces between the mating teeth surfaces are analyzed and simulated to validate the influence of the presence of damage on the pressure angle and the IAS. National Instruments hardware is used and NI LabVIEW software code is developed for real-time, online condition monitoring systems and fault detection techniques. The sensitivity of optical encoders to gear fault detection techniques is experimentally investigated by applying IAS analysis under different gear damage levels and different operating conditions. A reliable methodology is developed for selecting appropriate testing

  11. Study on inherent characteristics of transmission of 2K-H planetary gear%2K-H型行星齿轮传动的固有特性研究

    Institute of Scientific and Technical Information of China (English)

    刘爱敏; 王含英

    2012-01-01

    A high-speed and heavy-load planetary gear not reaching stable operation was taken as the study object,the dynamic model of a 2K-H planetary gear with double floating uniform-load mechanism was built.Each component of the model had two translation degrees of freedom and on torsional degree of freedom.Lagrange equation was used to deduce the movement differential equation of each component,and MATLAB was applied to obtain the natural frequency and corresponding vibration mode of speed-increasing planetary gear.The results showed that there were torsional vibration mode of central components and translation vibration mode of central components in the transmission of the speed-increasing planetary gear.The study could offer beneficial guidance for the dynamic design of the planetary gear.%以未达到稳定运转的高速重载行星齿轮传动为研究对象,建立了双浮动均载装置的2K-H型行星齿轮传动的动力学模型。模型设定每个构件具有2个平移自由度和一个扭转自由度,通过拉格朗日方程推导系统各构件的运动微分方程,并运用MatLab软件得出了增速行星齿轮传动的固有频率和相应的振型。结果表明,增速行星齿轮传动有中心构件扭转振动和中心构件平移振动两种模式。因此,该研究可为行星齿轮传动的动态设计提供有益借鉴。

  12. Multi-Objective Optimization of Two-Stage Helical Gear Train Using NSGA-II

    OpenAIRE

    Sanghvi, R. C.; Vashi, A. S.; Patolia, H. P.; R. G. Jivani

    2014-01-01

    Gears not only transmit the motion and power satisfactorily but also can do so with uniform motion. The design of gears requires an iterative approach to optimize the design parameters that take care of kinematics aspects as well as strength aspects. Moreover, the choice of materials available for gears is limited. Owing to the complex combinations of the above facts, manual design of gears is complicated and time consuming. In this paper, the volume and load carrying capacity are optimized. ...

  13. An Algorithm for Identifying the Isomorphism of Planar Multiple Joint and Gear Train Kinematic Chains

    Directory of Open Access Journals (Sweden)

    Yanhuo Zou

    2016-01-01

    Full Text Available Isomorphism identification of kinematic chains is one of the most important and challenging mathematical problems in the field of mechanism structure synthesis. In this paper, a new algorithm to identify the isomorphism of planar multiple joint and gear train kinematic chains has been presented. Firstly, the topological model (TM and the corresponding weighted adjacency matrix (WAM are introduced to describe the two types of kinematic chains, respectively. Then, the equivalent circuit model (ECM of TM is established and solved by using circuit analysis method. The solved node voltage sequence (NVS is used to determine the correspondence of vertices in two isomorphism identification kinematic chains, so an algorithm to identify two specific types of isomorphic kinematic chains has been obtained. Lastly, some typical examples are carried out to prove that it is an accurate, efficient, and easy mathematical algorithm to be realized by computer.

  14. Modular Dynamic Research on Multi-Stage Planetary Gear System%空间机械臂用多级2K-H行星传动系统模块化动力学研究

    Institute of Scientific and Technical Information of China (English)

    刘明; 赵永强; 徐冬梅; 李瑰贤

    2014-01-01

    The integral modeling method is usually used in dynamic research of multi-stage planetary gear system. But it is not convenient for the analysis of dynamic performance and for the selection of transmission scheme. The dynamic model has to be rebuilt when the transmission scheme is changed. So based on the modular method, four general modules are established with meshing stiffness, damping, friction, backlash and bearing supporting stiffness of planets considered. Then the nonlinear dynamical differential equations of multi-stage planetary gear trains are generated automatically by calling in the four modules. According to the modular method, the dynamic characteris-tics of the four-stage planetary gear train used in space manipulator are analyzed. In order to verify the applicability and availability of the modularly designed model, the calculation results of the modularly designed model and those of the integrally designed model are compared.%多级行星传动系统的动力学研究多采用整体式建模方法,此种方法不便于通过动态性能分析快速选取传动方案,而且模型不具有通用性,传动形式改变,需要重建系统动力学模型。为克服整体式建模方法的缺点,提出了模块化思想,将多级行星传动系统划分为4个分级子模块,综合考虑啮合刚度、阻尼和行星轮支撑刚度等因素,建立了各级子模块的动力学模型,通过各级模块的集成,得到了多级行星传动系统非线性动力学方程。以空间机械臂关节用多级行星传动系统为例,通过调用各级模块,形成4级行星传动系统动力学微分方程组,对其进行数值求解,得到了系统的时域及频域响应特性。通过与整体式建模方法所得响应结果进行对比,验证了模块化建模方法的同一性和有效性。

  15. Planetary gear fault diagnosis based on information fusion of multi-parameters and multi-points%多参数与多测点信息融合的行星轮故障诊断

    Institute of Scientific and Technical Information of China (English)

    徐玉秀; 赵晓清; 杨文平; 郭威

    2014-01-01

    为了找到多级行星齿轮传动系统复杂故障诊断的合适方法,对三级齿轮传动系统进行故障模拟和振动信号测试。针对行星齿轮传动系统振动信号的非线性和非平稳性、故障特征信号难以提取等特点,采用关联维数、最大Lyapunov指数、样本熵3个混沌特征参数作为故障辨识特征量。用不同测点和不同混沌特征参数的信息融合,通过支持向量机分类方法建立信息融合故障诊断模型及6种不同故障状态的训练集,实现对三级齿轮传动系统复杂故障类型的识别与诊断。分析结果表明:多测点信息融合或不同混沌特征参数融合,均能不同程度提高故障分类准确率。而经多测点与多混沌特征参数的信息融合后,通过支持向量机的故障分类准确率最高。%In order to find the appropriate method of multistage planetary gear transmission system complex fault diagnosis,fault simulation and vibration signal test were carried out on three stage gear transmission system.Aiming at the nonlinear and non-sta-tionary characteristics of the vibration signals of the planetary gear transmission system and the difficultly in picking up the fault fea-ture signals,3 chaotic characteristic parameters,including the correlation dimension,maximum Lyapunov exponent and sample entropy were adopted as fault identification features.The information of different measuring points and different chaotic characteris-tic parameters was fused;and the information fusion fault diagnosis model and the training set for 6 kinds of different fault states were established based on the classification method of support vector machine,then the recognition and diagnosis of the three stage gear transmission system with complex fault types were achieved.Analysis results show that the multiple measurement information fusion or different chaotic characteristic parameter fusion both can improve the accuracy of fault classification

  16. Modelling polymer draft gears

    Science.gov (United States)

    Wu, Qing; Yang, Xiangjian; Cole, Colin; Luo, Shihui

    2016-09-01

    This paper developed a new and simple approach to model polymer draft gears. Two types of polymer draft gears were modelled and compared with experimental data. Impact characteristics, in-train characteristics and frequency responses of these polymer draft gears were studied and compared with those of a friction draft gear. The impact simulations show that polymer draft gears can withstand higher impact speeds than the friction draft gear. Longitudinal train dynamics simulations show that polymer draft gears have significantly longer deflections than friction draft gears in normal train operations. The maximum draft gear working velocities are lower than 0.2 m/s, which are significantly lower than the impact velocities during shunting operations. Draft gears' in-train characteristics are similar to their static characteristics but are very different from their impact characteristics; this conclusion has also been reached from frequency response simulations. An analysis of gangway bridge plate failures was also conducted and it was found that they were caused by coupler angling behaviour and long draft gear deflections.

  17. Non-linear dynamic analysis of a multi-mesh gear train using multi-term harmonic balance method: period-one motions

    Science.gov (United States)

    Al-shyyab, A.; Kahraman, A.

    2005-06-01

    A non-linear time-varying dynamic model of a typical multi-mesh gear train is proposed in this study. The physical system includes three rigid shafts coupled by two gear pairs. The lumped parameter dynamic model includes the gear backlash in the form of clearance-type displacement functions and parametric variation of gear mesh stiffness values dictated by the gear contact ratios. The system is reduced to a two-degree-of-freedom definite model by using the relative gear mesh displacements as the coordinates. Dimensionless equations of motion are solved for the steady-state period-1 response by using a multi-term Harmonic Balance Method (HBM) in conjunction with discrete Fourier Transforms and a Parametric Continuation scheme. The accuracy of the HBM solutions is demonstrated by comparing them to direct numerical integration solutions. Floquet theory is applied to determine the stability of the steady-state harmonic balance solutions. An example gear train is used to investigate the influence of key system parameters including alternating mesh stiffness amplitudes, gear mesh damping, static torque transmitted, and the gear mesh frequency ratio.

  18. Strukturna analiza složenih planetarnih prenosnika snage / Structural analysis of compound planetary gear trains

    OpenAIRE

    Slavko Muždeka

    2005-01-01

    Određivanje osnovnih kinematičkih i dinamičkih karakteristika složenih planetarnih prenosnika je složen proces za koji je razvijeno više analitičkih, grafičkih i grafoanalitičkih metoda. U radu je prikazan način određivanja prenosnog odnosa, opterećenja elemenata i tokova snage za planetarni red sa spoljašnjim i unutrašnjim ozubljenjem preko polužne analogije i primene strukturnog (Wolfovog) simbola. Polužna analogija definisana je i za planetarni red sa spoljašnjim ozubljenjem, za koji je, t...

  19. Research on Design Technology of the Planetary Gear System for Open Rotor Engine%开式转子发动机齿轮传动系统设计技术研究

    Institute of Scientific and Technical Information of China (English)

    侯明曦; 信琦; 王飞鸣

    2013-01-01

      等速对转行星齿轮传动系统是对转风扇开式转子发动机的关键技术。与齿轮驱动单级风扇(GTF)发动机的行星齿轮传动系统相比较,该系统的结构更为复杂,工作条件更恶劣。本文以对转风扇开式转子发动机齿轮传动系统概念设计为基础,开展了行星齿轮传动系统初步设计、齿轮疲劳强度分析、行星轴承寿命分析和传动系统润滑设计技术研究,为开式转子发动机的发展提供参考。%As the key technology of the open rotor engine with counter-rotating fans, the planetary gear system with the same counter-rotating speeds owns more complicated conifguration and bears poorer working environment compared with the single fan of geared turbofan engine. Based on the concept design of gear driven system for the open rotor engine with counter-rotating fans, the preliminary design of planetary gear system, gear tooth strength analysis, planetary bearing life analysis and lubrication design technology research were accomplished in this paper, which contribute to the development and experience accumulation of the open rotor engine.

  20. Planetary Gearbox Fault Diagnosis Using Envelope Manifold Demodulation

    OpenAIRE

    Weigang Wen; Gao, Robert X.; Weidong Cheng

    2016-01-01

    The important issue in planetary gear fault diagnosis is to extract the dependable fault characteristics from the noisy vibration signal of planetary gearbox. To address this critical problem, an envelope manifold demodulation method is proposed for planetary gear fault detection in the paper. This method combines complex wavelet, manifold learning, and frequency spectrogram to implement planetary gear fault characteristic extraction. The vibration signal of planetary gear is demodulated by w...

  1. Micro Planetary Gear Medium Temperature Gas Carbonitriding%微型行星齿轮的中温气体碳氮共渗

    Institute of Scientific and Technical Information of China (English)

    杨金花; 刘忠; 吴亮

    2015-01-01

    Planetary wheel of micro planetary gear transmission using the new technology of gas carbonitriding, through trial and error, and constantly adjust the process parameters, obtained the reasonable heat treatment process route, reduces the total infiltration temperature, shortens the time of total infiltration products have obtained a higher surface hardness, wear resistance and improve the quality of products and scrap rate reduced to 5% from 15%~20%, heat energy consumption reduced by 20%~30%, and the new technology has been applied in industrial production, to achieve the service life of the request, has obtained the remarkable economic and social benefits.%对微型行星齿轮传动中的行星齿轮采用气体碳氮共渗的新工艺,通过反复试验,不断调整各工艺参数,取得了合理的热处理工艺路线,降低了共渗温度、缩短了共渗时间,产品获得了更高的耐磨性和表面硬度,提高了产品质量,废品率由15%~20%下降为5%,热处理能耗降低20%~30%,新工艺已应用于工业生产中,达到了使用寿命要求,取得了显著的经济效益和社会效益。

  2. Planetary Perspectives: Training Teachers about Rocks from Earth and Space Through Project WISER

    Science.gov (United States)

    Buxner, S.; Crown, D. A.; Lebofsky, L. A.; Croft, S. K.; Canizo, T.; Baldridge, A. M.; Kortenkamp, S.; Chuang, F.; Pierazzo, E.

    2011-12-01

    Within the exciting context of planetary exploration, the Planetary Science Institute is offering an ongoing series of professional development workshops for elementary and middle school science teachers in Southern Arizona. Each workshop is an opportunity for teachers to learn about current exploration of the Solar System, engage in modeling scientific inquiry, and interact with active planetary science researchers. Current workshops include the Moon-Earth System, Exploring the Terrestrial Planets, Impact Cratering, Asteroid-Meteorite Connection, and Volcanoes of the Solar System. Two more workshops, Deserts of the Solar System and Astrobiology and the Search for Extrasolar Planetary Systems are being developed. Three rock kits have been designed for use during these workshops: the Impact Rock Kit, Meteorite Kit, and Volcanic Rock Kit. Each kit includes supporting materials with scientific background, supporting presentations, and additional ideas for using the kits in the classroom. In response to teachers' request to be able to use these kits in their classrooms, we have created a series of stand-alone workshops to train educators to use the rock kits in their own educational settings. After completing the training, teachers and other community educators are able to check out the kits for use in their classrooms, science fairs, star parties, and educational and social events. This work is supported by NASA EPOESS award NNX10AE56G: Workshops in Science Education and Resources (Wiser): Planetary Perspectives.

  3. Study of utilizing differential gear train to achieve hybrid mechanism of mechanical press

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The problems of hybrid input of mechanical press are studied in this paper, with differential gear train as transmission mechanism. It is proposed that “adjust-able-speed amplitude” or “differential-speed ratio” is the important parameters for the hybrid input mechanism. It not only defines the amplitude of the adjustable speed, but also determines the ratio of the power of the servomotor to the power of the conventional motor. The calculating equations of the ratio of transmission in all axes, the power of two motors, and the working load distribution are deduced. The two kinds of driving schemes are put forward that the servomotor and the conven-tional motor simultaneously drive and the servomotor and the conventional motor separately drive. The calculating results demonstrate that the latter scheme can use much lower power of the servomotor, so this scheme makes manufacture and use cost much lower. The latter scheme proposes a feasible way to apply the hybrid mechanism of mechanical press in practice engineering.

  4. Study of utilizing differential gear train to achieve hybrid mechanism of mechanical press

    Institute of Scientific and Technical Information of China (English)

    HE YuPeng; ZHAO ShengDun; ZOU Jun; ZHANG ZhiYuan

    2007-01-01

    The problems of hybrid input of mechanical press are studied in this paper, with differential gear train as transmission mechanism. It is proposed that "adjustable-speed amplitude" or "differential-speed ratio" is the important parameters for the hybrid input mechanism. It not only defines the amplitude of the adjustable speed, but also determines the ratio of the power of the servomotor to the power of the conventional motor. The calculating equations of the ratio of transmission in all axes, the power of two motors, and the working load distribution are deduced. The two kinds of driving schemes are put forward that the servomotor and the conventional motor simultaneously drive and the servomotor and the conventional motor separately drive. The calculating results demonstrate that the latter scheme can use much lower power of the servomotor, so this scheme makes manufacture and use cost much lower. The latter scheme proposes a feasible way to apply the hybrid mechanism of mechanical press in practice engineering.

  5. 差动轮系中的循环功率分析%Cycle Power Analysis in Differential Gear Train

    Institute of Scientific and Technical Information of China (English)

    贺亮; 叶斯伦; 张庆春; 张浩; 李星晨

    2015-01-01

    通过分析典型的差动轮系中齿轮受力与转速的关系,推导出差动轮系中当2个不同构件作主动件时的2种典型工况下,轮系产生循环功率的条件和原因,并采用某液压机械无级变速箱中的双排差动轮系的工作实例进行了分析和验证.研究结果表明,差动轮系中是否产生循环功率取决于2个主动构件的转动方向.该结论可以为采用差动轮系传递动力的系统提供理论参考依据,使系统避免工作在产生循环功率的工况下,提高系统的工作效率.%The relation between gears' stress and rotating speed were analyzed when use two different parts as power input member,and condition when cycle power produced in differential gear train system were ob-tained in two typical working conditions.A kind of hydro-mechanical continuously variable transmission(HM-CVT)with double row differential gear train was analyzed to verify the conclusions.The results showed that whether recycle power was produced depends on the two active members' relative rotating directions.The conclusion provided theoretical reference for a system with a differential gear train to avoid producing cy-cle power and improving the work efficiency.

  6. 基于扭转几何大变形理论的并联行星传动太阳轮轴设计研究%Designing research on sun gear shaft of parallel planetary gear transmission based on theory of torsional geometric large deformation

    Institute of Scientific and Technical Information of China (English)

    姜世平; 马亚光; 李洁

    2009-01-01

    以潜油单螺杆泵采油系统中的并联行星齿轮减速器为研究对象,结合等圆截面杆的弹性扭转几何大变形位移公式,通过Matlab软件计算,建立了并联行星齿轮减速器中并联太阳轮轴扭转变形的数学模型,应用各段并联太阳轮轴扭转变形协调原理和等功率传递原理,设计了并联行星齿轮减速器.该减速器在传递额定功率的情况下可以大幅度减小径向尺寸.%Taking the parallel planetary gear reducer in the submersible single screw pump oil-extraction system as the target of research, combining with the displacement formula of elastic tor-sional geometric large deformation of equalized circular sectioned rod and through the calculation of Matlab software the mathematical model of torsional deformation of parallel sun gear shaft in the paral-lel planetary gear reducer was established. Using the coordination principle and the uniform power transmission principle of torsional deformations in each section of parallel sun gear shaft, the parallel planetary gear reducer was designed. The radial dimensions of this reducer could be minimized to a large range under the condition of transmitting rated power.

  7. Dynamic characteristics and sensitivities analysis of a power turret gear train

    Institute of Scientific and Technical Information of China (English)

    Xu Lijiao; Chen Nan

    2014-01-01

    The dynamic transmission characteristics and the sensitivities of the three stage idler gear system of the new NC power turret are studied in the paper. Considering the strongly nonlinear factors such as the periodically time-varying mesh stiffness, the nonlinear tooth backlash, the lump-parameter model of the gear system is developed with one rotational and two translational freedoms of each gear. The eigen-values and eigenvectors are derived and analyzed on the basis of the real modal theory. The sensitivities of natural frequencies to design parameters including supporting and meshing stiffnesses, gear masses, and moments of inertia by the direct differential method are also calculated. The results show the quantitative and qualitative impact of the parameters to the natural characteristics of the gear system. Furthermore, the periodic steady state solutions are obtained by the numerical approach based on the nonlinear model. These results are employed to gain insights into the primary controlling parameters, to forecast the severity of the dynamic response, and to assess the acceptability of the gear design.

  8. Influence of subtropical Rossby wave trains on planetary wave activity over Antarctica in September 2002

    Directory of Open Access Journals (Sweden)

    Dieter H. W. Peters

    2015-05-01

    Full Text Available At the beginning of September 2002, strong convection processes over south-eastern Indonesia and over south-eastern Africa have been observed. Due to the strong upper tropospheric divergent outflow, two Rossby wave trains (RWTs were generated. Their south-eastward propagation was controlled by the mean background flow. These two wave trains are visible in observations. It is hypothesised that these wave trains cause enhanced planetary wave activity fluxes which are a result of an amplified planetary wave 2 in the upper troposphere/lower stratosphere over Antarctica. Such a change of the planetary wave structure was diagnosed in September 2002, prior to the first observed major sudden stratospheric warming event on the Southern Hemisphere. A simplified version of GCM ECHAM4 is used to evaluate the hypothesis. Sensitivity experiments were performed for a mean background flow similar to September 2002. Furthermore, the wave maker approach was used to generate Rossby waves in the subtropical upper troposphere at two distinct locations which are corresponding to the observed regions of divergent outflow. As a main result, after about 2 weeks of model integration with wave maker forcing, we find two RWTs with a south-eastward propagation inducing a polar amplification of planetary wave 2 in the upper troposphere and lower/middle stratosphere. The poleward wave activity flux is enhanced in comparison to the control run without any wave maker forcing. The convergence of the Eliassen–Palm flux causes a 25% deceleration of zonal mean zonal wind in the model stratosphere but no wind reversal. Sensitivity runs support the robustness of these results. The obtained model results highlight the mechanism and confirm the hypothesis that enhanced planetary wave activity in austral polar region in 2002 is caused by enhanced subtropical forcing of two RWTs.

  9. Parameters Design and Simulation of New Double Crank Adjustable Backlash Precision Planetary Gears%新型双曲柄式可调侧隙精密行星传动装置参数设计与仿真

    Institute of Scientific and Technical Information of China (English)

    王光建; 蒋汉军; 褚志刚

    2011-01-01

    Aiming at performance requirements such as low inertia, high stiffness, high precision and small backlash of precision transmission device with high-speed input, the two-stage double crank adjustable backlash planetary reducer with external gears parallel moving and internal gear output is proposed on the basis of involute beveloid gears.According to the characteristics of involute beveloid internal gear pair with few teeth difference, mechanical analyses of key components such as planetary gear, turning arm bearing and support bearing are carried out, the corresponding mechanical analysis models are built, and the corresponding analyses and calculations are accomplished.Simulation modeling and calculation of the involute beveloid planetary gear transmission are completed in ADAMS.The analyses indicate that the weak links of the new-type involute beveloid planetary gear transmission is turning arm bearing and supporting bearing.The parametric analysis model is built, and relevant influencing parameters such as the center distance, axial distance of the bearings and the number of planetary gears are analyzed.For the said weak links, in the permission of the space in the transmission device, increasing the center distance of turning arm bearing and the axial distance of support bearings can greatly decrease the loads of the both bearings.%针对精密传动装置小惯量、大刚度、高精度、小回差等性能要求和通常高速输入等特点,提出两级减速基于变齿厚齿轮的外齿内平动内齿轮输出的双曲柄可调侧隙行星传动机构;针对变齿厚少齿差内啮合副的特点,对行星轮、转臂轴承和支撑轴承等关键件进行力学分析,建立相应的力学分析模型,完成相应的分析计算;在ADAMS中完成变齿厚行星传动的仿真.建模与计算,分析表明:该新型变齿厚行星传动的薄弱环节在支撑轴承和转臂轴承;建立参数化分析模型,对影响变齿厚双曲柄行星机构的轴

  10. Study on the Influence of Gear System Stiffness to Vibration Characteristics of Planetary Transmission System%系统刚度对行星齿轮传动振动特性影响研究

    Institute of Scientific and Technical Information of China (English)

    汤鱼; 常山; 王志强; 宿吉鹏

    2011-01-01

    The translational - rotational - coupling dynamic model has been founded of herringbone tooth planetary transmission for analyzing the influence of gear mesh stiflhess and bearing stiffness to vibration characteristics of planetary transmission system. In the dynamic model, the proposed model admits three degrees - of- freedom for each component and includes the key factors affecting planetary gears vibration such as component bearing stiffness, time -varying mesh stiffness and so on. The dynamic differential equation is obtained base on system kinematics equation and solve the eigenvalue question of it. The vibration characteristics can be obtained of transmission system.%为了分析齿轮啮合刚度、支承刚度对行星传动系统振动特性的影响,建立了基于人字齿行星传动的平移一扭转耦合的动力学模型.在动力学模型中,每个运动构件假定有3个自由度,同时考虑各构件的支承刚度、轮齿时变啮合刚度等影响因素.根据各构件的运动方程建立传动系统的动力学微分方程,并对其进行特征值问题求解,获取行星传动系统振动特性.

  11. Multi-Objective Optimization of Two-Stage Helical Gear Train Using NSGA-II

    Directory of Open Access Journals (Sweden)

    R. C. Sanghvi

    2014-01-01

    Full Text Available Gears not only transmit the motion and power satisfactorily but also can do so with uniform motion. The design of gears requires an iterative approach to optimize the design parameters that take care of kinematics aspects as well as strength aspects. Moreover, the choice of materials available for gears is limited. Owing to the complex combinations of the above facts, manual design of gears is complicated and time consuming. In this paper, the volume and load carrying capacity are optimized. Three different methodologies (i MATLAB optimization toolbox, (ii genetic algorithm (GA, and (iii multiobjective optimization (NSGA-II technique are used to solve the problem. In the first two methods, volume is minimized in the first step and then the load carrying capacities of both shafts are calculated. In the third method, the problem is treated as a multiobjective problem. For the optimization purpose, face width, module, and number of teeth are taken as design variables. Constraints are imposed on bending strength, surface fatigue strength, and interference. It is apparent from the comparison of results that the result obtained by NSGA-II is more superior than the results obtained by other methods in terms of both objectives.

  12. Flex-gear power transmission system for transmitting EMF between Sun and ring gears

    Science.gov (United States)

    Vranish, John M. (Inventor)

    1994-01-01

    A plurality of flexible cylindrical members, termed flex-gears and having gear tooth type perimeters are located in an annular space between two concentric rotating gear members, one an inner gear member and the other an outer ring gear member, both of which have mutually facing toothed surfaces which engage the flex-gears. The flex-gears rotate and orbit around the annular space as planetary gears when the inner and outer gear members rotate with respect to one another. Pairs of these elements located in two mutually parallel planes and separated by insulators provide two electrical conductor paths across which an electrical signal source, AC or DC, can be connected and coupled to an electrical device. Alternatively, one set of elements including outer gears segmented into mutually insulated semicircles and inner gears segmented into mutually insulated quadrants can be used.

  13. 基于振动模型的直升机行星齿轮故障分析与仿真研究%Analysis and Simulation of Helicopter Planetary Gear Fault Based on Vibration Signal

    Institute of Scientific and Technical Information of China (English)

    刘鑫; 贾云献; 周杰

    2015-01-01

    Aiming at diagnosing helicopter’s main gearbox fault based on the vibration signals by experiments requires high costs ,the helicopter’s planetary gear system is taken as an example ,to analyze and improve the model established by McFadden ,and to derive delay‐time model of the vibration signal to determine the phase‐change of sidebands when the sys‐tem is running .The cause and change‐rule of planetary gear syetem’ vibration signal is analyzed to establish the fault diagno‐sis model based on vibration signal ,and simulate the vibration signals which is on fault condition .By comparing the simula‐tion of vibration signals ,a reference is provided for fault monitoring and diagnosis of a planetary gear system .%针对直升机主减速器进行基于振动信号的故障诊断试验需要高昂费用的问题,以直升机主减速器的行星齿轮系统为例,对理想条件下 McFadden 建立的模型进行分析与改进,推导了振动信号的时间延迟模型,从而确定了系统运行时边频的相位变化。分析了行星齿轮系统振动信号的产生与变化规律,建立了故障状态的振动信号模型,并对其进行仿真。通过振动信号的仿真比较,为行星齿轮系统的故障监测与诊断提供借鉴。

  14. 对称式行星齿轮差速器的转矩转速分配特性研究%Torque and Speed Distribution Characteristic of Symmetrical Planetary Gear Differential

    Institute of Scientific and Technical Information of China (English)

    张利鹏; 祁炳楠

    2012-01-01

    Symmetric planetary gear differential is widely used in various types of vehicles,which restricts the driving stability of vehicles.In order to thoroughly analyze the interaction between the components of this kind of differential and the differential mechanism between the two half shaft gears, the force decomposition and the internal friction torque calculation were carried out,and the model of its torque and speed distribution characteristics was established;at last,the correctness of the model was proved by an example calculation.The research shows that,when the output speed of the both sides half shaft of symmetric planetary gear differential is not the same ,the differences of the torque output of both sides half shaft will be decided by the internal friction torque. Therefore,changing the structure parameters of differential planetary gear and half shaft gears can change the size of the internal friction torque, and further change the torque distribution characteristics of the differential.%对称式行星齿轮差速器在各类车辆上被广泛应用并制约着整车的行驶稳定性.为了透彻分析该类差速器各部件之间的相互作用关系和半轴齿轮的差速机理,对其进行了受力分解和内摩擦力矩的计算,并对其转矩转速分配特性进行了建模,最后,通过实例计算验证了所建模型的正确性.研究表明,当对称式行星齿轮差速器两侧输出端转速不同时,内摩擦力矩将对该差速器两侧半轴输出转矩的差异产生决定作用,因此,改变差速器行星齿轮和半轴齿轮的结构参数即可改变内摩擦力矩的大小,并进而改变该差速器的转矩分配特性.

  15. Hybrid Gear

    Science.gov (United States)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  16. Influencia del movimiento tridimensional sobre los engranajes planetarios tipo 2KH-A en aerogeneradores. // Influence of tridimensional movement in planetary gears type 2KH-A used in gearboxes for wind turbine generator systems.

    Directory of Open Access Journals (Sweden)

    J. Wellesley-Bourke Funcasta

    2007-09-01

    Full Text Available En el trabajo se desarrolla el basamento matemático para establecer el análisis del efecto nocivo que se produce sobre losrodamientos de los mecanismos planetarios empleados en los aerogeneradores, dado esto por las condiciones variables delviento en cuanto a su velocidad y dirección.Palabras claves: Efecto giroscópico, engranajes planetarios, cargas dinámicas, energía eólica.______________________________________________________________________________AbstractIn this paper is presented the mathematical base useful to establish the analysis that deals with the noxious effect producedon the planetary mechanisms in the gearboxes for wind turbine generator systems, given by the variable conditions of thevelocity and direction of the wind.Key words: Gyroscopic effect, planetary gears, dynamic loads, wind turbine, wind energy.

  17. Does limited gear ratio driven higher training cadence in junior cycling reflect in maximum effort sprint?

    OpenAIRE

    Rannama, Indrek; Port, Kristjan; Bazanov, Boriss

    2012-01-01

    Maximum gears for youth category riders are limited. As a result, youth category riders are regularly compelled to ride in a high cadence regime. The aim of this study was to investigate if regular work at high cadence regime due to limited transmission in youth category riders reflects in effectual cadence at the point of maximal power generation during the 10 second sprint effort. 24 junior and youth national team cyclist’s average maximal peak power at various cadence regimes was registere...

  18. 非H封闭式周转轮系效率计算%The Calculating for Efficiency of Non H Closed Epicyclic Gear Train

    Institute of Scientific and Technical Information of China (English)

    韩继光; 周欣; 任福君; 李瑰贤

    2001-01-01

    The relationship of efficiency,flow direc tion of meshing power and motion parameter of non-H closed epicyclic gear train are researched.A simple method is developed for judging flow direction of meshi ng power according to transmitting ratios of epicyclic gear train and closed tra nsmitting train,and the much difficult problem for calculating efficiency is sol ved with the meshing power method.A unified formula is derived for efficiency of non-H closed epicyclic gear train.In addition,self-locking conditions of gear train of this kind are also analyzed.%研究了非H封闭式周转轮系的效率、啮合功率流动方 向与有关运动参数之间的关系,得到了依据差动轮系及封闭传动链的有关传动比判断啮合功率流向的简捷方法,解决了用啮合功率法计算效率的难点问题;并在此基础上,推导出非H封闭式周转轮系的效率计算的统一公式;此外,还分析了非H封闭式周转轮系的自锁条件。

  19. Dynamic characteristics analysis for a co-axial counter-rotating planetary gear transmission system%同轴对转行星齿轮传动系统动态特性分析

    Institute of Scientific and Technical Information of China (English)

    石万凯; 刘敬; 龚建春

    2014-01-01

    以同轴对转行星齿轮传动系统为研究对象,基于齿轮系统动力学和Lagrange方程,采用集中参数法建立了同轴对转系统的耦合动力学模型,模型中考虑了轮系的支撑刚度、弹性耦合和功率流向。在各个齿轮副的偏心误差、齿频误差和时变啮合刚度共同作用下,用数值分析方法得到了同轴对转系统的位移响应和速度响应等时域动态特性,并对比了定轴轮系与差动轮系的载荷分配,为同轴对转传动系统的动态性能优化与振动噪声研究提供了依据。%Based on the gear system dynamics and Lagrange equation,a coupled dynamic model of a co-axial counter-rotating epicyclic transmission (CCET)system was built with the lumped-parameter method,and the support stiffness,elastic coupling and power flow of the gear train were considered in the model.Under the action of gear pairs'run-out error,meshing-frequency error and time-varying mesh stiffness together,the time-domain dynamic characteristics including the displacement response and speed response of the CCET system were achieved with the numerical analysis method,and the load distributions were compared between an ordinary gear train and a differential gear train.The results provided a basis for dynamic performance optimization and noise and vibration study of a CCET.

  20. Dynamic characteristic analysis of diesel timing gear trains%柴油机正时齿轮系动力学特性分析

    Institute of Scientific and Technical Information of China (English)

    李一民; 郝志勇; 叶慧飞

    2012-01-01

    为了分析柴油机正时齿轮系的动力学特性以及对前端噪声的影响,建立正时齿轮系的多体动力学模型.分析考虑各齿轮负载及曲轴角速度波动时的齿轮扭转角位移、啮合齿对相对运动以及动态啮合力,并对比了不考虑曲轴角速度波动时的计算结果.结果表明,由曲轴扭振引起的角速度波动能够明显加大齿轮系的振动与冲击.凸轮轴齿轮扭转角位移的实验结果与计算结果较为一致.前端声强实验表明在1 000 Hz以下,齿轮系动态特性对噪声影响较大,高频处由齿轮加工精度影响的传递误差引起的噪声较大.通过设计曲轴扭振减振器,可以改善齿轮系的啮合振动与冲击,相应地减小前端的辐射噪声.%To analyze dynamic characteristic of diesel timing gear trains and whose influence on noise of engine front, muti-body dynamic model of diesel timing gear trains was established. Gear torsional angular displacement, relative motion in the tooth pair meshed and dynamic meshing force were analyzed considering gear trains loads and crankshaft angular velocity fluctuation, which were compared with that without considering crankshaft angular velocity fluctuation. Results showed that angular velocity fluctuation caused by crankshaft torsional vibration can increase vibration and shock among gear trains obviously. Test result of camshaft gear torsional angular displacement was consistent with the simulation result. Front sound intensity experiment displayed that radiated noise is mainly affected by dynamic characteristic of gear trains below 1000'Hz and by transmission error due to machining accuracy in high frequency range. Through design of crankshaft torsional vibration damper, meshing vibration and shock of gear trains can be improved and the radiated noise can be reduced correspondingly.

  1. 基于UG的复合轮系齿轮传动三维建模及运动仿真分析%Three-dimensional Modeling and Motion Simulation Analysis of Compound Gear Train Based on UG

    Institute of Scientific and Technical Information of China (English)

    黄跃娟; 矫健; 肖明喆

    2015-01-01

    以复合轮系齿轮传动为例,对传动机构进行原理分析,利用传动比计算公式计算出复合轮系中关键齿轮的旋转速度,得出UG运动仿真参数。利用UG中齿轮工具箱完成锥齿轮和直齿轮的建模与啮合装配,对旋转副和齿轮副进行运动仿真,通过运动仿真可直观地观察齿轮传动状态,然后进行图表分析,以验证轮系设计的合理性。%With the compound gear train gear as an example,the principle of driving mechanism is analyzed,the transmis-sion ratio calculation formula is used to calculate the rotational speed of key gears in the compound gear train,obtaining UG motion simulation parameters. The gear toolbox in UG is utilized to complete modeling and engage assembly of spur gears and bevel gears,with motion simulation of rotating vice and gear pair conducted,which can realize intuitive observation of gear transmission state and graph-based analysis to verify the rationality of gear train design.

  2. 基于矩阵理论的AA80E型自动变速器行星传动分析%Planetary Gear Transmission Analysis of AA80E Automatic Transmission based on Matrix Theory

    Institute of Scientific and Technical Information of China (English)

    吴心平; 李玉生; 贾振华

    2012-01-01

    The transmission analysis of AA80E automatic transmission is carried out based on matrix theory. By studying the coupling form and shift constraints of three - row planetary gear mechanism, the method of building a mathematical model by coupling matrix, the constraint matrix and transmission matrix and analysis of the transmission by using the Matiab is proposed. A new path for the research and design of the complex planetary gear transmission is provided by using the matrix theory and the Matiab.%基于矩阵理论对AA80E型自动变速器进行了传动分析,通过对三排行星齿轮变速机构的行星排之间联结、换挡约束进行研究,提出了用联结矩阵、约束矩阵和传动矩阵构建数学模型并使用Matlab进行传动分析的方法.基于矩阵理论与Matlab的传动分析方法,为研究复杂行星齿轮变速机构提供了新的途径.

  3. Training the File Personnel Gearing to the 21st Century%跨世纪档案人才的培训与教育工作

    Institute of Scientific and Technical Information of China (English)

    徐素枫; 孙建华

    2000-01-01

    阐述了跨世纪档案人才的培训目标、素质条件、选拔原则、培训内容及培训措施。%Discussion is made on how to train the file personnel gearing to the 21st century, especially in the objects, qualification, principles, task and measures.

  4. A Virtools-based Training System of Virtual Assembly for Gear Pump%基于Virtools的齿轮泵虚拟装配训练系统

    Institute of Scientific and Technical Information of China (English)

    褚识广; 张志利; 李向阳; 龙勇

    2011-01-01

    The assembly training for gear pump is an important part of hydraulic system's maintenance training. In order to improve the training effect of schools and training agencies, and make workers grasp the method of gear pump's assembly quickly, the training system of virtual assembly for gear pump was designed. A generic design conception was proposed for the Virtools-based training system. The 3D solid models of gear pump's components were built using CATIA. The training system was designed via Virtools platform. The developed system provides an environment which is friendly, interactive and simple operated. It can meet the demand for training of schools and training agencies.%齿轮泵的装配训练是液压系统维修培训中重要的一部分.为了提高学校及培训机构的训练质量,使工人能够快速掌握齿轮泵的装配,设计了基于Virtools的齿轮泵虚拟装配训练系统.描述了基于Virtools的齿轮泵虚拟装配训练系统的总体设计思想,通过CATIA平台建立了齿轮泵产品元件的三维实体模型,在此基础上利用Virtools平台设计了交互式的齿轮泵虚拟装配训练系统.该系统为使用者提供了界面友好、交互性好、操作便利的训练环境,能够满足学校及培训机构的训练需求.

  5. 大功率高速行星齿轮减速器啮合刚度计算研究%Study on the Meshing Stiffness of a Planetary Reducer with Herringbone Gears

    Institute of Scientific and Technical Information of China (English)

    龚存忠

    2011-01-01

    针对某NGW型大功率高速行星齿轮减速器,运用自编程序生成内、外啮合齿轮副的精确啮合节点坐标,结合三维建模软件和有限元计算软件,将各啮合节点坐标导入仿真环境下生成真实齿面上的各个有限元节点,通过依次在各啮合节点上施加单位载荷进行变形计算,提取各啮合结点的综合变形结果并组装得到内、外齿啮合齿面的柔度系数矩阵,进而得到各啮合齿面的啮合刚度.根据此减速器内、外啮合齿面在各啮合位置的啮合刚度值及齿面啮合周期内的啮合刚度波动规律,对减速器的齿轮参数选取的优劣做出判断.%Aiming at the design of a NGW planetary reducer with high - power and high speed, it uses programs to generate the accurate meshing gears coordinate and unit load on the neshing crunodes, then establishes the flexible coefficient matrix of meshing gears, and finally obtains the meshing stiffness of internal and external meshing gears.According to the fluctuation orderliness of internal and external meshing gears stiffness, it validates the rationality of structure and parameters.

  6. 变载荷下风力发电机行星齿轮传动系统齿轮-轴承耦合动力学特性%Gear-bearing coupling dynamics characteristics of wind turbine planetary gear transmission system under variable load

    Institute of Scientific and Technical Information of China (English)

    周志刚; 秦大同; 杨军; 陈会涛

    2012-01-01

    Considering that the transmission system of wind turbine works in complex and changing load environment caused by stochastic wind speed,this paper uses sparse least squares support vector machine(SL-SVM) to simulate wind speed of true wind field,and obtains time-varying wind load caused by stochastic wind speed.The lumped-parameter method is used to develop a dynamic model of planetary gear transmission system of wind turbine coupled with bearing.The model includes the varying wind load,time-vary mesh stiffness of gear pair and time-vary stiffness of rolling element bearing.The numerical method is used to simulate the dynamic performance of planetary gear system of Multibrid Technology Wind Turbine with 1.5 MW rated power.The vibration displacement responses of the transmission system are obtained as well as dynamic meshing force each pair of gear and nonlinear bearing forces.The research can provide a foundation for optimizing dynamic performance and reliable design of gear transmission system of wind generator.%根据风力发电机传动系统在随机风场中复杂变工况的工作特点,建立了最小二乘支持向量机风场随机风速模型,获得了由随机风速引起的时变风载荷。采用集中质量参数法建立了风力发电机行星齿轮传动系统中齿轮滚动轴承耦合动力学模型,考虑了风力发电机行星齿轮传动的变风载输入、齿轮时变啮合刚度和滚动轴承时变刚度等影响因素,对变风速下1.5MW半直驱风力发电机行星齿轮传动系统的动力学特性进行了仿真计算分析,求得了变风速下行星齿轮传动系统的振动位移、各齿轮副的动态啮合力和非线性动态轴承力,为风力发电机传动系统的动态性能优化和可靠性设计奠定了基础。

  7. Varying Load Incentive Dynamics Model and Response Characteristic of Planetary Gear System of Wind Turbine%风电行星齿轮系统变载荷激励动力学模型及其响应特性

    Institute of Scientific and Technical Information of China (English)

    杨军; 张浬萍

    2013-01-01

    According to the characteristics of varying load and varying speed of the planetary gear system of a wind turbine,the dynamics model of the planetary gear system under varying load was proposed and the differential equation of system motion was obtained by analyzing the forces of components with rigid body or elastic body and applying theory of the composite motion.On the basis of these,the mechanism of influence of the internal and external incentive on dynamic load and dynamic factor of planetary gear system was analyzed.Taking a typical MW planetary gear system of wind turbine as an example,the dynamic response characteristics were simulated and analyzed,the results show that the time—varying mesh stiffness of gear pairs and the time—varying stiffness of bearing affect the size of response frequency,the low frequency components are found in response frequencies and energy allocation of various order frequencies is also influenced because of the external loads.The research results lay a foundation for dynamic optimization design and life analysis of wind turbine gearbox.%针对风电行星齿轮系统变载变速的运行特点,通过分析系统构件为刚体和弹性体时的受力情况,应用运动合成原理,提出了变载荷激励下行星齿轮系统动力学模型的建立方法,并推导出系统的运动微分方程.在此基础上,分析了行星齿轮系统的内外部激励因素及其对系统动载荷和动载系数的影响机理.计算并分析了某MW级风电行星齿轮系统的动态响应,结果表明:系统的时变啮合刚度和时变轴承刚度主要影响响应频率的数值大小和系统的振动能量;外部变载荷使响应频率中存在明显的低频成分,并影响各阶振动间的能量分配;齿轮啮合力的动载系数主要受到外部变载荷的影响,而轴承力的动载系数同时受到系统内部激励和外部激励的影响.研究结果为风电齿轮箱的疲劳寿命分析和动态优化设计奠定了基础.

  8. Carrier-less, anti-backlash planetary drive system

    Science.gov (United States)

    Vranish, John M. (Inventor)

    1995-01-01

    This invention relates to a carrier-less, anti-backlash planetary gear system that has an input sun gear, a force-balancing and planet-alignment 'speeder' gear above the sun gear, a split ring gear that has a fixed lower ring gear coaxial with the sun gear and a rotating upper ring gear also coaxial with the sun gear. A preload bolt is used for securing the split ring gears together. Within the split ring gear is an even number of planet gears between the split ring gear and the sun gear. Each planet gear consists of an upper planet gear, and lower planet gear with the upper and lower planet gears splined together and pushed apart by a spring which causes separation and relative twist between the upper and lower planet gears. The lower planet gear meshes with the input sun gear and the fixed ring gear while the upper planet gear is driven by the lower planet gear and meshes with the rotating ring gear.

  9. The Research of New Planetary Ring Tapered Gear Divergent Power on CVT%新型行星环锥齿轮功率分流式无级变速器的研究

    Institute of Scientific and Technical Information of China (English)

    王爽; 董小瑞; 毛虎平

    2014-01-01

    基于当前无级变速器油耗大,传动效率偏低,传动结构复杂的缺陷,设计一种新型行星环锥齿轮功率分流式无级变速器,即RX环锥齿轮无级变速器与2 K-H无级变速器的组合。对传统无级变速器进行结构改进设计,在原传动调速的基础上,以高效率,大变速比为研究设计目标,对其理论分析和研究。结果表明:该新型变速器传动效率高,变速范围广,有效实现传动比的无级变化,无封闭功率循环现象和无根切现象出现;且其传动系统中的调速性能及传动效率均优于原行星锥齿轮变速器;具有很高的推广实用价值。%Based on current fuel consumption slightly larger CVT, Lower transmission efficiency, defects of complex transmission structure, Proposes a new power split planetary ring bevel gear-type continuously vari-able transmission. That is RX gear CVT combination with a 2K-H CVT. To the structural of Conventional CVT’ s design improvements, On the basis of the original transmission speed control, High efficiency, gear ratio for the study of the design goals. And analysis and calculation its theoretical. The results show: the new gearbox drive have high efficiency, wide range, effectively infinitely variable transmission ratio, no closed cycling power phenomenon and no undercutting of phenomenon, and its transmission in speed per-formance and the drive efficiency are better than the original tapered planetary gear transmission. It possesses Promotion of high practical value.

  10. NASA's Planetary Science Summer School: Training Future Mission Leaders in a Concurrent Engineering Environment

    Science.gov (United States)

    Mitchell, K. L.; Lowes, L. L.; Budney, C. J.; Sohus, A.

    2014-12-01

    NASA's Planetary Science Summer School (PSSS) is an intensive program for postdocs and advanced graduate students in science and engineering fields with a keen interest in planetary exploration. The goal is to train the next generation of planetary science mission leaders in a hands-on environment involving a wide range of engineers and scientists. It was established in 1989, and has undergone several incarnations. Initially a series of seminars, it became a more formal mission design experience in 1999. Admission is competitive, with participants given financial support. The competitively selected trainees develop an early mission concept study in teams of 15-17, responsive to a typical NASA Science Mission Directorate Announcement of Opportunity. They select the mission concept from options presented by the course sponsors, based on high-priority missions as defined by the Decadal Survey, prepare a presentation for a proposal authorization review, present it to a senior review board and receive critical feedback. Each participant assumes multiple roles, on science, instrument and project teams. They develop an understanding of top-level science requirements and instrument priorities in advance through a series of reading assignments and webinars help trainees. Then, during the five day session at Jet Propulsion Laboratory, they work closely with concurrent engineers including JPL's Advanced Projects Design Team ("Team X"), a cross-functional multidisciplinary team of engineers that utilizes concurrent engineering methodologies to complete rapid design, analysis and evaluation of mission concept designs. All are mentored and assisted directly by Team X members and course tutors in their assigned project roles. There is a strong emphasis on making difficult trades, simulating a real mission design process as accurately as possible. The process is intense and at times dramatic, with fast-paced design sessions and late evening study sessions. A survey of PSSS alumni

  11. Training Early Career Scientists in Flight Instrument Design Through Experiential Learning: NASA Goddard's Planetary Science Winter School.

    Science.gov (United States)

    Bleacher, L. V.; Lakew, B.; Bracken, J.; Brown, T.; Rivera, R.

    2017-01-01

    The NASA Goddard Planetary Science Winter School (PSWS) is a Goddard Space Flight Center-sponsored training program, managed by Goddard's Solar System Exploration Division (SSED), for Goddard-based postdoctoral fellows and early career planetary scientists. Currently in its third year, the PSWS is an experiential training program for scientists interested in participating on future planetary science instrument teams. Inspired by the NASA Planetary Science Summer School, Goddard's PSWS is unique in that participants learn the flight instrument lifecycle by designing a planetary flight instrument under actual consideration by Goddard for proposal and development. They work alongside the instrument Principal Investigator (PI) and engineers in Goddard's Instrument Design Laboratory (IDL; idc.nasa.gov), to develop a science traceability matrix and design the instrument, culminating in a conceptual design and presentation to the PI, the IDL team and Goddard management. By shadowing and working alongside IDL discipline engineers, participants experience firsthand the science and cost constraints, trade-offs, and teamwork that are required for optimal instrument design. Each PSWS is collaboratively designed with representatives from SSED, IDL, and the instrument PI, to ensure value added for all stakeholders. The pilot PSWS was held in early 2015, with a second implementation in early 2016. Feedback from past participants was used to design the 2017 PSWS, which is underway as of the writing of this abstract.

  12. Planetary Gearbox Fault Diagnosis Using Envelope Manifold Demodulation

    Directory of Open Access Journals (Sweden)

    Weigang Wen

    2016-01-01

    Full Text Available The important issue in planetary gear fault diagnosis is to extract the dependable fault characteristics from the noisy vibration signal of planetary gearbox. To address this critical problem, an envelope manifold demodulation method is proposed for planetary gear fault detection in the paper. This method combines complex wavelet, manifold learning, and frequency spectrogram to implement planetary gear fault characteristic extraction. The vibration signal of planetary gear is demodulated by wavelet enveloping. The envelope energy is adopted as an indicator to select meshing frequency band. Manifold learning is utilized to reduce the effect of noise within meshing frequency band. The fault characteristic frequency of the planetary gear is shown by spectrogram. The planetary gearbox model and test rig are established and experiments with planet gear faults are conducted for verification. All results of experiment analysis demonstrate its effectiveness and reliability.

  13. 差速器行星齿轮冷挤压工艺及制造研究%Research of cold extrusion technology and manufacturing for differential planetary gear

    Institute of Scientific and Technical Information of China (English)

    林超; 徐萍

    2011-01-01

    结合开发差速器行星齿轮冷挤加工,根据该零件的技术要求,依据冷挤压理论,分析研究了该零件的冷挤压工艺及制造方案,特别对冷挤压工艺中的几个主要问题进行了研究.通过研究得到,冷挤压加工是该齿轮最合适的生产方式,它具有以下独特优势:降低生产成本,提高原材料利用率,提高齿轮质量,提高生产效率,降低环境污染,有利于可持续发展,是值得推广的低碳锥齿轮加工技术.%Examines the cold extrusion machining for the planetary pinion of differential, according to the part specifications and the cold extrusion theory ,the cold extrusion technology characters and machining for the part are studied and analyzed, the cold extrusion technology schedules are made, especially, several problems occurred in the cold extrusion processes are discussed.Through the research can know that using the cold extrusion method to process the gear is the most appropriate mode of production ,it has the following unique advantages :lower production costs and improve raw material utilization ;improve gear quality ;improve production efficiency; reduce pollution, contribute to sustainable development; is a low-carbon bevel gear technology which worth to promote.

  14. Analysis of internal drive train dynamics in a wind turbine

    Science.gov (United States)

    Peeters, Joris L. M.; Vandepitte, Dirk; Sas, Paul

    2006-01-01

    Three types of multibody models are presented for the investigation of the internal dynamics of a drive train in a wind turbine. The first approach is limited to the analysis of torsional vibrations only. Then a rigid multibody model is presented with special focus on the representation of the bearings and gears in the drive train. The generic model implementation can be used for parallel as well as planetary gear stages with both helical and spur gears. Examples for different gear stages describe the use of the presented formulations. Furthermore, the influence of the helix angle and the flexibility of the bearings on the results of eigenmode calculations are discussed. The eigenmodes of a planetary stage are classified as rotational, translational or out-of-plane modes. Thirdly, the extension to a flexible multibody model is presented as a method to include directly the drive train components' flexibilities. Finally, a comparison of two different modelling techniques is discussed for a wind turbine's drive train with a helical parallel gear stage and two planetary gear stages. In addition, the response calculation for a torque input at the generator demonstrates which eigenmodes can be excited through this path. Copyright

  15. Torque-Splitting Gear Drive

    Science.gov (United States)

    Kish, J.

    1991-01-01

    Geared drive train transmits torque from input shaft in equal parts along two paths in parallel, then combines torques in single output shaft. Scheme reduces load on teeth of meshing gears while furnishing redundancy to protect against failures. Such splitting and recombination of torques common in design of turbine engines.

  16. Expansion of epicyclic gear dynamic analysis program

    Science.gov (United States)

    Boyd, Linda Smith; Pike, James A.

    1987-01-01

    The multiple mesh/single stage dynamics program is a gear tooth analysis program which determines detailed geometry, dynamic loads, stresses, and surface damage factors. The program can analyze a variety of both epicyclic and single mesh systems with spur or helical gear teeth including internal, external, and buttress tooth forms. The modifications refine the options for the flexible carrier and flexible ring gear rim and adds three options: a floating Sun gear option; a natural frequency option; and a finite element compliance formulation for helical gear teeth. The option for a floating Sun incorporates two additional degrees of freedom at the Sun center. The natural frequency option evaluates the frequencies of planetary, star, or differential systems as well as the effect of additional springs at the Sun center and those due to a flexible carrier and/or ring gear rim. The helical tooth pair finite element calculated compliance is obtained from an automated element breakup of the helical teeth and then is used with the basic gear dynamic solution and stress postprocessing routines. The flexible carrier or ring gear rim option for planetary and star spur gear systems allows the output torque per carrier and ring gear rim segment to vary based on the dynamic response of the entire system, while the total output torque remains constant.

  17. Scuffing damage quantitative detection of planetary gear set based on physical model and grey relational analysis%基于物理模型和灰色理论的行星轮系胶合损伤定量检测方法

    Institute of Scientific and Technical Information of China (English)

    程哲; 胡茑庆; 高经纬

    2011-01-01

    Planetary gear set is the critical component of helicopter main transmission system, thus the quantitative detection of planetary gear set is a challenge for condition monitoring of helicopter. A novel approach to detect scuffing damage quantitatively in 2K-H planetary gear set is presented, which is based on the physical model and grey relational analysis of grey theory. Aiming at 2K-H planetary gear set, the physical model of sun gear scuffing damage is developed, and then the simulation signals of scuffing with different level severity are obtained. After that, the feature vectors extracted based on simulation signal are utilized as the standard damage mode of grey relational analysis. Based on the grey relational grade calculated by a grey relational analysis algorithm, the scuffing damage of sun gear in 2K-H planetary gear set is detected quantitatively. Finally,damage seeded tests are carried out on the fault simulation test rig of helicopter transmission system, and the proposed methodology is validated by the test data.%将物理模型的仿真信号与灰色关联分析方法相结合,提出了直升机主传动系统2K-H行星轮系胶合损伤定量检测的新方法.针对2K-H行星轮系,建立太阳轮胶合损伤的物理模型,通过仿真获得不同严重度的行星轮系损伤振动信号.将仿真信号的特征向量作为灰色关联分析的标准模式,采用灰色关联分析算法分析待检信号,根据得到的关联度对胶合损伤进行定量检测.最后在直升机传动系统故障模拟试验台上开展了故障植入试验,通过试验数据验证了方法的可行性.

  18. Performance improvement of magnetic gear and efficiency comparison with conventional mechanical gear

    Science.gov (United States)

    Nakamura, Kenji; Fukuoka, Michinari; Ichinokura, Osamu

    2014-05-01

    Magnetic gears can transmit torque without any mechanical contact. Hence, they have low vibration, no wear, and fatigue, which ensure maintenance-free operation. There are various types of magnetic gears. Among them, a planetary type magnetic gear, which consists of coaxial inner and outer rotors with surface-mounted permanent magnet and ferromagnetic stationary parts called pole-pieces, has recently attracted interest since it offers higher torque than other type magnetic gears. This paper presents a comprehensive investigation of the influence of geometry and position of the pole-pieces on torque characteristic based on finite element analysis and experiment. Surveyed parameters of the pole-pieces include lengths in the radial and axial directions and position in the radial direction. Finally, it is demonstrated that the maximum torque of the improved prototype magnetic gear is increased by 45% and the maximum efficiency achieves up to about 99%, which is equal to or more than a conventional planetary type mechanical gear.

  19. Research on stepless transmission utilizing noncircular gears

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In view of the lack of systemic analysis for stepless transmission using noncircular gears, two basic noncircular gear units, an addition unit adopting differential mechanism and a multiplication unit applying a fixed gear train, are proposed. Then, the design methods of the noncircular gear pair of each unit, transmission ratio relationship, rotation angle relationship and key parameters with specific physical meanings are studied. The adjusting properties, composing strategy and varying range of transmiss...

  20. Gear geometry of cycloid drives

    Institute of Scientific and Technical Information of China (English)

    CHEN BingKui; FANG TingTing; LI ChaoYang; WANG ShuYan

    2008-01-01

    According to differential geometry and gear geometry,the equation of meshing for small teeth difference planetary gearing and a universal equation of conjugated profile are established based on cylindrical pin tooth and given motion.The correct meshing condition,contact line,contact ratio,calculating method for pin tooth's maximum contact point are developed.Investigation on the theory of conjugated meshing is carried out when the tooth difference numbers between pin wheel and cycloidal gear are 1,2,3 and -1,respectively.A general method called enveloping method to generate hypocycloid and epicycloid is put forward.The correct mesh-ing condition for cycloid pin wheel gearing is provided,and the contact line and the contact ratio are also discussed.

  1. Gear geometry of cycloid drives

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    According to differential geometry and gear geometry, the equation of meshing for small teeth difference planetary gearing and a universal equation of conjugated profile are established based on cylindrical pin tooth and given motion. The correct meshing condition, contact line, contact ratio, calculating method for pin tooth’s maximum contact point are developed. Investigation on the theory of conjugated meshing is carried out when the tooth difference numbers between pin wheel and cycloidal gear are 1, 2, 3 and ?1, respectively. A general method called enveloping method to generate hypocycloid and epicycloid is put forward. The correct meshing condition for cycloid pin wheel gearing is provided, and the contact line and the contact ratio are also discussed.

  2. 行星齿轮精锻工艺分析与试验研究%Process analysis and experiment study on precision forging of planetary gear

    Institute of Scientific and Technical Information of China (English)

    闫红艳; 边翊; 彭冲; 刘桂华; 蒋智; 马晓晖

    2011-01-01

    According to indicator for gear accuracy testing, the questions that need pay attention to during accuracy controlling was put forward, and corresponding solution for each question was proposed. Based on systemic analysis of the problems such as elastic deformation of tooth profile, tooth surface and die life during the hot forging and cold forging process, the hot forging-cold finishing process was determined and the design of precision forging and hot forging dies were finished. The experiment study on the hot precision forging process for different blank dimensions and upsetting ratios was carried out, and the impact of blank and upsetting ratio to tooth file was analyzed. The result shows that, when billet diameter is less than the diameter at the small end of the gear and upset ratio is 1.5, the tooth profile and tooth head of the hot forging gear are filled well, and the tooth profile is full and accurate. After cleaning the iron oxide skin thoroughly, the surface quality of the forging is good.%根据齿轮精度检验的指标,提出了精度控制需要注意的问题,并针对每个问题提出解决办法.在系统分析热精锻和冷锻成形过程中齿形、齿面、弹性变形及模具寿命等问题的基础上,确定了热精锻—冷精整工艺流程,完成了精锻件及热精锻模的设计.对不同坯料尺寸和镦粗比的热精锻工艺过程进行了试验研究,分析了坯料和镦粗比对齿形充满的影响.研究结果表明,采用直径小于分锥角小端直径的坯料,选定镦粗比1.5进行热锻成形,锻造的热精锻齿轮齿形、齿顶充满效果较好,冷精整后的齿形饱满准确,在对氧化铁皮进行彻底清理后,锻件表面质量良好.

  3. Optimum Weight Design of Functionally Graded Material Gears

    Institute of Scientific and Technical Information of China (English)

    JING Shikai; ZHANG He; ZHOU Jingtao; SONG Guohua

    2015-01-01

    Traditional gear weight optimization methods consider gear tooth number, module, face width or other dimension parameters of gear as design variables. However, due to the complicated form and geometric features peculiar to the gear, there will be large amounts of design parameters in gear design, and the influences of gear parameters changing on gear trains, transmission system and the whole equipment have to be taken into account, which increases the complexity of optimization problem. This paper puts forward to apply functionally graded materials (FGMs) to gears and then conduct the optimization. According to the force situation of gears, the material distribution form of FGM gears is determined. Then based on the performance parameters analysis of FGMs and the practical working demands for gears, a multi-objective optimization model is formed. Finally by using the goal driven optimization (GDO) method, the optimal material distribution is achieved, which makes gear weight and the maximum deformation be minimum and the maximum bending stress do not exceed the allowable stress. As an example, the applying of FGM to automotive transmission gear is conducted to illustrate the optimization design process and the result shows that under the condition of keeping the normal working performance of gear, the method achieves in greatly reducing the gear weight. This research proposes a FGM gears design method that is able to largely reduce the weight of gears by optimizing the microscopic material parameters instead of changing the macroscopic dimension parameters of gears, which reduces the complexity of gear weight optimization problem.

  4. Negative stiffness in gear contact

    Directory of Open Access Journals (Sweden)

    Půst L.

    2015-12-01

    Full Text Available The tooth contact stiffness is very often included in dynamic mathematical models of gear drives. It is an important value for calculation of torsion eigenfrequencies as well as the dynamic properties of the whole transmission systems. Planetary gear drives have several advantages over simple parallel axis gears, especially due to theirs compact design and great torque-to-weight ratio caused by multiple parallel paths. However, the dimensional or mounting errors can cause that some planets have the tendency to take more load than the others. One of the ways how to improve load sharing is the application of flexible planetary pins or by using a free central wheel. However in such cases, the wheels motion is defined in one rotation coordinate and two translation coordinates — tangential and radial. The reaction force at radial change of axis distance is usually neglected. The focus of this contribution is to derive the stiffness of this radial connection and to analyse the influence of radial stiffness on planetary gear dynamics.

  5. 周转轮系三维选型设计的实现%Realization of Type-Selection and Design of the Epicyclical Gear Train 3D

    Institute of Scientific and Technical Information of China (English)

    刘淼; 王慧武

    2011-01-01

    Epicyclical gear trains are widely used, but it is inconvenient for users to choose the suitable type because of the diversity of structure types and the complexity of design. Based on the method of Pro/E(Pro/ENGINEER) redeveloping and the AGW(Automation Gateway)linkage software, 3D models of kinds of epicyclical gear trains are built by Pro/E. And then according to the need of users the selected 3D models can be opened by VB interface. The parameter can be entered freely and the attribute can be computed automatically. With this method, the type- selection can be more intuitive and more convenient, and an effective tool is provided for realization of 3D type - selection and design of the epicyclical gear train.%周转轮系使用广泛,但其结构类型的多样性和设计计算的复杂性使用户在选择类型时无法直观、快速地做出决定.运用基于Automation Gateway(AGW)工具的Pro/ENGINEER(Pro/E)二次开发方法,应用Pro/E软件建立了周转轮系的各类三维模型库,通过AGW与Visual Basic(VB)综合编程使用户可以根据需要,利用VB用户界面打开所选类型周转轮系三维模型,确定其参数值并进行属性计算,使周转轮系类型选择过程直观、简便,为周转轮系选型设计的三维直观实现提供了一种有效的工具.

  6. Research on stepless transmission utilizing noncircular gears

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In view of the lack of systemic analysis for stepless transmission using noncircular gears, two basic noncircular gear units, an addition unit adopting differential mechanism and a multiplication unit applying a fixed gear train, are proposed. Then, the design methods of the noncircular gear pair of each unit, transmission ratio relationship, rotation angle relationship and key parameters with specific physical meanings are studied. The adjusting properties, composing strategy and varying range of transmission ratio etc. are investigated in detail for each unit. Following this, several examples of using a noncircular gear pair in the units and their manipulation technique are introduced.

  7. Redundant Gear Train

    Science.gov (United States)

    Packard, D. T.

    1983-01-01

    Tandem harmonic drives are immune to single-point failure. One mechanism continues transmitting power regardless of how other fails. Harmonic drive mechanism, combination of elliptical wave generator and tooth differential between flexible spline and circular spline produces rotational speed reduction in compact volume.

  8. Spur Gear Train Static Analysis of Reinforced Bar Straightening Machine%钢筋调直机直齿轮系静态分析

    Institute of Scientific and Technical Information of China (English)

    陈士忠; 王永华; 陈博; 吴玉厚

    2015-01-01

    为了研究双槽辊输入轴转矩的变化对直齿轮传动的影响,运用SolidWorks 对钢筋调直机传动机构进行建模,并使用ANSYS Workbench 软件,对双槽辊输入轴施加转矩分别为2.472×107 N·mm、2.673×107 N·mm、2.874×107 N·mm以及3.075×107 N·mm时,对直齿轮系进行应力应变分析。模拟得出直齿轮系的应力、应变的大小及分布。%A software called SolidWorks was used to generate a model of a transmission mechanism of a reinforced bar straightening machine in order to study the influence of dual groove roller input shaft torque changes on the spur gear transmission.Furthermore,a software called ANSYS Workbench was used to con-duct stress strain analysis of the spur gear train when the applied torque on the dual groove roller shaft was at 2.472×107 N·mm,2.673×107 N·mm,2.874× 107 N·mm and 3.075 ×107 N·mm.The results of the simulation provided the size and distribution of stress and strain on the spur gear train.

  9. An Analysis on the Characteristics of Electromechanical Transmission with Multi-planetary Gearing%多行星排机电复合传动特性分析

    Institute of Scientific and Technical Information of China (English)

    胡纪滨; 何融; 彭增雄

    2014-01-01

    针对车辆常用机电复合无级传动的分速汇矩、分矩汇速和分速汇速3种功率耦合机构,分析了多行星排分流传动的转速、转矩和分流比特性,并对不同分流形式组合进行了分析。结果表明:多行星排分流特性与两行星排分流传动特性相同,分速汇矩式分流传动有一个机械点,在机械点之前分流比较小,适用于低速起步阶段;分矩汇速式分流有一个机械点,分流比成对称分布,传动比小于机械点时,成分流工况,效率高,适合于高速阶段。分速汇速式分流传动有两个机械点,在两个机械点之间分流比较小,适用于中高速阶段。对于多模式机电复合传动,低速起步采用分速汇矩式分流传动,中高速采用分速汇速式分流传动比较好,可实现电机无速差切换。%The characteristics of the speed,torque and split ratio of multi-planetary power split transmission are analyzed for input split,output split and compound split three power coupling mechanisms of vehicle electrome-chanical variable transmission ( EVT) , and the combinations of different power-split modes are analyzed. The re-sults show that the characteristic of multi-planetary power split transmission is the same as the dual-planetary one. The input split transmission has one mechanical point, before which the split ratio is relatively low, is suitable for low-speed start-up stage. The output split mode has one mechanical point with a symmetric distribution of split rati-o, and when transmission ratio is lower than mechanical point, the efficiency is high, suitable for high speed stage. The compound split has two mechanical points, between which the split ratio is relatively low with high efficiency, suitable for medium and high speed stages. For multi-mode EVT, it is recommended to adopt input split mode at low-speed start-up stage and adopt compound split mode at medium and high speed stages for achieving

  10. Motion Analysis and Efficiency Calculation for A CR-CR Gear Automatic Transmission%一种CR-CR型自动变速器的运动分析和效率计算

    Institute of Scientific and Technical Information of China (English)

    陈玲琳; 陈奇

    2012-01-01

    以CR- CR双排行星齿轮机构四挡自动变速器为例,运用单排行星齿轮机构一般运动规律的特性方程式对该类变速器进行运动分析,采用啮合功率法将行星齿轮机构转化为定轴轮系机构,对自动变速箱的传动效率进行计算.所述方法为其进一步自动变速箱的结构改进和性能提高提供了一定的理论基础.%In order to improve the structure and performance , a fourth gear automatic transmission which has a CR - CR double planetary gear mechanism is taken as the example. And a characteristic equation , which shows the general law of motion of the single - row planetary gear mechanism , is used to analysis the motion law of the automatic transmission . "meshing power method" is also used to calculate the efficiency of the automatic transmission. Meshing power method is an approach that first translates planetary gear mechanism into fixed axis gear trains , then solves the transmission efficiency problem . Key Words: Fourth gear automatic transmission Motion analysis Efficiency calculation Meshing power method

  11. Finite Element Analysis on Gear Transmission System of High-Speed Train%高速列车齿轮系统有限元分析

    Institute of Scientific and Technical Information of China (English)

    付永佩; 张卫华; 黄冠华; 梁树林; 王兴宇

    2015-01-01

    To explore the inherent characteristic and the dynamic response of high-speed train gear system, the statics a-nalysis, modal analysis and dynamic analysis of the gear system have been done by establishing three-dimensional entity model and finite element model based on the vibration theory, Hertz contact theory and finite element method. Research on the stress distribution of the gear system under the maximum starting torque is performed, and then the static strength of the system is checked. The possibility of resonance invalidation is researched by identifying modal parameters of the gear system based on modal analysis. There is obvious periodicity in the gear meshing process, the system dynamic re-sponse under rated speed conditions is analyzed and determined by transient dynamics in this process. The results prove that the static strength is in the range of security and the gear system will not produce resonance. On the premise of con-stant input, the internal excitation such as stiffness excitation, error excitation, etc. produced due to gear mesh makes the system output have a cyclical fluctuation and has an impact on the system stability.%为探究高速列车齿轮系统的固有特性和动力响应情况,通过建立齿轮系统三维实体模型和有限元模型,基于振动理论、Hertz接触理论以及有限单元法,对系统进行静力学分析、模态分析和动力学分析。研究在最大启动扭矩作用下齿轮系统应力分布情况,对齿轮系统静强度进行校核;通过模态分析识别齿轮系统模态参数,研究系统共振失效可能性;齿轮啮合过程具有明显周期性,通过瞬态动力学分析确定齿轮啮合周期内,系统在额定转速工况下的动力学响应情况。结果表明:静力学分析表明齿轮系统静强度在安全范围内,模态分析表明系统不会产生共振,瞬态分析表明在输入恒定的前提下,由于齿轮啮合产生了刚度激励、误差

  12. 全椭圆齿轮行星系液态肥深施机构优化设计与试验%Optimization Design and Experiment of Liquid-fertilizer Applying Deep-fertilization Mechanism for Planetary Elliptic Gears

    Institute of Scientific and Technical Information of China (English)

    王金武; 刘亚华; 王金峰; 何剑南

    2012-01-01

    To satisfy the requirements of high working efficiency and smooth operation of liquid-fertilizer applicator, a kind of transmission mechanism with planetary elliptic gears was designed for deep-fertilization of liquid fertilizer. The analysis model of this mechanism was established. Its kinematic model was accomplished by means of theoretical derivation. Optimization design on the flow route of liquid fertilizer was conducted by employing the method of anti-twisting design of the mechanism. Finally, the mechanism was tested on the test-bed. After the data processing by using Design-Expert 6. 0. 1 software, the optimum working parameters were determined, which the working pressure of liquid pump is 0. 47 MPa, the rotating rate of planetary frame is 40 r/min, therefore, the fertilizer volume is 20 mL at a time, and fertilizer loss rate is 3. 2% . Observation from the test showed that, the mechanism ran smoothly with no interference, the liquid fertilizer transmitted smoothly characterized by reliable seal, which met the requirement of the design.%为满足液态施肥机工作过程中作业效率高、运转平稳的要求,设计了一种全椭圆齿轮传动的液态肥深施机构.建立了该机构运动学模型,通过理论推导对机构进行运动学分析.优化液态肥流动路线,对机构进行防缠绕设计.进行试验台试验,应用Design-Expert 6.0.1软件进行数据处理,确定了机构最佳工作参数为:液泵压力0.47 MPa、喷肥针孔直径3.0 mm和行星架转速40 r/min,此时施肥量20 mL/次,施肥损失率3.2%.试验表明该机构运转平稳、机构之间无干涉,液态肥流动管路密封可靠,液态肥输送顺畅.

  13. Field/Lab Training Workshops in Planetary Geology and Astrobiology for Secondary School Teachers

    Science.gov (United States)

    Treiman, A.; Newsom, H.; Hoehler, T.; Tsairides, C.; Karlstrom, K.; Crossey, L.; Kiefer, W.; Kadel, S.; Garcia-Pichel, F.; Aubele, J.; Crumpler, L.

    2003-12-01

    Thematic field-lab-classroom workshops can be successful in training secondary teachers in planetary geology and astrobiology, from the LPI's 4 years experience. A typical workshop includes ˜4 days of field study and ˜3 days of related classroom/lab lectures and exercises. Up to 30 teachers have participated at once, and the staff averages 5 researchers and educators. The 2003 workshop, The Great Desert, focused on geology and life in the Colorado Plateau as analogs for Mars. Specific emphases were on geologic processes exemplified in the Grand Canyon, Sunset Crater and Meteor Crater, and on biotic communities in desert soils and hot springs. The classroom portion, hosted by UNM, included lectures, lab work, and teaching exercises keyed to the field experience and its extensions to Mars. Formal followups: non-directive exit questionnaires; email list-serves for participants; websites with images, presentations, and exercises from the workshop, and links to related materials (e.g., http://www.lpi.usra.edu/education/EPO/yellowstone2002/index.html); and interviews for six-month retrospective. Graduate and continuing education credit are available. Past workshops, all relevant to Mars, have targeted: geology and extremophiles of Yellowstone NP, geology of the Cascade volcanos; and giant floods and lava flows of central Washington. The greatest benefit of this workshop format is the teachers' intense, deep experience, emphasizing scientific content. They learn from field, classroom, and laboratory perspectives, and work with PhD level researchers who contribute their excitement, demonstrate and teach critical thought processes, and provide authoritative background and answers. The small group size permits personal interactions (among teachers and presenters) that complement each other's understanding and appreciation of the subject. They log ˜65 contact hours with the staff, in small groups or one-on-one. Teachers return to the classroom with personal experiences

  14. Analysis on Automatic Transmission ’s Power Transmission Characteristics of Five-element Double-row Planetary Gear Mechanism%五元件双排行星齿轮自动变速器动力传递特性分析

    Institute of Scientific and Technical Information of China (English)

    范毅

    2015-01-01

    行星齿轮机构的动力特性分析与研究是自动变速器设计的重要过程。针对5个独立运动构件的双排行星齿轮机构自动变速器,运用整体矢量法分析了该变速器的动力传递路线。根据三角形相似原理计算了各挡位传动比。结合转速矢量图,进一步分析了此类变速器的升降挡过程。运用整体矢量法能定性分析自动变速器动力传递特性及定量计算各挡位传动比及各元件转速大小。%It is a key process for the automatic transmission design to study and analyze the dynamic characteristics of the planetary gear mechanism. Applying whole vector method, the paper analyzes the power transmission route of the double-row planetary gear mechanism’s automatic transmissions on five independent motion components. The transmission ratios under dif-ferent gears are also calculated according to the triangle similarity theory. Combining with the speed vector graph , the lifting gear process of such kinds of automatic transmission is further analyzed. The whole vector method is of great help to qualitative analy-sis of the automatic transmission’s power transmission characteristics and quantitative calculation of transmission ratio and ele-ment speed.

  15. 复杂轮系基本单元的运动特征状态数学建模%Kinematic Characteristic State Models for Basic Units of Compound Gear Train

    Institute of Scientific and Technical Information of China (English)

    马雅丽; 张永珍

    2014-01-01

    提出了复杂齿轮轮系运动分析的单元运动特征状态建模方法。通过研究复杂齿轮轮系构成规律,并分解其构成,定义了轮系基本单元;以齿轮原型机构为基础,利用机构拓扑特征构建了轮系基本单元构型图谱;构建了运动特征状态向量用以描述运动的类型和方向特征等属性,并利用状态方程建立了轮系基本单元的运动特征状态模型,为后续的轮系运动方案设计提供了理论基础。%This paper presented a new modeling approach for unit kinematic characteristic state on the motion analysis of compound gear trains.Gear basic units were defined according to studying the composite rules and decomposing the constitution of compound gear trains.Based on prototypes of gear basic units,gear mechanism diagrams of basic units were set up using topological characteristics of mechanism.Kinematic vector was built to describe the type and direction characteristics of motion. The kinematic characteristic model was established by using state equation.All of them provides a solid theoretical basis for kinematic conceptual design of gear trains.

  16. Kinematical analysis of epicyclic gear trains based on Kirchhoff's law%基于基尔霍夫定律的轮系拓扑运动学分析

    Institute of Scientific and Technical Information of China (English)

    史晓影; 刘相蕊; 孟祥丰

    2013-01-01

    拓扑理论应用于周转轮系的重要目的是进行轮系机构的型综合及优选,在解决了轮系拓扑型综合问题之后,重点就是解决如何通过电网络参数对轮系机构参数进行优选的问题.首先证明了基尔霍夫定律和拓扑图中传动参数的对应关系,在此基础上利用回路矩阵解决了数学模型的运动学和动力学求解问题,最后通过实例验证了理论的正确性,进而真正达到了周转轮系优选的目的.%Topological theory is applied to the epicyclic gear train which an important object is to achieve the combination of the gear mechanism and the preferred of the train wheel type.After successfully pull off the wheel system topology comprehensive,it will focus on how to use the circuit network to solve the problem of the a kinematics of the gear train in topology model.First the paper proved a relationship of corresponding parameters between the Kirchhoff' s law and a topology of epicyclic gear train,on the basis,it solved the problem of the kinematics and dynamics of the topological model based on the use of loop matrix.Finally,through the practical examples verified the correctness of the theory,thus it truly achieved the purpose of the gear train' s preferred.

  17. ESTEC/GEOVUSIE/ILEWG Planetary Student Designer Workshop: a Teacher Training Perspective

    Science.gov (United States)

    Preusterink, J.; Foing, B. H.; Kaskes, P.

    2014-04-01

    An important role for education is to inform and create the right skills for people to develop their own vision, using their talents to the utmost and inspire others to learn to explore in the future. Great effort has been taken to prepare this interactive design workshop thoroughly. Three days in a row, starting with presentations of Artscience The Hague to ESA colleagues, followed by a Planetary research Symposium in Amsterdam and a student design workshop at the end complemented a rich environment with the focus on Planetary exploration. The design workshop was organised by GeoVUsie students, with ESTEC and ILEWG support for tutors and inviting regional and international students to participate in an interactive workshop to design 5 Planetary Missions, with experts sharing their expertise and knowhow on specific challenging items: 1. Mercury - Post BepiColombo (with Sebastien Besse, ESA) 2. Moon South Pole Mission (with Bernard Foing, ESA) 3. Post-ExoMars - In search for Life on Mars (with Jorge Vago, ESA) 4. Humans in Space - Mars One investigated(with Arno Wielders, Space Horizon) 5. Europa - life on the icy moon of Jupiter? (with Bert Vermeersen, TU Delft. Lectures were given for more than 150 geology students at the symposium "Moon, Mars and More" at VU university, Amsterdam (organized by GeoVUsie earth science students). All students were provided with information before and at start for designing their mission. After the morning session there was a visit to the exhibition at The Erasmus Facility - ESTEC to inspire them even more with real artifacts of earlier and future missions into space. After this visit they prepared their final presentations, with original results, with innovative ideas and a good start to work out further in the future. A telescope session for geology students had been organized indoor due to rain. A follow-up visit to the nearby public Copernicus observatory was planned for another clear sky occasion.

  18. Analysis and Simulation of the Kinematics and Dynamics for Plane tary Gear Train based on Electric Network%应用电网络分析行星轮系运动学特性并仿真验证

    Institute of Scientific and Technical Information of China (English)

    刘相蕊; 薛隆泉; 史晓影

    2009-01-01

    A kind of new method of theory to analyze kinematics and dynamics of epicyclical gear trains is provided. According to the systematization graph model, adopt the concrete systematization method to analysis epicyclical gear trains, In theory, the relation of Kirchoff's law and epicyclical gear trians' parameter has been proved. Kirchoff's law concrete mathematical formalism which can solve kinematics and dynamics of spicyclical gear trains of EGTs - loop - equations? Cut - e-quations is created. At last, by mean of smulation the validity of theory is proved.%为行星轮系的运动学及动力学的研究提供了一种新的理论方法.在分析拓扑图结构的基础上,建立拓扑图几何特征的数学描述.理论上证明了基尔霍夫第一、第二定律与轮系传动中相应参数的关系.应用基尔霍夫定律建立基于拓扑图理论的数学模型--回路方程组、切割方程组来解决行星轮系运动学的问题,并通过Pro/E建立模型进行机构分析,验证理论的正确性.

  19. 摆线针轮行星传动多目标稳健优化设计%Multi-objective Moderate Optimization in a Cycloid Pin Gear Planetary Drive

    Institute of Scientific and Technical Information of China (English)

    迟建华; 王承刚; 田志涛; 李培宏

    2016-01-01

    We could derive to meet the constraints of the Pareto solution set for cycloid pin gear planetary drive by the particle swarm optimization algorithm for constrained multi-objective optimization. As there is objective error in engineering, on the basis of seven factors, nine levels of uniform design and the look mesh characteristics of SNR calculation,We take the most robust design as the final stage from the Pareto which the multi-objective robust design principle is in. By the analysis of the results of the program in the objective function ( volume function and the modification error function) to the sensitivity of the various design varia-bles, it concluded that the most sensitive factors of the objective function and their impact on the objective function which can be used to guide the development of tolerance and the actual processing.%采用粒子群优化算法对摆线针轮行星传动进行约束多目标优化设计,求出满足约束条件的Pa-reto解集。考虑工程实际中误差的客观存在,进行了7因素9水平的均匀试验设计及望目特性的信噪比计算,在此基础上,依据多目标稳健优化设计原理在Pareto解集中选择最稳健的设计做为最终方案。分析了结果方案中目标函数(体积函数和修形误差函数)对各个设计变量的灵敏度,得出了目标函数最为敏感的因素及各因素对目标函数的影响程度用于指导公差的制定和实际加工制造。

  20. ESTEC/Geovusie/ILEWG planetary student design workshop: a teacher training perspective

    Science.gov (United States)

    Preusterink, Jolanda; Foing, Bernard H.; Kaskes, Pim

    An important role for education is to inform and create the right skills for people to develop their own vision, using their talents to the utmost and inspire others to learn to explore in the future. Great effort has been taken to prepare this interactive design workshop thoroughly. Three days in a row, starting with presentations of Artscience The Hague to ESA colleagues, followed by a Planetary research Symposium in Amsterdam and a student design workshop at the end complemented a rich environment with the focus on Planetary exploration. The design workshop was organised by GeoVUsie students, with ESTEC and ILEWG support for tutors and inviting regional and international students to participate in an interactive workshop to design 5 Planetary Missions, with experts sharing their expertise and knowhow on specific challenging items: 1. Mercury - Post BepiColombo (with Sébastien Besse, ESA) 2. Moon South Pole Mission (with Bernard Foing, ESA) 3. Post-ExoMars - In search for Life on Mars (with Jorge Vago, ESA) 4. Humans in Space - Mars One investigated(with Arno Wielders, Space Horizon) 5. Europa - life on the icy moon of Jupiter? (with Bert Vermeersen, TU Delft) Lectures were given for more than 150 geology students at the symposium “Moon, Mars and More” at VU university, Amsterdam (organized by GeoVUsie earth science students). All students were provided with information before and at start for designing their mission. After the morning session there was a visit to the exhibition at The Erasmus Facility - ESTEC to inspire them even more with real artifacts of earlier and future missions into space. After this visit they prepared their final presentations, with original results, with innovative ideas and a good start to work out further in the future. A telescope session for geology students had been organized indoor due to rain. A follow-up visit to the nearby public Copernicus observatory was planned for another clear sky occasion. The interactive character

  1. Vibration Based Sun Gear Damage Detection

    Science.gov (United States)

    Hood, Adrian; LaBerge, Kelsen; Lewicki, David; Pines, Darryll

    2013-01-01

    Seeded fault experiments were conducted on the planetary stage of an OH-58C helicopter transmission. Two vibration based methods are discussed that isolate the dynamics of the sun gear from that of the planet gears, bearings, input spiral bevel stage, and other components in and around the gearbox. Three damaged sun gears: two spalled and one cracked, serve as the focus of this current work. A non-sequential vibration separation algorithm was developed and the resulting signals analyzed. The second method uses only the time synchronously averaged data but takes advantage of the signal/source mapping required for vibration separation. Both algorithms were successful in identifying the spall damage. Sun gear damage was confirmed by the presence of sun mesh groups. The sun tooth crack condition was inconclusive.

  2. Hydrodynamic lubrication characteristics of planet gear thrust washer used in high-speed planetary transmission%高转速行星齿轮止推垫圈流体动压润滑特性

    Institute of Scientific and Technical Information of China (English)

    王宏伟; 马彪; 赵喜敬; 郑长松

    2012-01-01

    以直齿行星排的行星轮止推垫圈为对象,为了减小其与行星齿轮之间因轴向力而导致的磨损,通过对止推垫圈加工径向沟槽的方法,对其进行流体动压润滑设计,使止推垫圈与行星轮间有相对运动时产生流体动压承载力,从而使两者之间实现非接触而减小磨损.因结构的对称性,允许正反向旋转且加工容易而选择径向直线矩形槽.建立了定常雷诺方程的模型,应用有限体积法对其进行离散求解.分析了槽数、槽宽比、槽深和径向宽度等结构参数对垫圈流体动压力承载性能、润滑油流量和温升的影响规律.考虑到工程应用,着重对较少油槽数量(2 ~12)情况下的润滑特性进行了分析.结果表明:槽数约为20时,油膜具备最大的承载力;油槽数量介于10 ~60时具备较大的承载力;槽区角度与周期槽角度之比约为0.5时具有最佳承载力,径向宽度越大则承载力越大;槽数越多、槽深越大、径向宽度越大,流量越大,反之减小;槽宽比增大能使流量减小;降低润滑油温升的措施为增加垫圈槽数、增大径向宽度,使槽深处于10~40 μm.%For the washer in planetary transmission with spur gears, in order to reduce wear between the thrust washer and planet gear due to the force in the axis direction, hydrodynamic lubrication design was presented by machining rectangular grooves in the radial direction into one side of thrust washer. Such grooves can result in a hydrodynamic pressure to separate the contact surfaces and reduce the wear accordingly when there is a relative movement between the planet gear and thrust washer. Rectangular grooves were chosen due to their symmetrical structure, two rotational directions and easily to be machined. A steady Reynolds equation was set up and the finite volume method(FVM) was used to obtain its numerical solutions. The effects of number of grooves, ratio of groove angle to periodic groove

  3. Modern gear production

    CERN Document Server

    Watson, H J

    1970-01-01

    Modern Gear Production focuses on the processes and methods in gear making. The book first gives information on the history of gear making and types of gears. Topics such as the classification of gears based on the disposition of their shafts; shafts lying in the same plane with axes intersecting; and shafts lying in parallel planes but with axes inclined to one another are then discussed. The text describes gear groups, tooth forms, and gear materials. Heat treatment of steels, casehardening, nitriding, induction hardening, sulfinuzing, and flame hardening are explained. The book takes a look

  4. Electromechanical integrated magnetic gear

    OpenAIRE

    Xiu-hong Hao; Hong-fei Zhang; Ji-de Men

    2016-01-01

    This study proposes a new type of magnetic gear, namely, the electromechanical integrated magnetic gear, that integrates the traditional field-modulated magnetic gear, drive, and control. The topology and operating principle of the electromechanical integrated magnetic gear are described in detail in this article, and the constraints of parameter design and speed ratio of electromechanical integrated magnetic gear are presented. Moreover, magnetic field distribution is analyzed with the finit...

  5. 一种特殊W-W型的2K-H差动轮系的应用探究%Application of a Special W-W Type of 2 K-H Differential Gear Train

    Institute of Scientific and Technical Information of China (English)

    丁渭渭; 王振鹏; 刘航; 李耀; 赵悟

    2015-01-01

    为研究W-W型的2K-H差动轮系在实际应用中所要考虑的因素。以双中心轮输入行星架输出的特殊差动轮系为例,通过建立数学模型并应用运动学以及动力学方程进行分析,得出该特殊差动轮系系统的输入速度敏感度、传动效率等特性参数,为实际应用提供理论依据。%In order to find factors to take into account in the practical application of W-W style of 2K-H differential gear train, a special W-W style of 2K-H differential gear train which has double center-wheel input and planet carrier output is analyzed in this paper, and through building the mathematical model and studying on the kinematics and dynamics equations, the characteristic parameters such as the input speed sensitivity and the transmission efficiency are obtained. They can be used as a reference and a basis for the future application of the special differential gear train.

  6. Changing gear

    Energy Technology Data Exchange (ETDEWEB)

    Scott-Smith, P. [P.A.L. Management, Dunrobin, ON (Canada)

    1997-11-01

    Experiences learned during the past ten years in marketing geothermal heat pumps were recalled and future actions to increase market penetration for this technology were considered. According to this speaker, the events of the last ten years have clearly demonstrated that technology development, however desirable in socio-economic terms, is only as good as the ability to market and deliver the product in an efficient and cost effective manner. Studies over the past two years have revealed an almost universal distrust of energy and water service providers, the scarcity of reliable information and advice on technology options, and high levels of skepticism among contractors about most of the modern and environmentally-preferred technology options. Based on this evidence, it was concluded that there is an urgent need for the environmentally-preferred technology industry to `change gears`, to reassess its marketing and service delivery practices towards a more consumer-friendly process that includes education, information and guidance. It was emphasized that if energy use efficiency and responsible environmental management is to become a legitimate option for the consideration of consumers it must be freed from the hands of opportunistic service providers, and be backstopped by a dedicated approach to marketing, management and consumer relations.

  7. Planetary Gearbox Fault Detection Using Vibration Separation Techniques

    Science.gov (United States)

    Lewicki, David G.; LaBerge, Kelsen E.; Ehinger, Ryan T.; Fetty, Jason

    2011-01-01

    Studies were performed to demonstrate the capability to detect planetary gear and bearing faults in helicopter main-rotor transmissions. The work supported the Operations Support and Sustainment (OSST) program with the U.S. Army Aviation Applied Technology Directorate (AATD) and Bell Helicopter Textron. Vibration data from the OH-58C planetary system were collected on a healthy transmission as well as with various seeded-fault components. Planetary fault detection algorithms were used with the collected data to evaluate fault detection effectiveness. Planet gear tooth cracks and spalls were detectable using the vibration separation techniques. Sun gear tooth cracks were not discernibly detectable from the vibration separation process. Sun gear tooth spall defects were detectable. Ring gear tooth cracks were only clearly detectable by accelerometers located near the crack location or directly across from the crack. Enveloping provided an effective method for planet bearing inner- and outer-race spalling fault detection.

  8. Bearings and gears for advanced turbine engines and transmissions

    Science.gov (United States)

    Parker, R. J.

    1975-01-01

    The improved technology is discussed of engine main-shaft ball bearings, and spur gears in power transmission drive trains. Much of the technology can be applied to other ball and roller bearings, and to other spur and bevel gears throughout the engine, drive train, and accessory systems.

  9. Modular gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2009-01-01

    A gearing system using modular gear bearing components. Each component is composed of a core, one or more modules attached to the core and two or more fastening modules rigidly attaching the modules to the core. The modules, which are attached to the core, may consist of gears, rollers or gear bearing components. The core orientation affects the orientation of the modules attached to the core. This is achieved via the keying arrangement of the core and the component modules that attach to the core. Such an arrangement will also facilitate the phase tuning of gear modules with respect to the core and other gear modules attached to the core.

  10. Kinematic geometry of gearing

    CERN Document Server

    Dooner, David B

    2012-01-01

    Building on the first edition published in 1995 this new edition of Kinematic Geometry of Gearing has been extensively revised and updated with new and original material. This includes the methodology for general tooth forms, radius of torsure', cylinder of osculation, and cylindroid of torsure; the author has also completely reworked the '3 laws of gearing', the first law re-written to better parallel the existing 'Law of Gearing" as pioneered by Leonard Euler, expanded from Euler's original law to encompass non-circular gears and hypoid gears, the 2nd law of gearing describing a unique relat

  11. Anti-backlash gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2009-01-01

    A gear bearing having a first gear and a second gear, each having a plurality of teeth. Each gear operates on two non-parallel surfaces of the opposing gear teeth to perform both gear and bearing functions simultaneously. The gears are moving at substantially the same speed at their contact points. The gears may be roller gear bearings or phase-shifted gear bearings, and may be arranged in a planet/sun system or used as a transmission. One preferred embodiment discloses and describes an anti-backlash feature to counter ''dead zones'' in the gear bearing movement.

  12. A method of gear defect intelligent detection based on transmission noise

    Science.gov (United States)

    Chen, Hong-fang; Zhao, Yun; Lin, Jia-chun; Guo, Mian

    2015-02-01

    A new approach was proposed by combing Ensemble Empirical Mode Decomposition (EEMD) algorithm and Back Propagation (BP) neural network for detection of gear through transmission noise analysis. Then feature values of the feature signals are calculated. The feature values which have a great difference for different defect types are chosen to build an eigenvector. BP neural network is used to train and learn on the eigenvector for recognition of gear defects intelligently. In this study, a comparative experiment has been performed among normal gears, cracked gears and eccentric gears with fifteen sets of different gears. Experimental results indicate that the proposed method can detect gear defect features carried by the transmission noise effectively.

  13. The Application and Design of a Differential Gear Train in the Turnover Mechanisms%差动轮系在翻转机构中的应用与分析

    Institute of Scientific and Technical Information of China (English)

    杨通胜; 张宗峰; 李玉朋

    2014-01-01

    在工程实际中,为了满足各种不同传动的需求,大多数情况下,采用一系列彼此啮合的齿轮来实现传动。本文以差动轮系为例,介绍差动轮系在翻转机构的应用,并用ADAMS软件验证可行性,为以后的优化设计提供理论依据。%In engineering practice ,in order to meet the needs of a variety of different transmissions , in most cases ,the transmissions is realized by using a series of meshing gears to each other .Take the dif-ferential gear train as an example ,introduces the application of the differential gear train in the turnover mechanisms ,the simulation results of this software proved the feasibility of design ,and guaranteed fur-ther improve ment of design .

  14. Roller-gear drives for robotic manipulators design, fabrication and test

    Science.gov (United States)

    Anderson, William J.; Shipitalo, William

    1991-09-01

    Two single axis planetary roller-gear drives and a two axis roller-gear drive with dual inputs were designed for use as robotic transmissions. Each of the single axis drives is a two planet row, four planet arrangement with spur gears and compressively loaded cylindrical rollers acting in parallel. The two axis drive employs bevel gears and cone rollers acting in parallel. The rollers serve a dual function: they remove backlash from the system, and they transmit torque when the gears are not fully engaged.

  15. Two stage gear tooth dynamics program

    Science.gov (United States)

    Boyd, Linda S.

    1989-01-01

    The epicyclic gear dynamics program was expanded to add the option of evaluating the tooth pair dynamics for two epicyclic gear stages with peripheral components. This was a practical extension to the program as multiple gear stages are often used for speed reduction, space, weight, and/or auxiliary units. The option was developed for either stage to be a basic planetary, star, single external-external mesh, or single external-internal mesh. The two stage system allows for modeling of the peripherals with an input mass and shaft, an output mass and shaft, and a connecting shaft. Execution of the initial test case indicated an instability in the solution with the tooth paid loads growing to excessive magnitudes. A procedure to trace the instability is recommended as well as a method of reducing the program's computation time by reducing the number of boundary condition iterations.

  16. Gear bearing drive

    Science.gov (United States)

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  17. 单向驱动非圆齿轮差动轮系实现可调摆幅输出的研究%Study on Realizing of Adjustable Swing Output with Unidirectional Drive Non-circular Differential Gear Train

    Institute of Scientific and Technical Information of China (English)

    孙以涛; 王生泽

    2013-01-01

    A method of noncircular gear-circular gear differential gear train with unidirectional drive that could realize adjustable swing output is proposed,the condition that non-circular isn't concave is discussed,and suitable non-circular pitch curve and non-circular differential gear train are designed under this condition.Through simulation analysis different swing amplitude output can be obtained by changing the unidirectional servo drive input reasonably,especially the swing center movement of the swing output,the purpose of acquiring the adjustable output swing amplitude with unidirectional servo drive can be achieved.%提出了一种单向驱动非圆齿轮——圆齿轮差动轮系实现可调摆幅输出的方案;讨论了非圆齿轮不出现凹形的条件,并在此条件下设计出合适的非圆齿轮节曲线及非圆齿轮差动轮系;通过仿真分析合理改变单向伺服驱动输入运动规律可获得不同摆动幅值的输出,尤其是摆动中心运动的摆动输出,以达到伺服电机直接单向驱动便能实现摆幅可调输出的目的.

  18. A review of dynamics modelling of friction draft gear

    Science.gov (United States)

    Wu, Qing; Cole, Colin; Luo, Shihui; Spiryagin, Maksym

    2014-06-01

    Longer and heavier trains mean larger in-train forces and more complicated force patterns. Practical experience indicates that the development of fatigue failure of coupling systems in long heavy trains may differ from conventional understanding. The friction-type draft gears are the most widely used draft gears. The ever developing heavy haul transport environment requires further or new understanding of friction draft gear behaviour and its implications for train dynamics as well as fatigue damage of rolling stock. However, modelling of friction draft gears is a highly nonlinear question. Especially the poor predictability, repeatability and the discontinuity of friction make this task more challenging. This article reviews current techniques in dynamics modelling of friction draft gears to provide a starting point that can be used to improve existing or develop new models to achieve more accurate force amplitude and pattern predictions.

  19. Bevel gear driver and method having torque limit selection

    Science.gov (United States)

    Cook, Joseph S., Jr. (Inventor)

    1994-01-01

    This invention comprises a torque drive mechanism utilizing axially translatable, mutually engageable transmission members having mating crown gears, driven and driving members with a three-element drive train being biased together by resilient means or by a fluid actuator system, the apparatus being operable to transmit a precisely controlled degree of torque to a driven member. The apparatus is applicable for use in hand tools and as a replacement for impact torque drivers, torque wrenches, motorized screw drivers, or the like, wherein the applied torque must be precisely controlled or limited. The bevel torque drive includes a drive gear which is axially displaceable and rotatable within cylindrical driver housing, a rotatable intermediate gear, and an output gear. Key rotationally secures displaceable gear with respect to input shaft but permits axial movement therebetween. A thrust bearing is preferably connected to the lower end of shaft for support to reduce play and friction between shaft and a transmission joint disc during rotation of the gear train. Coaxially mounted coiled spring is footed against displaceable gear for biasing the displaceable gear toward and into engagement with the intermediate gear for driving intermediate gear and output gear. Torque control is achieved by the use of straight or spiral beveled gears which are of configurations adapted to withdraw from mutual engagement upon the torque exceeding a predetermined limit. The novel, advantageous features of the invention include the configuration of the mating, crown gear sets and the axially translatable, slidable drive gear. The mechanism is capable of transmitting a high degree of torque within a narrow, compact transmission housing. The compact size and narrow, elongated configuration of the housing is particularly applicable for use in hand tools and in multiple torque driver mechanisms in which it is necessary to drive multiple fasteners which are located in close proximity. Prior

  20. Landing gear noise attenuation

    Science.gov (United States)

    Moe, Jeffrey W. (Inventor); Whitmire, Julia (Inventor); Kwan, Hwa-Wan (Inventor); Abeysinghe, Amal (Inventor)

    2011-01-01

    A landing gear noise attenuator mitigates noise generated by airframe deployable landing gear. The noise attenuator can have a first position when the landing gear is in its deployed or down position, and a second position when the landing gear is in its up or stowed position. The noise attenuator may be an inflatable fairing that does not compromise limited space constraints associated with landing gear retraction and stowage. A truck fairing mounted under a truck beam can have a compliant edge to allow for non-destructive impingement of a deflected fire during certain conditions.

  1. Estimating Gear Teeth Stiffness

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2013-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation...... and secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffness’s of gears are highly non-linear, it is however found that the stiffness of an individual tooth can be expressed in a linear form assuming that the contact length is constant....

  2. 两级行星齿轮传动非线性啮合力频率耦合与动态特性研究%Frequency coupling and dynamic characteristics of nonlinear meshing force for two-stage planetary gears

    Institute of Scientific and Technical Information of China (English)

    刘辉; 蔡仲昌; 项昌乐

    2015-01-01

    Based on Lagrange's equation,the translational-torsional coupled nonlinear dynamic model of two stage planetary gears was established considering backlash,time-varying mesh stiffness and its phase difference,gear mesh composite errors,time-varying planet wheel position angle,and torsional and bending stiffnesses of connectors among different stages.According to the relationship among torques of connection shafts and vibration displacements of parts,the meshing frequency coupling phenomenon of mesh force for different stages was studied.Under different excitation conditions,the forms of meshing frequency coupling were analyzed.At the same time,the dynamic load coefficient and the load sharing coefficient of meshing force for different stages,and the dynamic characteristics of torques of connection shafts were calculated.The results provided a reference for design and dynamic analysis of multi-stage planetary gears.%利用拉格朗日方程推导了两级行星齿轮传动的平移-扭转非线性振动模型,模型考虑了齿侧间隙、时变啮合刚度及其相位差、综合啮合误差、行星轮位置角时变性以及各行星排级间连接件的弯曲和扭转刚度。从行星排级间连接轴的力与变形耦合关系出发,研究了两个行星排啮合力产生的啮合频率耦合现象。通过数值仿真对不同激励条件下啮合频率耦合的表现形式进行了研究,对不同行星排的动载系数、均载系数、连接轴转矩的动态特性进行了分析,为多级行星齿轮传动系统动力学分析与设计提供指导。

  3. DEFINITION OF THE GEAR’S GEOMETRY IN THE PLANETARY CYCLOIDAL TRANSMISSION

    Directory of Open Access Journals (Sweden)

    Sławomir BEDNARCZYK

    2014-03-01

    Full Text Available In the paper, the design and operation of the planetary cycloidal transmission have been discussed. The transmission is a synthesis of the planetary and the straight-line mechanism. The planetary mechanism is made of a planetary gear set with rollers, which is critical for the proper work of the transmission. Its basic and most important element is the planetary cycloidal gear. Influence of the parameters determining the cycloidal profile of the gear on the gear’s geometry and the forces has been presented. The straight-line mechanism carrying the motion from the driving onto the driven unit of the transmission is made of the pins and bushes located in the holes of the planetary gears. The influence of the number and geometry of the elements on the forces and occuring in the holes of the planetary gears has been presented. Therefore, the properly defined geometry of the gear and of the material of which the gear is made is crucial for the safe operation of the planetary cycloidal transmission.

  4. Ultrasonic test of highly stressed gear shafts

    Energy Technology Data Exchange (ETDEWEB)

    Schreiner, T. [Siemens AG, Power Generation, KWU, Muelheim (Germany); Heinrich, W. [Siemens AG, Power Generation, KWU, Berlin (Germany); Achtzehn, J. [Siemens AG, Power Generation, ICVW, Erlangen (Germany); Hensley, H. [Siemens Power Generation (Germany)

    1998-12-31

    In the power plant industry, gears are used for increasingly higher turbine capacities. Efficiency enhancements, particularly for the combined gas and steam turbine process, lead to an increase in stresses, even for high-performance gears. Consequently, the requirements for non-destructive material testing are on the increase as well. At Siemens KWU, high-performance gears are used so far only for gas turbines with lower rating (65 MW) to adapt the gas turbine speed (5413 rpm) to the generator speed (3000 rpm/ 50 Hz or 3600 rpm/60 Hz). The gear train consists of a forged and case-hardened wheel shaft and pinion shaft made of material 17 CrNiMo 6, where the wheel shaft can be either a solid or a hollow shaft. Dimensions are typically 2.3 m length and 1 m diameter. As a rule, pinion shafts are solid. The gear design, calling for an additional torsion shaft turning inside the hollow wheel shaft, can absorb more torsional load surges and is more tolerant of deviations during gear train alignment. This design requires two additional forgings (torsion shaft and hub) and an additional bearing 2 refs.

  5. An investigation on development of the planetary gearheads for small precision mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joo Han; Chung, Jung Kee; Sung, Ha Kyeong [Korea Electronics Technology Institute, Seongnam (Korea, Republic of)

    2003-07-01

    Planetary gearheads are widely used in the transmissions of small precision mechanism, automation, robotics, heavy machinery and marine vehicles. Planetary gearheads have advantages that same-axle structure, high torque transmission, low noise in comparison with spur gearheads. And, planetary gearheads are typically specified in applications where space is limited. In this study included planetary type gearheads design, manufacture, efficiency test. Especially, this time performed gear mesh stiffness simulation and vibration analysis for planetary gearheads.

  6. 50 CFR 665.127 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Fisheries § 665.127 Allowable gear and gear restrictions. (a) American Samoa coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun;...

  7. 50 CFR 665.427 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Archipelago Fisheries § 665.427 Allowable gear and gear restrictions. (a) Mariana coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3)...

  8. 50 CFR 665.227 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Allowable gear and gear restrictions. 665... Fisheries § 665.227 Allowable gear and gear restrictions. (a) Hawaii coral reef ecosystem MUS may be taken only with the following allowable gear and methods: (1) Hand harvest; (2) Spear; (3) Slurp gun;...

  9. Preparing Graduate Students for Solar System Science and Exploration Careers: Internships and Field Training Courses led by the Lunar and Planetary Institute

    Science.gov (United States)

    Shaner, A. J.; Kring, D. A.

    2015-12-01

    To be competitive in 21st century science and exploration careers, graduate students in planetary science and related disciplines need mentorship and need to develop skills not always available at their home university, including fieldwork, mission planning, and communicating with others in the scientific and engineering communities in the U.S. and internationally. Programs offered by the Lunar and Planetary Institute (LPI) address these needs through summer internships and field training programs. From 2008-2012, LPI hosted the Lunar Exploration Summer Intern Program. This special summer intern program evaluated possible landing sites for robotic and human exploration missions to the lunar surface. By the end of the 2012 program, a series of scientifically-rich landing sites emerged, some of which had never been considered before. Beginning in 2015 and building on the success of the lunar exploration program, a new Exploration Science Summer Intern Program is being implemented with a broader scope that includes both the Moon and near-Earth asteroids. Like its predecessor, the Exploration Science Summer Intern Program offers graduate students a unique opportunity to integrate scientific input with exploration activities in a way that mission architects and spacecraft engineers can use. The program's activities may involve assessments and traverse plans for a particular destination or a more general assessment of a class of possible exploration targets. Details of the results of these programs will be discussed. Since 2010 graduate students have participated in field training and research programs at Barringer (Meteor) Crater and the Sudbury Impact Structure. Skills developed during these programs prepare students for their own thesis studies in impact-cratered terrains, whether they are on the Earth, the Moon, Mars, or other solar system planetary surface. Future field excursions will take place at these sites as well as the Zuni-Bandera Volcanic Field. Skills

  10. Zero torque gear head wrench

    Science.gov (United States)

    Mcdougal, A. R.; Norman, R. M. (Inventor)

    1976-01-01

    A gear head wrench particularly suited for use in applying torque to bolts without transferring torsional stress to bolt-receiving structures is introduced. The wrench is characterized by a coupling including a socket, for connecting a bolt head with a torque multiplying gear train, provided within a housing having an annulus concentrically related to the socket and adapted to be coupled with a spacer interposed between the bolt head and the juxtaposed surface of the bolt-receiving structure for applying a balancing counter-torque to the spacer as torque is applied to the bolt head whereby the bolt-receiving structure is substantially isolated from torsional stress. As a result of the foregoing, the operator of the wrench is substantially isolated from any forces which may be imposed.

  11. Electromechanical integrated magnetic gear

    Directory of Open Access Journals (Sweden)

    Xiu-hong Hao

    2016-06-01

    Full Text Available This study proposes a new type of magnetic gear, namely, the electromechanical integrated magnetic gear, that integrates the traditional field-modulated magnetic gear, drive, and control. The topology and operating principle of the electromechanical integrated magnetic gear are described in detail in this article, and the constraints of parameter design and speed ratio of electromechanical integrated magnetic gear are presented. Moreover, magnetic field distribution is analyzed with the finite element method. Subsequently, the harmonics of the magnetic field and the electromagnetic torque are calculated. The static torques on all the components are exhibited by finite element method and torque test. The effects of the design parameters on the torques and the torque densities are discussed, and the results show that electromechanical integrated magnetic gear has a high speed ratio and can generate a high torque at low speed. The maximum torques are affected by air-gap thickness and other parameters.

  12. Fuze Gear-Train Analysis

    Science.gov (United States)

    1979-12-01

    A-86) is given by F3in 2 ) - 23co(2- 2) F 12u"n(Pl +1) + Aa 1F 12 00s( 1 + 01) + T2 cosv 2 - Fx2 + AFY 2 .0 (A-88) -F- 02) - Fs2F2 3 sin(#12...before, i.e., C * = sin" -- See Equation (D-2)a i I~ P y sin- - See Equation (D-5) a "• - 8 See Equation (D-6) f a cosv See Equation (D-7) Imin --. - v

  13. Customized Multiwavelets for Planetary Gearbox Fault Detection Based on Vibration Sensor Signals

    Directory of Open Access Journals (Sweden)

    Lue Chen

    2013-01-01

    Full Text Available Planetary gearboxes exhibit complicated dynamic responses which are more difficult to detect in vibration signals than fixed-axis gear trains because of the special gear transmission structures. Diverse advanced methods have been developed for this challenging task to reduce or avoid unscheduled breakdown and catastrophic accidents. It is feasible to make fault features distinct by using multiwavelet denoising which depends on the feature separation and the threshold denoising. However, standard and fixed multiwavelets are not suitable for accurate fault feature detections because they are usually independent of the measured signals. To overcome this drawback, a method to construct customized multiwavelets based on the redundant symmetric lifting scheme is proposed in this paper. A novel indicator which combines kurtosis and entropy is applied to select the optimal multiwavelets, because kurtosis is sensitive to sharp impulses and entropy is effective for periodic impulses. The improved neighboring coefficients method is introduced into multiwavelet denoising. The vibration signals of a planetary gearbox from a satellite communication antenna on a measurement ship are captured under various motor speeds. The results show the proposed method could accurately detect the incipient pitting faults on two neighboring teeth in the planetary gearbox.

  14. Customized multiwavelets for planetary gearbox fault detection based on vibration sensor signals.

    Science.gov (United States)

    Sun, Hailiang; Zi, Yanyang; He, Zhengjia; Yuan, Jing; Wang, Xiaodong; Chen, Lue

    2013-01-18

    Planetary gearboxes exhibit complicated dynamic responses which are more difficult to detect in vibration signals than fixed-axis gear trains because of the special gear transmission structures. Diverse advanced methods have been developed for this challenging task to reduce or avoid unscheduled breakdown and catastrophic accidents. It is feasible to make fault features distinct by using multiwavelet denoising which depends on the feature separation and the threshold denoising. However, standard and fixed multiwavelets are not suitable for accurate fault feature detections because they are usually independent of the measured signals. To overcome this drawback, a method to construct customized multiwavelets based on the redundant symmetric lifting scheme is proposed in this paper. A novel indicator which combines kurtosis and entropy is applied to select the optimal multiwavelets, because kurtosis is sensitive to sharp impulses and entropy is effective for periodic impulses. The improved neighboring coefficients method is introduced into multiwavelet denoising. The vibration signals of a planetary gearbox from a satellite communication antenna on a measurement ship are captured under various motor speeds. The results show the proposed method could accurately detect the incipient pitting faults on two neighboring teeth in the planetary gearbox.

  15. CVT封闭的2K-H型差动轮系啮合效率分析%Meshing efficiency analysis of 2K-H type differential gear train closed by CVT

    Institute of Scientific and Technical Information of China (English)

    黄云峰

    2012-01-01

    For the problem that power circulation and low efficiency easily occur in closed Continuously Variable Transmission (CVT) ,the input-coupled CVT drive system was taken as the object of study, the fundamental structure and working principle of the input-coupled CVT drive system were briefly introduced.Without loss of energy in the input-coupled CVT drive system,the sufficient condition for the input-coupled CVT drive system to realize power split was deduced in detail.Next,under the sufficient condition, the meshing efficiency expression for the 2K-H type differential gear train acting as power confluence in the input-coupled CVT drive system was simplified, and the factors related to meshing efficiency of the 2K-H type differential gear train such as the structural parameter and motion state of input components were obtained.The conditions for meshing efficiency of the 2K-H type differential gear train to be maximized were demonstrated.Finally ,the conditions of maximum meshing efficiency for the 2K-H type differential gear train were verified by analyzing the examples.The results show that the conditions of maximum meshing efficiency ensure the highest meshing efficiency of the 2K-H type differential gear train from thedesign point of view.The idea of maximizing the meshing efficiency analysis of the 2K-H type differentialgear train is an effective design approach.%针对封闭式无级变速器内部容易发生功率循环而造成效率降低的问题,以输入耦合CVT(Continuously Variable Transmission)传动系统为研究对象,简单地介绍了其基本结构及工作原理,在无能量损失的理想状态下详细推导了该传动系统实现功率分流的充分条件.其次,在该充分条件下简化了输入耦合CVT传动系统中起汇流作用的2K-H型差动轮系啮合效率表达式,得到了影响啮合效率的输入构件结构参数和运动状态等因素,求证了其获得最大值的条件.最后,通过实例验证了所得到的2K-H

  16. 2K-V型摆线针轮减速器传动系统的动态特性分析%Dynamic Characteristics Analysis of 2K - V Planetary Gears Train with Cycloid Gears

    Institute of Scientific and Technical Information of China (English)

    戚厚军; 孙涛; 刘继岩; 李充宁

    2004-01-01

    建立了2K-V型摆线针轮减速器的动力学模型.以2K-V6型摆线针轮减速器为研究对象,在不改变减速器的外形尺寸和结构的情况下,分析了摆线轮修形和短幅系数对摆线轮啮合刚度的影响规律,以及传动系统中的各种刚度和针径系数对整机振动性能的影响.

  17. 椭圆齿轮行星系分插机构推秧装置的动力学模型的建立及验证%Establishment and verification of dynamics model of seedling-pushing device in transplanting mechanism with planetary elliptic gears

    Institute of Scientific and Technical Information of China (English)

    陈建能; 赵匀; 俞高红; 张国凤; 李革

    2003-01-01

    In order to set up the dynamics model of the transplanting mechanism with planetary elliptic gears of high-speed rice transplanter, the effect of seedling-pushing device on it must be analyzed. In this paper, the dynamics characteristics of seedling-pushing device were analyzed by method which was derived by authors. The method is analytical form differential equations of rigid body compound motion. As a result, the dynamics model of seedling-pushing device was deduced. By programming calculation, some conclusions were drawn: ①the relationship between the angle of gears trunk and the angle of shifter and the position of seedling-pushing rod in the course of seedling-pushing and collision, which were tested and verified by high-speed Video Tape Recorder; ②the relationship between the angle of gears trunk and the bearing force of spring, shifter shaft and seedling-pushing rod in the course of seedling-pushing and collision. These conclusions provide basis to analyze this kind of transplanting mechanism.%为了建立高速水稻插秧机椭圆齿轮行星系分插机构的动力学模型,必须分析推秧装置对该机构的作用.该文采用作者推导的解析形式刚体复合运动微分方程对该机构的推秧装置进行动力学分析,推导出推秧装置的动力学模型.通过编程计算得到:①推秧和碰撞过程行星架转角与拨叉转角及推秧杆位置的关系,并由高速录像验证;②在推秧和碰撞过程拨叉转动中心受力、推秧杆对栽植臂作用力和弹簧作用力与行星架转角的关系,为分析整个分插机构的动力学特性奠定基础.

  18. Planetary Radar

    Science.gov (United States)

    Neish, Catherine D.; Carter, Lynn M.

    2015-01-01

    This chapter describes the principles of planetary radar, and the primary scientific discoveries that have been made using this technique. The chapter starts by describing the different types of radar systems and how they are used to acquire images and accurate topography of planetary surfaces and probe their subsurface structure. It then explains how these products can be used to understand the properties of the target being investigated. Several examples of discoveries made with planetary radar are then summarized, covering solar system objects from Mercury to Saturn. Finally, opportunities for future discoveries in planetary radar are outlined and discussed.

  19. Gear Crack Propagation Investigation

    Science.gov (United States)

    1995-01-01

    Reduced weight is a major design goal in aircraft power transmissions. Some gear designs incorporate thin rims to help meet this goal. Thin rims, however, may lead to bending fatigue cracks. These cracks may propagate through a gear tooth or into the gear rim. A crack that propagates through a tooth would probably not be catastrophic, and ample warning of a failure could be possible. On the other hand, a crack that propagates through the rim would be catastrophic. Such cracks could lead to disengagement of a rotor or propeller from an engine, loss of an aircraft, and fatalities. To help create and validate tools for the gear designer, the NASA Lewis Research Center performed in-house analytical and experimental studies to investigate the effect of rim thickness on gear-tooth crack propagation. Our goal was to determine whether cracks grew through gear teeth (benign failure mode) or through gear rims (catastrophic failure mode) for various rim thicknesses. In addition, we investigated the effect of rim thickness on crack propagation life. A finite-element-based computer program simulated gear-tooth crack propagation. The analysis used principles of linear elastic fracture mechanics, and quarter-point, triangular elements were used at the crack tip to represent the stress singularity. The program had an automated crack propagation option in which cracks were grown numerically via an automated remeshing scheme. Crack-tip stress-intensity factors were estimated to determine crack-propagation direction. Also, various fatigue crack growth models were used to estimate crack-propagation life. Experiments were performed in Lewis' Spur Gear Fatigue Rig to validate predicted crack propagation results. Gears with various backup ratios were tested to validate crack-path predictions. Also, test gears were installed with special crack-propagation gages in the tooth fillet region to measure bending-fatigue crack growth. From both predictions and tests, gears with backup ratios

  20. Partial tooth gear bearings

    Science.gov (United States)

    Vranish, John M. (Inventor)

    2010-01-01

    A partial gear bearing including an upper half, comprising peak partial teeth, and a lower, or bottom, half, comprising valley partial teeth. The upper half also has an integrated roller section between each of the peak partial teeth with a radius equal to the gear pitch radius of the radially outwardly extending peak partial teeth. Conversely, the lower half has an integrated roller section between each of the valley half teeth with a radius also equal to the gear pitch radius of the peak partial teeth. The valley partial teeth extend radially inwardly from its roller section. The peak and valley partial teeth are exactly out of phase with each other, as are the roller sections of the upper and lower halves. Essentially, the end roller bearing of the typical gear bearing has been integrated into the normal gear tooth pattern.

  1. Gear noise origins

    Science.gov (United States)

    Mark, W. D.

    1985-01-01

    Each pair of meshing gears in a transmission gives rise to a source of vibratory excitation that can result in the radiation of sound. Each such source is most conveniently characterized as a displacement form of excitation generally referred to as the static transmission error of the gear pair. Contributions to the frequency spectrum of the static transmission error of spur and helical gears arising from tooth and gear body elastic deformations and from deviations of tooth surfaces from perfect involute surfaces are considered. Tooth surface deviations are decomposed into contributions giving rise to tooth meshing harmonic excitations and rotational harmonic or sideband excitations. Various types of gear tooth errors are defined and the contributions of these errors to different parts of the frequency spectrum are described. The attenuating effect on the static transmission error spectrum arising from the smoothing action of multiple tooth contact is explained.

  2. AHP-QFD综合模式在行星齿轮减速器多目标优化设计中的应用%Research on the application of AHP-QFD comprehensive mode in multi-objective optimization design of planetary gear reducer

    Institute of Scientific and Technical Information of China (English)

    江擒虎; 胡文超; 年陈陈

    2012-01-01

    文章介绍了质量功能展开(QFD)是一种将顾客需求进行多层次的演绎与变换,最终实现基于需求的产品方案设计及技术设计方法;为了弥补QFD方法需求变换中的主观片面性,将层次分析法(AHP)引入QFD应用过程中,对需求进行分析并得到不同需求的重要度,进而进行优化设计,以行星齿轮减速器的多目标优化设计为例,验证了AHP-QFD设计方法的实用效果.%Quality function deployment (QFD) puts the customer demands into multi-level deduction and commutation, and finally realizes the product design and technical design based on customer demands. In order to make up the subjectiveness and one-sidedness of QFD method during demands commutation, the analytic hierarchy process(AHP) is introduced into QFD. Through the AHP analysis of the customer demands, the importance degree of different customer demands is obtained. Finally by taking the multi-objective optimization design of planetary gear reducer as an example, the practical effect of QFD-AHP design method is verified.

  3. 盾构机双驱动大功率行星齿轮的传动原理及特性%Gearing theory and transmission characteristic for dual drive planetary transmission system with large capacity of shield machine

    Institute of Scientific and Technical Information of China (English)

    林超; 宿新红; 秦大同

    2011-01-01

    在研究盾构机及行星齿轮机构的基础之上,针对盾构机刀盘驱动系统,提出一种新型盾构机双驱动大功率行星齿轮传动系统,分析了传动系统的原理及其结构;建立了新型传动系统的运动学模型,对该系统的传动特性进行了分析,获得了系统的传动比、系统内部的转速、扭矩的关系和变化规律;通过对比简化实验得到的结果与理论计算得到的结果,其变化规律基本一致,验证了数学模型及分析方法的正确性.双驱动大功率行星齿轮传动系统具有传动比大、承载能力强的特点,能实现低转速、大扭矩输出的功能,满足盾构机的基本工作要求,不仅可取代传统的多个电机同时驱动多个减速器的传动系统,还能实现3种不同型式的盾构机传动系统功能.%On the basis of studying shield machine and planetary transmission, to address cutting drive system of shield machine, a novel dual drive planetary transmission system with large capacity is presented, and its principle and structure are analyzed. Through establishing a new kinematical model of the transmission system and analyzing its characteristics, the transmission ratio, rev and torque relationship and changing rules within the system are acquired. By comparing the simplified experimental results with theoretical results,it is shown that the variation is basically the same, which verifies the correctness of the model and analysis method. The high-power dual-driven planetary geartransmission system with great transmission ratio, strong carrying capacity, can perform the function of low-speed and high-torque output, and meet basic requirements of shield machine. It can not only replace the traditional multi-driven transmission system, but also achieve the transmission function in three different types of shield machine.

  4. Computing Stresses In Spur Gears

    Science.gov (United States)

    Oswald, F. B.; Lin, H. H.

    1995-01-01

    Dynamic Analysis of Spur Gear Transmissions (DANST) developed as easy-to-use program for static and dynamic analysis of spur-gear systems. Used for parametric studies to predict effects of operating speed, torque, stiffness, damping, inertia, and tooth profile on dynamic loads and tooth-bending stresses in spur gears. Performs geometric modeling and dynamic analysis for low- or high-contact-ratio spur gears. Simulates gear systems with contact ratios ranging from one to three. Written in FORTRAN 77.

  5. The cycloid Permanent Magnetic Gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Andersen, Torben Ole; Jørgensen, Frank T.

    2008-01-01

    This paper presents a new permanent-magnet gear based on the cycloid gearing principle. which normally is characterized by an extreme torque density and a very high gearing ratio. An initial design of the proposed magnetic gear was designed, analyzed, and optimized with an analytical model...... regarding torque density. The results were promising as compared to other high-performance magnetic-gear designs. A test model was constructed to verify the analytical model....

  6. 弧齿锥齿轮功率分流传动系统建模与承载特性分析%Modeling and load analysis of spiral bevel gears power split system

    Institute of Scientific and Technical Information of China (English)

    谷建功; 方宗德; 庞辉; 王成

    2009-01-01

    针对齿轮功率分流的平行轴传动,星型传动和行星传动形式,提出了一种新型交叉轴传动形式的弧齿锥齿轮功率分流传动系统并介绍了其构成及工作状态.在此基础上,计算了系统各齿轮副的传递功率,分析了系统在各安装误差作用下的功率分流情况.研究表明,在输入齿轮、其相对的输出齿轮的轴交角误差或其相邻的输出齿轮的轴向误差单独影响下,系统主承载齿轮副传递的功率减小,可大大提高系统承载能力,并有利于功率分流均载;系统各齿轮都具有安装误差时,各齿轮副承载情况受误差累加或相反作用的影响.%According to different forms of gear power split transmission including parallel axes, star gear train and planetary gear train, a new type of spiral bevel gears power split system with cross axes transmission was proposed and its structure and working state was explained. The transmission powers of every gear pair in the system were then calculated, and the power split situations were analyzed under conditions of all kinds of installation errors. The results show that, in consideration of the installation errors in shaft angle of input gear and its opposite output gear or axial error of its adjacent output gear, the power transferred by main load gear pair of the system can be decreased, so the load capacity of the system is improved obviously, contributing to uniform load of the system. When every gear has different installation errors, the load situations are influenced by the error accumulation and opposition.

  7. Crankshaft gearing. Kurbelwellengetriebe

    Energy Technology Data Exchange (ETDEWEB)

    Helmer, W.; Brunner, H.

    1990-12-13

    Crankshaft gearing. In this, the driven shaft of a main engine is connected at its free end to the main shaft by an elastic coupling. The crankshaft gearing with its housing is made directly as a flanged gearing for the engine or with its housing is fixed as a separate unit independent of the engine on the same or a separate base. It is characterized by the fact that to accommodate the alternating torque of the engine a double Cardan geared spindle and a coupling damping rotary vibration are provided by its crankshaft, from which the coupling acts as a hollow shaft and to support the drive wheel and in which it is fitted in a force-locking manner.

  8. Modal Analysis of Gearbox of Spiral Bevel-gear Planetary Transmission%一种弧齿锥齿轮行星传动齿轮箱体的模态分析

    Institute of Scientific and Technical Information of China (English)

    魏冰阳; 周贺; 陈金瑞

    2013-01-01

    通过在CATIA V5 R19中建立新型弧齿锥齿轮行星传动箱体的三维实体模型,利用ANSYS对齿轮箱体仿真模态分析,得出较为合理的齿轮箱体的有限元模型.利用Block Lanczos法计算出箱体前十阶约束模态的固有频率和相应振型,为箱体后继的动态响应分析提供理论依据.运用此方法可以在箱体设计时避开齿轮箱啮合的频率,避免由于机械振动造成的箱体故障,并且为箱体的优化改进提供理论参考.%The 3-dimensional solid modal of new spiral bevel gearbox was established by using CATIA V5 R19. The gearbox simulation modal was analyzed by means of Ansys to get a better new finite element analysis model of spiral bevel gearbox. The natural frequencies and corresponding vibration modes of the first ten steps of the gear box were worked out by using Lanczos method. The dynamic response analysis of the gearbox was supplied. With that method, the engagement assigned frequency can be avoided in design. The fault of the gearbox machines created by resonance can be avoided. The theoretical reference for the optimization and improvement of the gearbox is provided.

  9. ANALYSIS METHOD OF AUTOMATIC PLANETARY TRANSMISSION KINEMATICS

    Directory of Open Access Journals (Sweden)

    Józef DREWNIAK

    2014-06-01

    Full Text Available In the present paper, planetary automatic transmission is modeled by means of contour graphs. The goals of modeling could be versatile: ratio calculating via algorithmic equation generation, analysis of velocity and accelerations. The exemplary gears running are analyzed, several drives/gears are consecutively taken into account discussing functional schemes, assigned contour graphs and generated system of equations and their solutions. The advantages of the method are: algorithmic approach, general approach where particular drives are cases of the generally created model. Moreover, the method allows for further analyzes and synthesis tasks e.g. checking isomorphism of design solutions.

  10. Communication: Molecular gears

    Science.gov (United States)

    Burnell, E. Elliott; de Lange, Cornelis A.; Meerts, W. Leo

    2016-09-01

    The 1H nuclear magnetic resonance spectrum of hexamethylbenzene orientationally ordered in the nematic liquid crystal ZLI-1132 is analysed using covariance matrix adaptation evolution strategy. The spectrum contains over 350 000 lines with many overlapping transitions, from which four independent direct dipolar couplings are obtained. The rotations of the six methyl groups appear to be correlated due to mutual steric hindrance. Adjacent methyl groups show counter-rotating or geared motion. Hexamethylbenzene thus behaves as a molecular hexagonal gear.

  11. 摩擦式缓冲器阻抗特性在列车纵向动力学中的应用%Application of Dynamic Impedance Characteristics of Frictional Draft Gear in Longitudinal Train Dynamics

    Institute of Scientific and Technical Information of China (English)

    齐朝晖; 黄志浩; 孔宪超

    2011-01-01

    The dynamics characteristics of the draft gear determine the longitudinal train dynamics performance to a great extent. The relation between the resistance force and the penetration velocity obtained by traditional methods is not accurate enough. Moreover,the discontinuity with respect to the penetration velocity results in many insurmountable numerical difficulties in the longitudinal train dynamics applications. In this paper, on the basis of the achievement of contact mechanics,the modified model of frictional draft gear characteristics is presented, in which the discontinuity is smoothed according to the method of dealing with the switching effects in the Coulomb s law. The numerical example validates the proposed method.%缓冲器的动力学特性在较大程度上决定着列车纵向动力学性能.传统缓冲器的阻抗特性曲线未能完整描述阻抗力与缓冲器行程变化率之间的关系,并且存在间断点.在列车纵向动力学应用中,引起很多难以克服的困难.本文以摩擦式缓冲器为研究对象,利用接触力学方法,给出阻抗力与缓冲器行程变化率之间的关系;根据处理静摩擦开关效应的相关理论,提出一种处理阻抗力曲线间断点的实用方法.数值算例验证了所提方法的合理性.

  12. Planetary Magnetism

    Science.gov (United States)

    Connerney, J. E. P.

    2007-01-01

    The chapter on Planetary Magnetism by Connerney describes the magnetic fields of the planets, from Mercury to Neptune, including the large satellites (Moon, Ganymede) that have or once had active dynamos. The chapter describes the spacecraft missions and observations that, along with select remote observations, form the basis of our knowledge of planetary magnetic fields. Connerney describes the methods of analysis used to characterize planetary magnetic fields, and the models used to represent the main field (due to dynamo action in the planet's interior) and/or remnant magnetic fields locked in the planet's crust, where appropriate. These observations provide valuable insights into dynamo generation of magnetic fields, the structure and composition of planetary interiors, and the evolution of planets.

  13. Comparison and Implementation of a Rigid and a Flexible Multibody Planetary Gearbox Model

    DEFF Research Database (Denmark)

    Jørgensen, Martin Felix; Pedersen, Niels Leergaard; Sørensen, Jens Nørkær

    2014-01-01

    We propose algorithms for developing (1) a rigid (constrained) and (2) a flexible planetary gearbox model. The two methods are compared against each other and advantages/disadvantages of each method are discussed. The rigid model (1) has gear tooth reaction forces expressed by Lagrange multipliers...... between one and two gear teeth in mesh. The final results are from modelling the planetary gearbox in a 500 kW wind turbine which we also described in Jørgensen et al. (2013)....

  14. 大功率高速行星齿轮减速器动载系数计算研究%Study on the Dynamic Load Coefficient of Certain Planetary Reducer with Herringbone Gears using on Marine

    Institute of Scientific and Technical Information of China (English)

    尤明明

    2011-01-01

    In order to manufacture the certain NGW planetary reducer with high- power and high speed, it uses the method of convergence mass to predigest rotary parts and the coupings between parts, and finally gets a spring-mass system.In this process, it takes the vibrancy displacement of parts along planar orientation and rotational orientation into accout, finds the retortion- planar couping model, and finally gets the reducer' dynamic load coefficient via solving differential eguation.Based on the design rotating speed, it validates the rationality of structure and parameters.%针对某NGW型大功率高速行星齿轮减速器,采用集中质量法将减速器各运动构件简化为集中质量,各个构件之间以及构件与机架之间的连接简化为弹性元件,整个系统简化为一个弹簧质量系统.建模中考虑了齿轮类构件、行星架组件的质心沿横向和纵向的振动位移以及构件由于扭转振动产生的角位移,最终建立了系统的扭转-横向振动耦合模型.通过求解动力学微分方程组,获取表征系统振动特性的内外啮合齿轮副在频域内的动载系数,根据设计输入转速,验证了此减速器各结构参数设计的合理性.

  15. Fabrication and manipulation of solid-state SiO2 nano-gears on a gold surface

    Science.gov (United States)

    Deng, J.; Troadec, C.; Ample, F.; Joachim, C.

    2011-07-01

    A process is presented to fabricate solid-state nano-gears down to a 60 nm outer diameter with six teeth, where the 350 nm diameter ones already have 24 teeth. The small gears are free to move on a polycrystalline gold surface. The gears can be manipulated one by one, using an atomic force microscope (AFM) tip, to construct a train of gears where mechanical motion can be transmitted from one gear to another by mastering the surface friction. This is a first step on the way to bridge the fabrication gap between microfabricated and molecule gears.

  16. 33 CFR 150.505 - When must the operator service and examine lifeboat and rescue boat release gear?

    Science.gov (United States)

    2010-07-01

    ... inspection by personnel trained in examining the gear. Inflatable Lifesaving Appliances ... and examine lifeboat and rescue boat release gear? 150.505 Section 150.505 Navigation and Navigable... and examine lifeboat and rescue boat release gear? (a) The operator must service lifeboat and...

  17. 77 FR 56870 - New Process Gear, a Division of Magna Powertrain, Including On-Site Leased Workers From ABM...

    Science.gov (United States)

    2012-09-14

    ... Employment and Training Administration New Process Gear, a Division of Magna Powertrain, Including On- Site... of New Process Gear, a division of Magna Powertrain, East Syracuse, New York, The workers produce... Syracuse, New York location of New Process Gear, a division of Magna Powertrain. The Department...

  18. 50 CFR 665.627 - Allowable gear and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ..., Johnston Atoll and Palmyra Atoll. (d) Existing FEP fisheries shall follow the allowable gear and methods... decision on the permissibility of this gear type will be made by the Regional Administrator...

  19. Magnetic Gearing Versus Conventional Gearing in Actuators for Aerospace Applications

    Science.gov (United States)

    Puchhammer, Gregor

    2014-01-01

    Magnetic geared actuators (MGA) are designed to perform highly reliable, robust and precise motion on satellite platforms or aerospace vehicles. The design allows MGA to be used for various tasks in space applications. In contrast to conventional geared drives, the contact and lubrication free force transmitting elements lead to a considerable lifetime and range extension of drive systems. This paper describes the fundamentals of magnetic wobbling gears (MWG) and the deduced inherent characteristics, and compares conventional and magnetic gearing.

  20. Dynamic Analysis Considering Planetary Gears of Semi direct Drive Wind Turbines Using the ARMA Windspeed Model%考虑AR MA风速模型半直驱风电行星齿轮传动系统动力学分析

    Institute of Scientific and Technical Information of China (English)

    程言丽; 肖正明; 张威

    2015-01-01

    针对半直驱风电行星齿轮系统的变速变载的特点,考虑风速变化引起的外部载荷激励,采用自回归滑动平均(ARMA)方法建立模拟风速模型,在考虑时变啮合刚度、啮合阻尼等因素的基础上,采用集中参数法建立了行星齿轮传动系统平移扭转耦合动力学模型。并采用四阶龙格库塔法,求解1.5 MW半直驱风力发电行星齿轮传动系统的动态响应。%Due to the variable speed and varia-ble load characteristics of semi direct drive wine turbines,external load excitation caused by varia-ble speed is considered and a simulated wind speed model is set up using the Auto Regressive and Moving Average Model (ARMA).A translational rotational coupling dynamic model of the planeta-ry gears transmission system is established using the lumped parameter method,which considers the time varying mesh stiffness and mesh damp-ing.The Runge Kutta method is used to derive the vibration dynamic response to the 1 .5 MW semi direct drive wind turbine system and accord-ing which the vibration performance is analyzed.

  1. ARTIFICIAL NEURAL NETWORKS BASED GEARS MATERIAL SELECTION HYBRID INTELLIGENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    X.C. Li; W.X. Zhu; G. Chen; D.S. Mei; J. Zhang; K.M. Chen

    2003-01-01

    An artificial neural networks(ANNs) based gear material selection hybrid intelligent system is established by analyzing the individual advantages and weakness of expert system (ES) and ANNs and the applications in material select of them. The system mainly consists of tow parts: ES and ANNs. By being trained with much data samples,the back propagation (BP) ANN gets the knowledge of gear materials selection, and is able to inference according to user input. The system realizes the complementing of ANNs and ES. Using this system, engineers without materials selection experience can conveniently deal with gear materials selection.

  2. 基于承载接触分析的双重功率分流机构均载特性%Load Sharing Characteristics Analysis of Dual Power-split Gear Train Based on Loaded Tooth Contact Analysis

    Institute of Scientific and Technical Information of China (English)

    董皓; 方宗德; 王宝宾; 杜进辅

    2013-01-01

    In order to research load sharing characteristics of the dual power-split gear train, the mechanical structure model was established. With the method of the tooth contact analysis and loaded tooth contact analysis, the actual meshing process of gear pair was simulated and the time-varying mesh stiffness was obtained, which can enhance the precision of the computation. According to the closed-loop characteristic of the power flow of the system, the reverse angle deformation coordination conditions were deduced, which were combined with the mechanical equilibrium equations and elastic support conditions to calculate the transfer torque and load sharing coefficient of system. The influences of errors on the power split characteristics were analyzed. It provided an important role in the reference for the design of the dual power-split transmission system.%建立了双重功率分流系统弹性支承下的力学模型.运用轮齿几何接触分析(TCA)和承载接触分析(LTCA)方法对齿轮副实际啮合过程进行仿真,拟合了齿轮副的时变啮合刚度,提高了计算精确度.根据系统构成功率流闭环的特点推导出系统的变形协调条件,并结合力矩平衡方程和弹性支承条件计算各齿轮副传递的扭矩,得到系统的均载系数.讨论了各种误差对系统功率分流的影响,为双重功率分流传动系统的设计提供了参考.

  3. A superconducting magnetic gear

    Science.gov (United States)

    Campbell, A. M.

    2016-05-01

    A comparison is made between a magnetic gear using permanent magnets and superconductors. The objective is to see if there are any fundamental reasons why superconducting magnets should not provide higher power densities than permanent magnets. The gear is based on the variable permeability design of Attilah and Howe (2001 IEEE Trans. Magn. 37 2844-46) in which a ring of permanent magnets surrounding a ring of permeable pole pieces with a different spacing gives an internal field component at the beat frequency. Superconductors can provide much larger fields and forces but will saturate the pole pieces. However the gear mechanism still operates, but in a different way. The magnetisation of the pole pieces is now constant but rotates with angle at the beat frequency. The result is a cylindrical Halbach array which produces an internal field with the same symmetry as in the linear regime, but has an analytic solution. In this paper a typical gear system is analysed with finite elements using FlexPDE. It is shown that the gear can work well into the saturation regime and that the Halbach array gives a good approximation to the results. Replacing the permanent magnets with superconducting tapes can give large increases in torque density, and for something like a wind turbine a combined gear and generator is possible. However there are major practical problems. Perhaps the most fundamental is the large high frequency field which is inevitably present and which will cause AC losses. Also large magnetic fields are required, with all the practical problems of high field superconducting magnets in rotating machines. Nevertheless there are ways of mitigating these difficulties and it seems worthwhile to explore the possibilities of this technology further.

  4. Gear Fatigue Diagnostics and Prognostics

    Science.gov (United States)

    2013-01-01

    The first objective was to collect meaningful gear fault progression data starting from healthy NASA-designed spur test gears and ending with failed...and D. P. Townsend, "Analysis of the effects of surface pitting and wear on the vibration of a gear transmission system," Tribology International...Reporting Period: April 15, 2012 to September 27, 2012 Attached is the Gear Fatigue Diagnostics and Prognostics project progress report for the

  5. Research on theory of gearing for epicycloidal bevel gear

    Institute of Scientific and Technical Information of China (English)

    ZOU Min; ZHU Hai-lin; ZHANG You-liang

    2005-01-01

    The engaged feature of a pair of gears was determined by the geometrical characteristics of their tooth surfaces. Through an analysis of gearing theory on epicycloidal bevel gears, the method to examine if there exists undercut during manufacturing of epicycloidal bevel gears, the approximate formulae to calculate the gap between the convex and concave tooth surfaces in meshing so as to guarantee against the occurrence of point-contact for tooth surfaces even in maximum angle of inclination are derived in this paper. Those formula derived are simple, compact and have practical value to the design and production of epicycloidal bevel gears.

  6. Planetary Rings

    Science.gov (United States)

    Cuzzi, Jeffrey N.

    1994-01-01

    Just over two decades ago, Jim Pollack made a critical contribution to our understanding of planetary ring particle properties, and resolved a major apparent paradox between radar reflection and radio emission observations. At the time, particle properties were about all there were to study about planetary rings, and the fundamental questions were, why is Saturn the only planet with rings, how big are the particles, and what are they made of? Since then, we have received an avalanche of observations of planetary ring systems, both from spacecraft and from Earth. Meanwhile, we have seen steady progress in our understanding of the myriad ways in which gravity, fluid and statistical mechanics, and electromagnetism can combine to shape the distribution of the submicron-to-several-meter size particles which comprise ring systems into the complex webs of structure that we now know them to display. Insights gained from studies of these giant dynamical analogs have carried over into improved understanding of the formation of the planets themselves from particle disks, a subject very close to Jim's heart. The now-complete reconnaissance of the gas giant planets by spacecraft has revealed that ring systems are invariably found in association with families of regular satellites, and there is ark emerging perspective that they are not only physically but causally linked. There is also mounting evidence that many features or aspects of all planetary ring systems, if not the ring systems themselves, are considerably younger than the solar system

  7. On gear tooth stiffness evaluation

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Jørgensen, Martin Felix

    2014-01-01

    The estimation of gear stiffness is important for determining the load distribution between the gear teeth when two sets of teeth are in contact. Two factors have a major influence on the stiffness; firstly the boundary condition through the gear rim size included in the stiffness calculation...... and secondly the size of the contact. In the FE calculation the true gear tooth root profile is applied. The meshing stiffnesses of gears are highly non-linear, it is however found that the stiffness of an individual tooth can be expressed in a linear form assuming that the contact width is constant. © 2014...

  8. Research on transmission principle and kinematics analysis for involute spherical gear

    Institute of Scientific and Technical Information of China (English)

    PAN Cun-yun; WEN Xi-sen; YANG Kun-yu; XU Xiao-jun; LIU Min; YAO Qi-shui

    2006-01-01

    A new kind of transmission-type spherical gear called 'ring involute spherical gear mechanism' is introduced.Compared to the famous TRALLFA spherical gear,this new spherical gear has an involute tooth profile,and a ring tooth that is distributed continuously on the surface of the sphere.This allows the gear to overcome two disadvantages of the TRALLFA spherical gear:the drive principle error and the manufacturing difficulty.The new transmission and the formation principle of the tooth's surface of the new spherical gear mechanism are first introduced,then another mechanism,called disk rack,is introduced,which is derived from the spherical gear mechanism when one of the spherical gear's tooth number reaches infinity.To make the research more convenient,every part of the new spherical gear mechanism is named.In the following sections,some problems are discussed,such as the assembly form,the construction characteristics,the correct meshing condition,the continuum transmission condition and so on.Furthermore,the paper deduces the surface formula of the conjugate teeth profiles,which proves that the conjugate teeth profiles is also one of the ringed involute spherical gear.In order to analyze the relationship between two coordinate systems,which is attached respectively to the diving spherical gear and the driven spherical gear,the orientation cosine matrix method is utilized.By series rotational transformation, the kinematics model and inverse kinematics model are deduced.Using the method for calculating the transmission ratio of planet gear train,the relationship of the two oscillating angle between output axis and the bracket is established.Based on the research,the kinematics graphic simulation of spherical gear mechanism and disk rack are made respectively.The results prove correctness of the kinematics model.

  9. Displaceable Gear Torque Controlled Driver

    Science.gov (United States)

    Cook, Joseph S., Jr. (Inventor)

    1997-01-01

    Methods and apparatus are provided for a torque driver including a displaceable gear to limit torque transfer to a fastener at a precisely controlled torque limit. A biasing assembly biases a first gear into engagement with a second gear for torque transfer between the first and second gear. The biasing assembly includes a pressurized cylinder controlled at a constant pressure that corresponds to a torque limit. A calibrated gage and valve is used to set the desired torque limit. One or more coiled output linkages connect the first gear with the fastener adaptor which may be a socket for a nut. A gear tooth profile provides a separation force that overcomes the bias to limit torque at the desired torque limit. Multiple fasteners may be rotated simultaneously to a desired torque limit if additional output spur gears are provided. The torque limit is adjustable and may be different for fasteners within the same fastener configuration.

  10. Bevel gear fundamentals and applications

    CERN Document Server

    2016-01-01

    This is the first book to offer a complete presentation of bevel gears. An expert team of authors highlights the areas of application for these machine elements and presents the geometrical features of bevel gears as well as the various gear cutting processes based on gear cutting theory. The aspect of three-dimensional gearing is assessed in detail in terms of flank design, load capacity and noise behavior. A representation of production processes with the required technologies provides a knowledge base on which sound decisions can be based. The authors offer a thorough introduction to the complex world of bevel gears and present the rapid advances of these machine elements in a detailed, comprehensible manner.  This book addresses design engineers in mechanical engineering and vehicle manufacturing, as well as producers of bevel gears and students in mechanical engineering.

  11. Numerical Analysis of Plastic Gear Stiffness

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This paper established practical 3-D gear models to study the stiffness influencing factors of a loaded gear by finite element method, such as friction parameters, material properties, and gear structures. The research shows that, in elastic deformation, gear stiffness increases when sliding friction ability of contact pair decreases;meanwhile, the gear structure, especially asymmetric design in gear's shaft direction will also decrease gear stiffness.

  12. Planetary Society

    Science.gov (United States)

    Murdin, P.

    2000-11-01

    Carl Sagan, Bruce Murray and Louis Friedman founded the non-profit Planetary Society in 1979 to advance the exploration of the solar system and to continue the search for extraterrestrial life. The Society has its headquarters in Pasadena, California, but is international in scope, with 100 000 members worldwide, making it the largest space interest group in the world. The Society funds a var...

  13. Planetary Rings

    CERN Document Server

    Tiscareno, Matthew S

    2011-01-01

    Planetary rings are the only nearby astrophysical disks, and the only disks that have been investigated by spacecraft. Although there are significant differences between rings and other disks, chiefly the large planet/ring mass ratio that greatly enhances the flatness of rings (aspect ratios as small as 1e-7), understanding of disks in general can be enhanced by understanding the dynamical processes observed at close-range and in real-time in planetary rings. We review the known ring systems of the four giant planets, as well as the prospects for ring systems yet to be discovered. We then review planetary rings by type. The main rings of Saturn comprise our system's only dense broad disk and host many phenomena of general application to disks including spiral waves, gap formation, self-gravity wakes, viscous overstability and normal modes, impact clouds, and orbital evolution of embedded moons. Dense narrow rings are the primary natural laboratory for understanding shepherding and self-stability. Narrow dusty...

  14. Transmission Efficiency Calculation of 2K-H Negative Differential Gear Train in Main Hoisting Reducer of Ladle Crane%铸造起重机主起升减速器用2K-H负号差动轮系传动效率计算

    Institute of Scientific and Technical Information of China (English)

    史文杰; 杨立强; 刘世军; 王永; 黄红涛; 蒋晶

    2015-01-01

    For a long time,the theoretical derivation value of the transmission efficiency of 2K-H negative differential gear train is high,however,there is large power loss of hoisting reducer epicyclic gear train in practice.The theoretical analysis and practical application is combined to discuss various factors and their proportion that impact the actual transmission efficiency of 2K-H negative differential gear train in main hoisting reducer of ladle crane,aiming to make the calculated value is closer to actual value.%长期以来,2K-H负号差动轮系传动效率理论推导值较高,而实际使用中减速器周转轮系部分的功率损失较大.试图将理论推导与实际应用相结合,浅谈一下影响铸造起重机主起升减速器用2K-H负号差动轮系实际传动效率的各种因素及因素所占权重,以求效率计算值更接近于实际值.

  15. Application and Analysis of Differential Gear Train in the Artillery Shells Complement System%差动轮系在火炮补弹系统中的应用与分析

    Institute of Scientific and Technical Information of China (English)

    杨臻; 原永亮; 王圣辉; 高骁波

    2015-01-01

    This article describes the characteristics of a small caliber artillery shells complement system,and a new type of differential gear trains revering mechanism.Using simulation software of ADAMS mechanical system dynamics astablish the dynamics model and simulation analysis and calculation are parformed dynamic curves and the law of motion are obtained,and simulation data with the theoretical calculated data in a consistent and the results show that ADAMS software to complex models of emulation is accurate and reliable,and guaranteed further has the certain reference value.%描述了某小口径火炮补弹系统的特点,设计了一种新型的差动轮系翻转机构。通过使用ADAMS机械系统动力学仿真软件建立动力学模型并仿真分析计算,得到翻转机构的动力学曲线和运动规律,仿真数据与理论计算数据相一致,结果表明ADAMS软件对复杂模型的仿真准确可靠,对以后的优化设计具有一定的参考价值。

  16. Research on mechanical characteristics of closed planetary bevel-type CVT%封闭式行星锥盘无级变速器的传动性能研究

    Institute of Scientific and Technical Information of China (English)

    谢观如; 刘开昌

    2012-01-01

    介绍了封闭式行星锥盘无级变速器的基本结构与传动原理.利用负号差动轮系的特点,将行星锥盘无级变速器与差动轮系封闭组合,列出了几种主要的结构形式,并对其运动、功率分配和功率流流向进行分析,通过效率计算表明该思路的可行性与优越性.%This paper describes the basic structure and driving principle of the closed planetary bevel - type CVT. The characteristics of negative differential gear - train are applied to combine planetary bevel - type CVT with the differential gear - train. Several major structural forms to close the planetary bevel - type CVT are listed and its movement and power flow are analyzed. The calculated efficiency results proved the feasibility and superiority of this idea.

  17. Bar Mechanism Design of Irregular Gear Planetary System Based on the Parallel Algorithm of Granular Computing and Decision Tree%非规则齿轮行星系扎穴机构设计-基于粒计算决策树并行算法

    Institute of Scientific and Technical Information of China (English)

    魏小燕

    2016-01-01

    As a large agricultural country with 21%people in the world , China should develop advanced modern agricul-ture , need to use chemical fertilizer and improve the efficiency of fertilizer use .Compared with the solid state fertilizer , the liquid is more easily absorbed by crops , and the fertilizer use is more direct , efficient and economical .International-ly, Russia, the United States, Australia and other countries have taken the lead in the use of liquid fertilizer .In order to save the fertilizer , improve the utilization rate of the fertilizer , save the economic cost and reduce the pollution to the soil .Based on the parallel algorithm of the decision tree , this paper designs and studies the mechanism of the planetary system of irregular gear , which is a little waste of chemical fertilizer and the absorption efficiency .%作为占据世界21%人口的农业大国,中国要发展先进的现代农业,需要合理使用化学肥料,提高肥料的使用效率。与固态肥料相比较,液态更容易被作物吸收,肥料利用更直接,效率较高,经济成本更低。在国际上,俄罗斯、美国、澳大利亚等国家已经率先使用了液态肥料。为了节省肥料、提高农作物对肥料的吸收利用率、节省经济成本及降低对土壤的污染,基于粒计算决策树并行算法,设计了非规则齿轮行星系扎穴机构。该扎穴装置在作业中,化学肥液浪费较少、吸收效率较高。

  18. Gear Windage Modeling Progress - Experimental Validation Status

    Science.gov (United States)

    Kunz, Rob; Handschuh, Robert F.

    2008-01-01

    In the Subsonics Rotary Wing (SRW) Project being funded for propulsion work at NASA Glenn Research Center, performance of the propulsion system is of high importance. In current rotorcraft drive systems many gearing components operate at high rotational speed (pitch line velocity > 24000 ft/ min). In our testing of high speed helical gear trains at NASA Glenn we have found that the work done on the air - oil mist within the gearbox can become a significant part of the power loss of the system. This loss mechanism is referred to as windage. The effort described in this presentation is to try to understand the variables that affect windage, develop a good experimental data base to validate, the analytical project being conducted at Penn State University by Dr. Rob Kunz under a NASA SRW NRA. The presentation provides an update to the status of these efforts.

  19. Tool Gear Documentation

    Energy Technology Data Exchange (ETDEWEB)

    May, J; Gyllenhaal, J

    2002-04-03

    Tool Gear is designed to allow tool developers to insert instrumentation code into target programs using the DPCL library. This code can gather data and send it back to the Client for display or analysis. Tools can use the Tool Gear client without using the DPCL Collector. Any collector using the right protocols can send data to the Client for display and analysis. However, this document will focus on how to gather data with the DPCL Collector. There are three parts to the task of using Tool Gear to gather data through DPCL: (1) Write the instrumentation code that will be loaded and run in the target program. The code should be in the form of one or more functions, which can pass data structures back to the Client by way of DPCL. The collections of functions is compiled into a library, as described in this report. (2) Write the code that tells the DPCL Collector about the instrumentation and how to forward data back to the Client. (3) Extend the client to accept data from the Collector and display it in a useful way. The rest of this report describes how to carry out each of these steps.

  20. Load-Sharing Characteristics of Gear Train with Dual Power Split Based on Deflection Compatibility%基于变形协调的双重功率分流轮系均载特性

    Institute of Scientific and Technical Information of China (English)

    董皓; 方宗德; 王宝宾; 杜进辅

    2012-01-01

    In order to implement the uniform load distribution of the gear train with dual power split, first, a pseudo-static model is built. Next, according to the closed-loop characteristics of system power flow, the conditions for the deflection compatibility of torsional angle are proposed, which are then combined with the moment equilibrium conditions and the elastic support conditions to calculate the transmission torque of each gear pair with the help of the equivalent mesh error theory and the equivalent mesh stiffness theory. Finally, the load-sharing coefficient of the system is obtained and the influences of the installation and manufacturing errors of each component on the power split are analyzed based on the statics theory. The results show that the above-mentioned errors collectively influence the load-sharing characteristics, and that the reduction of a single error is ineffective in achieving perfect load-sharing characteristics.%针对双重功率分流系统的载荷均匀分布问题,建立了该系统的拟静力学模型,并根据系统构成功率流闭环的特点,推导出了系统的扭转角变形协调条件.将该条件与系统 的力矩平衡条件和弹性支撑条件联立,并运用当量啮合误差和等效啮合刚度理论,计算出了各齿轮副传递的扭矩,最终得到了系统的均载系数.文中还从静力学角度分析了各构件安装误差和制造误差对系统功率分流的影响.结果表明,这些误差对系统的均载特性共同起作用,单独减小某一种误差,并不能达到最好的均载效果.

  1. APPLICATION OF ASYMMETRIC PROFILE IN GEARINGS WITH ECCENTRIC GEARS

    OpenAIRE

    2014-01-01

    Gearing was designed to meet specific requirement, during one rotation was continuous change of gear ratio. The gearing consists of two identical gears. The basic shape of the wheel is formed by an ellipse. One of the foci is the center of rotation. Wheels are designed for only one direction of rotation. Active and passive side involute curve were created by rolling the basic evoluta elliptical wheel independently. It was used for the production of NC cutting machine for EDM 005 B EIR with ma...

  2. 49 CFR 230.89 - Reverse gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Reverse gear. 230.89 Section 230.89 Transportation... Reversing Gear § 230.89 Reverse gear. (a) General provisions. Reverse gear, reverse levers, and quadrants... quadrant. Proper counterbalance shall be provided for the valve gear. (b) Air-operated power reverse...

  3. Research on synchronous gear pump

    Institute of Scientific and Technical Information of China (English)

    LUAN Zhen-hui

    2010-01-01

    Based on a comprehensive analysis of the structure and existing problems of the gear pump, provided a structure principle of a synchronous gear pump. The discussions focused on the working principle, construction features and finite element analysis of the hydraulic gear. The research indicates that the new pump has such advantages as lower noise, better distributed flow and a high work pressure, and it can be widely used in hydraulic systems.

  4. Alpha Stable Distribution Based Morphological Filter for Bearing and Gear Fault Diagnosis in Nuclear Power Plant

    Directory of Open Access Journals (Sweden)

    Xinghui Zhang

    2015-01-01

    Full Text Available Gear and bearing play an important role as key components of rotating machinery power transmission systems in nuclear power plants. Their state conditions are very important for safety and normal operation of entire nuclear power plant. Vibration based condition monitoring is more complicated for the gear and bearing of planetary gearbox than those of fixed-axis gearbox. Many theoretical and engineering challenges in planetary gearbox fault diagnosis have not yet been resolved which are of great importance for nuclear power plants. A detailed vibration condition monitoring review of planetary gearbox used in nuclear power plants is conducted in this paper. A new fault diagnosis method of planetary gearbox gears is proposed. Bearing fault data, bearing simulation data, and gear fault data are used to test the new method. Signals preprocessed using dilation-erosion gradient filter and fast Fourier transform for fault information extraction. The length of structuring element (SE of dilation-erosion gradient filter is optimized by alpha stable distribution. Method experimental verification confirmed that parameter alpha is superior compared to kurtosis since it can reflect the form of entire signal and it cannot be influenced by noise similar to impulse.

  5. Planetary gear dynamic response to mesh parametric excitation

    Directory of Open Access Journals (Sweden)

    Vojislav Jovan Batinić

    2013-02-01

    Full Text Available Normal 0 MicrosoftInternetExplorer4 Unutrašnje dinamičke sile i pomeranja po predviđenim stepenima slobode u planetarnim prenosnicima posledica su, prvenstveno, promen-ljivih elastičnih deformacija zubaca u sprezi, vibracija delova prenosnika i odstupanja geometrije ozubljenja usled habanja zubaca i grešaka izrade. U radu se razmatra uticaj vremenski promenljive sprežne krutosti na moguća pomeranja i sile u kontaktima zubaca. Ove funkcije su korišćene kao nelinearni koeficijenti krutosti u sistemu jednačina za ekvivalentni zupčani prenosnik pri utvrđivanju prirode pomeranja i unutrašnjih dinamičkih sila. Rezultati numeričke analize sistema jednačina kojima je opisano dinamičko ponašanje su vremenski - promenljive funkcije pomeranja tačaka sistema i dinamičkih sila u spregama zubaca centralni zupčanik/satelit i satelit/venčanik.

  6. Parametric analysis and inversion of transplanting mechanism with planetary non-circular gears for potted-seedling transplanter%钵苗移栽机非圆齿轮行星轮系栽植机构参数分析与反求

    Institute of Scientific and Technical Information of China (English)

    陈建能; 黄前泽; 王英; 孙良; 赵雄; 武传宇

    2013-01-01

    The transplanting mechanism is the ultimate mechanism that plants seedlings into fields, and whose performance directly affects the verticality rate and injury rate of seedlings, thus affecting the survival rate of seedlings and final productivity. At present, in order to achieve "zero speed" transplanting to improve upright degree after transplanting, research into transplanting mechanisms focus on the trajectory of the transplanting tip and planting speed. However, due to the diversity of seedling organisms and the kinematic accuracy of transplanting mechanism, it is still difficult to achieve “zero speed” transplanting; thus, the upright degree of seedlings cannot be guaranteed. To meet the agricultural demands of seedling transplanting in dry land, the transplanting mechanism with planetary non-circular gears was proposed. Several discrete points on the motion trace of the transplanting tip were selected as data points, and then the cubic non-uniform B-spline curve was applied to control and express the whole trace curve. On this basis, the parameter inverse model aimed to the curve of this mechanism was established, and the equations of (angular) displacement, (angular) velocity, and (angular) acceleration for the transplanting tip were deduced. The parameter inverse and design software for this mechanism, based on the development platform of MATLAB GUI, was compiled to analyze the effect of several main date points on the trajectory and posture of the transplanting tip and the hole shape. On the basis of the analysis of the effect of the data points, and in order to meet the demands of the trajectory and posture of the transplanting tip and the hole shape, the data points were adjusted to optimize the mechanism parameters by the software. The new mechanism parameters improved the verticality rate of seedlings and reduced the injury rate of seedlings. The data points affected the inclination angle between the transplanting tip and horizontal axis when

  7. Design and construction of permanent magnetic gears

    DEFF Research Database (Denmark)

    Jørgensen, Frank Thorleif

    This thesis deals with design and development of permanent magnetic gears. The goal of this thesis is to develop knowledge and calculation software for magnetic gears. They use strong NdFeB permanent magnets and a new magnetic gear technology, which will be a serious alternative to classical...... calculation models for determination of gear output torque from different magnetic gear types are analysed. These analytical calculations models are used together with optimisation tools in order to improve the performance of investigated magnetic gear types. Experimental test gears are designed to validate...... is searched and only a single reference [74] is found and that is why the combination of a cycloidal gear and a magnetic gear are considered as an innovative supplement to magnetic gear technology. A magnetic cycloidal gear is designed with a gearing of 1:21 and a calculated active torque density of 142 [Nm...

  8. High Pressure Angle Gears: Comparison to Typical Gear Designs

    Science.gov (United States)

    Handschuh, Robert F.; Zabrajsek, Andrew J.

    2010-01-01

    A preliminary study has been completed to determine the feasibility of using high-pressure angle gears in aeronautic and space applications. Tests were conducted in the NASA Glenn Research Center (GRC) Spur Gear Test Facility at speeds up to 10,000 rpm and 73 N*m (648 in.*lb) for 3.18, 2.12, and 1.59 module gears (8, 12, and 16 diametral pitch gears), all designed to operate in the same test facility. The 3.18 module (8-diametral pitch), 28 tooth, 20deg pressure angle gears are the GRC baseline test specimen. Also, 2.12 module (12-diametral pitch), 42 tooth, 25deg pressure angle gears were tested. Finally 1.59 module (16-diametral pitch), 56 tooth, 35deg pressure angle gears were tested. The high-pressure angle gears were the most efficient when operated in the high-speed aerospace mode (10,000 rpm, lubricated with a synthetic turbine engine oil), and produced the lowest wear rates when tested with a perfluoroether-based grease. The grease tests were conducted at 150 rpm and 71 N*m (630 in.*lb).

  9. Frictional Effects on Gear Tooth Contact Analysis

    OpenAIRE

    Zheng Li; Ken Mao

    2013-01-01

    The present paper concentrates on the investigations regarding the situations of frictional shear stress of gear teeth and the relevant frictional effects on bending stresses and transmission error in gear meshing. Sliding friction is one of the major reasons causing gear failure and vibration; the adequate consideration of frictional effects is essential for understanding gear contact behavior accurately. An analysis of tooth frictional effect on gear performance in spur gear is presented us...

  10. Review of Composite Asymmetric Spur Gear

    OpenAIRE

    Sandeep C. Dhaduti; Dr. S. G. Sarganachari

    2015-01-01

    Gears made from composite materials are widely used in many power and motion transmission applications. Due to lower weight to stiffness ratio, composite gears may be replaced by conventional material gears in power transmission systems. Design of gears with asymmetric teeth enables to increase load capacity, reduce weight, size and vibration level. This article includes a summary of asymmetric gear design parameters, new developments of asymmetric spur gear and their ...

  11. Precise low cost chain gears for heliostats

    Science.gov (United States)

    Liedke, Phillip; Lewandowski, Arkadiusz; Pfahl, Andreas; Hölle, Erwin

    2016-05-01

    This work investigates the potential of chain gears as precise and low cost driving systems for rim drive heliostats. After explaining chain gear basics the polygon effect and chain lengthening are investigated. The polygon effect could be measured by a heliostat with chain rim gear and the chain lengthening with an accordant test set up. Two gear stages are scope of this work: a rim gear and an intermediate gear. Dimensioning, pretensioning and designing for both stages are explained.

  12. Fault Detection in Gear Drives with Non-Stationary Rotational Speed - Part II: the Time-Quefrency Approach

    Science.gov (United States)

    Meltzer, G.; Ivanov, Yu. Ye.

    2003-03-01

    This paper deals with the recognition of faults in toothing during non-stationary start up and run down of gear drives. In the first part, this task was solved by means of the time-frequency analysis. A planetary gear was used as a case study. Part II contains a new approach using the time-quefrency analysis. The same example was successfully subjected in this procedure.

  13. On transmission errors and profile modifications minimising dynamic tooth loads in multi-mesh gears

    Science.gov (United States)

    Velex, Ph.; Chapron, M.; Fakhfakh, H.; Bruyère, J.; Becquerelle, S.

    2016-09-01

    A modular three-dimensional model of multi-mesh gears is used to analyse theoretically the link between dynamic mesh excitations and transmission errors. It is demonstrated that dynamic mesh forces are mostly controlled by the local transmission errors associated with each individual mesh. A design criterion is derived which can be used to define the tooth shape modifications minimising dynamic tooth loads. The results from two examples of application on idler and planetary systems prove that the proposed theory is sound and can be applied to a variety of gear geometries. Finally, the interest and limits of using transmission errors from a single pinion-gear pair in the context of multi-mesh gears are discussed.

  14. 功率分流四分支轮系建模与承载特性分析%Modeling and Load Characteristic Analysis of Power Split Four-branching Gear Train

    Institute of Scientific and Technical Information of China (English)

    王冀; 尹逊民

    2013-01-01

    为了准确得到弹性支撑下功率分流四分支轮系的承载特性,建立其力学结构模型,推导出变形协调条件.考虑中心距安装误差、轴交角误差、轴承弹性支撑刚度对轮齿接触轨迹及传递误差曲线的影响会导致时变啮合刚度曲线的变化,进而在轮齿承载接触法的基础上分析了弹性支撑下各误差存在时功率分配的情况.结果表明,弹性支撑刚度条件会导致仿真结果差异较大,弹性支承更符合实际.为四分支传动系统的设计与分析提供参考.%In order to accurately obtain load characteristic of power split four - branching gear train with elastic supports, the mechanical structure model is established and the deformation coordination conditions are deduced. Considering that the center distance assembly errors, shaft crossed angle errors and bearing elastic support stiffness have a significant impact on the contact path direct and transmission error curves lead to a variation of time - varying mesh stiffness curves, therefore the power split situation in various errors is analyzed under the elastic support based on the load tooth contact analysis method. The results show that the different elastic support conditions can lead to the different simulation results, the elastic supports are more accord with the actual. A reference for the design and analysis of four - branching transmission system is provided.

  15. Vibroacoustical diagnosis of planetary precessional kinematical transmission

    Science.gov (United States)

    Malcoci, Iu; Bodnariuc, I.

    2016-08-01

    An ideal dynamical system should not generate any vibrations, because vibrations mean a loss of energy. Vibration in planetary precessional gear box occurs at bearings, gear wheels, misaligned shafts, imbalance rotating parts, couplings. If damage occurs, not only the dynamic processes change, but also the forces that act on system components. Regarding this aspects, sound level was measured by using Brüel & Kjær Sound Level Meter Type 2250 Light that has everything needed to perform high-precision, Class 1 measurement tasks in environmental, occupational and industrial application areas. Obtained and measured results were presented in diagrams and tables to be compared with German standard VDI-2058 Limit value for vibration severity and noise level.

  16. Gear fatigue damage for a 500 kW wind turbine exposed to increasing turbulence using a flexible multibody model

    DEFF Research Database (Denmark)

    Jørgensen, Martin Felix; Pedersen, Niels Leergaard; Sørensen, Jens Nørkær

    2014-01-01

    This paper investigates gear tooth fatigue damage in a 500 kW wind turbine using FLEX5 and own multibody code. FLEX5 provides the physical wind eld, rotor and generator torque and the multibody code is used for obtaining gear tooth reaction forces in the planetary gearbox. Dierent turbulence levels...... and therefore increased fatigue damage levels. This article contributes to a better understanding of gear fatigue damage when turbulence is increased (e.g. in the center of large wind farms or at places where turbulence is pronounced)....

  17. Fault Detection in Gear Drives with Non-Stationary Rotational Speed-Part i: the Time-Frequency Approach

    Science.gov (United States)

    Meltzer, G.; Ivanov, Yu Ye

    2003-09-01

    This paper deals with the recognition of faults in toothing during non-stationary start-up and run-down of gear drives. In the first part, this task will be solved by means of the time-frequency analysis. As a practical case study, we investigated a planetary gear for passenger cars. New exponental smoothing kernels which respect to the known-in-advance angular acceleration of gear drive were created. These kernels must be adapted in the case of an in-advance-unknown course of rotational speed.

  18. Investigation for Molecular Attraction Impact Between Contacting Surfaces in Micro-Gears

    Science.gov (United States)

    Yang, Ping; Li, Xialong; Zhao, Yanfang; Yang, Haiying; Wang, Shuting; Yang, Jianming

    2013-10-01

    The aim of this research work is to provide a systematic method to perform molecular attraction impact between contacting surfaces in micro-gear train. This method is established by integrating involute profile analysis and molecular dynamics simulation. A mathematical computation of micro-gear involute is presented based on geometrical properties, Taylor expression and Hamaker assumption. In the meantime, Morse potential function and the cut-off radius are introduced with a molecular dynamics simulation. So a hybrid computational method for the Van Der Waals force between the contacting faces in micro-gear train is developed. An example is illustrated to show the performance of this method. The results show that the change of Van Der Waals force in micro-gear train has a nonlinear characteristic with parameters change such as the modulus of the gear and the tooth number of gear etc. The procedure implies a potential feasibility that we can control the Van Der Waals force by adjusting the manufacturing parameters for gear train design.

  19. 基于多源信息的高速列车走行部故障识别方法%High-speed train running gear fault recognition based on information fusion of multi-source

    Institute of Scientific and Technical Information of China (English)

    朱建渠; 金炜东; 郑高; 朱斌

    2014-01-01

    针对高速列车安全性能跟踪监测点多、监测数据量大而导致的走行部故障识别难的问题,提出了一种基于模糊证据理论的多特征、多源信息融合的走行部故障识别方法。首先根据不同传感器信息的某类特征属于不同故障模式下的隶属度间的差异来计算传感器间的信息融合度,利用融合度来确定不同传感器在融合中的权重,从而得到同类特征不同传感器间信息融合后的隶属度;然后由融合后的隶属度转化为基本概率分配函数;最后用证据理论对不同特征间信息进行融合。实验结果表明,该方法能有效地识别列车正常、空气弹簧失气、抗蛇形减震器全拆、横向减震器全拆四种情况,同时在不同速度下均取得了满意的识别率,验证了该方法的有效性。%To solve the problem that it is difficult to identify faults of high-speed train running gears caused by multiple detection points and large amount of data,a running gear fault recognition method with multi-feature and multi-source information fusion was proposed based on the fuzzy evidence theory.Firstly,the information fusion levels of sensors were obtained by calculating the difference of membership degrees reflecting a certain feature of different sensors belonging to different fault modes.The fusion levels were used to determine the weights of different sensors during fusion,thus the membership degrees after information fusion between different sensors with similar characteristics were obtained.Then,the fused membership degrees were converted into the basic probability assignment functions.Finally,the information of different characteristics was fused on the basis of the evidence theory.Experimental results showed that the four cases including normal running,air loss of air spring,without anti-yaw shock absorber and without transverse shock absorber can be identified effectively with the proposed method,and the

  20. 50 CFR 648.84 - Gear-marking requirements and gear restrictions.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear-marking requirements and gear... Management Measures for the NE Multispecies and Monkfish Fisheries § 648.84 Gear-marking requirements and gear restrictions. (a) Bottom-tending fixed gear, including, but not limited to, gillnets and...

  1. 29 CFR 1918.54 - Rigging gear.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Rigging gear. 1918.54 Section 1918.54 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Vessel's Cargo Handling Gear § 1918.54 Rigging gear. (a... other alternate device shall be provided to allow trimming of the gear and to prevent employees...

  2. Tooth bending fatigue failures in gears

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1996-09-01

    Full Text Available A gear is a machine element designed to transmit force and motion from one mechanical unit to another. The design and function of gears are usually closely associated, since gears are designed for a specific function. Various types of gears have...

  3. A comparative study between axial and radial fluxfocusing magnetic gear topologies and mechanical gearboxes

    Science.gov (United States)

    Calvin, Matthew

    A variety of magnetic gear topologies have been investigated in recent years as alternatives to traditional mechanical gearboxes. In general these magnetic gears offer advantages in the non-contact transmission of torque including inherent overload protection, reduced acoustic emissions, and a reduction in the number of contacting components subject to wear. The earliest magnetic gear designs however suffered from low volumetric torque densities, which limited their utility for industrial applications. Research into flux focusing magnetic gearbox topologies has resulted in increased volumetric torque densities by actively engaging all of the magnets in the transmission of torque throughout the process. This research compared the volumetric torque density of axial and radial flux focusing magnetic gearbox designs and prototypes to planetary, cycloidal, and harmonic mechanical gearboxes. The rare earth scaled up radial and axial flux focusing topologies were found to have consistently higher volumetric torque densities than planetary gearboxes of comparable diameter. The cycloidal and harmonic gearboxes had comparable volumetric torque densities, with greater volumetric torque densities for some models and lesser volumetric torque densities for others. The expectation is that further improvements in volumetric torque density are possible for flux focusing magnetic gears with additional refinement and optimization of the designs. The current study does show that flux focusing magnetic gear topologies are a plausible future alternative to mechanical gearboxes in applications where their unique torque transmission mechanism would be advantageous.

  4. Bispectrum Analysis in Fault Diagnosis of Gears

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The application of bispectrum analysis in fault diagnosis of gears is studied in this paper. Bispectrum analysis is capable of removing Gaussian or symmetric non-Gaussian noise and providing more information than power spectrum analysis. The results of the research show that normal gear signals, cracked gear signals and broken gear signals can be easily distinguished by using bispectrum as the signal features. The bispectrum diagonal slice Bx(ω1,ω2) can be used to identify the gear condition automatically.

  5. Optimization of compound gear pump

    Institute of Scientific and Technical Information of China (English)

    栾振辉

    2002-01-01

    This paper introduces the performances of compound gear pump. Based on the target of having the smallest mass per unit volume, the paper established a mathematical model of optimization, and obtained the results of optimization of the pump.

  6. Planetary gearbox fault diagnosis using an adaptive stochastic resonance method

    Science.gov (United States)

    Lei, Yaguo; Han, Dong; Lin, Jing; He, Zhengjia

    2013-07-01

    Planetary gearboxes are widely used in aerospace, automotive and heavy industry applications due to their large transmission ratio, strong load-bearing capacity and high transmission efficiency. The tough operation conditions of heavy duty and intensive impact load may cause gear tooth damage such as fatigue crack and teeth missed etc. The challenging issues in fault diagnosis of planetary gearboxes include selection of sensitive measurement locations, investigation of vibration transmission paths and weak feature extraction. One of them is how to effectively discover the weak characteristics from noisy signals of faulty components in planetary gearboxes. To address the issue in fault diagnosis of planetary gearboxes, an adaptive stochastic resonance (ASR) method is proposed in this paper. The ASR method utilizes the optimization ability of ant colony algorithms and adaptively realizes the optimal stochastic resonance system matching input signals. Using the ASR method, the noise may be weakened and weak characteristics highlighted, and therefore the faults can be diagnosed accurately. A planetary gearbox test rig is established and experiments with sun gear faults including a chipped tooth and a missing tooth are conducted. And the vibration signals are collected under the loaded condition and various motor speeds. The proposed method is used to process the collected signals and the results of feature extraction and fault diagnosis demonstrate its effectiveness.

  7. analysis of gear milling at vari gear milling at various gear milling at ...

    African Journals Online (AJOL)

    eobe

    K. A. Oladejo. 1DEPARTMENT OF MECHANICAL ... commonly used gears for mechanical power transmission. Form .... developed an algorithm for the design of a system for selecting ..... Optimization for minimizing production Time of. Turning ...

  8. A study of the optimum configuration of injection molded plastic gear by modification of gear tooth

    Science.gov (United States)

    Lee, Dae-Suep; Kwon, Young-Doo; Doc, Jin-Uk; Leed, Jun-Hyuk

    2009-07-01

    In this study, the gear system is optimized by modifying the tooth configuration of the plastic gears. Plastic gear is widely used as a machine element in industries of electric and electronic parts, automotive parts etc. Unlike the steel gear, the plastic gear has low load- transmission, durability and reliability. On the other hand, it is light-weight, low-noise, operable without a lubricant, shock absorptive, and anti-corrosive. The gear characteristics are calculated and analyzed by Hexagon and FEM (Finite Element Method) tools, and the characteristics of the standard gear and the addendum modified gear of the steel gear and the plastic gear are compared. When torque is applied to these gear systems, the system using the addendum modified gear can realize soft contact between gears. So, the noise of the addendum modified gear system was less than that of the common normal gear system. However, this is not applicable to any material, such as steel which is governed by DIN (Deuteshe Industrie Norm) recommendation. This study adopted the narrow tip tooth plastic gear, and proposed the optimum addendum modified gear with respect to stress, noise and contact ratio. To calculate and analyze the simulation of gear matching, we used commercial tools like CATIA, Auto-CAD, MARC for simulation and Hexagon for calculation.

  9. Transmission error and load distribution analysis of spur and double helical gear pairs used in a split path helicopter transmission design

    Science.gov (United States)

    Hochmann, David; Houser, Donald R.; Thomas, Jacob

    1991-05-01

    Because the reduction of gear noise in next-generation rotorcraft depends on the reduction of transmission errors, attention is presently given to the prediction of such errors and the load distributions of both a spur-gear pair and a double helical gear train used in a split-path helicopter transmission. Two cases are examined: (1) the spur gear mesh between the spur shaft and the lower spur/helical shaft, and (2) the double helical gear mesh between the lower spur/helical shaft and the output bull bear shaft.

  10. Planetary Data System (PDS)

    Data.gov (United States)

    National Aeronautics and Space Administration — The Planetary Data System (PDS) is an archive of data products from NASA planetary missions, which is sponsored by NASA's Science Mission Directorate. We actively...

  11. Proposal of an Axial Gap Magnetic Gear

    Science.gov (United States)

    Hirata, Katsuhiro; Yamamoto, Masafumi; Muramatsu, Masari

    Magnetic gears have some benefits such as low noise, low vibration, and they are maintenance free as opposed to mechanical gears. In the view of these advantages, some high-performance magnetic gears have been proposed; however, these gears have a complex structure because they require several magnets. In this paper, we propose a new magnetic gear with a high reduction ratio comprising only two magnets. From the result of 3D-FE analysis, it was found that our model generated large transmitted torque and less cogging torque despite its thin compact size. This result shows the possibility of the application of the proposed gear in various industries.

  12. Design and construction of permanent magnetic gears

    OpenAIRE

    Jørgensen, Frank Thorleif

    2010-01-01

    This thesis deals with design and development of permanent magnetic gears. The goal of this thesis is to develop knowledge and calculation software for magnetic gears. They use strong NdFeB permanent magnets and a new magnetic gear technology, which will be a serious alternative to classical mechanical gears. The new magnetic gear will have a high torque density1 relationship –high efficiency and are maintenance free. In this project was manufactured two test gears which is tested and verifie...

  13. Theory of gearing kinematics, geometry, and synthesis

    CERN Document Server

    Radzevich, Stephen P

    2012-01-01

    The first book of its kind, Theory of Gearing: Kinematics, Geometry, and Synthesis systematically develops a scientific theory of gearing that makes it possible to synthesize novel gears with the desired performance. Written by a leading gearing expert who holds more than 200 patents, it presents a modern methodology for gear design. The proposed theory is based on a key postulate: all the design parameters for an optimal gear pair for a particular application can be derived from (a) a given configuration of the rotation vectors of the driving and driven shafts and (b) the power transmitted by

  14. Monolithic geared-mechanisms driven by a polysilicon surface-micromachined on-chip electrostatic microengine

    Energy Technology Data Exchange (ETDEWEB)

    Sniegowski, J.J.; Miller, S.L.; LaVigne, G.F.; Rodgers, M.S.; McWhorter, P.J.

    1996-05-01

    We have previously described a practical micromachined power source: the polysilicon, surface-micromachined, electrostatically actuated microengine. Here we report on 3 aspects of implementing the microengine. First, we discuss demonstrations of the first-generation microengine actuating geared micromechanisms including gear trains with elements having dimensions comparable to the drive gear (about 50 {mu}m) and a relatively large (1600-{mu}m-diameter) rotating optical shutter element. These configurations span expected operating extremes for the microengine and address the coupling and loading issues for very-low-aspect-ratio micromechanisms which are common to the design of surface-micromachined devices. Second, we report on a second-generation of designs that utilize improved gear teeth design, a gear speed-reduction unit, and higher force-per-unit-area electrostatic comb drives. The speed-reduction unit produces an overall angular speed reduction of 9.63 and requires dual-level compound gears. Third, we discuss a dynamics model developed to accomplish 3 objectives: drive inertial loads in a controlled fashion, minimize stress and frictional forces during operation, and determine as a function of time the forces associated with the drive gear (eg load torque on drive gear from friction).

  15. New progressive technology of flat gears processing development

    Directory of Open Access Journals (Sweden)

    Михайло Володимирович Маргуліс

    2015-11-01

    Full Text Available Relevant scientific and technical problems in relation to mechanical engineering is development of new technological processes that make it possible to achieve high accuracy and durability of machine parts that meet the requirements imposed on them. So it is important to develop a new method to make a flat gear teeth by plastic deformation of the ingot. The article deals with the actual problem of improving productivity and quality of plane wheels teeth that are widely used in advanced wave, planetary and other transmissions. A progressive method to produce flat gear teeth gear by plastic deformation of the ingot with two knurl rollers alternately moving reciprocally in the direction not intersecting the axis of the ingot mounting surface has been described in the article. The working surface of the rollers corresponds to the resulting shape of the teeth. The schemes of the teeth installing and knurling have been shown. The necessary material and the heat treatment of the knurling tools have been described. Its use will significantly increase the wear resistance of the working surfaces of the teeth and their durability as well as to increase productivity and its manufacturing costs. The material of the rollers is BC15steel. The surface layer of the knurling tools was subjected to nitration, surface hardness being up to 65 HRC. Knurling is made in the5236P shaper suited for this purpose

  16. Geared rotor dynamic methodologies for advancing prognostic modeling capabilities in rotary-wing transmission systems

    Science.gov (United States)

    Stringer, David Blake

    The overarching objective in this research is the development of a robust, rotor dynamic, physics based model of a helicopter drive train as a foundation for the prognostic modeling for rotary-wing transmissions. Rotorcrafts rely on the integrity of their drive trains for their airworthiness. Drive trains rely on gear technology for their integrity and function. Gears alter the vibration characteristics of a mechanical system and significantly contribute to noise, component fatigue, and personal discomfort prevalent in rotorcraft. This research effort develops methodologies for generating a rotor dynamic model of a rotary-wing transmission based on first principles, through (i) development of a three-dimensional gear-mesh stiffness model for helical and spur gears and integration of this model in a finite element rotor dynamic model, (ii) linear and nonlinear analyses of a geared system for comparison and validation of the gear-mesh model, (iii) development of a modal synthesis technique for potentially providing model reduction and faster analysis capabilities for geared systems, and (iv) extension of the gear-mesh model to bevel and epicyclic configurations. In addition to model construction and validation, faults indigenous to geared systems are presented and discussed. Two faults are selected for analysis and seeded into the transmission model. Diagnostic vibration parameters are presented and used as damage indicators in the analysis. The fault models produce results consistent with damage experienced during experimental testing. The results of this research demonstrate the robustness of the physics-based approach in simulating multiple normal and abnormal conditions. The advantages of this physics-based approach, when combined with contemporary probabilistic and time-series techniques, provide a useful method for improving health monitoring technologies in mechanical systems.

  17. Planetary protection in the framework of the Aurora exploration program

    Science.gov (United States)

    Kminek, G.

    The Aurora Exploration Program will give ESA new responsibilities in the field of planetary protection. Until now, ESA had only limited exposure to planetary protection from its own missions. With the proposed ExoMars and MSR missions, however, ESA will enter the realm of the highest planetary protection categories. As a consequence, the Aurora Exploration Program has initiated a number of activities in the field of planetary protection. The first and most important step was to establish a Planetary Protection Working Group (PPWG) that is advising the Exploration Program Advisory Committee (EPAC) on all matters concerning planetary protection. The main task of the PPWG is to provide recommendations regarding: Planetary protection for robotic missions to Mars; Planetary protection for a potential human mission to Mars; Review/evaluate standards & procedures for planetary protection; Identify research needs in the field of planetary protection. As a result of the PPWG deliberations, a number of activities have been initiated: Evaluation of the Microbial Diversity in SC Facilities; Working paper on legal issues of planetary protection and astrobiology; Feasibility study on a Mars Sample Return Containment Facility; Research activities on sterilization procedures; Training course on planetary protection (May, 2004); Workshop on sterilization techniques (fall 2004). In parallel to the PPWG, the Aurora Exploration Program has established an Ethical Working Group (EWG). This working group will address ethical issues related to astrobiology, planetary protection, and manned interplanetary missions. The recommendations of the working groups and the results of the R&D activities form the basis for defining planetary protection specification for Aurora mission studies, and for proposing modification and new inputs to the COSPAR planetary protection policy. Close cooperation and free exchange of relevant information with the NASA planetary protection program is strongly

  18. Investigation into nitrided spur gears

    Energy Technology Data Exchange (ETDEWEB)

    Yilbas, B.S.; Coban, A.; Nickel, J.; Sunar, M.; Sami, M.; Abdul Aleem, B.J. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia)

    1996-12-01

    The cold forging method has been widely used in industry to produce machine parts. In general, gears are produced by shaping or hobbing. One of the shaping techniques is precision forging, which has several advantages over hobbing. In the present study, cold forging of spur gears from Ti-6Al-4V material is introduced. To improve the surface properties of the resulting gears, plasma nitriding was carried out. Nuclear reaction analysis was carried out to obtain the nitrogen concentration, while the micro-PIXE technique was used to determine the elemental distribution in the matrix after forging and nitriding processes. Scanning electron microscopy and x-ray powder diffraction were used to investigate the metallurgical changes and formation of nitride components in the surface region. Microhardness and friction tests were carried out to measure the hardness depth profile and friction coefficient at the surface. Finally, scoring failure tests were conducted to determine the rotational speed at which the gears failed. Three distinct regions were obtained in the nitride region, and at the initial stages of the scoring tests, failure in surface roughness was observed in the vicinity of the tip of the gear tooth. This occurred at a particular rotational speed and work input.

  19. Investigation into nitrided spur gears

    Science.gov (United States)

    Yilbas, B. S.; Coban, A.; Nickel, J.; Sunar, M.; Sami, M.; Aleem, B. J. Abdul

    1996-12-01

    The cold forging method has been widely used in industry to produce machine parts. In general, gears are produced by shaping or hobbing. One of the shaping techniques is precision forging, which has several advantages over hobbing. In the present study, cold forging of spur gears from Ti-6A1-4V material is introduced. To improve the surface properties of the resulting gears, plasma nitriding was carried out. Nuclear reaction analysis was carried out to obtain the nitrogen concentration, while the micro-PIXE technique was used to determine the elemental distribution in the matrix after forging and nitriding processes. Scanning electron microscopy and x-ray powder diffraction were used to investigate the metallurgical changes and formation of nitride components in the surface region. Microhardness and friction tests were carried out to measure the hardness depth profile and friction coefficient at the surface. Finally, scoring failure tests were conducted to determine the rotational speed at which the gears failed. Three distinct regions were obtained in the nitride region, and at the initial stages of the scoring tests, failure in surface roughness was observed in the vicinity of the tip of the gear tooth. This occurred at a particular rotational speed and work input.

  20. Mechanical Analysis of P- S Closed Differential Planetary Gear Trains%一种P-S型封闭差动行星齿轮系的力学分析

    Institute of Scientific and Technical Information of China (English)

    孙金风; 饶建华

    2004-01-01

    运用力学的基本分析方法,选择轮系力学分析单元,对P-S型封闭差动行星齿轮系中各个活动构件进行了力学分析,该分析不仅可以得到输入与输出的力矩关系,而且可以得到强度设计中十分重要的轮系在不同位形时的各运动副的作用力.

  1. Gear Fault Diagnosis Based on Rough Set and Support Vector Machine

    Institute of Scientific and Technical Information of China (English)

    TIAN Huifang; SUN Shanxia

    2006-01-01

    By introducing Rough Set Theory and the principle of Support vector machine, a gear fault diagnosis method based on them is proposed. Firstly, diagnostic decision-making is reduced based on rough set theory, and the noise and redundancy in the sample are removed, then, according to the chosen reduction, a support vector machine multi-classifier is designed for gear fault diagnosis. Therefore, SVM' training data can be reduced and running speed can quicken. Test shows its accuracy and efficiency of gear fault diagnosis.

  2. 考虑内部激励随机性的两级分流式人字齿轮传动动力学特性%Dynamic characteristics of two-stage split herringbone gear trains considering the randomness of internal excitations

    Institute of Scientific and Technical Information of China (English)

    廖映华; 秦大同; 刘长钊

    2015-01-01

    According to the configurational characteristics,a bearing-gear coupled non-linear dynamics model of two-stage split herringbone gear trains used in special equipment was presented.In the model,bearing stiffness,mesh stiffness,mesh errors and gear backlash were all included.Then the Runge-Kutta step-by-step integration method was used to solve the non-linear differential equations of motion,the time history curves and frequency spectrums of the dynamic meshing force and dynamic bearing force were obtained considering the random mesh stiffness and mesh error excitations, and further,their statistical characteristics were determined by Monte Carlo simulation to analyze the influences of the randomness of mesh stiffness and mesh errors on the dynamic mesh force and dynamic bearing force.The research results lay a foundation for the dynamic optimization and dynamic reliability optimization of two-stage split herringbone gear trains.%根据某特种装备用两级分流式人字齿轮传动系统的构型特点,考虑轴承变形、啮合刚度、啮合误差和齿侧间隙等因素,建立了两级分流式人字齿轮传动系统的轴承-齿轮耦合非线性动力学模型。采用 Runge-Kutta 逐步积分法求解系统的非线性动力学微分方程,从而获得随机啮合刚度和啮合误差激励作用下两级分流式人字齿轮传动系统的动态啮合力和动态支承力及其频谱,采用 Monte Carlo 仿真获得动态啮合力和动态支承力的统计特征,研究了啮合刚度和啮合误差随机性对动态啮合力和动态支承力的影响规律,为两级分流式人字齿轮传动系统动力学优化以及动态可靠性优化奠定基础。

  3. Design and Dynamics Simulation of a Novel Double-Ring-Plate Gear Reducer

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A patented double-ring-plate gear reducer was designed and its dynamic performance was simulated. One unique characteristic of this novel drive is that the phase angle difference between two parallelogram mechanisms is a little less than 180 degree and four counterweights on two crankshafts are designed to balance inertia forces and inertia moments of the mechanisms. lts oper ating principle, advantages, and design issues were discussed. An elasto-dynamics model was presented to acquire its dynamic response by considering the elastic deformations of ring-plates,gears, bearings, etc. The simulation results reveal that compared with housing bearings, planetary bearings work in more severe conditions. The fluctuation of loads on gears and bearings indicates that the main reason for reducer vibration is elastic deformations of the system rather than inertia forces and inertia moments of the mechanisms.

  4. Development of a gear vibration indicator and its application in gear wear monitoring

    Science.gov (United States)

    Hu, Chongqing; Smith, Wade A.; Randall, Robert B.; Peng, Zhongxiao

    2016-08-01

    Gear tooth wear is an inevitable phenomenon and has a significant influence on gear dynamic features. Although vibration analysis has been widely used to diagnose localised gear tooth faults, its techniques for gear wear monitoring have not been well-established. This paper aims at developing a vibration indicator to evaluate the effects of wear on gear performance. For this purpose, a gear state vector is extracted from time synchronous averaged gear signals to describe the gear state. This gear state vector consists of the sideband ratios obtained from a number of tooth meshing harmonics and their sidebands. Then, two averaged logarithmic ratios, ALR and mALR, are defined with fixed and moving references, respectively, to provide complementary information for gear wear monitoring. Since a fixed reference is utilised in the definition of ALR, it reflects the cumulated wear effects on the gear state. An increase in the ALR value indicates that the gear state deviates further from its reference condition. With the use of a moving reference, the indicator mALR shows changes in the gear state within short time intervals, making it suitable for wear process monitoring. The efficiency of these vibration indicators is demonstrated using experimental results from two sets of tests, in which the gears experienced different wear processes. In addition to gear wear monitoring, the proposed indicators can be used as general parameters to detect the occurrence of other faults, such as a tooth crack or shaft misalignment, because these faults would also change the gear vibrations.

  5. Computer simulation of gear tooth manufacturing processes

    Science.gov (United States)

    Mavriplis, Dimitri; Huston, Ronald L.

    1990-01-01

    The use of computer graphics to simulate gear tooth manufacturing procedures is discussed. An analytical basis for the simulation is established for spur gears. The simulation itself, however, is developed not only for spur gears, but for straight bevel gears as well. The applications of the developed procedure extend from the development of finite element models of heretofore intractable geometrical forms, to exploring the fabrication of nonstandard tooth forms.

  6. Advanced theories of hypoid gears

    CERN Document Server

    Wang, Xudong

    2013-01-01

    In order to develop more efficient types of gears, further investigation into the theories of engagement is necessary. Up until now most of the research work on the theories of engagement has been carried out separately on different groups, and based on individual types of profiles. This book aims at developing some universal theories, which can not only be used for all types of gears, but can also be utilized in other fields such as sculptured surfaces. The book has four characteristics: the investigations are concentrated on mismatched tooth surfaces; all the problems are dealt with from a

  7. The Casimir Torque on a Cylindrical Gear

    CERN Document Server

    Vaidya, Varun

    2013-01-01

    We utilize Effective Field Theory(EFT) techniques to calculate the casimir torque on a cylindrical gear in the presence of a polarizable but neutral object. We present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.

  8. Casimir torque on a cylindrical gear

    Science.gov (United States)

    Vaidya, Varun

    2014-08-01

    I utilize effective field theory(EFT) techniques to calculate the Casimir torque on a cylindrical gear in the presence of a polarizable but neutral object and present results for the energy and torque as a function of angle for a gear with multiple cogs, as well as for the case of a concentric cylindrical gear.

  9. 7 CFR 2902.47 - Gear lubricants.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Gear lubricants. 2902.47 Section 2902.47 Agriculture... Gear lubricants. (a) Definition. Products, such as greases or oils, that are designed to reduce... qualifying biobased gear lubricants. By that date, Federal agencies that have the responsibility for...

  10. 46 CFR 28.885 - Cargo gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Cargo gear. 28.885 Section 28.885 Shipping COAST GUARD... Aleutian Trade Act Vessels § 28.885 Cargo gear. (a) The safe working load (SWL) for the assembled gear shall be marked on the heel of each cargo boom, crane, or derrick. These letters and figures are to...

  11. 经验模态分解和Laplace小波在机车柴油机齿轮系故障诊断中的应用%Fault Diagnosis for Gear Train of Locomotive Diesel Engine Based on Empirical Mode Decomposition and Laplace Wavelet

    Institute of Scientific and Technical Information of China (English)

    杨江天; 周培钰

    2011-01-01

    The acoustic signal of the valve gear train in a locomotive diesel engine is proved non-stationary and carries intense background noise. In view of these characteristics, empirical mode decomposition (EMD) and Laplace wavelet are used in acoustic signal analysis of locomotive diesel engines. The principles and algorithms of EMD are briefly introduced. Applying EMD to the real signal measured from locomotive diesel engines, the ability of signal denoising is demonstrated. EMD acts essentially as an adaptive filter bank. Acoustic signal acquired from diesel engine valve gear train is decomposed into a number of intrinsic mode functions (IMFs), with each IMF corresponding to a specific range of frequency components contained within the signal. The power spectrum analysis is applied to the intrinsic mode function which contains the gear fault characteristics for detecting the gear faults. Due to the fact that the signature of a damaged bearing consists of exponentially decaying sinusoids and the characteristic frequency is of very Iow energy level masked by noise, the correlation filtering based on Laplace wavelet is used to identify the signature and extract the characteristic defect frequencies of the bearings. The proposed method is effectively applied to the operation tests of locomotive diesel engines, and the faults of the valve gear train are diagnosed successfully.%针对机车柴油机配气齿轮系故障信号呈现时变非平稳特征且信噪比低的特点,提出基于经验模态分解和Laplace小波的机车柴油机声信号分析方法,并成功用于工业现场.简要介绍信号经验模态分解的基本原理与算法,以机车柴油机实际声信号为例,分析其抑制噪声干扰的能力.经验模态分解相当于自适应滤波器组,可将信号分解成不同频带的固有模态函数(Intrinsic mode functions,IMF).试验表明对表征齿轮故障的IMF分量进行功率谱分析,能有效检测齿轮故障.根据滚动轴承故障

  12. GEAR UP Aspirations Project Evaluation

    Science.gov (United States)

    Trimble, Brad A.

    2013-01-01

    The purpose of this study was to conduct a formative evaluation of the first two years of the Gaining Early Awareness and Readiness for Undergraduate Programs (GEAR UP) Aspirations Project (Aspirations) using a Context, Input, Process, and Product (CIPP) model so as to gain an in-depth understanding of the project during the middle school…

  13. TOOTH CONTACT ANALYSIS OF CONICAL INVOLUTE GEARS

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mathematical model of conical involute gears is developed based on the theory of gearing and the generating mechanism. Tooth contact analysis (TCA) is performed to examine the meshing and bearing contact of the conical involute gear pairs with intersected and crossed axes. In addition, the principal directions and curvatures of the gear surfaces are investigated and the contact ellipses of the mating tooth surfaces are also studied. Finally, the numerical illustrative examples are provided to demonstrate the computational results, test gears are made for tooth-bearing tests, and the conclusion is verified that the theory has the applicability.

  14. Asymmetric gear rectifies random robot motion

    Science.gov (United States)

    Li, He; Zhang, H. P.

    2013-06-01

    We experimentally study the dynamics of centimetric robots and their interactions with rotary gears through inelastic collisions. Under the impacts of self-propelled robots, a gear with symmetric teeth diffuses with no preferred direction of motion. An asymmetric gear, however, rectifies random motion of nearby robots which, in return, exert a torque on the gear and drive it into unidirectional motion. Rectification efficiency increases with the degree of gear asymmetry. Our work demonstrates that asymmetric environments can be used to rectify and extract energy from random motion of macroscopic self-propelled particles.

  15. 基于刚柔耦合的高速列车齿轮传动系统动态特性研究%Research on The Dynamic Characteristics of Gear Transmission System of High-speed Train Based on the Rigid-flexible Coupling Dynamics

    Institute of Scientific and Technical Information of China (English)

    邓晓宇; 张卫华

    2016-01-01

    文章研究了高速列车齿轮传动系统的动态特性及齿轮箱箱体的高频振动响应特性,基于多体动力学分析软件SIMPACK建立了国内某高速动车组列车动车的车辆动力学模型,并在模型中对车辆的齿轮传动系统进行了精确建模。同时,利用有限元分析软件ANSYS与SIMPACK联合仿真,将齿轮箱箱体考虑为柔性体,建立了刚柔耦合车辆系统动力学模型,比较分析了柔性箱体与刚性箱体的动态响应特性。结果表明:(1)刚性箱体与柔性箱体的振动位移差别不大;(2)柔性箱体振动速度、加速度响应均大于刚性箱体;(3)柔性箱体相对于刚性箱体产生了高频振动响应,并能引发箱体共振,使箱体振动加剧。%In order to study the dynamic characteristics of gear transmission system of the high-speed train and the high frequency vibration response characteristics of gear box,a vehicle dynamics model based on SIMPACK is established. And the gear transmission system is modeled accurately in the model.Meanwhile,a rigid-flexible coupling dynamic system model of the vehicle is established by considering the gear box as a flexible body with joint simulation using ANSYS and SIMPACK.The differences of the dynamic characteristics between the flexible/rigid gearboxes are compared and analyzed.The results show that:1 .there are little difference of vibration displacement between the rigid box and the flexible box;2.the vibration velocity and acceleration response of the flexible box are larger than those of the rigid body;3 .the high frequency vibration response is generated in the flexible box body,which can cause the box body to resonate.

  16. From Planetary Intelligence to Planetary Wisdom

    Science.gov (United States)

    Moser, S. C.

    2016-12-01

    "Planetary intelligence" - when understood as an input into the processes of "managing" Earth - hints at an instrumental understanding of scientific information. At minimum it is a call for useful data of political (and even military) value; at best it speaks to an ability to collect, integrate and apply such information. In this sense, 21st century society has more "intelligence" than any generation of humans before, begging the question whether just more or better "planetary intelligence" will do anything at all to move us off the path of planetary destruction (i.e., beyond planetary boundaries) that it has been on for decades if not centuries. Social scientists have argued that there are at least four shortcomings in this way of thinking that - if addressed - could open up 1) what is being researched; 2) what is considered socially robust knowledge; 3) how science interacts with policy-makers and other "planet managers"; and 4) what is being done in practice with the "intelligence" given to those positioned at the levers of change. To the extent "planetary management" continues to be approached from a scientistic paradigm alone, there is little hope that Earth's future will remain in a safe operating space in this or coming centuries.

  17. Frictional Effects on Gear Tooth Contact Analysis

    Directory of Open Access Journals (Sweden)

    Zheng Li

    2013-01-01

    Full Text Available The present paper concentrates on the investigations regarding the situations of frictional shear stress of gear teeth and the relevant frictional effects on bending stresses and transmission error in gear meshing. Sliding friction is one of the major reasons causing gear failure and vibration; the adequate consideration of frictional effects is essential for understanding gear contact behavior accurately. An analysis of tooth frictional effect on gear performance in spur gear is presented using finite element method. Nonlinear finite element model for gear tooth contact with rolling/sliding is then developed. The contact zones for multiple tooth pairs are identified and the associated integration situation is derived. The illustrated bending stress and transmission error results with static and dynamic boundary conditions indicate the significant effects due to the sliding friction between the surfaces of contacted gear teeth, and the friction effect can not be ignored. To understand the particular static and dynamic frictional effects on gear tooth contact analysis, some significant phenomena of gained results will also be discussed. The potentially significant contribution of tooth frictional shear stress is presented, particularly in the case of gear tooth contact analysis with both static and dynamic boundary conditions.

  18. Planetary Atmospheric Electricity

    CERN Document Server

    Leblanc, F; Yair, Y; Harrison, R. G; Lebreton, J. P; Blanc, M

    2008-01-01

    This volume presents our contemporary understanding of atmospheric electricity at Earth and in other solar system atmospheres. It is written by experts in terrestrial atmospheric electricity and planetary scientists. Many of the key issues related to planetary atmospheric electricity are discussed. The physics presented in this book includes ionisation processes in planetary atmospheres, charge generation and separation, and a discussion of electromagnetic signatures of atmospheric discharges. The measurement of thunderstorms and lightning, including its effects and hazards, is highlighted by articles on ground and space based instrumentation, and new missions.Theory and modelling of planetary atmospheric electricity complete this review of the research that is undertaken in this exciting field of space science. This book is an essential research tool for space scientists and geoscientists interested in electrical effects in atmospheres and planetary systems. Graduate students and researchers who are new to t...

  19. Dudley's handbook of practical gear design and manufacture

    CERN Document Server

    Radzevich, Stephen P

    2012-01-01

    A unique, single source reference for all aspects of gears, Dudley's Handbook of Practical Gear Design and Manufacture, Second Edition provides comprehensive and consistent information on the design and manufacture of gears for the expert and novice alike. The second edition of this industry standard boasts seven new chapters and appendices as well as a wealth of updates throughout. New chapters and expanded topics include: Gear Types and Nomenclature, Gear Tooth Design, Gear Reactions and Mountings, Gear Vibration, The Evolution of the Gear Art, Novikov Gearing and the Inadequacy of the Term,

  20. High-torque quiet gear

    Science.gov (United States)

    Moody, Paul E.

    1995-07-01

    A high-torque quiet gear construction consists of an inner hub having a plurality of circumferentially spaced arms extending radially outwardly therefrom, and an outer ring member having a plurality of circumferentially spaced-teeth extending radially inwardly therefrom. The ring member further includes a plurality of gear formations on an outer surface thereof for intermeshing with other gears. The teeth of the ring member are received in spaced relation in corresponding spaces formed between adjacent arms of the hub. An elastomeric member is received in the space formed between the hub and the ring member to form a resilient correction between the arms of the hub and the teeth of the ring member. The side surfaces of the arms and the teeth extend generally parallel to each other and at least partially overlap in a longitudinal direction. The purpose of this configuration is to place the elastomeric member in compression when torque is applied to the hub. Since elastomeric material is relatively incompressible, the result is low shear loads on the adhesive bonds which hold the elastomeric member to both the hub and outer ring member.

  1. RPG 行星减速器齿面应力均化分析%The homogenization analysis for tooth surface stress of RPG planetary reductor

    Institute of Scientific and Technical Information of China (English)

    孔霞; 蔡云龙

    2015-01-01

    为避免RPG行星减速器因齿面应力分布不均导致的齿面接触应力增加、齿根弯曲强度下降、行星轮轴承受力不均等问题,以RPG39-50型行星减速器为例,利用有限元方法,构建该型减速器的系统柔性模型,依托行星排框架、行星轮销轴、行星轮轴承及输出排齿轮等关键结构件的变形分析,进行了针对性的齿面优化修形,从而实现了齿面应力均化,有效提高了该齿轮系统的寿命与可靠性。%The RPG planetary redactor is a special redactor with the conditions of large power , low speed and large torque output .The output structure of the RPG planetary redactor is easy to deform of many components , and the unbalanced distribution of tooth surface stress is inevitable .All these problems may cause the worse transmission conditions such as the raise of tooth surface contact stress , the drop of tooth flexural strength and the unbalanced loads of planetary gear bears .Taking RPG39-50 planetary redactor as an example , it uses the finite element method to build the flexible model of the redactor , analyzes the deformation of the components such as the planetary gear frame , the planetary gear shafts , the planetary gear bears and the output gears .At last , it re-alizes the tooth optimization repair .The result homogenizes the tooth surface stress and improves the reliability of the gear transmission system .

  2. 29 CFR 1919.19 - Gear requiring welding.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Gear requiring welding. 1919.19 Section 1919.19 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels' Cargo Gear § 1919.19 Gear requiring welding. Chains or other gear which have been lengthened, altered or repaired by welding shall be properly...

  3. 50 CFR 697.23 - Restricted gear areas.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Restricted gear areas. 697.23 Section 697... Measures § 697.23 Restricted gear areas. (a) Resolution of lobster gear conflicts with fisheries managed...) Restricted Gear Area I—(1) Duration—(i) Mobile Gear. From October 1 through June 15 of each fishing year,...

  4. Effects of gear box vibration and mass imbalance on the dynamics of multistage gear transmission

    Science.gov (United States)

    Choy, F. K.; Tu, Y. K.; Zakrajsek, J. J.; Townsend, D. P.

    1991-01-01

    The dynamic behavior of multistage gear transmission system, with the effects of gear-box-induced vibrations and rotor mass-imbalances is analyzed. The model method, using undamped frequencies and planar mode shapes, is used to reduce the degree-of-freedom of the system. The various rotor-bearing stages as well as lateral and torsional vibrations of each individual stage are coupled through localized gear-mesh-tooth interactions. Gear-box vibrations are coupled to the gear stage dynamics through bearing support forces. Transient and steady state dynamics of lateral and torsional vibrations of the geared system are examined in both time and frequency domain. A typical three-staged geared system is used as an example. Effects of mass-imbalance and gear box vibrations on the system dynamic behavior are presented in terms of modal excitation functions for both lateral and torsional vibrations. Operational characteristics and conclusions are drawn from the results presented.

  5. Pneumatic, PLC Controlled, Automotive Gear Shifting Mechanism

    Directory of Open Access Journals (Sweden)

    Muntaser Momani

    2010-05-01

    Full Text Available In this study, a gear shifting mechanism was designed and applied to make the shifting process faster and less destructible for the driver. The new device must be reliable, has a small dimensions, low construction and maintenance cost. This paper aims to improve gear shifting process using devices as: a manual four speed gear box, four pneumatic double acting cylinders, four pneumatic two position five ways directional control valves, Programmable Logic Controller (PLC LOGO unit, an electrical motor, an electrical clutch, a belt, two pulleys, limit switches, push buttons, bulbs, a table (holder and power supply. According to suggested gear_ shifting method the driver can select the transmission gear ratio without moving his hands from the steering wheel by putting the gear shifting push buttons on the steering wheel. Using this method leaves to the driver the excitement of choosing the shifting moment.

  6. Optical gears in a nanophotonic directional coupler

    CERN Document Server

    Zhang, Fengchun; Zhang, Heran; Zhang, Yong; Huang, Xu-Guang; Jia, Baohua; Liu, Songhao

    2016-01-01

    Gears are rotating machines, meshing with each other by teeth to transmit torque. Interestingly, the rotating directions of two meshing gears are opposite, clockwise and counterclockwise. Although this opposite handedness motion has been widely investigated in machinery science, the analogue behavior of photons remains undiscovered. Here, we present a simple nanophotonic directional coupler structure which can generate two meshing gears of angular momentum (AM) of light, optical gears. Due to the abrupt phase shift effect and birefringence effect, the AM states of photons vary with the propagation distance in two adjacent waveguides of the coupler. Thus, by the choice of coupling length, it is able to obtain two light beams with opposite handedness of AM, confirming the appearance of optical gears. The full control in the handedness of output beams is achieved via tuning the relative phase between two orthogonal modes at the input ports. Optical gears thus offer the possibility of exploring light-matter inter...

  7. Tool Gear: Infrastructure for Parallel Tools

    Energy Technology Data Exchange (ETDEWEB)

    May, J; Gyllenhaal, J

    2003-04-17

    Tool Gear is a software infrastructure for developing performance analysis and other tools. Unlike existing integrated toolkits, which focus on providing a suite of capabilities, Tool Gear is designed to help tool developers create new tools quickly. It combines dynamic instrumentation capabilities with an efficient database and a sophisticated and extensible graphical user interface. This paper describes the design of Tool Gear and presents examples of tools that have been built with it.

  8. 汽车变速箱齿轮传动系动力学振动特性的研究%Vibration characteristics of transmission gear-train for a car

    Institute of Scientific and Technical Information of China (English)

    郭磊; 郝志勇; 蔡军; 刘波

    2010-01-01

    建立发动机曲柄连杆系统的扭振当量模型,得到飞轮端动态转速波动及扭振角位移作为齿轮传动系主轴输入端的动态激励;采用多体动力学方法建立某五挡手动变速箱齿轮传动系动力学模型,以二档为例,分析了上档齿轮在齿面啮合时变刚度作用下产生的呜呜噪声(Gear Whine)特性,及未上档齿轮在其自由惯量和齿侧隙下产生的咔嗒噪声(Gear Rattle)特性;分析了发动机二档转速范围内齿轮传动轴各处轴承动态载荷的频谱特性;同时,利用实验测量的曲轴系扭振各阶次曲线验证了扭振当量系统模型的正确性,并利用实验表面振动速度法识别了转速范围内变速箱结构的振动速度级,验证了动力学仿真模型中得到的动态啮合冲击载荷的特性.

  9. Cálculo de engranajes plásticos. // Directions about plastic gear calculation.

    Directory of Open Access Journals (Sweden)

    J. L. Moya Rodríguez

    2007-09-01

    Full Text Available En los últimos tiempos los materiales plásticos han tenido una proliferación en todos los campos de la Industria Mecánica,debido esencialmente a su bajo costo y a las mejoras de las propiedades mecánicas que se han ido logrando. En el casoparticular de las transmisiones por engranajes existe una gran cantidad de estos materiales que pueden ser usados y dehecho se utilizan para la fabricación de ruedas dentadas de características muy disímiles. En la literatura científica existemuy poca información disponible sobre las fallas de engranajes plásticos, métodos de cálculo a resistencia y posiblesmateriales a emplear con sus respectivas propiedades mecánicas. Inclusive este tema no se aborda en los currículos deestudio tradicionales en Ibero-América. Queda mucho por discutir aun acerca del empleo de las correcciones del dentado enestas ruedas dentadas plásticas. En el presente trabajo se hace un análisis de los materiales, características, estudio de lasfallas principales, métodos de cálculo y ejemplos de aplicación de los engranajes plásticos.Palabras claves: Plásticos, engranes, perfil dentado.____________________________________________________________________________Abstract.Recently the use of plastic materials has been growing up due to their low cost and the improvements achieved on theirmechanical properties. In the particular case of gear transmissions there are great quantities of polymers that can be usedfor gears. Plastic gears are powerful means of cutting drive cost, weight, noise, and wear. Plastic gears also open newopportunities for smaller and more efficient transmissions. Scientific literature about plastic gears failures, designingmethods and materials is insufficient. Most engineering reference books are desicated to steel gears but there areremarkably silent about plastic gears. Design methods for plastic gears and gear trains must be modernized, because muchof the information available is derived from

  10. Planetary data definition

    Science.gov (United States)

    1984-10-01

    Planetary data include all of those data which have resulted from measurements made by the instruments carried aboard planetary exploration spacecraft, and (for our purposes) exclude observations of Moon and Earth. The working, planetary data base is envisioned to contain not only these data, but also a wide range of supporting measurements such as calibration files, navigation parameters, spacecraft engineering states, and the various Earth-based and laboratory measurements which provide the planetary research scientist with historical and comparative data. No convention exists across the disciplines of the planetary community for defining or naming the various levels through which data pass in the progression from a sensed impulse at the spacecraft to a reduced, calibrated, and/or analyzed element in a planetary data set. Terms such as EDR (experiment data record), RDR (reduced data record), and SEDR (supplementary experiment data record) imply different meanings depending on the data set under consideration. The development of standard terminology for the general levels of planetary data is necessary.

  11. NEW DESIGN METHOD FOR HYPOID GEARS

    Institute of Scientific and Technical Information of China (English)

    Su Zhijiang; Wu Xutang; Mao Shimin

    2005-01-01

    A digital model is presented for the purpose of design, manufacture and measurement of hypoid gear, based on the non-uniform rational B-spline surface (NURBS) method. The digital model and the function-oriented active design technique are combined to form a new design method for hypoid gears. The method is well adaptable to CNC bevel gear cutting machines and CNC-controlled gear inspection machines, and can be used to create the initial machine tool cutting location data or program measurement path. The presented example verifies the method is correct.

  12. Gear Noise and Vibration : A Literature Survey

    OpenAIRE

    Åkerblom, Mats

    2001-01-01

    This paper is a survey of the literature on gear noise and vibration. It is divided into three parts, “Transmission error”, “Dynamic models” and “Noise and vibration measurement”. Transmission error (TE) is considered to be an important excitation mechanism for gear noise and vibration. The definition of transmission error is “The difference between the actual position of the output gear and the position it would occupy if the gear drive were perfectly conjugate”. Dynamic models of the system...

  13. Evaluation of Carburized and Ground Face Gears

    Science.gov (United States)

    Lewicki, David G.; Handschuh, Robert F.; Heath, Gregory F.; Sheth, Vijay

    1999-01-01

    Experimental durability tests were performed on carburized and ground AIS19310 steel face gears. The tests were in support of a Defense Advanced Research Projects Agency (DARPA) Technology Reinvestment Program (TRP) to enhance face-gear technology. The tests were conducted in the NASA Glenn spiral-bevel-gear/face-gear test facility. Tests were run at 2300 rpm face gear speed and at loads of 64, 76, 88, 100, and 112-percent of the design torque of 377 N-m (3340 in-lb). The carburized and ground face gears demonstrated the required durability when run for ten-million cycles at each of the applied loads. Proper installation was critical for the successful operation of the spur pinions and face gears. A large amount of backlash produced tooth contact patterns that approached the inner-diameter edge of the face-gear tooth. Low backlash produced tooth contact patterns that approached the outer-diameter edge of the face-gear tooth. Measured backlashes in the range of 0.178 to 0.254 mm (0.007 to 0.010 in) produced acceptable tooth contact patterns.

  14. Load Sharing Behavior of Star Gearing Reducer for Geared Turbofan Engine

    Science.gov (United States)

    Mo, Shuai; Zhang, Yidu; Wu, Qiong; Wang, Feiming; Matsumura, Shigeki; Houjoh, Haruo

    2017-07-01

    Load sharing behavior is very important for power-split gearing system, star gearing reducer as a new type and special transmission system can be used in many industry fields. However, there is few literature regarding the key multiple-split load sharing issue in main gearbox used in new type geared turbofan engine. Further mechanism analysis are made on load sharing behavior among star gears of star gearing reducer for geared turbofan engine. Comprehensive meshing error analysis are conducted on eccentricity error, gear thickness error, base pitch error, assembly error, and bearing error of star gearing reducer respectively. Floating meshing error resulting from meshing clearance variation caused by the simultaneous floating of sun gear and annular gear are taken into account. A refined mathematical model for load sharing coefficient calculation is established in consideration of different meshing stiffness and supporting stiffness for components. The regular curves of load sharing coefficient under the influence of interactions, single action and single variation of various component errors are obtained. The accurate sensitivity of load sharing coefficient toward different errors is mastered. The load sharing coefficient of star gearing reducer is 1.033 and the maximum meshing force in gear tooth is about 3010 N. This paper provides scientific theory evidences for optimal parameter design and proper tolerance distribution in advanced development and manufacturing process, so as to achieve optimal effects in economy and technology.

  15. Development of austempered ductile iron timing gears; Austemper kyujo kokuen chutetsu timing gear no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, M.; Yamamoto, S.; Numajiri, S.; Nakajima, K. [Mitsubishi Motors Corp., Tokyo (Japan)

    1996-05-01

    To reduce vibration and noise of gears compared with ordinary steel gears for four cycle diesel engine of small commercial vehicles, austempered ductile iron (ADI) gears have been developed, which have excellent mechanical properties and vibration damping properties equivalent to steel gears. ADI is a material with tensile strength of 1,000 MPa, which is made by austempering the ductile iron to change matrix texture into tough bainite. For a new process method of ADI gears, austempering is conducted after gear cutting, and shaving is conducted, finally. Gear materials before austempering can be smoothly machined without deteriorating their machinability, to produce highly accurate gears. Fifteen percent of noise can be reduced for ADI gears during idling of engine, where 0.7 dB can be reduced in the noise level. The ADI gears provide superior pitting resistance to ordinary steel gears. They have nearly equivalent dedendum bending fatigue strength to ordinary soft nitrided steel gears. 6 refs., 12 figs., 2 tabs.

  16. Load Sharing Behavior of Star Gearing Reducer for Geared Turbofan Engine

    Science.gov (United States)

    Mo, Shuai; Zhang, Yidu; Wu, Qiong; Wang, Feiming; Matsumura, Shigeki; Houjoh, Haruo

    2017-03-01

    Load sharing behavior is very important for power-split gearing system, star gearing reducer as a new type and special transmission system can be used in many industry fields. However, there is few literature regarding the key multiple-split load sharing issue in main gearbox used in new type geared turbofan engine. Further mechanism analysis are made on load sharing behavior among star gears of star gearing reducer for geared turbofan engine. Comprehensive meshing error analysis are conducted on eccentricity error, gear thickness error, base pitch error, assembly error, and bearing error of star gearing reducer respectively. Floating meshing error resulting from meshing clearance variation caused by the simultaneous floating of sun gear and annular gear are taken into account. A refined mathematical model for load sharing coefficient calculation is established in consideration of different meshing stiffness and supporting stiffness for components. The regular curves of load sharing coefficient under the influence of interactions, single action and single variation of various component errors are obtained. The accurate sensitivity of load sharing coefficient toward different errors is mastered. The load sharing coefficient of star gearing reducer is 1.033 and the maximum meshing force in gear tooth is about 3010 N. This paper provides scientific theory evidences for optimal parameter design and proper tolerance distribution in advanced development and manufacturing process, so as to achieve optimal effects in economy and technology.

  17. Involute Spur Gear Template Development by Parametric Technique ...

    African Journals Online (AJOL)

    ... Gear Template Development by Parametric Technique Using Computer Aided Design. ... cylindrical coordinate systems to create the involute curve profile. Since spur gear geometry is controlled by a few basic parameters, a generic gear

  18. Visual Impairment Training Reviewed.

    Science.gov (United States)

    Maychell, Karen; Smart, David

    1989-01-01

    A British study of training provided for social services workers with the visually impaired found that emphasis was on workers' learning the skills their clients would need, rather than on how to teach those skills; most training is geared toward the totally blind, a small proportion of the population; and workers felt the need to acquire…

  19. Application of Reassigned Wavelet Scalogram in Wind Turbine Planetary Gearbox Fault Diagnosis under Nonstationary Conditions

    Directory of Open Access Journals (Sweden)

    Xiaowang Chen

    2016-01-01

    Full Text Available Wind turbine planetary gearboxes often run under nonstationary conditions due to volatile wind conditions, thus resulting in nonstationary vibration signals. Time-frequency analysis gives insight into the structure of an arbitrary nonstationary signal in joint time-frequency domain, but conventional time-frequency representations suffer from either time-frequency smearing or cross-term interferences. Reassigned wavelet scalogram has merits of fine time-frequency resolution and cross-term free nature but has very limited applications in machinery fault diagnosis. In this paper, we use reassigned wavelet scalogram to extract fault feature from wind turbine planetary gearbox vibration signals. Both experimental and in situ vibration signals are used to evaluate the effectiveness of reassigned wavelet scalogram in fault diagnosis of wind turbine planetary gearbox. For experimental evaluation, the gear characteristic instantaneous frequency curves on time-frequency plane are clearly pinpointed in both local and distributed sun gear fault cases. For in situ evaluation, the periodical impulses due to planet gear fault are also clearly identified. The results verify the feasibility and effectiveness of reassigned wavelet scalogram in planetary gearbox fault diagnosis under nonstationary conditions.

  20. New Gear Transmission Error Measurement System Designed

    Science.gov (United States)

    Oswald, Fred B.

    2001-01-01

    The prime source of vibration and noise in a gear system is the transmission error between the meshing gears. Transmission error is caused by manufacturing inaccuracy, mounting errors, and elastic deflections under load. Gear designers often attempt to compensate for transmission error by modifying gear teeth. This is done traditionally by a rough "rule of thumb" or more recently under the guidance of an analytical code. In order for a designer to have confidence in a code, the code must be validated through experiment. NASA Glenn Research Center contracted with the Design Unit of the University of Newcastle in England for a system to measure the transmission error of spur and helical test gears in the NASA Gear Noise Rig. The new system measures transmission error optically by means of light beams directed by lenses and prisms through gratings mounted on the gear shafts. The amount of light that passes through both gratings is directly proportional to the transmission error of the gears. A photodetector circuit converts the light to an analog electrical signal. To increase accuracy and reduce "noise" due to transverse vibration, there are parallel light paths at the top and bottom of the gears. The two signals are subtracted via differential amplifiers in the electronics package. The output of the system is 40 mV/mm, giving a resolution in the time domain of better than 0.1 mm, and discrimination in the frequency domain of better than 0.01 mm. The new system will be used to validate gear analytical codes and to investigate mechanisms that produce vibration and noise in parallel axis gears.

  1. Planetary mass function and planetary systems

    CERN Document Server

    Dominik, M

    2010-01-01

    With planets orbiting stars, a planetary mass function should not be seen as a low-mass extension of the stellar mass function, but a proper formalism needs to take care of the fact that the statistical properties of planet populations are linked to the properties of their respective host stars. This can be accounted for by describing planet populations by means of a differential planetary mass-radius-orbit function, which together with the fraction of stars with given properties that are orbited by planets and the stellar mass function allows to derive all statistics for any considered sample. These fundamental functions provide a framework for comparing statistics that result from different observing techniques and campaigns which all have their very specific selection procedures and detection efficiencies. Moreover, recent results both from gravitational microlensing campaigns and radial-velocity surveys of stars indicate that planets tend to cluster in systems rather than being the lonely child of their r...

  2. CNC FLEXIBLE GENERATING SPECIFIC GEAR TOOTH PROFILE BASED ON STANDARD INVOLUTE GEAR HOB

    Institute of Scientific and Technical Information of China (English)

    Feng Xianying; Li Hui; Ai Xing

    2004-01-01

    A new method named orthogonal two-way link-shift here has been proposed. Based on the method and a standard involute gear hob, a specific gear tooth profile (including an arbitrary gear tooth profile and a modified involute gear tooth profile) can be generated on a CNC(computer numerical control) hobbing machine. Computer simulation has been carried out, and the results prove that the method is right and practicable. So, the fabrication costs can be greatly decreased than before. The new method has momentous significance to realize gear's optimized modification under different work conditions.

  3. The Planetary Project

    Science.gov (United States)

    Pataki, Louis P.

    2016-06-01

    This poster presentation presents the Planetary Project, a multi-week simulated research experience for college non-science majors. Students work in research teams of three to investigate the properties of a fictitious planetary system (the “Planetary System”) created each semester by the instructor. The students write team and individual papers in which they use the available data to draw conclusions about planets, other objects or general properties of the Planetary System and in which they compare, contrast and explain the similarities between the objects in the Planetary System and comparable objects in the Solar System.Data about the orbital and physical properties of the planets in the Planetary System are released at the start of the project. Each week the teams request data from a changing pool of available data. For example, in week one pictures of the planets are available. Each team picks one planet and the data (pictures) on that planet are released only to that team. Different data are available in subsequent weeks. Occasionally a news release to all groups reports an unusual occurrence - e.g. the appearance of a comet.Each student acts as principal author for one of the group paper which must contain a description of the week’s data, conclusions derived from that data about the Planetary System and a comparison with the Solar System. Each students writes a final, individual paper on a topic of their choice dealing with the Planetary System in which they follow the same data, conclusion, comparison format. Students “publish” their papers on a class-only restricted website and present their discoveries in class talks. Data are released to all on the website as the related papers are “published.” Additional papers commenting on the published work and released data are encouraged.The successes and problems of the method are presented.

  4. Research of the Pressure Angle for Whole Cycloidal Gears

    Institute of Scientific and Technical Information of China (English)

    LIU Ling-tao; WANG Jian-hua

    2011-01-01

    The working profile of whole cycloidal gear is made up of epicycloid and hypocycloid entirely, according to the theory of meshing of gears and the properties of the cycloid, deals with the derivation of the pressure angle formula for the whole cycloidal gear in theory, and reveals changes of the pressure angle of whole cycloidal gear through examples, finds the application relationships between the pressure angle and other design parameters of the whole cycloidal gear, proves the possibility that the whole cycloidal gear can be used in internal parallel move gear mechanism, also provides theoretic fundament for designing internal parallel move whole cycloidal gear correctly.

  5. Gear Crack Level Classification Based on EMD and EDT

    Directory of Open Access Journals (Sweden)

    Haiping Li

    2015-01-01

    Full Text Available Gears are the most essential parts in rotating machinery. Crack fault is one of damage modes most frequently occurring in gears. So, this paper deals with the problem of different crack levels classification. The proposed method is mainly based on empirical mode decomposition (EMD and Euclidean distance technique (EDT. First, vibration signal acquired by accelerometer is processed by EMD and intrinsic mode functions (IMFs are obtained. Then, a correlation coefficient based method is proposed to select the sensitive IMFs which contain main gear fault information. And energy of these IMFs is chosen as the fault feature by comparing with kurtosis and skewness. Finally, Euclidean distances between test sample and four classes trained samples are calculated, and on this basis, fault level classification of the test sample can be made. The proposed approach is tested and validated through a gearbox experiment, in which four crack levels and three kinds of loads are utilized. The results show that the proposed method has high accuracy rates in classifying different crack levels and may be adaptive to different conditions.

  6. Gear fatigue damage for a 500 kW wind turbine exposed to increasing turbulence using a flexible multibody model

    Directory of Open Access Journals (Sweden)

    Martin Felix Jørgensen

    2014-04-01

    Full Text Available This paper investigates gear tooth fatigue damage in a 500 kW wind turbine using FLEX5 and own multibody code. FLEX5 provides the physical wind field, rotor and generator torque and the multibody code is used for obtaining gear tooth reaction forces in the planetary gearbox. Different turbulence levels are considered and the accumulated fatigue damage levels are compared. An example where the turbulence/fatigue sensitivity could be important, is in the middle of a big wind farm. Interior wind turbines in large wind farms will always operate in the wake of other wind turbines, causing increased turbulence and therefore increased fatigue damage levels. This article contributes to a better understanding of gear fatigue damage when turbulence is increased (e.g. in the center of large wind farms or at places where turbulence is pronounced.

  7. Detection and Diagnosis of Gear Fault By the Single Gear Tooth Analysis Technique

    Institute of Scientific and Technical Information of China (English)

    MENG Tao; LIAO Ming-fu

    2003-01-01

    This paper presents a procedure of single gear tooth analysis for early detection and diagnosis of gear faults. The objective of this procedure is to develop a method for more sensitive detection of the incipient faults and locating the faults in the gear. The main idea of the single gear tooth analysis is that the vibration signals collected with a high sampling rate are divided into a number of segments with the same time interval. The number of signal segments is equal to that of the gear teeth. The analysis of individual segments reveals more sensitively the changes of the vibration signals in both time and frequency domain caused by gear faults. In addition, the location of a failed tooth can be indicated in terms of the position of the segment that deviates from the normal segments. An experimental investigation verified the advantages of the single gear tooth analysis.

  8. The transfer function method for gear system dynamics applied to conventional and minimum excitation gearing designs

    Science.gov (United States)

    Mark, W. D.

    1982-01-01

    A transfer function method for predicting the dynamic responses of gear systems with more than one gear mesh is developed and applied to the NASA Lewis four-square gear fatigue test apparatus. Methods for computing bearing-support force spectra and temporal histories of the total force transmitted by a gear mesh, the force transmitted by a single pair of teeth, and the maximum root stress in a single tooth are developed. Dynamic effects arising from other gear meshes in the system are included. A profile modification design method to minimize the vibration excitation arising from a pair of meshing gears is reviewed and extended. Families of tooth loading functions required for such designs are developed and examined for potential excitation of individual tooth vibrations. The profile modification design method is applied to a pair of test gears.

  9. Analysis on Temperature Reliability Sensitivity to Parameters of Meshing Gear Tooth%啮合轮齿温度可靠性对齿轮参数的灵敏度分析

    Institute of Scientific and Technical Information of China (English)

    王春华; 安达

    2015-01-01

    为降低齿轮啮合轮齿高温失效风险,基于响应面法构建了啮合轮齿温度的极限状态函数,得到轮齿温度可靠度与各相关参数间的数学关系式,应用Monte-Carlo模拟法得出轮齿温度可靠度对各参数的灵敏度表达式.以行星齿轮传动的太阳轮为例,分析得到轮齿温度可靠度对齿宽、转速、模数和压力角的灵敏度,分别为-0.519、-0.712、0.211和0.384.结果表明:模数、压力角、齿宽和转速对温度可靠性的影响程度依次增大;减小齿宽、转速或者增大模数、压力角可提高轮齿温度可靠度.啮合轮齿温度可靠度对齿轮参数的灵敏度分析为轮齿温度可靠性设计提供了依据.%To reduce the risk of high-temperature failure of meshing gear tooth,the limit temperature state function of meshing gear tooth was built based on response surface method,and the mathematical relation bewteen temperature reliability and relative parameters was obtained.The formula for temperature reliability sensitivity to relative parameters was obtained by using Monte-Carlo method.With the Sun gear of planetary gear train as research object,temperature reliability sensitivity to tooth width,rotating speed,module,pressure angle was-0.519,-0.712,0.211,0.384 respectively.The result showed that module,pressure angle,tooth width,rotating speed had a crescent influence on temperature reliability sensitivity of meshing gear tooth,and temperature reliability sensitivity would be improved by increasing module and pressure angle or decreasing tooth width and rotating speed.Temperature reliability sensitivity analysis provided basis for the design of temperature reliability.

  10. Application of Artificial Neural Network for Damage Detection in Planetary Gearbox of Wind Turbine

    Directory of Open Access Journals (Sweden)

    Marcin Strączkiewicz

    2016-01-01

    Full Text Available In the monitoring process of wind turbines the utmost attention should be given to gearboxes. This conclusion is derived from numerous summary papers. They reveal that, on the one hand, gearboxes are one of the most fault susceptible elements in the drive-train and, on the other, the most expensive to replace. Although state-of-the-art CMS can usually provide advanced signal processing tools for extraction of diagnostic information, there are still many installations, where the diagnosis is based simply on the averaged wideband features like root-mean-square (RMS or peak-peak (PP. Furthermore, for machinery working in highly changing operational conditions, like wind turbines, those estimators are strongly fluctuating, and this fluctuation is not linearly correlated to operation parameters. Thus, the sudden increase of a particular feature does not necessarily have to indicate the development of fault. To overcome this obstacle, it is proposed to detect a fault development with Artificial Neural Network (ANN and further observation of linear regression parameters calculated on the estimation error between healthy and unknown condition. The proposed reasoning is presented on the real life example of ring gear fault in wind turbine’s planetary gearbox.

  11. Surface contact fatigue failures in gears

    CSIR Research Space (South Africa)

    Fernandes, PJL

    1997-06-01

    Full Text Available Surface contact fatigue is the most common cause of gear failure. It results in damage to contacting surfaces which can significantly reduce the load-carrying capacity of components, and may ultimately lead to complete failure of a gear. Three types...

  12. Helical Gears Modified To Decrease Transmission Errors

    Science.gov (United States)

    Handschuh, R. F.; Coy, J. J.; Litvin, F. L.; Zhang, J.

    1993-01-01

    Tooth surfaces of helical gears modified, according to proposed design concept, to make gears more tolerant of misalignments and to improve distribution of contact stresses. Results in smaller transmission errors, with concomitant decreases in vibrations and noise and, possibly, increases in service lives.

  13. Study on corrosive grinding of gears

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Careful grinding or honing is usually required in machining of gears in order to improvethe machining quality of gear surface. Thus several grinding additives were used to formulate syn-thetic grinding lubricants similar to superior running-in lubricants. Experimental results show thatthe tooth surface of the produced oblique gear and steel worm becomes extremely smooth aftergrinding at a certain load for about a half to one hour. Especially, the gear surface finished withspecially formulated grinding lubricant reaches mirror-like smoothness. The quality of the geartooth can be improved by corrosive grinding, while the corrosive grinding time can be controlled byadjusting the quantity of the corrosive additives and the speed and load of the gears.

  14. Vibration signature analysis of multistage gear transmission

    Science.gov (United States)

    Choy, F. K.; Tu, Y. K.; Savage, M.; Townsend, D. P.

    1989-01-01

    An analysis is presented for multistage multimesh gear transmission systems. The analysis predicts the overall system dynamics and the transmissibility to the gear box or the enclosed structure. The modal synthesis approach of the analysis treats the uncoupled lateral/torsional model characteristics of each stage or component independently. The vibration signature analysis evaluates the global dynamics coupling in the system. The method synthesizes the interaction of each modal component or stage with the nonlinear gear mesh dynamics and the modal support geometry characteristics. The analysis simulates transient and steady state vibration events to determine the resulting torque variations, speeds, changes, rotor imbalances, and support gear box motion excitations. A vibration signature analysis examines the overall dynamic characteristics of the system, and the individual model component responses. The gear box vibration analysis also examines the spectral characteristics of the support system.

  15. FATIGUE PROPERTIES OF SPRING REINFORCES POLYMER GEARS

    Directory of Open Access Journals (Sweden)

    Hilal CAN

    2005-03-01

    Full Text Available Failure of gears, occur surface pressure stress and fracture at base of teeth. For steel gears, it is known that process of carburizing increases fatigue strength. Internal stress on the surface increases of fracture fatigue strength. In this study fatigue properties of polypropylene gear reinforced with 1.2 mm wire diameter metallic springs was investigated. Extension springs were used as reinforcement element and placed into the mould and stretched before injection of polypropylene material into the mould. After injection of polypropylene, stretched springs were loosened in order to obtain pre-stressing. Fatigue tests were performed on the produced gear. Reinforcement increased the strength of gears. At result of experiments, pre-stressing increase in service life 12 times more than that of specimens without reinforcement.

  16. The Dilemma of Derelict Gear

    Science.gov (United States)

    Scheld, A. M.; Bilkovic, D. M.; Havens, K. J.

    2016-01-01

    Every year, millions of pots and traps are lost in crustacean fisheries around the world. Derelict fishing gear has been found to produce several harmful environmental and ecological effects, however socioeconomic consequences have been investigated less frequently. We analyze the economic effects of a substantial derelict pot removal program in the largest estuary of the United States, the Chesapeake Bay. By combining spatially resolved data on derelict pot removals with commercial blue crab (Callinectes sapidus) harvests and effort, we show that removing 34,408 derelict pots led to significant gains in gear efficiency and an additional 13,504 MT in harvest valued at US $21.3 million—a 27% increase above that which would have occurred without removals. Model results are extended to a global analysis where it is seen that US $831 million in landings could be recovered annually by removing less than 10% of the derelict pots and traps from major crustacean fisheries. An unfortunate common pool externality, the degradation of marine environments is detrimental not only to marine organisms and biota, but also to those individuals and communities whose livelihoods and culture depend on profitable and sustainable marine resource use.

  17. Multi-objectve Optimization Design of Differential Gear with Few Tooth Based on Fuzzy Algorithm%基于模糊算法的少齿差齿轮多目标优化设计

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Based on the basic theory of optimization design of fuzzy algorithm,this paper mainly researches the running state of fewer teeth difference planetary gears reducer and its relevant working conditions. Taking advantage of the transmission characteristic of gear pair with small teeth difference,the authors built a mathematical model of planetary gear reducer and optimized the geometric parameters of few-tooth-difference planetary wheel by establishing the objective function of gear size and contact ratio.Besides,af-ter comparing the results obtained from the normal design with the results of optimization design of fuzzy algorithm,the authors find that both gear size and contact ratio of fewer teeth difference planetary trans-mission were optimized.%基于优化设计模糊算法的基本理论,研究少齿差行星减速器的运行状态及相关工况条件,针对少齿差齿轮副的传动特性,建立少齿差行星轮减速器的数学模型,通过确立齿轮体积和重合度的目标函数,优化少齿差行星轮的几何参数,并与常规设计相比,少齿差行星传动的体积和重合度都得到优化。

  18. The optimal design of involute gear teeth with unequal addenda

    Science.gov (United States)

    Savage, M.; Coy, J. J.; Townsend, D. P.

    1982-01-01

    The design of a gear mesh is treated with the objective of minimizing the gear size for a given gear ratio, pinion torque, pressure angle, and allowable tooth lengths. Tooth strengths considered include scoring, pitting fatigue, and bending fatigue. Kinematic involute interference is avoided. The design variation on standard spur gear teeth called the long and short addendum system, is considered. In this system the mesh center distance and pressure angle are maintained as is the ability to manufacture the teeth with standard tooling. However, the pinion and gear tooth proportions are altered in order to obtain fewer teeth numbers for the same ratio as standard gears without kinematic involute interference. The effect of this nonstandard gearing geometry with on tooth strengths and gear mesh size are studied. For a 2:1 gearing ratio, the optimal nonstandard gear design is compared with the optimal standard gear design.

  19. Vehicle transmission gear 2009; Getriebe in Fahrzeugen 2009

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    with single dry clutch and electric torque support (G. Hellenbroich); (37) New solutions to increase cost-effectiveness of city bus drive lines with modern automatic powershift transmissions (P. Wunderlich); (38) Evaluation of the gearchanging comfort at commercial vehicles (W. Wessel); (39) New structure-optimised transmission systems for advanced commercial vehicles (R. Resch); (40) Depth of details of powertrain models for depocting driveability effects (F. Matthies); (41) A nonlinear transmission approach for dual mass flywheels (C. Benatzky); (42) Clattering and rattling is still a challenge for vehicle transmission developers (M. Dally); (43) Study on the effect of driving cycles on energy efficiency of electric vehicles (J. Fenzhu); (44) Modular modelling and simulation of hybrid power trains (G. Kelz); (45) The integration of electrical axle drives in hybrid vehicle and electric vehicles (H. Schaefer); (46) Energy balance of the optimized CVT hybrid driveline (B.-R. Hoehm); (47) Functional efficiency comparison between split- and parallel-hybrid using advanced energy flow analysis methods (P. Guttenberg); (48) Simulation of the fuel consumption benefits of various transmission arrangements and control strategies within a flywheel based mechanical hybrid system (W. Body); (49) Ideal test specifications for transmissions (T. Kassel); (50) The 'Hybrid Effect': Influence of hybridisation on the durability of automatic transmissions (T. Lavall); (51) Schaeffler lightweight differentials (R. Malik); (52) Integrated all wheel drive in the ZF eight-speed automatic gear (D. Baasch); (53) Optimized structures for amplifying torque vectoring systems (A. Sue); (54) The new sport differential in the Audi S4 (U. Pinschmidt).

  20. Nonlinear Dynamics and Optimization of Spur Gears

    Science.gov (United States)

    Pellicano, Francesco; Bonori, Giorgio; Faggioni, Marcello; Scagliarini, Giorgio

    In the present study a single degree of freedom oscillator with clearance type non-linearity is considered. Such oscillator represents the simplest model able to analyze a single teeth gear pair, neglecting: bearings and shafts stiffness and multi mesh interactions. One of the test cases considered in the present work represents an actual gear pair that is part of a gear box of an agricultural vehicle; such gear pair gave rise to noise problems. The main gear pair characteristics (mesh stiffness and inertia) are evaluated after an accurate geometrical modelling. The meshing stiffness of the gear pair is piecewise linear and time varying (in particular periodic); it is evaluated numerically using nonlinear finite element analysis (with contact mechanics) for different positions along one mesh cycle, then it is expanded in Fourier series. A direct numerical integration approach and a smoothing technique have been considered to obtain the dynamic scenario. Bifurcation diagrams of Poincaré maps are plotted according to some sample case study from literature. Optimization procedures are proposed, in order to find optimal involute modifications that reduce gears vibration.

  1. Foundations of planetary quarantine.

    Science.gov (United States)

    Hall, L. B.; Lyle, R. G.

    1971-01-01

    Discussion of some of the problems in microbiology and engineering involved in the implementation of planetary quarantine. It is shown that the solutions require new knowledge in both disciplines for success at low cost in terms of both monetary outlay and man's further exploration of the planets. A related problem exists in that engineers are not accustomed to the wide variation of biological data and microbiologists must learn to work and think in more exact terms. Those responsible for formulating or influencing national and international policies must walk a tightrope with delicate balance between unnecessarily stringent requirements for planetary quarantine on the one hand and prevention of contamination on the other. The success of planetary quarantine measures can be assured only by rigorous measures, each checked, rechecked, and triple-checked to make sure that no errors have been made and that no factor has been overlooked.

  2. Elaboration and research of planetary precessional multiplier type K-H-V

    Science.gov (United States)

    Bostan, I.; Dulgheru, V.; Ciobanu, R.

    2016-08-01

    The multiplier is an indispensable part of the micro hydropower plant and high power wind turbine. It helps to increase rotor low speeds limited by the water flow small velocity and by the relative big placement diameter of the blades that participate in the energy conversion. For example, the microhydrostation rotor's speed is (2 - 3) min'1 for water flow velocity V= (1...1,6) m/s and for blade placement diameter D = 4 m. Diversity of requirements forwarded by the beneficiaries of mechanical transmissions consists, in particular, in increasing reliability, efficiency and lifting capacity, and in reducing the mass and dimensions. It becomes more and more difficult to satisfy the mentioned demands by partial updating of traditional transmissions. The target problem can be solved with special effects by developing new types of multipliers based on precessional planetary transmissions with multiple gear, that were developed by the authors. Absolute multiplicity of precessional gear (up to 100% pairs of teeth simultaneously involved in gearing, compared to 5%-7% - in classical gearings) provides increased lifting capacity and small mass and dimensions. To mention that until now precessional planetary transmissions have been researched and applied mainly in reducers. Therefore it was necessary to carry out theoretical research to determine the geometrical parameters of the precessional gear that operates in multiplier mode. Also, it was necessary to develop new conceptual diagrams of precessional transmissions that function under multiplier regime. The majority of precessional planetary transmissions diagrams developed previously operate efficiently in reducer's regime. Depending on the structural diagram, precessional transmissions fall into two main types - K-H-V and 2K-H, from which a wide range of constructive solutions with wide kinematical and functional options that operate in multiplier regime.

  3. 46 CFR 108.641 - Instructions for changing steering gear.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Instructions for changing steering gear. 108.641 Section... steering gear. Instructions stating, in order, the different steps to be taken for changing to emergency and secondary steering gear must be posted in the steering gear room and at each secondary...

  4. 29 CFR 1919.31 - Proof tests-loose gear.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Proof tests-loose gear. 1919.31 Section 1919.31 Labor... (CONTINUED) GEAR CERTIFICATION Certification of Vessels: Tests and Proof Loads; Heat Treatment; Competent Persons § 1919.31 Proof tests—loose gear. (a) Chains, rings, shackles and other loose gear...

  5. 49 CFR 230.77 - Foundation brake gear.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foundation brake gear. 230.77 Section 230.77... Tenders Brake and Signal Equipment § 230.77 Foundation brake gear. (a) Maintenance. Foundation brake gear...) Distance above the rails. No part of the foundation brake gear of the steam locomotive or tender shall...

  6. 14 CFR 25.1515 - Landing gear speeds.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear speeds. 25.1515 Section 25... Limitations § 25.1515 Landing gear speeds. (a) The established landing gear operating speed or speeds, V LO, may not exceed the speed at which it is safe both to extend and to retract the landing gear,...

  7. Airships for Planetary Exploration

    Science.gov (United States)

    Colozza, Anthony

    2004-01-01

    The feasibility of utilizing an airship for planetary atmospheric exploration was assessed. The environmental conditions of the planets and moons within our solar system were evaluated to determine their applicability for airship flight. A station-keeping mission of 50 days in length was used as the baseline mission. Airship sizing was performed utilizing both solar power and isotope power to meet the baseline mission goal at the selected planetary location. The results show that an isotope-powered airship is feasible within the lower atmosphere of Venus and Saturn s moon Titan.

  8. Engagement of Metal Debris into Gear Mesh

    Science.gov (United States)

    handschuh, Robert F.; Krantz, Timothy L.

    2010-01-01

    A series of bench-top experiments was conducted to determine the effects of metallic debris being dragged through meshing gear teeth. A test rig that is typically used to conduct contact fatigue experiments was used for these tests. Several sizes of drill material, shim stock and pieces of gear teeth were introduced and then driven through the meshing region. The level of torque required to drive the "chip" through the gear mesh was measured. From the data gathered, chip size sufficient to jam the mechanism can be determined.

  9. Roller/Gear Drives For Robotic Manipulators

    Science.gov (United States)

    Anderson, William J.; Shipitalo, William

    1995-01-01

    Pitch/yaw roller/gear drive and wrist-roll roller/gear drive designed to incorporate several features desirable in robotic-joint actuators. Includes zero backlash, high efficiency, smooth motion (little ripple in torque and in speed ratio), and high degree of back-drivability. Pitch/yaw drive is novel two-axis drive containing combination of gears, rollers, and springs acting together eliminating backlash and cogging. Wrist-roll drive more-conventional single-axis drive offering advantages like those of pitch/yaw drive.

  10. Automatic gear sorting system based on monocular vision

    Directory of Open Access Journals (Sweden)

    Wenqi Wu

    2015-11-01

    Full Text Available An automatic gear sorting system based on monocular vision is proposed in this paper. A CCD camera fixed on the top of the sorting system is used to obtain the images of the gears on the conveyor belt. The gears׳ features including number of holes, number of teeth and color are extracted, which is used to categorize the gears. Photoelectric sensors are used to locate the gears׳ position and produce the trigger signals for pneumatic cylinders. The automatic gear sorting is achieved by using pneumatic actuators to push different gears into their corresponding storage boxes. The experimental results verify the validity and reliability of the proposed method and system.

  11. Efficiency of nonstandard and high contact ratio involute spur gears

    Science.gov (United States)

    Anderson, N. E.; Loewenthal, S. H.

    1986-01-01

    A power loss prediction was extended to include involute spur gears of nonstandard proportions. The method is used to analyze the effects of modified addendum, tooth thickness, and gear center distance in addition to the parameters previously considered which included gear diameter, pitch, pressure angle, face width, oil viscosity, speed, and torque. Particular emphasis was placed on high contact ratio gearing (contact ratios greater than two). Despite their higher sliding velocities, high contact ratio gears are designed to levels of efficiency comparable to those of conventional gears while retaining their advantages through proper selection of gear geometry.

  12. 面向我国铁路实际的动车组运用计划编制问题%Train-set scheduling problem geared to practical production process of railway in China

    Institute of Scientific and Technical Information of China (English)

    李华; 韩宝明; 赵鹏

    2012-01-01

    从广义和狭义两个角度阐述了我国动车组运用问题的内涵,指出当前关注的重点是以动车组运用计划编制为核心的狭义范畴.从我国动车组产品系列、列车开行特征、动车组检修与管理体制等方面对动车组运用计划相关影响因素的现状进行了说明;将动车组运用计划编制过程划分为交路计划和检修计划两个阶段,从我国铁路生产实际需求出发,分析了计划编制过程中考虑的约束条件和评价指标;最后总结提出了亟待解决的具体问题,对后续相关研究具有借鉴意义.%This paper explains the connotations of the train-set operation issue from both broad sense and narrow sense, and points out that the connotation from narrow sense with the train-set scheduling problem at its core is the current focus of concern. First, the current situations of several influencing factors of train-set routing schedule are illustrated, in terms of the train-set product series, train operation characteristics, train-set maintenance system and management system in China. Then, the process of train-set scheduling is divided into circulation planning and maintenance routing stages, and the constraints and evaluation indices of both stages are analyzed from the practical production demands of railway in China. Finally, several key points of the train-set scheduling problem are proposed to support the related studies in the future.

  13. Estimation of gear tooth transverse crack size from vibration by fusing selected gear condition indices

    Science.gov (United States)

    Choi, Sukhwan; Li, C. James

    2006-09-01

    Gears are common power transmission elements and are frequently responsible for transmission failures. Since a tooth crack is not directly measurable while a gear is in operation, one has to develop an indirect method to estimate its size from some measurables. This study developed such a method to estimate the size of a tooth transverse crack for a spur gear in operation. Using gear vibrations measured from an actual gear accelerated test, this study examined existing gear condition indices to identify those correlated well to crack size and established their utility for crack size estimation through index fusion using a neural network. When tested with vibrations measured from another accelerated test, the method had an averaged estimation error of about 5%.

  14. High Speed Gear Sized and Configured to Reduce Windage Loss

    Science.gov (United States)

    Kunz, Robert F. (Inventor); Medvitz, Richard B. (Inventor); Hill, Matthew John (Inventor)

    2013-01-01

    A gear and drive system utilizing the gear include teeth. Each of the teeth has a first side and a second side opposite the first side that extends from a body of the gear. For each tooth of the gear, a first extended portion is attached to the first side of the tooth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates. The gear may be utilized in drive systems that may have high rotational speeds, such as speeds where the tip velocities are greater than or equal to about 68 m/s. Some embodiments of the gear may also utilize teeth that also have second extended portions attached to the second sides of the teeth to divert flow of fluid adjacent to the body of the gear to reduce windage losses that occur when the gear rotates.

  15. Bending Fatigue Strength of Austempered Ductile Iron Spur Gears

    Science.gov (United States)

    Yamanaka, Masashi; Tamura, Ryo; Inoue, Katsumi; Narita, Yukihito

    This paper deals with an experimental evaluation of bending fatigue strength for austempered ductile iron (ADI) spur gears. The module is 2.5 and the number of teeth is 26 in the test gears. The material of the test gears corresponds to Japan Industrial Standard (JIS) FCAD1100-15. Some gears are processed by one of two types of fine particle bombarding (FPB). The surface roughness is slightly increased by FPB. The obtained strengths are 623 MPa for the as-austempered gears, and 1011 and 1085 MPa for the gears after FPB. The strength is expressed by the fillet stress level, which is calculated by FEM. The strength of a gear with the same dimensions made of carburized SCr420H alloy steel is 1205 MPa, and the strength of the ADI gear is approximately half that of the carburized steel gear. The FPB process has a significant effect on the ADI gear, improving its strength by 62-74%.

  16. Prediction of potential failures in hydraulic gear pumps

    OpenAIRE

    E. Lisowski(Cracow Tech. U); J. Fabiś

    2010-01-01

    Hydraulic gear pumps are used in many machines and devices. In hydraulic systems of machines gear pumps are main component ofsupply unit or perform auxiliary function. Gear pumps opposite to vane pumps are less complicated. They consists of such components as:housing, gear wheels, bearings, shaft, seal for rotation motion which are not very sensitive for damage and that is why they are using veryoften. However, gear pumps are break down from time to time. Usually damage of pump cause shutting...

  17. Gear servicing in the wind power industry; Getriebeservice Windenergie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    JaKe (Jahnel-Kestermann) is a producer of gears for wind power systems. They offer: Damage analysis anddocumentation; supply of replacement parts; repair and modification of gears; world-wide gear servicing; new gears for own and external products; mobile measuring systems; technological improvements; production of components; toothing, grinding, meshing measurements; production of exchange gears; test performance up to 3 MW; short supply times. (orig.)

  18. Surface micromachined microengine as the driver for micromechanical gears

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, E.J.; Sniegowski, J.J.

    1995-05-01

    The transmission of mechanical power is often accomplished through the use of gearing. The recently developed surface micromachined microengine provides us with an actuator which is suitable for driving surface micromachined geared systems. In this paper we will present aspects of the microengine as they relate to the driving of geared mechanisms, issues relating to the design of micro gear mechanisms, and details of a design of a microengine-driven geared shutter mechanism.

  19. Deformation and stiffness of spur gear teeth and their influence on gear noise

    Directory of Open Access Journals (Sweden)

    Silvia MEDVECKÁ-BEŇOVÁ

    2015-12-01

    Full Text Available Gear teeth are deformed due to the load. The deformation of gear teeth is causing some negative as well as positive effects. A tooth has a complex shape and due to the complex shape of the teeth, a theoretical determination of the deformation is difficult. The existing experimental techniques are based on static deflection measurements gearing loaded of constant force or seismic measurement deviations at slow rotation. Recently, at ever faster evolving computer technology and the available literature, we can encounter modern numerical methods, such as finite element method (FEM, which can serve as methods for the determination of teeth of gearing. The article is devoted to the problems of gearing stiffness analysis. The problem is solved for spur gears. Deformation analysis solved by FEM is used for calculations of the gearing stiffness. There are many influences that cause vibrations in the gearbox and that have to be taken into account already in the phase of design, manufacture, installation and operation. Detailed analysis of gearboxes manufacturers have shown that improving of the gear accuracy cannot reduce the transmission unit noise to the desired level. Only fundamental changes to the shape of the tooth and changes in production technology can achieve stronger noise reduction of gear mechanism.

  20. Autocorrelation-based time synchronous averaging for condition monitoring of planetary gearboxes in wind turbines

    Science.gov (United States)

    Ha, Jong M.; Youn, Byeng D.; Oh, Hyunseok; Han, Bongtae; Jung, Yoongho; Park, Jungho

    2016-03-01

    We propose autocorrelation-based time synchronous averaging (ATSA) to cope with the challenges associated with the current practice of time synchronous averaging (TSA) for planet gears in planetary gearboxes of wind turbine (WT). An autocorrelation function that represents physical interactions between the ring, sun, and planet gears in the gearbox is utilized to define the optimal shape and range of the window function for TSA using actual kinetic responses. The proposed ATSA offers two distinctive features: (1) data-efficient TSA processing and (2) prevention of signal distortion during the TSA process. It is thus expected that an order analysis with the ATSA signals significantly improves the efficiency and accuracy in fault diagnostics of planet gears in planetary gearboxes. Two case studies are presented to demonstrate the effectiveness of the proposed method: an analytical signal from a simulation and a signal measured from a 2 kW WT testbed. It can be concluded from the results that the proposed method outperforms conventional TSA methods in condition monitoring of the planetary gearbox when the amount of available stationary data is limited.

  1. Planetary polarization nephelometer

    NARCIS (Netherlands)

    Banfield, D.; Dissly, R.; Mishchenko, M.; Muñoz, O.; Roos-Serote, M.; Stam, D.M.; Volten, H.; Wilson, A.

    2004-01-01

    We have proposed to develop a polarization nephelometer for use on future planetary descent probes. It will measure both the scattered intensity and polarization phase functions of the aerosols it encounters descending through an atmosphere. These measurements will be taken at two wavelengths

  2. The planetary scientist's companion

    CERN Document Server

    Lodders, Katharina

    1998-01-01

    A comprehensive and practical book of facts and data about the Sun, planets, asteroids, comets, meteorites, the Kuiper belt and Centaur objects in our solar system. Also covered are properties of nearby stars, the interstellar medium, and extra-solar planetary systems.

  3. Planetary polarization nephelometer

    NARCIS (Netherlands)

    Banfield, D.; Dissly, R.; Mishchenko, M.; Muñoz, O.; Roos-Serote, M.; Stam, D.M.; Volten, H.; Wilson, A.

    2004-01-01

    We have proposed to develop a polarization nephelometer for use on future planetary descent probes. It will measure both the scattered intensity and polarization phase functions of the aerosols it encounters descending through an atmosphere. These measurements will be taken at two wavelengths separa

  4. Catalogues of planetary nebulae.

    Science.gov (United States)

    Acker, A.

    Firstly, the general requirements concerning catalogues are studied for planetary nebulae, in particular concerning the objects to be included in a catalogue of PN, their denominations, followed by reflexions about the afterlife and comuterized versions of a catalogue. Then, the basic elements constituting a catalogue of PN are analyzed, and the available data are looked at each time.

  5. Planetary ring systems

    CERN Document Server

    Miner, Ellis D; Cuzzi, Jeffrey N

    2007-01-01

    This is the most comprehensive and up-to-date book on the topic of planetary rings systems yet written. The book is written in a style that is easily accessible to the interested non expert. Each chapter includes notes, references, figures and tables.

  6. Planetary rings - Theory

    Science.gov (United States)

    Borderies, Nicole

    1989-01-01

    Theoretical models of planetary-ring dynamics are examined in a brief analytical review. The mathematical description of streamlines and streamline interactions is outlined; the redistribution of angular momentum due to collisions between particles is explained; and problems in the modeling of broad, narrow, and arc rings are discussed.

  7. Gulf of Mexico Shrimp Permit Gear Survey

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data set contains annual vessel gear characterization of permit holders shrimp vessel. Data includes net type, TED type, BRD type, etc.

  8. Sea Turtle Human/Gear Interactions Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Southeast Fisheries Science Center Mississippi Laboratories is responsible for new gear development and testing to reduce bycatch and incidental interactions of...

  9. 50 CFR 300.109 - Gear disposal.

    Science.gov (United States)

    2010-10-01

    ... articles and substances include, but are not limited to, fishing gear, net scraps, bale straps, plastic... waters. (c) The operator of a harvesting vessel must provide a copy of the CCAMLR information...

  10. Modelling of vibration of gear transmissions

    Science.gov (United States)

    Zeman, Vladimir; Nemecek, Josef

    The method for mathematical modeling of spatial vibrations of the spur gear transmissions is presented. This method enables a substantial reduction of the number of degrees of freedom with relatively high accuracy in calculating vibration amplitude.

  11. Gear noise behavior induced by their topological quality

    Science.gov (United States)

    Jolivet, S.; Mezghani, S.; El Mansori, M.; Zahouani, H.

    2014-01-01

    The upcoming fuel economy standards will result in the rapid development of electric or hybrid vehicles. Such regulatory demands will affect transmission design, which is currently driving changes in the number, type, size and quality levels of gears. Thus, gear manufacturers need to create high quality gear flanks with special topological modifications. The most important objectives are to increase the load-carrying capacity of gears and also to reduce the gear noise behavior. The teeth surface is at the heart of gear meshing mechanics and is one of the main elements in the generation of noise. The most common gear wear mechanisms are micro-pitting, pitting and spalling, which often occur on teeth surface during the early stage of failure. This study aims to identify the scale effect of pitting defects of gear teeth surface on the acoustics response of a spur gear pair. Consequently, we have developed a two-dimensional finite-element simulation model of a one-stage gear system. The transmission system was composed of two identical spur gears with one degree of freedom. Pitting defects versus topological features at different scales were modeled on the gear tooth flanks. To quantify their impact on gear noises and vibrations, we used contact stiffness as our criteria because it is directly linked to gear noise. The prevalence of the gear quality and its topological features on power density and sound issues are computed and discussed in this paper.

  12. ハイポサイクロイド型2K-H遊星歯車機構の効率と軸トルク計算式

    OpenAIRE

    岸, 佐年; 両角, 宗晴

    1990-01-01

    A 2K-H type planetary gear train with two pairs of internal and external gears, the teeth difference between these pairs of gears are small, is called a hypocycloid type 2K-H planetary gear train. This type of planetary gear train can choice a wide range of reduction ratio and can be designed compactly. The efficiency and torque formulas of this planetary gear train are derived from the theoretical analysis and tabulated. The formulas tabulated can be utilized safely without any understanding...

  13. Instrumentation and test gear circuits manual

    CERN Document Server

    Marston, R M

    2013-01-01

    Instrumentation and Test Gear Circuits Manual provides diagrams, graphs, tables, and discussions of several types of practical circuits. The practical circuits covered in this book include attenuators, bridges, scope trace doublers, timebases, and digital frequency meters. Chapter 1 discusses the basic instrumentation and test gear principles. Chapter 2 deals with the design of passive attenuators, and Chapter 3 with passive and active filter circuits. The subsequent chapters tackle 'bridge' circuits, analogue and digital metering techniques and circuitry, signal and waveform generation, and p

  14. The processing accuracy of the gear

    Directory of Open Access Journals (Sweden)

    Mazuru Sergiu

    2017-01-01

    Full Text Available The paper presents analysis of processing quality of gears. A special attention was drawn to detecting and removing burns, the existence of which greatly reduced operating properties of gears. The study emphases the influence of schemes, processing modes and abrasive tools features on the physico-mechanical layer of teeth processed and phase changes, micro-cracks appearances, depth and degree of hardening, meaning and character of residual stresses distribution.

  15. The Differential Planet Gear Box Speed Ratio and Power Allocation Calculation%行星差动齿轮箱速比及功率分配计算

    Institute of Scientific and Technical Information of China (English)

    陈华平; 冯仲; 刘小刚; 杨胜; 郭宗礼

    2013-01-01

    Trough an example of Maag DPPV wind power planetary diferential gear unit, this paper set up the virtual prototype model of planetary diferential by Romax sofware ,verfying inherent law of transmission ratio and power fow in planetary diferential gear unit. It also provided the basis for system analysis of the reliability of gearbox by seting up Romax model, also provided a new method for analysis of the planetary diferential gear unit.%本文以Maag DPPV风电行星差动齿轮机构为例,使用Romax软件建立了此行星差动齿轮机构的虚拟样机模型,验证了行星差动机构传动比与功率分流的内在规律,同时建立的Romax模型为后续系统分析齿轮箱的可靠性提供了基础,这也为行星差动齿轮机构的分析提供了一条新途径。

  16. Bearing and gear steels for aerospace applications

    Science.gov (United States)

    Zaretsky, Erwin V.

    1990-01-01

    Research in metallurgy and processing for bearing and gear steels has resulted in improvements in rolling-element bearing and gear life for aerospace application by a factor of approximately 200 over that obtained in the early 1940's. The selection and specification of a bearing or gear steel is dependent on the integration of multiple metallurgical and physical variables. For most aerospace bearings, through-hardened VIM-VAR AISI M-50 steel is the material of preference. For gears, the preferential material is case-carburized VAR AISI 9310. However, the VAR processing for this material is being replaced by VIM-VAR processing. Since case-carburized VIM-VAR M-50NiL incorporates the desirable qualities of both the AISI M-50 and AISI 9310 materials, optimal life and reliability can be achieved in both bearings and gears with a single steel. Hence, this material offers the promise of a common steel for both bearings and gears for future aerospace applications.

  17. Lightly loaded lubricated impacts: Idle gear rattle

    Science.gov (United States)

    Tangasawi, O.; Theodossiades, S.; Rahnejat, H.

    2007-12-01

    Idle gear rattle is associated with the characteristic noise that unselected impacting gears radiate to the environment. It is induced by engine order vibration in the presence of backlash in the unengaged gear pairs, resulting in oscillatory response within their backlash range. A tribo-dynamic model of a front wheel drive manual transmission has been developed to study idle rattle, considering the hydrodynamic contact film reaction and flank friction. The model includes the torsional motions of the idle gears and the lateral motions of the supporting output shafts. The hydrodynamic lubricant film formed between the gear teeth under light impact loads behaves as a nonlinear spring-damper mechanism, whilst the inclusion of the shafts' bearing compliances introduces additional nonlinear terms, which are modelled as piecewise linear functions. The aim of the paper is to extend the existing methodology reported by the authors on idle rattle investigations of geared lubricated systems, based on torsional vibrations only, by considering the system response, which is eventually transferred to the gearbox case through the bearings. These are preliminary results found, which conform closely to experimental measurements taken from a vehicle equipped with a manual transmission of the same type.

  18. Design rules to enhance HUMS sensitivity to spur gear faults

    Science.gov (United States)

    Liu, Lin

    This dissertation describes the investigation of spur gear design rules that may enhance the sensitivity of conventional fault metrics to typical gear tooth damage. Spur gears represent a fundamental gear geometry that is commonly used in complex transmission system. This thesis explores the influence of simple spur gear design parameters such as diametral pitch, tooth number and pressure angle on gear tooth fault sensitivity. Using static and dynamic analysis, coupled with vibration based fault metrics (FM0, FM4, DI), this work attempts to determine the influence of RPM level, and gear geometry on vibration signatures. Specifically, three types of gear damage are modeled. These include pitting, crack and wear damage. Using a Cornell's gear tooth deflection method, a quasi-static nonlinear mesh gear model is developed that includes effects associated with gear tooth damage. This quasi-static model is integrated into a rigid body model of spur gear mesh dynamics under an applied load. This model is used to simulate the gear mesh dynamics under various RPM levels and applied torque loads. Additionally, the filtering effect of bearing is investigated based on a bearing model. Simulated vibration signatures of bearing case with and without gear tooth damage are used as input into conventional vibration based fault metrics. Assuming that for each spur gear design the gear tooth critical tensile or contact stress is held constant, this dynamic model enables one to vary gear design parameters to evaluate their effect on the vibration signature with and without damage. In this dissertation, the sensitivity of gear design parameters to gear tooth damage is investigated under quasi-static and dynamic loading conditions. Experimental validation is carried out for spur gear designs with various diametral pitch values and for spur gears with increasing crack damage. In the static analysis, enhanced sensitivity is measured with respect to the transmission error. In the dynamic

  19. Firefighter burn injuries: predictable patterns influenced by turnout gear.

    Science.gov (United States)

    Kahn, Steven A; Patel, Jignesh H; Lentz, Christopher W; Bell, Derek E

    2012-01-01

    Approximately 100 firefighters suffer fatal injuries annually and tens of thousands receive nonfatal injuries. Many of these injuries require medical attention and restricted activity but may be preventable. This study was designed to elucidate etiology, circumstances, and patterns of firefighter burn injury so that further prevention strategies can be designed. In particular, modification of protective equipment, or turnout gear, is one potential strategy to prevent burn injury. An Institutional Review Board-approved retrospective review was conducted with records of firefighters treated for burn injury from 2005 to 2009. Data collected included age, gender, TBSA, burn depth, anatomic location, total hospital days per patient, etiology, and circumstances of injury. Circumstances of injury were stratified into the following categories: removal/dislodging of equipment, failure of equipment to protect, training errors, and when excessive external temperatures caused patient sweat to boil under the gear. Over the 4-year period, 20 firefighters were treated for burn injury. Mean age was 38.9 ± 8.9 years and 19 of 20 patients were male. Mean burn size was 1.1 ± 2.7% TBSA. Eighteen patients suffered second-degree burns, while two patients suffered first-degree burns. Mean length of hospitalization was 2.45 days. Scald burns were responsible for injury to 13 firefighters (65%). Flame burns caused injury to four patients (20%). Only three patients received contact burns (15%). The face was the site most commonly burned, representing 29% of injuries. The hand/wrist and ears were the next largest groups, with 23 and 16% of the injuries, respectively. Other areas burned included the neck (10%), arm (6.5%), leg (6.5%), knees (3%), shoulders (3%), and head (3%). Finally, the circumstance of injury was evaluated for each patient. Misuse and noncontiguous areas of protective equipment accounted for 14 of the 20 injuries (70%). These burns were caused when hot steam

  20. Gear Tooth Root Stresses of a Very Heavily Loaded Gear Pair-Case Study: Orbiter Body Flap Actuator Pinion and Ring Gear

    Science.gov (United States)

    Krantz, Timothy L.; Handschuh, Robert F.

    2015-01-01

    The space shuttle orbiter's body flap actuator gearing was assessed as a case study of the stresses for very heavily loaded external-internal gear pairs (meshing pinion and ring gear). For many applications, using the high point of single tooth contact (HPSTC) to locate the position of the tooth force is adequate for assessing the maximum tooth root stress condition. But for aerospace gearing such an approach may be inadequate for assessing the stress condition while also simultaneously minimizing mass. In this work specialized contact analyses and finite element methods were used to study gear tooth stresses of body flap actuator gears. The analytical solutions considered the elastic deformations as an inherent part of the solutions. The ratio for the maximum tooth stresses using the HPSTC approach solutions relative to the contact analysis and finite element solutions were 1.40 for the ring gear and 1.28 for the pinion gear.

  1. Optimization design of wind turbine drive train based on Matlab genetic algorithm toolbox

    Science.gov (United States)

    Li, R. N.; Liu, X.; Liu, S. J.

    2013-12-01

    In order to ensure the high efficiency of the whole flexible drive train of the front-end speed adjusting wind turbine, the working principle of the main part of the drive train is analyzed. As critical parameters, rotating speed ratios of three planetary gear trains are selected as the research subject. The mathematical model of the torque converter speed ratio is established based on these three critical variable quantity, and the effect of key parameters on the efficiency of hydraulic mechanical transmission is analyzed. Based on the torque balance and the energy balance, refer to hydraulic mechanical transmission characteristics, the transmission efficiency expression of the whole drive train is established. The fitness function and constraint functions are established respectively based on the drive train transmission efficiency and the torque converter rotating speed ratio range. And the optimization calculation is carried out by using MATLAB genetic algorithm toolbox. The optimization method and results provide an optimization program for exact match of wind turbine rotor, gearbox, hydraulic mechanical transmission, hydraulic torque converter and synchronous generator, ensure that the drive train work with a high efficiency, and give a reference for the selection of the torque converter and hydraulic mechanical transmission.

  2. Laser Heat Treatment on Gear Surface and Its Practical Application

    Institute of Scientific and Technical Information of China (English)

    MA Chun-yin; DAI Zhong-sen; SU Bao-rong

    2004-01-01

    Making gears with hardened tooth flank is one of the important developments in gear manufacturing. However, the conventional heat treating methods have a common shortcoming--producing big deformation. In this work, we demonstrate, by study, experiment and practical use, that not only has the laser heat treatment solved the difficult problems in conventional technique, but also it has great superiority. The use cases proved that the laser-treated gears are able to substitute for all the gears including gears with complicated shape, high precision and high performance imported gears and all those gears that cannot be manufactured by conventional methods. Moreover, our laser-treated gears have won quite good economic benefit.Obviously, the laser heat treatment for gears is a highly competitive technique having good prospects.

  3. Application of face-gear drives in helicopter transmissions

    Science.gov (United States)

    Litvin, F. L.; Wang, J.-C.; Bossler, R. B., Jr.; Chen, Y.-J. D.; Heath, G.; Lewicki, D. G.

    1992-05-01

    The use of face gears in helicopter transmissions was explored. A light-weight, split torque transmission design utilizing face gears was described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. Analytical study of transmission error showed face-gear drives were relatively insensitive to gear misalignment, but tooth contact was affected by misalignment. A method of localizing bearing contact to compensate for misalignment was explored. The proper choice of shaft support stiffness enabled good load sharing in the split torque transmission design. Face-gear experimental studies were also included and the feasibility of face gears in high-speed, high-load applications such as helicopter transmissions was demonstrated.

  4. Handbook on Face Gear Drives with a Spur Involute Pinion

    Science.gov (United States)

    Litvin, F. L.; Egelja, A.; Tan, J.; Chen, D. Y.-D.; Heath, G.

    2000-01-01

    The use of face gears in power transmission and drive systems has a significant number of benefits. Face gears allow a variety of new transmission arrangements as well as high reduction ratio capability. This leads to drive system weight reduction and improvements in performance. In this work, basic information about the design and analysis of face gear drives is presented. The work considers face gears in mesh with spur involute pinions for both intersecting axes and offset drives. Tooth geometry, kinematics, generation of face gears with localized bearing contact by cutting and grinding, avoidance of tooth undercutting, avoidance of tooth pointing, tooth contact analysis, and algorithms for the simulation of meshing and contact arc all topics which are discussed. In addition, applications of face gear drives are presented. Included are design uses in aerospace applications such as helicopter transmissions, split-torque face gear arrangements, comparisons of face gears with bevel gears, and general design considerations.

  5. Application of Face-Gear Drives in Helicopter Transmissions

    Science.gov (United States)

    Litvin, F. L.; Wang, J.-C.; Bossler, R. B., Jr.; Chen, Y.-J. D.; Heath, G.; Lewicki, D. G.

    1992-01-01

    The use of face gears in helicopter transmissions was explored. A light-weight, split torque transmission design utilizing face gears was described. Face-gear design and geometry were investigated. Topics included tooth generation, limiting inner and outer radii, tooth contact analysis, contact ratio, gear eccentricity, and structural stiffness. Design charts were developed to determine minimum and maximum face-gear inner and outer radii. Analytical study of transmission error showed face-gear drives were relatively insensitive to gear misalignment, but tooth contact was affected by misalignment. A method of localizing bearing contact to compensate for misalignment was explored. The proper choice of shaft support stiffness enabled good load sharing in the split torque transmission design. Face-gear experimental studies were also included and the feasibility of face gears in high-speed, high-load applications such as helicopter transmissions was demonstrated.

  6. Analysis of the Dynamic Characteristics of Elliptical Gears

    Science.gov (United States)

    Liu, Xing; Nagamura, Kazuteru; Ikejo, Kiyotaka

    To date, elliptical gear has been commonly used in automobile, automatic machinery, pumps, flow meters and printing presses for its particular non-uniform rotation. However, the dynamic characteristics of elliptical gears have not been clarified yet. In this study, The calculation as well as the experiment of two elliptical gears, which are a single elliptical gear and a double elliptical gear, is carried out to analyze the dynamic characteristics of elliptical gears. General factors including the torque, the rotation speed and the tooth root stress of the test gears are investigated. According to the analysis conducted in this study, the dynamic input torque variation of elliptical gear becomes larger along with the increase of operating gear rotation speed and the experimental one increases much faster than the calculated one over the Critical Rotation Speed of Tooth Separation (CRSTS) of elliptical gear. The experimental input rotation speed varies according to the variation of input torque, leading to the difference between the experimental output rotation speed and the desired one. The calculation results of the CRSTS of elliptical gears are almost equal to the experimental ones. The dynamic load variation ratios of elliptical gear at different angular position as well as their changing trends with operating gear rotation speed are quite different from each other. And the experimental dynamic load variation ratios of elliptical gear show difference from the calculated ones because of tooth separation and tooth impact. The agreement of the calculation and experimental results proves the validity of this study.

  7. Research on the Problem of Spur Gear Teeth Contact in the Car Gear Box

    Directory of Open Access Journals (Sweden)

    Viktor Skrickij

    2011-04-01

    Full Text Available The article presents research on the problem of two gear contact in the car gearbox. Contact stiffness is evaluated for the whole period of mesh. Also, contact stresses are evaluated in the contact place. The presented method can be used for calculating spur gear.Article in Lithuanian

  8. Strongly Interacting Planetary Systems

    Science.gov (United States)

    Ford, Eric

    2017-01-01

    Both ground-based Doppler surveys and NASA's Kepler mission have discovered a diversity of planetary system architectures that challenge theories of planet formation. Systems of tightly-packed or near-resonant planets are particularly useful for constraining theories of orbital migration and the excitation of orbital eccentricities and inclinations. In particular, transit timing variations (TTVs) provide a powerful tool to characterize the masses and orbits of dozens of small planets, including many planets at orbital periods beyond the reach of both current Doppler surveys and photoevaporation-induced atmospheric loss. Dynamical modeling of these systems has identified some ``supper-puffy'' planets, i.e., low mass planets with surprisingly large radii and low densities. I will describe a few particularly interesting planetary systems and discuss the implications for the formation of planets ranging from gaseous super-Earth-size planets to rocky planets the size of Mars.

  9. Forming different planetary systems

    Institute of Scientific and Technical Information of China (English)

    Ji-Lin Zhou; Ji-Wei Xie; Hui-Gen Liu; Hui Zhang; Yi-Sui Sun

    2012-01-01

    With the increasing number of detected exoplanet samples,the statistical properties of planetary systems have become much clearer.In this review,we summarize the major statistical results that have been revealed mainly by radial velocity and transiting observations,and try to interpret them within the scope of the classical core-accretion scenario of planet formation,especially in the formation of different orbital architectures for planetary systems around main sequence stars.Based on the different possible formation routes for different planet systems,we tentatively classify them into three major catalogs:hot Jupiter systems,standard systems and distant giant planet systems.The standard systems can be further categorized into three sub-types under different circumstances:solar-like systems,hot Super-Earth systems,and subgiant planet systems.We also review the theory of planet detection and formation in binary systems as well as planets in star clusters.

  10. Gear and Transmission Research at NASA Lewis Research Center

    Science.gov (United States)

    Townsend, Dennis P.

    1997-01-01

    This paper is a review of some of the research work of the NASA Lewis Research Center Mechanical Components Branch. It includes a brief review of the NASA Lewis Research Center and the Mechanical Components Branch. The research topics discussed are crack propagation of gear teeth, gear noise of spiral bevel and other gears, design optimization methods, methods we have investigated for transmission diagnostics, the analytical and experimental study of gear thermal conditions, the analytical and experimental study of split torque systems, the evaluation of several new advanced gear steels and transmission lubricants and the evaluation of various aircraft transmissions. The area of research needs for gearing and transmissions is also discussed.

  11. ESA Planetary Science Archive

    Science.gov (United States)

    Arviset, C.; Dowson, J.; Ortiz, I.; Parrilla, E.; Salgado, J.; Zender, J.

    2007-10-01

    The (ESA Planetary Science Archive {http://www.rssd.esa.int/psa} (PSA) hosts all the data from ESA's planetary missions into a single archive. It currently contains data from the Giotto, Mars Express, Rosetta, and Huygens spacecraft, some ground-based observations, and will host data from the Smart-1, Venus Express, and BepiColombo spacecraft in the future. Based on the NASA Planetary Data Systems (PDS) data dictionary, all datasets provided by the instrument teams are scientifically peer-reviewed and technically validated by software before being ingested into the Archive. Based on a modular and flexible architecture, the PSA offers a classical user-interface based on input fields, with powerful query and display possibilities. Data can be downloaded directly or through a more detailed shopping basket. Furthermore, a map-based interface is available to access Mars Express data without requiring any knowledge of the mission. Interoperability between the ESA PSA and the NASA PDS archives is also in progress, re-using concepts and experience gained from existing IVOA protocols. Prototypes are being developed to provide functionalities like GoogleMars, allowing access to both ESA PSA and NASA PDS data.

  12. Galactic planetary science.

    Science.gov (United States)

    Tinetti, Giovanna

    2014-04-28

    Planetary science beyond the boundaries of our Solar System is today in its infancy. Until a couple of decades ago, the detailed investigation of the planetary properties was restricted to objects orbiting inside the Kuiper Belt. Today, we cannot ignore that the number of known planets has increased by two orders of magnitude nor that these planets resemble anything but the objects present in our own Solar System. Whether this fact is the result of a selection bias induced by the kind of techniques used to discover new planets--mainly radial velocity and transit--or simply the proof that the Solar System is a rarity in the Milky Way, we do not know yet. What is clear, though, is that the Solar System has failed to be the paradigm not only in our Galaxy but even 'just' in the solar neighbourhood. This finding, although unsettling, forces us to reconsider our knowledge of planets under a different light and perhaps question a few of the theoretical pillars on which we base our current 'understanding'. The next decade will be critical to advance in what we should perhaps call Galactic planetary science. In this paper, I review highlights and pitfalls of our current knowledge of this topic and elaborate on how this knowledge might arguably evolve in the next decade. More critically, I identify what should be the mandatory scientific and technical steps to be taken in this fascinating journey of remote exploration of planets in our Galaxy.

  13. Kinetics of borided gear steels

    Indian Academy of Sciences (India)

    Ibrahim Gunes

    2013-06-01

    In this study, the case properties and diffusion kinetics of GS18NiMoCr36 (GS18), GS22NiMoCr56 (GS22) and GS32NiCrMo6.4 (GS32) gear steels borided in Ekabor-II powder were investigated by conducting a series of experiments at temperatures of 1123, 1173 and 1223 K for 2, 4 and 6 h. The boride layer was characterized by optical microscopy, X-ray diffraction technique and microVickers hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed the existence of FeB, Fe2B, CrB and Cr2B compounds. The thickness of the boride layer increases by increasing boriding time and temperature for all steels. The hardness of the boride compounds formed on the surface of the steels GS18, GS22 and GS32 ranged from 1624 to 1905 HV0,05, 1702 to 1948 HV0,05, and 1745 to 2034 HV0,05 respectively, whereas Vickers hardness values of the untreated steels GS18, GS22 and GS32 were 335 HV0,05, 358 HV0,05 and 411 HV0,05, respectively. The activation energies (Q) of borided steels were 228.644 kJ/mol for GS18, 280.609 kJ/mol for GS22 and 294.359 kJ/mol for GS32. The growth kinetics of the boride layers forming on the GS18, GS22 and GS32 steels and the thickness of boride layers were also investigated.

  14. A Computational Investigation of Gear Windage

    Science.gov (United States)

    Hill, Matthew J.; Kunz, Robert F.

    2012-01-01

    A CFD method has been developed for application to gear windage aerodynamics. The goals of this research are to develop and validate numerical and modeling approaches for these systems, to develop physical understanding of the aerodynamics of gear windage loss, including the physics of loss mitigation strategies, and to propose and evaluate new approaches for minimizing loss. Absolute and relative frame CFD simulation, overset gridding, multiphase flow analysis, and sub-layer resolved turbulence modeling were brought to bear in achieving these goals. Several spur gear geometries were studied for which experimental data are available. Various shrouding configurations and free-spinning (no shroud) cases were studied. Comparisons are made with experimental data from the open literature, and data recently obtained in the NASA Glenn Research Center Gear Windage Test Facility. The results show good agreement with experiment. Interrogation of the validative and exploratory CFD results have led, for the first time, to a detailed understanding of the physical mechanisms of gear windage loss, and have led to newly proposed mitigation strategies whose effectiveness is computationally explored.

  15. RELIABILITY BASED DESIGN OF A GEAR BOX

    Directory of Open Access Journals (Sweden)

    D.MADHUSEKHAR

    2014-08-01

    Full Text Available Reliability is the probability that a system, component or device will perform without failure for a specified period of time under specified operating conditions. The concept of reliability is of great importance in the design of various machine members. Conventional engineering design uses a deterministic approach. It disregards the fact that the material properties, the dimensions of the components and the externally applied loads are statistical in nature. In conventional design this uncertainties are covered with a factor of safety, which is not always successful. The growing trend towards reducing uncertainty and increasing reliability is to use the probabilistic approach. In the present work a three shaft four speed gear box and six speed gear box are designed using reliability principles. For the specified reliability of the system (Gear box, component reliability (Gear pair is calculated by considering the system as a series system. Design is considered to be safe and adequate if the probability of failure of gear box is less than or equal to a specified quantity in each of the two failure modes. . All the parameters affecting the design are considered as random variables and all the random variables are assumed to follow normal distribution. A computer program in C++ is developed to calculate the face widths in bending and surface failure modes. The larger one out of the two values is considered. By changing the variations in the design parameters, variations in the face widths are studied.

  16. Contactless Magnetic Gear for Robot Control Application

    Science.gov (United States)

    Komiyama, Hiroki; Uchimura, Yutaka

    This paper describes the application of a magnetic gear to a robot by fulfilling the essential requirements for a robot control, which are velocity control, position control, and force control. A magnetic gear is a transmission device that realizes contactless torque transmission by applying a magnetic force. When using a magnetic gear, cogging torque and spring characteristics need to be considered. In this paper, we introduce an approximate model of cogging torque. This model is used for velocity control to attenuate the disturbance due to cogging torque. In the case of position control, the oscillations due to the spring effect of the magnetic attractive force become a problem. To reduce the adverse effect due to these oscillations, resonance ratio control is applied. We also propose to use a magnetic gear for realizing the force sensorless bilateral control of teleoperation. Thanks to the frictionless transmission of a magnetic gear, the force sensorless estimation of a reaction force can be realized using a reaction force observer.

  17. Gear Transmission Error Measurement System Made Operational

    Science.gov (United States)

    Oswald, Fred B.

    2002-01-01

    A system directly measuring the transmission error between the meshing spur or helical gears was installed at the NASA Glenn Research Center and made operational in August 2001. This system employs light beams directed by lenses and prisms through gratings mounted on the two gear shafts. The amount of light that passes through both gratings is directly proportional to the transmission error of the gears. The device is capable of resolution better than 0.1 mm (one thousandth the thickness of a human hair). The measured transmission error can be displayed in a "map" that shows how the transmission error varies with the gear rotation or it can be converted to spectra to show the components at the meshing frequencies. Accurate transmission error data will help researchers better understand the mechanisms that cause gear noise and vibration and will lead to The Design Unit at the University of Newcastle in England specifically designed the new system for NASA. It is the only device in the United States that can measure dynamic transmission error at high rotational speeds. The new system will be used to develop new techniques to reduce dynamic transmission error along with the resulting noise and vibration of aeronautical transmissions.

  18. New Ideas in Orreries and Planetary System Simulations

    Science.gov (United States)

    Gould, A.; Koch, D.; Devore, E.; Harman, P.

    2008-11-01

    The NASA Kepler EPO team has created models and simulations of planetary systems (orreries) to use in demonstrating the transit technique of finding exoplanets. The first successful orrery, consisting of a three-planet orrery with an electric lamp (model star) at the center, and a Vernier light sensor system connected to a laptop computer with real-time graphing software, was first on display at the Kepler booth at the 2006 AAS conference. That system was extended to a four-planet model (one planet with a moon as well) and has been on display at many astronomy and teacher education conferences in the past few years. Construction of duplicate models costs about 60 for LEGO parts, plus 100 or so for light sensor hardware and software. The LEGO orrery effort stemmed from successful work in creating a large museum-grade orrery that was used in the Planet-Finding portion of the ``Alien Earths'' exhibit, a collaboration of Space Science Institute, NSF, NASA Kepler mission EPO and other NASA EPO groups. Replication of that model would cost in the neighborhood of $25,000. In recent months, Kepler EPO has worked on design of a more rudimentary, inexpensive orrery made of cardboard, paper plates, wine corks, and rubber bands. Work is also underway on a new plastic-geared orrery for use in classrooms with a Full Option Science System (FOSS) Planetary Science Unit for middle school. This presentation relays results and status of these new developments in planetary model systems.

  19. 某汽车差速器齿轮的强度分析及疲劳寿命预测%A Car Differential Gear Strength Analysis and Fatigue Life Prediction

    Institute of Scientific and Technical Information of China (English)

    王良模; 刘飞; 夏汉关; 赵红军; 王小乾; 张艳伟

    2012-01-01

    运用现代设计方法进行了某汽车差速器齿轮静强度分析和疲劳寿命预测。将几何模型导入HyperMesh中,利用壳单元和实体单元划分网格,并建立合适的MPC单元以方便载荷和约束的施加。根据齿轮的对称性,建立了行星齿轮和半轴齿轮单齿的有限元模型。利用有限元分析软件ANSYS进行行星齿轮和半轴齿轮静强度分析。分析结果表明所设计的齿轮能满足强度要求。基于齿轮有限元分析结果,利用疲劳分析软件MSC.Fatigue得出行星齿轮和半轴齿轮寿命云图及最低疲劳寿命,均满足寿命要求。%Modern design method is used for a car differential gear static strength analysis and fatigue life prediction. The geometric model is imported to HyperMesh, the shell element and entity unit are used for division grid, and proper MPC unit are established for load and constraint applied. According to the gear of symmetry, planetary gear and axle side gear single tooth finite element model are established. Using finite element analysis software ANSYS, planetary gear and axle shaft gear static strength are analyzed, and the results show that the designed gears can meet the requirements. Based on gear finite element analysis results, planetary gear and axle shaft gear life nephogram and minimum fatigue life are analyzed by using fatigue analysis software MSC. Fatigue. Both gears can satisfy actual life requirement.

  20. Stuck in gear: age-related loss of variable gearing in skeletal muscle.

    Science.gov (United States)

    Holt, Natalie C; Danos, Nicole; Roberts, Thomas J; Azizi, Emanuel

    2016-04-01

    Skeletal muscles power a broad diversity of animal movements, despite only being able to produce high forces over a limited range of velocities. Pennate muscles use a range of gear ratios, the ratio of muscle shortening velocity to fiber shortening velocity, to partially circumvent these force-velocity constraints. Muscles operate with a high gear ratio at low forces; fibers rotate to greater angles of pennation, enhancing velocity but compromising force. At higher forces, muscles operate with a lower gear ratio; fibers rotate little so limiting muscle shortening velocity, but helping to preserve force. This ability to shift gears is thought to be due to the interplay of contractile force and connective tissue constraints. In order to test this hypothesis, gear ratios were determined in the medial gastrocnemius muscles of both healthy young rats, and old rats where the interaction between contractile and connective tissue properties was assumed to be disrupted. Muscle fiber and aponeurosis stiffness increased with age (Pmuscles, indicating that variable gearing is lost in old muscle. These findings support the hypothesis that variable gearing results from the interaction between contractile and connective tissues and suggest novel explanations for the decline in muscle performance with age.