WorldWideScience

Sample records for adi internal gears

  1. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, REMOVAL OF ARSENIC IN DRINKING WATER: ADI INTERNATIONAL INC. ADI PILOT TEST UNIT NO. 2002-09 WITH MEDIA G2®; PHASE II

    Science.gov (United States)

    Verification testing of the ADI International Inc. Unit No. 2002-09 with MEDIA G2® arsenic adsorption media filter system was conducted at the Hilltown Township Water and Sewer Authority (HTWSA) Well Station No. 1 in Sellersville, Pennsylvania from October 8, 2003 through May 28,...

  2. Bifurcation phenomena in internal dynamics of gear systems

    Directory of Open Access Journals (Sweden)

    Hortel M.

    2007-10-01

    Full Text Available The impact effects in gear mesh represent specific phenomena in the dynamic investigation of highspeed light transmission systems with kinematic couplings. They are caused of greater dynamic than static elastic deformations in meshing gear profiles. In term of internal dynamics they are influenced among others by time heteronomous stiffness functions in gear mesh and resonance tuning of stiffness level. The damping in gear mesh and in gear system is concerned significantly in the amplitude progress, greatness and phase shift of relative motion towards stiffness function alternatively towards its modify form in gear mesh. In consequence of these and another actions rise above resonance characteristics certain singular locations with jump amplitude course.

  3. Bending strength model for internal spur gear teeth

    Science.gov (United States)

    Savage, Michael; Rubadeux, K. L.; Coe, H. H.

    1995-01-01

    Internal spur gear teeth are normally stronger than pinion teeth of the same pitch and face width since external teeth are smaller at the base. However, ring gears which are narrower have an unequal addendum or are made of a material with a lower strength than that of the meshing pinion may be loaded more critically in bending. In this study, a model for the bending strength of an internal gear tooth as a function of the applied load pressure angle is presented which is based on the inscribed Lewis constant strength parabolic beam. The bending model includes a stress concentration factor and an axial compression term which are extensions of the model for an external gear tooth. The geometry of the Lewis factor determination is presented, the iteration to determine the factor is described, and the bending strength J factor is compared to that of an external gear tooth. This strength model will assist optimal design efforts for unequal addendum gears and gears of mixed materials.

  4. On optimization of internal/external spur gears tooth bending strength

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2014-01-01

    level at the tooth root. As with most machine elements the design/geometry is defined in standards (ISO). The present work focuses on changing the tooth root design of both external and internal gears, in order to improve the stress concentration factor. The design changes made are compliant...

  5. 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

  6. Holmes-Adie Syndrome

    Science.gov (United States)

    ... pupil. Thoracic sympathectomy, which severs the involved sympathetic nerve, is the definitive treatment for excessive sweating. What is the prognosis? Holmes-Adie syndrome is not life-threatening or disabling. The loss of deep tendon reflexes is permanent. Some symptoms of the disorder may ...

  7. Nonlinear dynamic analysis of coupled gear-rotor-bearing system with the effect of internal and external excitations

    Science.gov (United States)

    Zhou, Shihua; Song, Guiqiu; Ren, Zhaohui; Wen, Bangchun

    2016-03-01

    Extensive studies on nonlinear dynamics of gear systems with internal excitation or external excitation respectively have been carried out. However, the nonlinear characteristics of gear systems under combined internal and external excitations are scarcely investigated. An eight-degree-of-freedom(8-DOF) nonlinear spur gear-rotor-bearing model, which contains backlash, transmission error, eccentricity, gravity and input/output torque, is established, and the coupled lateral-torsional vibration characteristics are studied. Based on the equations of motion, the coupled spur gear-rotor-bearing system(SGRBS) is investigated using the Runge-Kutta numerical method, and the effects of rotational speed, error fluctuation and load fluctuation on the dynamic responses are explored. The results show that a diverse range of nonlinear dynamic characteristics such as periodic motion, quasi-periodic motion, chaotic behaviors and impacts exhibited in the system are strongly attributed to the interaction between internal and external excitations. Significantly, the changing rotational speed could effectively control the vibration of the system. Vibration level increases with the increasing error fluctuation. Whereas the load fluctuation has an influence on the nonlinear dynamic characteristics and the increasing excitation force amplitude makes the vibration amplitude increase, the chaotic motion may be restricted. The proposed model and numerical results can be used for diagnosis of faults and vibration control of practical SGRBS.

  8. Nonlinear Dynamic Analysis of Coupled Gear-Rotor-Bearing System with the Effect of Internal and External Excitations

    Institute of Scientific and Technical Information of China (English)

    ZHOU Shihua; SONG Guiqiu; REN Zhaohui; WEN Bangchun

    2016-01-01

    Extensive studies on nonlinear dynamics of gear systems with internal excitation or external excitation respectively have been carried out. However, the nonlinear characteristics of gear systems under combined internal and external excitations are scarcely investigated. An eight-degree-of-freedom(8-DOF) nonlinear spur gear-rotor-bearing model, which contains backlash, transmission error, eccentricity, gravity and input/output torque, is established, and the coupled lateral-torsional vibration characteristics are studied. Based on the equations of motion, the coupled spur gear-rotor-bearing system(SGRBS) is investigated using the Runge-Kutta numerical method, and the effects of rotational speed, error fluctuation and load fluctuation on the dynamic responses are explored. The results show that a diverse range of nonlinear dynamic characteristics such as periodic motion, quasi-periodic motion, chaotic behaviors and impacts exhibited in the system are strongly attributed to the interaction between internal and external excitations. Significantly, the changing rotational speed could effectively control the vibration of the system. Vibration level increases with the increasing error fluctuation. Whereas the load fluctuation has an influence on the nonlinear dynamic characteristics and the increasing excitation force amplitude makes the vibration amplitude increase, the chaotic motion may be restricted. The proposed model and numerical results can be used for diagnosis of faults and vibration control of practical SGRBS.

  9. Reduction gear for a turbo compound drive of a supercharged internal combustion engine. Reduktionsgetriebe fuer einen Turbocompoundantrieb einer aufgeladenen Brennkraftmaschine

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, H.; Fischer, G.; Bueschel, W.

    1991-01-24

    The invention concerns a reduction gear within the turbocompound drive of a supercharged internal combustion engine with at least two reduction stages and a one-way clutch. In order to decouple the vibrations of the turbine and the power plant of the internal combustion engine at least one torsion bushing is provided as which acts as a vibration damper. The one-way clutch is located in the hub of the drive of the second reduction stage in order to save space.

  10. Triple gear

    OpenAIRE

    Schleimer, Saul; Segerman, Henry

    2013-01-01

    A relatively common sight in graphic designs is a planar arrangement of three gears in contact. However, since neighboring gears must rotate in opposite directions, none of the gears can move. We give a non-planar, and non-frozen, arrangement of three linked gears.

  11. 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.

  12. Design of Vibration Abrasive Machine for Internal Gear Pair%内齿轮副振动研磨机设计

    Institute of Scientific and Technical Information of China (English)

    赵显日

    2015-01-01

    A kind of vibration abrasive machine for internal gear pair finishing was introduced. Its main movement was formed by the high frequency reciprocating translation of the internal gear, and the engagement was created by the revolution and rotation of the external gear. The loading of the pair was realized by the automatic adjustment of its eccentric amount. The structure of the whole equip-ment is simple and its cost is low.%介绍一种能对成对内齿轮副实施齿面研磨加工的机械加工设备. 由内齿轮轴向高频往复构成主运动, 外齿轮的公转和自转形成啮合运动, 自动调整内、 外齿轮偏心量实现加载. 整个设备结构简单, 成本低廉.

  13. 新型内平动齿轮减速器的设计%Design of a new internal parallel moving gear reducer

    Institute of Scientific and Technical Information of China (English)

    周利锋; 廖启征; 魏世民; 宋原

    2012-01-01

    在内平动齿轮传动原理的基础上利用平行四边形放缩机构作为外齿轮平动的发生机构,设计了一种新的内平动齿轮减速器.采用周向均布的4套放缩机构驱动两片啮合点相位差为180°的外齿轮,有效地平衡了传动过程中的惯性力.分析了平行四边形放缩机构的最佳传动角.通过分析渐开线少齿差啮合齿轮的干涉,得到了啮合参数的选择依据和计算步骤.最后设计了该减速器的三维实体模型,进行了运动仿真.该减速器具有传动比大、体积小、输入输出同轴线等优点.%Based on internal parallel moving gear drive principle and by using the scaling parallel four-bar linkage as the generator for parallel moving of external gear, a new internal parallel moving gear reducer was designed. Four four-bar linkages equally distributed in circumference were used to drive two external gears with 180° of phase difference at meshing point, and the inertial force during the transmission process was balanced effectively. The optimum transmission angle of the four-bar linkage had been calculated. After analyzing the interference of involute less tooth number difference gear mesh, the constraint condition and calculation procedure were given out. At last, the 3D model of the new gear ret ducer had been designed, and the kinematic simulation had been completed. The new reducer has advantages in large transmission radio, small volume, light weight and coaxial input and output.

  14. Recent ADI iteration analysis and results

    Energy Technology Data Exchange (ETDEWEB)

    Wachspress, E.L.

    1994-12-31

    Some recent ADI iteration analysis and results are discussed. Discovery that the Lyapunov and Sylvester matrix equations are model ADI problems stimulated much research on ADI iteration with complex spectra. The ADI rational Chebyshev analysis parallels the classical linear Chebyshev theory. Two distinct approaches have been applied to these problems. First, parameters which were optimal for real spectra were shown to be nearly optimal for certain families of complex spectra. In the linear case these were spectra bounded by ellipses in the complex plane. In the ADI rational case these were spectra bounded by {open_quotes}elliptic-function regions{close_quotes}. The logarithms of the latter appear like ellipses, and the logarithms of the optimal ADI parameters for these regions are similar to the optimal parameters for linear Chebyshev approximation over superimposed ellipses. W.B. Jordan`s bilinear transformation of real variables to reduce the two-variable problem to one variable was generalized into the complex plane. This was needed for ADI iterative solution of the Sylvester equation.

  15. The gears design methods

    OpenAIRE

    Dřevický, Miroslav

    2012-01-01

    Summary: The purpose of this thesis is to present some methods for gear calculation. In the chapter "Design methods for gears" are described four methods of calculation. Detail description of procedure for calculation by using these methods is in this chapter, including designing calculation and checking calculation. There are primary mentioned the calculation methods for a front gears with straight gearing. In the chapter "Calculation of gear set" is the gear set computed by using each meth...

  16. Analysis of the Flow Pulsation of Straight Conjugated Internal Gear Pump%直线共轭内啮合齿轮泵流量脉动分析

    Institute of Scientific and Technical Information of China (English)

    张惠; 汪中厚

    2015-01-01

    Based on flow pulsation formula of the straight internal gear pump,the straight conju gate internal gear pump is studied,the instantaneous flow rate formula is derived and the reliability of the formula is verified by experiment.The maximum and minimum of the instantaneous flow are obtained after the analysis of engagement characteristic in detail and the formula for the flow pulsation is derived.The influence of factors such as dedendum coefficient and half profile angle on the pulsation are analyzed,the impact curves are plotted in MATLAB and the optional dedendum coefficient is obtained through the curves.It can help improve the transmission stability of the pump.%以直线共轭内啮合齿轮泵为研究对象,推导了瞬时流量公式,并通过实验验证了该瞬时流量公式的可靠性,又对该泵的啮合特性进行细致的研究,利用极值方法找出其瞬时流量的最大值及最小值,并结合经典的渐开线齿轮泵流量脉动率公式,推导出直线共轭内啮合齿轮泵的流量脉动率公式.分析了包括齿根高系数、齿形半角在内的因数对流量脉动的影响趋势,在MATLAB中绘制出了影响曲线,并直观地找出了最优化的齿根高系数,以利于进一步改进齿轮泵的传动平稳性.

  17. 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.

  18. AERODYNAMIC IMPROVEMENT OF KhADI 33 RACING CAR RADIATOR COMPARTMENT

    Directory of Open Access Journals (Sweden)

    A. Avershyn

    2011-01-01

    Full Text Available Aerodynamic characteristics of radiator compartment of KhADI 33 racing car on the basis of the decision of the interfaced problem of internal and external aerodynamics are numerically investigated. The rational variant of radiator compartment which is characterized by high throughput and low level of non-uniformity of speed field at the input is offered.

  19. 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

  20. Optimal Design of Internal Gear Shaper Cutter Based on Matlab Genetic Algorithm Optimization Toolbox%基于Matlab遗传算法工具箱的内插齿刀优化设计

    Institute of Scientific and Technical Information of China (English)

    唐德威; 刘丹; 邓宗全; 姜生元

    2012-01-01

    插齿刀参数的选取决定着插齿刀寿命、耐用度和被加工齿轮质量.为了使渐开线内齿轮插齿刀获得更好的切削性能,综合考虑切入顶切、干涉顶切等约束条件,建立了以插齿刀最大重磨厚度、最大变位系数及最大齿数参数为优化目标的数学模型,该模型为插齿刀参数优化设计奠定了基础.在所建立的教学模型基础上,针对传统插齿刀参数优化方法不易全局寻优、速代收敛慢等不足,提出了一种基于Matlab遗传算法工具箱求解渐开线直齿内插齿刀参数的优化设计方法.%The parameter selection of the gear shaper cutter will affect the cutting characters including the service life & endurance of the gear shaper cutter and the quality of the processed gears. By comprehensive consideration of the constraint conditions for cut—in top cut and interfered top cut, a mathematical model is established by taking the parameters such as regrinding thickness of gear shaper cutter, the maximum deflection coefficient and the maximum number of teeth as the optimization objectives in order to enable the gear shaper cutter for inner gears with involute curve to obtain preferable cutting performances. This model has laid the foundation in design for parameter optimization of gear shaper cutter. On the base of established mathematical model and aiming at the deficiency i.e. the traditional parameter optimization method for gear shaper cutter is difficult in global optimization and slow in iterative convergence, this article proposes a new design method to optimize the parameters of the internal gear shaper cutter for processing of the involute straight tooth which is built on the toolbox of Matlab genetic algorithm.

  1. Microadditions of boron and vanadium in ADI

    Directory of Open Access Journals (Sweden)

    Rzychoń T.

    2007-01-01

    Full Text Available In the second part of the study, describing the role of vanadium and boron microadditions in the process of structure formation in heavy-walled castings made from ADI, the results of own investigations were presented. Within this study two series of melts of the ductile iron were made, introducing microadditions of the above mentioned elements to both unalloyed ductile iron and the ductile iron containing high levels of nickel and copper (the composition typical of ADI. Melts were conducted with iron-nickel-magnesium master alloy. Thermal analysis of the solidification process of the cast keel blocks was conducted, the heat treatment of the alloys was carried out, and then the effect of the introduced additions of boron and vanadium on the hardenability of the investigated cast iron was examined and evaluated.

  2. 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.

  3. Research of Austempered ductile Iron Gears in Diesel Engine%奥贝球铁齿轮在柴油机上的应用研究

    Institute of Scientific and Technical Information of China (English)

    刘海霞; 傅明喜; 孙少纯; 司乃潮; 杨永涛; 陈柏林; 钱鲁阳

    2001-01-01

    The influences of different austemper temperatures,content of manganese,silicon,copper and molybdenum on the microstructures and mechanical properties of austempered ductile iron (ADI) were studied.The effects of work hardening on machinablities of ADI were also discussed.Meanwhile some ADI gears replaced the 40Cr hardened and tempered steel gears in a diesel engine to test their functions of reducing noise and wear resistance.It was found that the mechanical properties of ADI gears were higher than that of 40Cr hardened and tempered steel gears.The ADI gears decreased the working noise of the whole diesel engine by 1.92dB and the noise in side of the gears by 5.3dB.After 45 hours' run-in and 200 hours' continuous operation in demarcated conditions,there was no abnormal wear in the ADI gears and there still existed allowance of 0.13mm between limit gap and gear gap.So the frictional wear properties of ADI gears were qualified and the ADI gears produced could meet the design and appilication requirements.%研究了不同等温温度及Mn、Si、Cu、Mo对奥贝球铁组织和力学性能的影响,讨论了奥贝球铁加工硬化对机加工性能的影响。同时,将奥贝球铁齿轮代替40Cr调质钢齿轮进行装机试验,对降噪声和耐磨性进行了测试。结果表明,奥贝球铁齿轮与40Cr调质钢齿轮相比,力学性能高,柴油机整机噪声下降1.92dB,齿轮侧噪声下降5.3dB。奥贝球铁齿轮经过45h磨合后,在标定工况下连续运转200h,齿轮无异常磨损,齿轮间隙离极限间隙还有0.13mm的余量,所以其摩擦磨损性能合格,所生产的奥贝球铁齿轮满足设计使用要求。

  4. 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

  5. Noncircular gears design and generation

    CERN Document Server

    Litvin, Faydor L; Gonzalez-Perez, Ignacio

    2009-01-01

    Noncircular Gears: Design and Generation represents the extension of the modern theory of gearing applied to the design and manufacture of the main types of noncircular gears: conventional and modified elliptical gears, eccentric gears, oval gears, gears with lobes, and twisted gears. This book is enhanced by updated theoretical description of the methods of generation of noncircular gears by enveloping methods similar to those applied to the generation of circular gears. Noncircular Gears: Design and Generation also offers new developments directed to extend the application of noncircular gea

  6. 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.

  7. Unique microstructure and excellent mechanical properties of ADI

    OpenAIRE

    Jincheng Liu

    2006-01-01

    Amongst the cast iron family, ADI has a unique microstructure and an excellent, optimised combination of mechanical properties. The main microstructure of ADI is ausferrite, which is a mixture ofextremely fine acicular ferrite and stable, high carbon austenite. There are two types of austenite in ADI:(1) the coarser and more equiaxed blocks of austenite between non-parallel acicular structures, which exist mainly in the last solidified area, and (2) the thin films of ustenite between the indi...

  8. 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...

  9. ADI After Austenitising From Intercritical Temperature

    OpenAIRE

    A. Kowalski; S. Kloska-Nawarecka; Regulski, K.

    2013-01-01

    ADI subjected to austenitising at intercritical temperatures contains in its matrix the precipitates of pre-eutectoid ferrite. Studies were carried out on the ductile iron of the following chemical composition: C = 3,80%, Si = 2,30%, Mn = 0,28%, P = 0,060%, S = 0,010%, Mg = 0,065%, Ni = 0,60%, Cu = 0,70%, Mo = 0,21% This cast iron was austenitised at three different temperatures, i.e. 800, 815 and 830oC and austempered at 360 and 380oC. For each variant of the cast iron heat treatment, the me...

  10. Low alloy steel versus ADI – differences and similarities

    Directory of Open Access Journals (Sweden)

    A. Krzyńska

    2009-01-01

    Full Text Available The results of comparison between the microstructure of selected bainitic low alloy steel and austempered ductile iron ADI are presented. The aim of the comparison was to find out differences and similarities existing in these iron carbon commercial alloys. In this paper our own results on ADI structure and literature data were used. It follows from discussion presented here that both microstructure and properties of ADI are very close that which are observed in low alloy carbon steel. Moreover, we suggest that there is no so doubt to treat ADI mechanical properties as steel containing nodular inclusions of graphite.

  11. Landing Gear Door Liners for Airframe Noise Reduction

    Science.gov (United States)

    Jones, Michael G. (Inventor); Howerton, Brian M. (Inventor); Van De Ven, Thomas (Inventor)

    2014-01-01

    A landing gear door for retractable landing gear of aircraft includes an acoustic liner. The acoustic liner includes one or more internal cavities or chambers having one or more openings that inhibit the generation of sound at the surface and/or absorb sound generated during operation of the aircraft. The landing gear door may include a plurality of internal chambers having different geometries to thereby absorb broadband noise.

  12. Study on Dynamic Characteristic of Double Crank Input Internal Parallel Moving Gear Transmission%双曲柄输入内平动齿轮传动的动态特性研究

    Institute of Scientific and Technical Information of China (English)

    温芳; 张海霞; 张冰川

    2012-01-01

    Aiming at the problem of large structure, severe vibration and high level of noise for the present external parallel moving gear transmission, a kind of internal parallel moving gears transmission with compact structure and complete balance is proposed. Hie elastic dynamics equation of the system is established by synthetically considering some factors. In the modeling process, the factors including the elastic deformation of all eccentric shafts, the elastic deformation of meshing gears, the elastic deformation of planetary bearing on eccentric shafts and supporting bearing on output shaft, and some dynamic characteristics such as the natural frequency, gear engaging force, bearing loads of system are derived according to the equation, and the results are analyzed. The basis on further optimizing the design of gear transmission, reducing vibration and improving mechanical properties is provided.%针对目前外平动齿轮传动结构庞大、振动大、噪声高的问题,提出一种结构紧凑、完全平衡的内平动齿轮传动装置.在综合考虑偏心轴弹性变形,齿轮副处弹性变形及偏心轴行星轴承、输出轴支撑轴承弹性变形的情况下,建立了该系统的弹性动力学方程,根据该方程求解出它的固有频率,齿轮啮合力及轴承载荷等一些动态特性,并对结果进行分析,为进一步优化齿轮传动设计,减少振动,提高机械性能提供依据.

  13. 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.

  14. Estimating Gear Teeth Stiffness

    OpenAIRE

    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 ...

  15. 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.

  16. 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

  17. ADI After Austenitising From Intercritical Temperature

    Directory of Open Access Journals (Sweden)

    A. Kowalski

    2013-01-01

    Full Text Available ADI subjected to austenitising at intercritical temperatures contains in its matrix the precipitates of pre-eutectoid ferrite. Studies were carried out on the ductile iron of the following chemical composition: C = 3,80%, Si = 2,30%, Mn = 0,28%, P = 0,060%, S = 0,010%, Mg = 0,065%, Ni = 0,60%, Cu = 0,70%, Mo = 0,21% This cast iron was austenitised at three different temperatures, i.e. 800, 815 and 830oC and austempered at 360 and 380oC. For each variant of the cast iron heat treatment, the mechanical properties, i.e. YS, TS, EL and Hardness, were measured, and structure of the matrix was examined. Higher plastic properties were obtained owing to the presence of certain amount of pre-eutectoid ferrite. The properties were visualised using fuzzy logic model in a MATLAB. software.

  18. Unique microstructure and excellent mechanical properties of ADI

    Directory of Open Access Journals (Sweden)

    Jincheng Liu

    2006-11-01

    Full Text Available Amongst the cast iron family, ADI has a unique microstructure and an excellent, optimised combination of mechanical properties. The main microstructure of ADI is ausferrite, which is a mixture ofextremely fine acicular ferrite and stable, high carbon austenite. There are two types of austenite in ADI:(1 the coarser and more equiaxed blocks of austenite between non-parallel acicular structures, which exist mainly in the last solidified area, and (2 the thin films of ustenite between the individual ferriteplatelets in the acicular structure. It is this unique microstructure, which gives ADI its excellent static and dynamic properties, and good low temperature impact toughness. The effect of microstructure on the mechanical properties is explained in more detail by examining the microstructure at the atomic scale. Considering the nanometer grain sizes, the unique microstructure, the excellent mechanical properties,good castability, (which enables near net shape components to be produced economically and in large volumes, and the fact that it can be 100% recycled, it is not overemphasized to call ADI a high-tech,nanometer and “green” material. ADI still has the potential to be further improved and its production and the number of applications for ADI will continue to grow, driven by the resultant cost savings over alternative materials.

  19. Research of HCR Gearing Properties from Warm Scuffing Damage Point of View

    Directory of Open Access Journals (Sweden)

    Kuzmanović Siniša

    2014-12-01

    Full Text Available The issue of design and dimensioning of HCR gearing, particularly of the gearings with an internal engagement, it nowadays, especially in the design of hybrid cars drives, highly topical. This kind of gearing has many advantages in operation, but at the same time it is more complicated in stage of its design and load capacity calculation. Authors in this contribution present some results of temperature scuffing research of internal and external HCR gearing. There are given the equations for calculation of warm scuffing resistance of both external and internal HCR gearing derived according to the integral temperature criterion.

  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. 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 regard...

  2. Communication: Molecular gears.

    Science.gov (United States)

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

    2016-09-01

    The (1)H 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. PMID:27608981

  3. 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.

  4. Evaluación de las cargas dinámicas internas en engranajes cilíndricos de contacto exterior. // Calculation of internal dynamic load on cylindrical gears with external contact.

    Directory of Open Access Journals (Sweden)

    G. González Rey

    2001-04-01

    Full Text Available En el articulo se presentan y esclarecen las cinco diferentes metodologías de cálculo del coeficiente de carga dinámicapresentes en la Norma ISO 6336-96. Con el objetivo de conocer la conveniencia de aplicación y las limitaciones quepresentan los diferentes métodos de cálculo son comparados estos con algunos resultados prácticos. Aunque lasvaloraciones del coeficiente de carga dinámica en los engranajes cilíndricos están en una etapa bastante avanzada aún losprocedimientos contemplados en la actual Norma ISO muestran dificultades en la precisión de la frecuencia de resonanciadel engranaje.Palabras claves: Engranajes cilíndricos, cargas dinámicas, norma ISO, factor de carga dinámica._____________________________________________________________________Abstract:Five different methods of calculation procedures of the dynamic factor Kv on cylindrical gears is exposed in thispaper, taking into account the International Standard ISO 6336:96. In order to analyze consistence and limit ofapplication of ISO methods for Kv , they are confronted with some experimental results.Key words: cylindrical gear, dynamic load, ISO Standard, dynamic factor.

  5. 二齿差纯滚动活齿内齿圈的数字化设计与加工%Digital Design and Manufacturing on New Two-tooth Difference Pure Rolling Movable Teeth Internal Gear

    Institute of Scientific and Technical Information of China (English)

    张帅; 梁尚明; 蒋立茂; 张杰; 姚进

    2012-01-01

    Aimingat the problem of the low machining precision and manufacturing difficulties of the new two-tooth difference pure rolling internal gear profile,α method of 3D digital design and manufacturing was proposed based on UG NX design platfomuThree-dimensional modeling of the internal gear profile was established though envelope equationAnd the tooth profile was analyzed and digital processing was illustrated in detail With the help of UG NX design platform,the problems in manufacturing procession were effectively solved,which reduced costs in product design and production and improved work efficiency.Though NC machine cutting simulation,the risk of parts false processing was reduced.The digital design and manufacturing based on UG NX design platform provided a new method for the design and manufacture of internal gear.%针对新型二齿差纯滚动活齿内齿圈轮廓曲线加工精度低,加工难度大的问题,提出了基于UG NX设计平台的三维数字化设计与加工的方法.通过二齿差纯滚动滚柱活齿外端曲线的包络方程,在UG NX设计平台对内齿圈三维建模.对齿形进行了分析并对数字化加工做了详细的说明.借助UG NX设计平台,有效解决了内齿圈加工过程中的难题,降低了产品设计、生产成本,提高了工作效率.通过数控机床的切削仿真,降低了零件加工错误的风险.UG NX设计平台的数字化设计与加工为内齿圈的设计与制造提供了新的方法.

  6. p-adična števila

    OpenAIRE

    Grešak, Rozalija

    2015-01-01

    Realna števila običajno vpeljemo s pomočjo Dedekindovih rezov. V magistrskem delu se osredotočimo na konstrukcijo realnih števil s pomočjo metrične napolnitve racionalnih števil, torej s pomočjo Cauchyjevih zaporedij. Nato na podoben način konstruiramo p-adična števila, opišemo njihove glavne značilnosti in nekaj njihovih topoloških lastnosti. V nadaljevanju opišemo konstrukcijo kompleksnih p-adičnih števil in primerjamo običajna kompleksna števila s p-adičnimi kompleksnimi števili. Magistrsk...

  7. The comparative studies of ADI versus Hadfield cast steel wear resistance

    Directory of Open Access Journals (Sweden)

    Mieczysław Kaczorowski

    2011-04-01

    Full Text Available The results of comparative studies of wear resistance of ADI versus high manganese Hadfield cast steel are presented. For evaluation ofwear resistance three type of ADI were chosen. Two of them were of moderate strength ADI with 800 and 1000MPa tensile strength whilethe third was 1400MPa tensile strength ADI. The specimens were cut from ADI test YII type casting poured and heat treated in Institute ofFoundry in Krakow. The pin on disc method was used for wear resistance experiment. The specimens had a shape of 40mm long rod withdiameter 6mm. The load and speed were 100N and 0,54m/s respectively. It was concluded that the wear resistance of ADI is comparablewith high manganese cast steel and in case of low tensile grade ADI and is even better for high strength ADI than Hadfield steel.

  8. 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.

  9. NEW TECHNIQUES FOR HIGH-CONTRAST IMAGING WITH ADI: THE ACORNS-ADI SEEDS DATA REDUCTION PIPELINE

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, Timothy D.; Turner, Edwin L. [Department of Astrophysical Sciences, Princeton University, Princeton, NJ (United States); McElwain, Michael W.; Grady, C. A. [Goddard Space Flight Center, Greenbelt, MD (United States); Abe, L. [Laboratoire Hippolyte Fizeau, Nice (France); Brandner, W.; Feldt, M.; Henning, T. [Max Planck Institute for Astronomy, Heidelberg (Germany); Carson, J. [College of Charleston, Charleston, SC (United States); Egner, S.; Golota, T.; Guyon, O.; Hayano, Y.; Hayashi, S.; Ishii, M. [Subaru Telescope, Hilo, HI (United States); Goto, M. [Universitaets-Sternwarte Muenchen, Ludwig-Maximilians-Universitaet, Munich (Germany); Hashimoto, J.; Hayashi, M.; Iye, M. [National Astronomical Observatory of Japan, Tokyo (Japan); Hodapp, K. W. [Institute for Astronomy, University of Hawai' i, Hilo, HI (United States); and others

    2013-02-20

    We describe Algorithms for Calibration, Optimized Registration, and Nulling the Star in Angular Differential Imaging (ACORNS-ADI), a new, parallelized software package to reduce high-contrast imaging data, and its application to data from the SEEDS survey. We implement several new algorithms, including a method to register saturated images, a trimmed mean for combining an image sequence that reduces noise by up to {approx}20%, and a robust and computationally fast method to compute the sensitivity of a high-contrast observation everywhere on the field of view without introducing artificial sources. We also include a description of image processing steps to remove electronic artifacts specific to Hawaii2-RG detectors like the one used for SEEDS, and a detailed analysis of the Locally Optimized Combination of Images (LOCI) algorithm commonly used to reduce high-contrast imaging data. ACORNS-ADI is written in python. It is efficient and open-source, and includes several optional features which may improve performance on data from other instruments. ACORNS-ADI requires minimal modification to reduce data from instruments other than HiCIAO. It is freely available for download at www.github.com/t-brandt/acorns-adi under a Berkeley Software Distribution (BSD) license.

  10. New Techniques for High-contrast Imaging with ADI: The ACORNS-ADI SEEDS Data Reduction Pipeline

    NARCIS (Netherlands)

    T.D. Brandt; M.W. McElwain; E.L. Turner; L. Abe; W. Brandner; J. Carson; S. Egner; M. Feldt; T. Golota; M. Goto; C.A. Grady; O. Guyon; J. Hashimoto; Y. Hayano; M. Hayashi; S. Hayashi; T. Henning; K.W. Hodapp; M. Ishii; M. Iye; M. Janson; R. Kandori; G.R. Knapp; T. Kudo; N. Kusakabe; M. Kuzuhara; J. Kwon; T. Matsuo; S. Miyama; J.-I. Morino; A. Moro-Martín; T. Nishimura; T.-S. Pyo; E. Serabyn; H. Suto; R. Suzuki; M. Takami; N. Takato; H. Terada; C. Thalmann; D. Tomono; M. Watanabe; J.P. Wisniewski; T. Yamada; H. Takami; T. Usuda; M. Tamura

    2013-01-01

    We describe Algorithms for Calibration, Optimized Registration, and Nulling the Star in Angular Differential Imaging (ACORNS-ADI), a new, parallelized software package to reduce high-contrast imaging data, and its application to data from the SEEDS survey. We implement several new algorithms, includ

  11. New Techniques for High-Contrast Imaging with ADI: The ACORNS-ADI SEEDS Data Reduction Pipeline

    Science.gov (United States)

    Brandt, Timothy D.; McElwain, Michael W.; Turner, Edwin L.; Abe, L.; Brandner, W.; Carson, J.; Egner, S.; Feldt, M.; Golota, T.; Grady, C. A.; Guyon, O.; Hashimoto, J.; Hayano, Y.; Hayashi, M.; Hayashi, S.; Henning, T.; Hodapp, K. W.; Ishil, M.; Lye, M.; Janson, M.; Kandori, R.; Knapp, G. R.; Kudo, T.; Kusakabe, N.; Kuzuhara, M.

    2012-01-01

    We describe Algorithms for Calibration, Optimized Registration, and Nulling the Star in Angular Differential Imaging (ACORNS-ADI), a new, parallelized software package to reduce high-contrast imaging data, and its application to data from the Strategic Exploration of Exoplanets and Disks (SEEDS) survey. We implement seyeral new algorithms, includbg a method to centroid saturated images, a trimmed mean for combining an image sequence that reduces noise by up to approx 20%, and a robust and computationally fast method to compute the sensitivitv of a high-contrast obsen-ation everywhere on the field-of-view without introducing artificial sources. We also include a description of image processing steps to remove electronic artifacts specific to Hawaii2-RG detectors like the one used for SEEDS, and a detailed analysis of the Locally Optimized Combination of Images (LOCI) algorithm commonly used to reduce high-contrast imaging data. ACORNS-ADI is efficient and open-source, and includes several optional features which may improve performance on data from other instruments. ACORNS-ADI is freely available for download at www.github.com/t-brandt/acorns_-adi under a BSD license

  12. 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.

  13. The comparative studies of ADI versus Hadfield cast steel wear resistance

    OpenAIRE

    Mieczysław Kaczorowski; Anna Krzyńska; Paweł Skoczylas

    2011-01-01

    The results of comparative studies of wear resistance of ADI versus high manganese Hadfield cast steel are presented. For evaluation ofwear resistance three type of ADI were chosen. Two of them were of moderate strength ADI with 800 and 1000MPa tensile strength whilethe third was 1400MPa tensile strength ADI. The specimens were cut from ADI test YII type casting poured and heat treated in Institute ofFoundry in Krakow. The pin on disc method was used for wear resistance experiment. The specim...

  14. Energy efficiency improvement by gear shifting optimization

    Directory of Open Access Journals (Sweden)

    Blagojevic Ivan A.

    2013-01-01

    Full Text Available Many studies have proved that elements of driver’s behavior related to gear selection have considerable influence on the fuel consumption. Optimal gear shifting is a complex task, especially for inexperienced drivers. This paper presents an implemented idea for gear shifting optimization with the aim of fuel consumption minimization with more efficient engine working regimes. Optimized gear shifting enables the best possible relation between vehicle motion regimes and engine working regimes. New theoretical-experimental approach has been developed using On-Board Diagnostic technology which so far has not been used for this purpose. The matrix of driving modes according to which tests were performed is obtained and special data acquisition system and analysis process have been developed. Functional relations between experimental test modes and adequate engine working parameters have been obtained and all necessary operations have been conducted to enable their use as inputs for the designed algorithm. The created Model has been tested in real exploitation conditions on passenger car with Otto fuel injection engine and On-Board Diagnostic connection without any changes on it. The conducted tests have shown that the presented Model has significantly positive effects on fuel consumption which is an important ecological aspect. Further development and testing of the Model allows implementation in wide range of motor vehicles with various types of internal combustion engines.

  15. The ADI-FDTD method for high accuracy electrophysics applications

    Science.gov (United States)

    Haeri Kermani, Mohammad

    The Finite-Difference Time-Domain (FDTD) is a dependable method to simulate a wide range of problems from acoustics, to electromagnetics, and to photonics, amongst others. The execution time of an FDTD simulation is inversely proportional to the time-step size. Since the FDTD method is explicit, its time-step size is limited by the well-known Courant-Friedrich-Levy (CFL) stability limit. The CFL stability limit can render the simulation inefficient for very fine structures. The Alternating Direction Implicit FDTD (ADI-FDTD) method has been introduced as an unconditionally stable implicit method. Numerous works have shown that the ADI-FDTD method is stable even when the CFL stability limit is exceeded. Therefore, the ADI-FDTD method can be considered an efficient method for special classes of problems with very fine structures or high gradient fields. Whenever the ADI-FDTD method is used to simulate open-region radiation or scattering problems, the implementation of a mesh-truncation scheme or absorbing boundary condition becomes an integral part of the simulation. These truncation techniques represent, in essence, differential operators that are discretized using a distinct differencing scheme which can potentially affect the stability of the scheme used for the interior region. In this work, we show that the ADI-FDTD method can be rendered unstable when higher-order mesh truncation techniques such as Higdon's Absorbing Boundary Condition (ABC) or Complementary Derivatives Method (COM) are used. When having large field gradients within a limited volume, a non-uniform grid can reduce the computational domain and, therefore, it decreases the computational cost of the FDTD method. However, for high-accuracy problems, different grid sizes increase the truncation error at the boundary of domains having different grid sizes. To address this problem, we introduce the Complementary Derivatives Method (CDM), a second-order accurate interpolation scheme. The CDM theory is

  16. 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....... This magnetic gear type 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...

  17. APPLICATION OF ASYMMETRIC PROFILE IN GEARINGS WITH ECCENTRIC GEARS

    Directory of Open Access Journals (Sweden)

    Silvia MEDVECKÁ-BEŇOVÁ

    2014-12-01

    Full Text Available 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 managing RS-ER5. This machine allows you to create a constructed shape gears, keeping the necessary accuracy of 0.01 mm and roughness of Ra 1.6 micron. The basic of production, a draft gear was designed using AutoCAD software. Thus follows designed and manufactured elliptical gearing was subjected to the tests and meets all the requirements that were imposed on the gear. Proportion loads of teeth are different from the standard load of circular gears.

  18. APPLICATION OF ASYMMETRIC PROFILE IN GEARINGS WITH ECCENTRIC GEARS

    OpenAIRE

    Silvia MEDVECKÁ-BEŇOVÁ; Vojtková, Jarmila

    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...

  19. Mechanical properties and structure of austempered ductile iron -ADI

    Directory of Open Access Journals (Sweden)

    Krzyńska A.

    2007-01-01

    Full Text Available The results of experimental study of austempered ductile iron are presented. The aim of the investigations was to look closer into the structure – mechanical properties relationships of this very attractive cast material. The experiment was carried out with 500 7 grade ductile iron, which was austempered using different parameters of heat treatment. The specimens were first solution treated 1 hour in 910oC and then isothermally quenched for different time in silicon oil bath of temperature 275, 325, 300 and 350oC. The mechanical properties heat treated specimens were tested in tensile to evaluate yield stress Re, 0.2, tensile strength Rm and elongation A10. Additionally hardness of heat treated samples was measured using Brinell-Rockwell hardness tester. Structure of the specimens was studied either with conventional metallography, scanning (SEM and transmission (TEM electron microscopy. It followed from the study that conventional grade ductile iron enabled to produce both low and high strength ADI, depend on heat treatment parameters. As expected the low temperature isothermal quenching produced higher strength ADI compare to the same ductile iron but austempered at 350oC. It was discovered however, that low yield strength ADI obtained for short time quenching at 275oC exhibited high strengthening effect while strained in tensile. So it was concluded that this had to by cause by large amount of untransformed austenite, which FCC lattice is characterized by high strengthening coefficient.

  20. The changes of ADI structure during high temperature annealing

    Directory of Open Access Journals (Sweden)

    A. Krzyńska

    2010-01-01

    Full Text Available The results of structure investigations of ADI during it was annealing at elevated temperature are presented. Ductile iron austempered at temperature 325oC was then isothermally annealed 360 minutes at temperature 400, 450, 500 and 550oC. The structure investigations showed that annealing at these temperatures caused substantial structure changes and thus essential hardness decrease, which is most useful property of ADI from point of view its practical application. Degradation advance of the structure depends mainly on annealing temperature, less on the time of the heat treatment. It was concluded that high temperature annealing caused precipitation of Fe3C type carbides, which morphology and distribution depend on temperature. In case of 400oC annealing the carbides precipitates inside bainitic ferrite lath in specific crystallographic planes and partly at the grain boundaries. The annealing at the temperature 550oC caused disappearing of characteristic for ADI needle or lath – like morphology, which is replaced with equiaxed grains. In this case Fe3C carbides take the form very fine precipitates with spheroidal geometry.

  1. Ideally Efficient Irreversible Molecular Gears

    OpenAIRE

    Sokolov, I. M.

    2000-01-01

    Typical man-made locomotive devices use reversible gears, as cranks, for transforming reciprocating motion into directed one. Such gears are holonomic and have the transduction efficiency of unity. On the other hand, a typical gear of molecular motors is a ratchet rectifier, which is irreversible. We discuss what properties of rectifier mostly influence the transduction efficiency and show that an apliance which locks under backwards force can achieve the energetic efficiency of unity, withou...

  2. 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.

  3. Gears Based on Carbon Nanotubes

    Science.gov (United States)

    Jaffe, Richard; Han, Jie; Globus, Al; Deardorff, Glenn

    2005-01-01

    Gears based on carbon nanotubes (see figure) have been proposed as components of an emerging generation of molecular- scale machines and sensors. In comparison with previously proposed nanogears based on diamondoid and fullerene molecules, the nanotube-based gears would have simpler structures and are more likely to be realizable by practical fabrication processes. The impetus for the practical development of carbon-nanotube- based gears arises, in part, from rapid recent progress in the fabrication of carbon nanotubes with prescribed diameters, lengths, chiralities, and numbers of concentric shells. The shafts of the proposed gears would be made from multiwalled carbon nanotubes. The gear teeth would be rigid molecules (typically, benzyne molecules), bonded to the nanotube shafts at atomically precise positions. For fabrication, it may be possible to position the molecular teeth by use of scanning tunneling microscopy (STM) or other related techniques. The capability to position individual organic molecules at room temperature by use of an STM tip has already been demonstrated. Routes to the chemical synthesis of carbon-nanotube-based gears are also under investigation. Chemical and physical aspects of the synthesis of molecular scale gears based on carbon nanotubes and related molecules, and dynamical properties of nanotube- based gears, have been investigated by computational simulations using established methods of quantum chemistry and molecular dynamics. Several particularly interesting and useful conclusions have been drawn from the dynamical simulations performed thus far: The forces acting on the gears would be more sensitive to local molecular motions than to gross mechanical motions of the overall gears. Although no breakage of teeth or of chemical bonds is expected at temperatures up to at least 3,000 K, the gears would not work well at temperatures above a critical range from about 600 to about 1,000 K. Gear temperature could probably be controlled by

  4. Translation and validation of Autism Diagnostic Interview-Revised (ADI-R for autism diagnosis in Brazil

    Directory of Open Access Journals (Sweden)

    Michele M. Becker

    2012-03-01

    Full Text Available OBJECTIVE: To translate into Brazilian Portuguese the Autism Diagnostic Interview-Revised (ADI-R, an extremely useful diagnostic tool in autism. METHODS: A case-control study was done to validate the ADI-R. After being translated, the interview was applied in a sample of 20 patients with autism and 20 patients with intellectual disability without autism, in order to obtain the initial psychometric properties. RESULTS: The internal consistency was high, with a of Crombach of 0.967. The validity of criterion had sensitivity and specificity of 100%, having as a gold standard the DSM-IV diagnostic criteria. The interview had high discriminant validity, with higher scores in the group of patients with autism, as well as high interobserver consistency, with median kappa of 0.824. CONCLUSION: The final version of ADI-R had satisfactory psychometric characteristics, indicating good preliminary validation properties. The instrument needs to be applied in bigger samples in other areas of the country.

  5. Gearing Up for the Fair——Promoters are attracting overseas attention to the upcoming annual international investment and trade fair in Xiamen,southeast China

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    As the 10th China International Fair for Investment and Trade (CIFIT) draws near, a variety of promotional events are being intensively planned by the CIFIT organizing committee. The fair starts September 8, and in a bid to further raise the level of the exposition and better integrate it into the

  6. 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.

  7. On gear tooth stiffness evaluation

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard; Jørgensen, Martin Felix

    2014-01-01

    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. Clinical Validity of the ADI-R in a US-Based Latino Population

    Science.gov (United States)

    Vanegas, Sandra B.; Magaña, Sandra; Morales, Miguel; McNamara, Ellyn

    2016-01-01

    The Autism Diagnostic Interview-Revised (ADI-R) has been validated as a tool to aid in the diagnosis of Autism; however, given the growing diversity in the United States, the ADI-R must be validated for different languages and cultures. This study evaluates the validity of the ADI-R in a US-based Latino, Spanish-speaking population of 50 children…

  9. Theoretical Proof of Unconditional Stability of the 3-D ADI-FDTD Method

    Institute of Scientific and Technical Information of China (English)

    WANG Yingjun; WANG Bingzhong; SHAO Wei

    2003-01-01

    In order to eliminate Courant-Friedrich-Levy(CFL) condition restraint and improve computational efficiency, a new finite-difference time-domain(FDTD) methodbased on the alternatingdirection implicit(ADI) technique is introduced recently. In this paper, a theoretical proof of the stability of the three-dimensional(3-D) ADI-FDTD method is presented. It is shown that the 3-D ADI-FDTD method is unconditionally stable and free from the CFL condition restraint.

  10. Untersuchungen zur Zerspanbarkeit von austenitisch-ferritischem Gusseisen mit Kugelgraphit (ADI)

    OpenAIRE

    Klöpper, Carsten Felix

    2006-01-01

    In many applications increasing demands on weight and cost saving require the application of new materials. In this regard austempered ductile iron (ADI) offers a high potential. Cast iron materials exhibit a high freedom of shape combined with rather low manufacturing costs. In addition, ADI offers an excellent combination of high strength, high toughness and a good wear resistance. The fabrication of ADI-parts consists of a casting process and a following special heat treatment. Depending o...

  11. Development in Geared Turbofan Aeroengine

    Science.gov (United States)

    Mohd Tobi, A. L.; Ismail, A. E.

    2016-05-01

    This paper looks into the implementation of epicyclic gear system to the aeroengine in order to increase the efficiency of the engine. The improvement made is in the direction of improving fuel consumption, reduction in pollutant gasses and perceived noise. Introduction of epicyclic gear system is capable to achieve bypass ratio of up to 15:1 with the benefits of weight and noise reduction. Radical new aircraft designs and engine installation are being studied to overcome some of the challenges associated with the future geared turbofan and open-rotor engine.

  12. Numerical Simulation Of Cutting Of Gear Teeth

    Science.gov (United States)

    Oswald, Fred B.; Huston, Ronald L.; Mavriplis, Dimitrios

    1994-01-01

    Shapes of gear teeth produced by gear cutters of specified shape simulated computationally, according to approach based on principles of differential geometry. Results of computer simulation displayed as computer graphics and/or used in analyses of design, manufacturing, and performance of gears. Applicable to both standard and non-standard gear-tooth forms. Accelerates and facilitates analysis of alternative designs of gears and cutters. Simulation extended to study generation of surfaces other than gears. Applied to cams, bearings, and surfaces of arbitrary rolling elements as well as to gears. Possible to develop analogous procedures for simulating manufacture of skin surfaces like automobile fenders, airfoils, and ship hulls.

  13. 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.

  14. Results of a landing gear loads test using a 0.0405-scale model (16-0) of the space shuttle orbiter in the Rockwell International NAAL wind tunnel (OA163B), volume 1

    Science.gov (United States)

    Mennell, R. C.

    1977-01-01

    Aerodynamic loads on a sting mounted 0.045-scale representation of the 140C outer mold line space shuttle orbiter configuration were measured to verify orbiter landing gear system pressure loading and hinge moment levels. Pressure, force, and hinge moment data, recorded over smaller increments of the landing gear deployment schedule to insure data accuracy and to investigate the effects of asymmetric gear deployment on all parameters, are presented. Tests were conducted at a Mach number of 0.17, and freestream dynamic pressure of 42.5 psf, and a Reynolds number per unit length of 1.2 million foot. Angle of attack variation was -2 to 10 degrees while angles of sideslip varied from -5 to 5 degrees.

  15. Effect of austempering temperature on cavitation behaviour of unalloyed ADI material

    Energy Technology Data Exchange (ETDEWEB)

    Dojcinovic, Marina [University of Belgrade, Faculty of Technology and Metallurgy, Karnegijeva 4, Belgrade (Serbia); Eric, Olivera [Innovation Centre, Faculty of Mechanical Engineering, University of Belgrade, Kraljice Marije 16, Belgrade (Serbia); Rajnovic, Dragan; Sidjanin, Leposava [Department of Production Engineering, Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovića 6, Novi Sad (Serbia); Balos, Sebastian, E-mail: sebab@uns.ac.rs [Department of Production Engineering, Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovića 6, Novi Sad (Serbia)

    2013-08-15

    This paper provides an in-depth study and description of cavitation damage and microstructural changes in two types of unalloyed austempered ductile iron (ADI). ADI materials used were austempered at 300 and 400 °C having ausferrite microstructure with 16 and 31.4% of retained austenite, respectively. Metallographic examination was carried out to study the morphology of their cavitation-damaged surfaces. Cavitation damage was initiated at graphite nodules as well as in the interface between a graphite nodule and an ausferrite matrix. Furthermore, microcracking and ferrite/retained austenite morphology were proved to be of great importance for cavitation resistance. Mass loss rate revealed that ADI austempered at 400 °C has a higher cavitation resistance in water than ADI austempered at 300 °C. A higher amount of retained austenite in ADI austempered at 400 °C played an important role in increasing cavitation resistance. The good cavitation behaviour of ADI austempered at 400 °C was due to the matrix hardening by stress assisted phase transformation of retained austenite into martensite (SATRAM) phenomenon, as shown by X-ray diffraction analysis. - Highlights: • Cavitation rate of two ADI materials was tested. • ADI material with a lower hardness has had a lower cavitation rate. • The main reason is microstructural transformations during cavitation. • SATRAM phenomenon increases cavitation resistance.

  16. 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.

  17. 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.

  18. 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.

  19. Effect of Si, Mn and Al on the Microstructure and Mechanical Properties of ADI Weld Metal

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The effects of Si, Mn and Al on the microstructure and mechanical properties of ADI weld have been studied. The microstructure of ADI weld metal mainly consists of bainitic ferrite and retained austenite. Mechanical properties of ADI weld increase with increasing Si content, but an excess of Si(3.79%) results in decreasing the austemperability owing to decreasing the carbon content of the matrix austenite. Mn increases the retained austenite volume fraction,but the ductility and impact toughness of weld obviously decrease with increasing Mn content because of increased amount of martenite and twin martenite. In the range of 0.13%~0.64%Al, increasing Al content favours improving the mechanical properties of ADI weld. Therefore, it is very important to select suitable Si, Mn and Al contents to improve mechanical properties of ADI weld.

  20. 50 CFR 660.212 - Fixed gear fishery-prohibitions.

    Science.gov (United States)

    2010-10-01

    ... vessel subject to subparts C and E a set net, trap or pot, longline, or commercial vertical hook-and-line... by Annex V of the International Convention for the Prevention of Pollution From Ships, 1973 (Annex V... permit with a longline or trap (pot) endorsement and longline and/or trap gear onboard in an...

  1. Update on the National Center for Gear Metrology

    Energy Technology Data Exchange (ETDEWEB)

    Cox, B.L.

    2000-09-26

    Traceability to national or international standards is clearly required by commercial sector standards including ISO 9001:1994 (Ref. 1), ISO/IEC Guide 25 (Ref. 2), and the US equivalent of ISO/IEC Guide 25-ANSI/NCSL Z540-2-1997 (Ref. 3). In the draft replacement to ISO/IEC Guide 25-ISO 17025; measurements, not just equipment, must be traceable to SI units or reference to a natural constant. The implications of traceability to the US gear industry are significant. In order to meet the standards, either gear manufacturers must have calibrated artifacts or must establish their own traceability to SI units.

  2. Advanced Face Gear Surface Durability Evaluations

    Science.gov (United States)

    Lewicki, David G.; Heath, Gregory F.

    2016-01-01

    The surface durability life of helical face gears and isotropic super-finished (ISF) face gears was investigated. Experimental fatigue tests were performed at the NASA Glenn Research Center. Endurance tests were performed on 10 sets of helical face gears in mesh with tapered involute helical pinions, and 10 sets of ISF-enhanced straight face gears in mesh with tapered involute spur pinions. The results were compared to previous tests on straight face gears. The life of the ISF configuration was slightly less than that of previous tests on straight face gears. The life of the ISF configuration was slightly greater than that of the helical configuration.

  3. 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

  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. Numerical investigation of landing gear noise

    OpenAIRE

    Liu, Wen

    2011-01-01

    Noise generated by aircraft landing gears is a major contributor to the overall airframe noise of a commercial aircraft during landing approach. Because of the complex geometry of landing gears, the prediction of landing gear noise has been very difficult and currently relies on empirical tools, which have limited reliability and flexibility on the applications of unconventional gear architectures. The aim of this research is to develop an efficient and accurate numerical method to investigat...

  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 transmiss...

  7. 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.

  8. 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

  9. Gear teeth impacts in hydrodynamic conjunctions promoting idle gear rattle

    Science.gov (United States)

    Theodossiades, S.; Tangasawi, O.; Rahnejat, H.

    2007-06-01

    The rattle phenomenon in vehicular transmissions and its impact on the automotive industry have been widely reported in the literature. A variety of palliative measures have been suggested for attenuation of rattle such as use of backlash eliminators, clutch dampers or dual-mass flywheels. These palliative measures incur further costs and can have untoward implications in powertrain noise and vibration problems. A fundamental investigation of the dynamics of impacting gears is undoubtedly the way forward for a root cause solution. This paper introduces a new approach for understanding the interactions between the transmission gears during engine idle conditions by taking into account the effect of lubrication. Gear impacting surfaces are treated as lubricated conjunctions rather than the usually reported dry impacting solids. Depending on load and speed of entraining motion of the lubricant into the contact domains, the regime of lubrication alters. In this paper, the influence of lubricant in torsional vibration of lightly loaded idling gears is examined which promotes iso-viscous hydrodynamic conditions. It is shown that the lubricant film under these conditions behaves as a time-varying nonlinear spring-damper element. Spectral analysis of the system response is compared to the findings of the linearised system.

  10. ABORDAGENS PARADIGMÁTICAS ALTERNATIVAS: POSSIBILIDADES PARA ESTUDOS EM ADI

    Directory of Open Access Journals (Sweden)

    Christine da Silva Schröeder

    2012-12-01

    Full Text Available Nossa proposta é incentivar a apropriação de abordagens paradigmáticas alternativas para a pesquisa na área de Administração da Informação (ADI, a partir de perspectivas que se contrapõem à ontologia positivista-funcionalista – ou, de outro lado, podem complementá-la, oportunizando a realização de estudos reflexivos, não necessariamente performativos, e “desnaturalizados”. Adotamos os conceitos de reflexividade, não-performatividade e desnaturalização a partir de seu uso por Fournier e Grey (2007, ao referirem-se aos estudos críticos em Administração (ou Critical Management Studies - CMS. Atestamos que os três conceitos nos são valiosos porque nos auxiliam a definir condições pelas quais entendemos que se manifesta pensamento crítico – e, por assim dizer, inspiram a pesquisa multi e interparadigmática. Através das possibilidades deste tipo de pesquisa, podemos lançar olhares potencialmente ampliados sobre a teoria e a prática em Administração da Informação, que trazem implicações não apenas epistemológicas, mas, sobretudo, metodológicas para os estudos da área.

  11. Automatic classification of the sub-techniques (gears) used in cross-country ski skating employing a mobile phone.

    Science.gov (United States)

    Stöggl, Thomas; Holst, Anders; Jonasson, Arndt; Andersson, Erik; Wunsch, Tobias; Norström, Christer; Holmberg, Hans-Christer

    2014-10-31

    The purpose of the current study was to develop and validate an automatic algorithm for classification of cross-country (XC) ski-skating gears (G) using Smartphone accelerometer data. Eleven XC skiers (seven men, four women) with regional-to-international levels of performance carried out roller skiing trials on a treadmill using fixed gears (G2left, G2right, G3, G4left, G4right) and a 950-m trial using different speeds and inclines, applying gears and sides as they normally would. Gear classification by the Smartphone (on the chest) and based on video recordings were compared. Formachine-learning, a collective database was compared to individual data. The Smartphone application identified the trials with fixed gears correctly in all cases. In the 950-m trial, participants executed 140 ± 22 cycles as assessed by video analysis, with the automatic Smartphone application giving a similar value. Based on collective data, gears were identified correctly 86.0% ± 8.9% of the time, a value that rose to 90.3% ± 4.1% (P < 0.01) with machine learning from individual data. Classification was most often incorrect during transition between gears, especially to or from G3. Identification was most often correct for skiers who made relatively few transitions between gears. The accuracy of the automatic procedure for identifying G2left, G2right, G3, G4left and G4right was 96%, 90%, 81%, 88% and 94%, respectively. The algorithm identified gears correctly 100% of the time when a single gear was used and 90% of the time when different gears were employed during a variable protocol. This algorithm could be improved with respect to identification of transitions between gears or the side employed within a given gear.

  12. Automatic Classification of the Sub-Techniques (Gears Used in Cross-Country Ski Skating Employing a Mobile Phone

    Directory of Open Access Journals (Sweden)

    Thomas Stöggl

    2014-10-01

    Full Text Available The purpose of the current study was to develop and validate an automatic algorithm for classification of cross-country (XC ski-skating gears (G using Smartphone accelerometer data. Eleven XC skiers (seven men, four women with regional-to-international levels of performance carried out roller skiing trials on a treadmill using fixed gears (G2left, G2right, G3, G4left, G4right and a 950-m trial using different speeds and inclines, applying gears and sides as they normally would. Gear classification by the Smartphone (on the chest and based on video recordings were compared. Formachine-learning, a collective database was compared to individual data. The Smartphone application identified the trials with fixed gears correctly in all cases. In the 950-m trial, participants executed 140 ± 22 cycles as assessed by video analysis, with the automatic Smartphone application giving a similar value. Based on collective data, gears were identified correctly 86.0% ± 8.9% of the time, a value that rose to 90.3% ± 4.1% (P < 0.01 with machine learning from individual data. Classification was most often incorrect during transition between gears, especially to or from G3. Identification was most often correct for skiers who made relatively few transitions between gears. The accuracy of the automatic procedure for identifying G2left, G2right, G3, G4left and G4right was 96%, 90%, 81%, 88% and 94%, respectively. The algorithm identified gears correctly 100% of the time when a single gear was used and 90% of the time when different gears were employed during a variable protocol. This algorithm could be improved with respect to identification of transitions between gears or the side employed within a given gear.

  13. ADI, autophagy and apoptosis: metabolic stress as a therapeutic option for prostate cancer.

    Science.gov (United States)

    Kim, Randie H; Bold, Richard J; Kung, Hsing-Jien

    2009-05-01

    Prostate cancer, the leading incidence of cancer in American males, is a disease in which treatment of nonlocalized tumors remains largely unsuccessful. These cancers lose expression of an arginine synthesis enzyme, argininosuccinate synthetase (ASS), and are susceptible to arginine deprivation by arginine deiminase (ADI). We show CWR22Rv1 prostate cancer cells are susceptible to ADI in a caspase-independent manner in vitro and in a xenograft model in vivo. We demonstrate that single amino acid deprivation by ADI is able to trigger autophagy. Inhibition of autophagy by chloroquine and siRNA enhances and accelerates ADI-induced cell death, suggesting that autophagy is a protective response to ADI, at least in the early phases. In addition, the co-administration of docetaxel, a caspase-dependent chemotherapy, with ADI inhibits tumor growth in vivo. Thus, targeting multiple cell death pathways, either through autophagy modulation or non-canonical apoptosis, may find expanded use as adjuvant chemotherapies, providing additional avenues for cancer treatment.

  14. THE TORQUE METHOD USED FOR STUDYING COUPLED TWO-CARRIER PLANETARY GEAR TRAINS

    OpenAIRE

    Arnaudov, Kiril; Karaivanov, Dimitar

    2013-01-01

    Using the torque method, one can determine not only the speed ratios in complex compound planetary gear trains, but also the magnitude and direction of internal power flows and thus the efficiency. A brief description of the torque method is given in this paper. As an example, a two-carrier compound planetary gear train connected in series was studied. Some more specific and difficult cases of application of this clear and simple method are reviewed a planetary gear train with two degrees of ...

  15. 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.

  16. Forced oscillations with time-varying mesh stiffness and backlash in gear systems

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ying; WEN Jian-min; WANG Xiao-ming; LIU Hong; WANG Wei-ling

    2009-01-01

    A dynamic model to describe the torsional vibration behaviors of a spur gear system is presented in this paper. Differential equations of nonlinear dynamics for the gear system exhibiting combined nonlinearity in-fluence such as time-varying mesh stiffness, backlash and dynamic transmission error (DTE) were obtained. The method of multiple scales was employed to solve the nonlinear differential equations with parametric excita-tion in gear systems, by which both the frequency-response curves of the primary resonance caused by internal excitation and the analytical periodic solutions of nonlinear differential equations were obtained. The nonlinear influence of stiffness variation, the damping and the internal excitation on the system response was shown by fre-quency-response curves. Compared with numerical examples, the approximate analytical solutions are in good a-greement with exact solutions, which proves that the method of multiple scales is effective for solving nonlinear problems in gear systems.

  17. Thermal influence on precise gear transmission

    Science.gov (United States)

    Zhang, Yong; Fei, Yetai; Miao, EnMing; Zhang, Xiao-rou

    2013-01-01

    Conjugate meshing of involute gears is required in precise gear transmission. However, in the working process, the heat generated in friction results in deformation of the tooth profile of the gear, radial and axial deformation of the shaft and bearing. Meanwhile, there is thermal deformation with non-similarity in the gear box that the shafts and bearings are installed on, which leads to a change of the bearing clearance, axis deflection of the shaft and the gear meshing state. As a result of all these effects, vibration and noise are generated in the transmission system, and it intensifies the possibility of damaging the parts. In this paper, mathematical physics methods and thermal elastic theory are employed to analyze the influence of tooth profiles, gear parameters (transmission ratio i, overlapping coefficients ɛ, backlash jn, etc), gear meshing, working clearance of the bearing (it relates with the initial clearance, tolerance matching, rotational speed, temperature changes, etc) and the shape of the gear box (cylindricity error, axis deflection, etc) caused by the temperature change. The result can be employed in selecting gear parameters and designing the shape of the gear tooth, bearing clearance and shell structure, and it is also helpful to the design of gear transmissions and screw transmissions.

  18. Hainan Gears Up

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZHIPING

    2010-01-01

    @@ Hainan, the southernmost province and the second largest island in China, is well known as a fascinating tropical locale with blue seas basking in beautiful sunshine. At the end of 2009, the island's plan to build it into an international tourist destination was approved by the Central Government. The state is to give greater support and set in place favorable policies for Hainan to fuel its opening up and development.

  19. Identification of a Non-Linear Landing Gear Model Using Nature-Inspired Optimization

    OpenAIRE

    Felipe A.C. Viana; Valder Steffen Jr.; Marcelo A.X. Zanini; Sandro A. Magalhães; Góes, Luiz C.S.

    2008-01-01

    This work deals with the application of a nature-inspired optimization technique to solve an inverse problem represented by the identification of an aircraft landing gear model. The model is described in terms of the landing gear geometry, internal volumes and areas, shock absorber travel, tire type, and gas and oil characteristics of the shock absorber. The solution to this inverse problem can be obtained by using classical gradient-based optimization methods. However, this is a difficult ta...

  20. Design of plastic wave drive gears using the example of the WAVE DRIVE {sup registered} gear; Die Auslegung von Wellgetrieben aus Kunststoff am Beispiel des WAVE DRIVE {sup registered} -Getriebes

    Energy Technology Data Exchange (ETDEWEB)

    Paetzold, K.

    2004-07-01

    Daily we are using a lot of devices whose functions are accomplished by smallish electromotive actuators. For their functions these devices must rely on according gear units. The application range for such electromotive actuators comprises simple electrical appliances like pieces of furniture, air conditioning technology, medical and optical devices and last but not least many devices in the automotive industry. Against this background wave-drive-gears turn out to be a suitable draft. These gear units are working as strain-wave gears, which is the same principle harmonic drive gears use. Strain wave gears are particularly suited when large gear transmission ratios are needed. However, for this solution only thermoplastic material will be used. Very low weight and cost is characteristic for these gears. The wave- drive gear consists essentially of three parts: an elliptical formed shaft, a flexible tooth element (flexible spline) and a thermoplastic ring with internal teeth (circular spline). The kinematics of strain wave gears do not allow for an application of the classical toothing law. This law demands for a pure roll off the teeth. In strain wave gears sliding between the teeth occur. In case of the gear principle there are some advantages: high precision, coaxial composition and high gear ratios in one step. In addition the manufacturing process - injection moulding - guarantees the design engineer a great freedom in the designing phase. First the Kinematic and forces in the gear unit will be described and explained. Based on the model for forces and moments it was possible to extract those parts of the gear, where the stiffness was considerably reformed which consider peculiarities of these gears. Simulations with the finite element method aided the development of an optimal geometry. In the result a series of geometry suggestions appeared which promised essential improvements for efficiency and transmitted moments. This will facilitate a statement about the

  1. Lubricants for wind power plants. Gear oils. Requirements and properties; Schmierstoffe fuer Windenergieanlagen. Getriebeoele. Anforderungen und Eigenschaften

    Energy Technology Data Exchange (ETDEWEB)

    Bock, Wolfgang [Fuchs Europe Schmierstoffe GmbH, Mannheim (Germany)

    2012-11-01

    Alternative energy supply is in the focus and in the discussion world-wide. Electrical energy coming from wind power plants is an important part in the energy supply chain. The lubricants used in wind power plants are often special lubricants, developed for the specific requirements of the application. The range of lubricants included adhesive lubricants, greases, pastes, hydraulic fluids, gear and lubricating oils as well as other specialities. Besides the greases and the hydraulic oils, the gear oil is the most important lubricant in wind power plants. The gear oil is used in the main gear of a wind power plant or in the Azimut gear sets. The lubricant has to be developed to match the requirements of the gear set, the tooth sets, the bearings, the seals, paints, etc. The gear oil has to fulfil the requirements according to DIN 51517, part 3 - CLP / CKC industrial gear oils, and in addition the specific requirements of gear and bearing manufacturers according to wind power plant specifications have to be fulfilled. The presentation ''Lubricants for Wind Power Plants - Requirements and Properties'' gives an overview of the industrial gear oils market, the classification of gear oils according to German and international standards is presented, and it describes the properties of a fully synthetic industrial gear oil based on polyalphaolefin which was especially developed for the main gear unit in wind power plants. The mechanical-dynamic tests for gear oils used in wind power plants (anti-scuffing properties, roller bearing wear protection, micro-pitting protection) are presented, together with the specific tests required by world-wide known bearing manufacturers. In addition the presentation shows test results of low speed wear tests. Compatibility tests with elastomers and sealing materials and the low temperature properties of fully synthetic gear oils based on polyalphaolefin are also discussed. The industrial gear oils for wind power plants

  2. 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,

  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. 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...

  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. Magnetorheological landing gear: 1. A design methodology

    OpenAIRE

    Batterbee, D.C.; N.D. Sims; STANWAY, R.; Wolejsza, Zbigniew

    2007-01-01

    Aircraft landing gears are subjected to a wide range of excitation conditions, which result in conflicting damping requirements. A novel solution to this problem is to implement semi-active damping using magnetorheological (MR) fluids. This paper presents a design methodology that enables an MR landing gear to be optimized, both in terms of its damping and magnetic circuit performance, whilst adhering to stringent packaging constraints. Such constraints are vital in landing gear, if MR techno...

  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. 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.

  9. 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.

  10. Effects of gear crack propagation paths on vibration responses of the perforated gear system

    Science.gov (United States)

    Ma, Hui; Pang, Xu; Zeng, Jin; Wang, Qibin; Wen, Bangchun

    2015-10-01

    This paper investigates the dynamic behaviors of a perforated gear system considering effects of the gear crack propagation paths and this study focuses on the effects of a crack propagating through the rim on the time-varying mesh stiffness (TVMS) and vibration responses. Considering the effects of the extended tooth contact, a finite element (FE) model of a gear pair is established based on ANSYS software. TVMS of the perforated gear with crack propagating through tooth and rim are calculated by using the FE model. Furthermore, a lumped mass model is adopted to investigate the vibration responses of the perforated gear system. The results show that there exist three periods related to slots of the gear body in a rotating period of the perforated gear. Gear cracks propagating through tooth and rim both reduce the gear body stiffness and lead to reduction of TVMS besides the crack tooth contact moment, and the TVMS weakening for the former is less than that for the latter. Moreover, the results also show that the gear crack propagating through the rim (CPR) has a greater effect on vibration responses than the gear crack propagating through the tooth (CPT) under the same crack level. Vibration level increases with the increasing crack depth, especially for the gear with CPR.

  11. Testing of heating and cooling process of ADI cast iron with use of ATND method

    Directory of Open Access Journals (Sweden)

    A. Białobrzeski

    2008-10-01

    Full Text Available ADI (Austempered Ductile Iron cast iron, owing to its unique combination of high tensile strength and abrasion resistance with very goodplasticity, founds implementation in many branches of industry as a substitute of alloy cast steel and carburized or heat treated steels. Inspite of its solid position among producers and recipients of castings, there are still undertaken studies aimed at perfection of its propertiesand recognition of mechanisms enabling obtaining such properties.The paper presents implementation of thermal-voltage-derivative (ATND method to registration of heating and cooling course of ADIcast iron with EN-GJS-1200-2 grade. ADI cast iron with EN-GJS-1200-2 grade underwent the study. Heat treatment of the cast iron wasperformed in Foundry Institute with use of LT ADI-350/1000 processing line. Results obtained from the testing illustrate in graphic formregistered heating and cooling curves of investigated cast irons obtained with use of the ATND method.

  12. GENETIC ALGORITHM IN REDUCTION OF NUMERICAL DISPERSION OF 3-D ADI-FDTD METHOD

    Institute of Scientific and Technical Information of China (English)

    Zhang Yan; Lǖ Shanwei; Gao Wenjun

    2007-01-01

    A new method to reduce the numerical dispersion of the three-dimensional Alternating Direction Implicit Finite-Difference Time-Domain(3-D ADI-FDTD)method is proposed.Firstly,the numerical formulations of the 3-D ADI-FDTD method are modified with the artificial anisotropy,and the new numerical dispersion relation is derived.Secondly,the relative permittivity tensor of the artificial anisotropy can be obtained by the Adaptive Genetic Algorithm(AGA).In order to demonstrate the accuracy and efficiency of this new method,a monopole antenna is simulated as an example.And the numerical results and the computational requirements of the proposed method are cornpared with those of the conventional ADI-FDTD method and the measured data.In addition the reduction of the numerical dispersion is investigated as the objective function of the AGA.It is found that this new method is accurate and efficient by choosing proper objective function.

  13. Optimum weight design of functionally graded material gears

    Science.gov (United States)

    Jing, Shikai; Zhang, He; Zhou, Jingtao; Song, Guohua

    2015-11-01

    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.

  14. OSOBITOSTI STIJENKE MOKRAĆNOG MJEHURA U DOJENČADI DO 6 MJESECI ŽIVOTA

    OpenAIRE

    Saraga, Marijan; Drnasin, Kristina; Čapkun, Vesna

    2007-01-01

    Cilj: Odrediti ultrazvukom normalne vrijednosti debljine stijenke mokraćnog mjehura zdrave dojenčadi u prvih 6 mjeseci života i utvrditi postoje li razlike s obzirom na spol. Ispitanici i metode: Obavljen je ultrazvučni probir mokraćnog mjehura 416-ero zdrave donošene dojenčadi (216 muške i 200 ženske) u dobi od 0,5 do 6 mjeseci života. Debljine stijenke mokraćnog mjehura analizirane su ultrazvučnim aparatom Siemens Sonoline Prima, semikonveksnom sondom od 5,0 MHz i linearnom sondom od 7,5 MH...

  15. 基于ADIS16365的惯性传感系统设计%Design of Inertial Sensing System Based on ADIS16365

    Institute of Scientific and Technical Information of China (English)

    邓德源; 蔺震; 高林

    2011-01-01

    系统以ADIS16365为惯性传感器,LM3S8962为核心处理器,IAR为开发平台,卡尔曼滤波和辛普森积分为数据处理方法,研制基于ADIS16365的惯性传感系统.结果表明,该系统具有较高的角度稳定性和准确性.为了使该系统具有应用的灵活性,将该传感系统作为CAN节点应用在整个系统设计中.该系统已用于亚太机器人比赛中,实现了准确定位.%An inertial sensing system was designed by taking ADIS16365 as inertial senser, LM3S8962 as kernel processor, IAR as development platform, Kalman filter and Simpson integration as data processing methods. The results of static and dynamic tests show that the system has high stability and high accuracy. The sensing system is used as a CAN node in the design of a whole equipment to make the equipment more flexible. The inertial sensing system was successfully used in ABU Robocon Contest and implemented the accurate location.

  16. 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.

  17. 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.

  18. Computer aided design of spur gear teeth

    Science.gov (United States)

    Huston, R. L.; Mavriplis, D.; Oswald, F. B.

    1989-01-01

    Procedures for computer-modeling of spur gear tooth fabrication are given. It is shown that the standard involute tooth form results from a cutter with an involute shape rolling onto a gear blank. Specifically, the envelope of an involute is an involute. Examples are given and applications are discussed.

  19. Polyamide worm gear: manufacturing and performance

    Directory of Open Access Journals (Sweden)

    Alexandre Luís Gasparin

    2012-06-01

    Full Text Available The focus of this paper is to establish a characterisation method for seven polyamide (PA grades to determine the major material to manufacture an automotive worm gear. The composite properties were measured according to the worm gear loadings: tensile strength, Young's modulus, abrasion and impact resistance. They were also correlated to the PA moisture absorption and its glass fibre (GF reinforcement. The data from mechanical tests were applied in the finite element analysis (FEA using the von Mises stress criterion. Before the rig tests of the PA worm gears, the injection process was evaluated, through the capillary rheometry. A higher difficulty to process PA 6/6 30% GF was found, due to its lower apparent viscosity. In the end, the influence of moisture absorption was as decisive to the gear's material selection as the GF to the pinion. Thus, the PAs with the best performance were: PA 6 with 30% GF (gear and with PA 60% GF (pinion.

  20. 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.

  1. Advanced hardware and software methods for thread and gear dimensional metrology. CRADA final report

    Energy Technology Data Exchange (ETDEWEB)

    Miller, A.C. Jr.; Grann, E.B.

    1997-03-05

    The Oak Ridge Centers for Manufacturing Technology (ORCMT) and Apeiron Incorporated have collaborated on an effort to develop a frequency modulated continuous wave (FMCW) fiber lidar system for dimensional metrology of internal threads, gears, and splines. The purpose of this effort was to assist a small company in developing an instrument that would exceed the performance of competing foreign instruments and provide measurement capabilities necessary to assure compliance for NASA facilities and other industrial facilities. The two parties collaborated on design, assembly, and bench testing of the prototype instrument. The prototype system was targeted to have the capability of profiling internally machined gears and threads to an accuracy of less than a micron.

  2. FATIGUE PROPERTIES OF AUSTEMPERED DUCTILE IRON (ADI)IN WATER ENVIRONMENT

    Institute of Scientific and Technical Information of China (English)

    Q.Z.Cai; B.K.Wei; Y.Tanaka

    2004-01-01

    The acicular ferrite in austempered ductile iron(ADI)matrix around graphite was corroded preferentially in wet condition,promoting crack origination and propagation and resulting in the disappearance of ADI fatigue limit.ADI fatigue strength was gradually reduced with increasing the time of test and was reduced by 50% in wet condition at 107 cycles compared with the fatigue limit in dry condition.The fatigue strength variation of ferritic ductile iron in wet condition was similar to that of ADI.The ferritic ductile iron,however,has better corrosion resistance so that the fatigue strength was lowered only by 10% in wet condition at 107 cycles compared with the fatigue limit in dry condition.On the other hand,the fatigue limits of A DI and ferritic ductile iron were dropped by 32% and 25% in tap water dipping 480h/dry condition respectively compared with those in dry condition.The reduction of fatigue limit was attributed to corrosion pits formation correlated with stress concentration,resulting in origination and propagation of fatigue crack.

  3. A hypothetical immunemediated unifying mechanism for the Holmes-Adie syndrome

    Directory of Open Access Journals (Sweden)

    C. M. de Castro Costa

    1988-06-01

    Full Text Available The Holmes-Adie syndrome consists of pupillotonia, arreflexia and autonomic dysfunction. Some explanations for these different symptoms have been attempted, centred upen neuropathological and electrophysiological findings. A hypothetical immunemediated mechanism, as in the Guillain Barré syndrome, is presented in this paper for explaining the three chief symptoms of the syndrome.

  4. 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,...

  5. 14 CFR 23.477 - Landing gear arrangement.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear arrangement. 23.477 Section 23....477 Landing gear arrangement. Sections 23.479 through 23.483, or the conditions in appendix C, apply to airplanes with conventional arrangements of main and nose gear, or main and tail gear....

  6. NASA Orbiter Extended Nose Landing Gear

    Science.gov (United States)

    King, Steven R.; Jensen, Scott A.; Hansen, Christopher P.

    1999-01-01

    This paper discusses the design, development, test, and evaluation of a prototype Extended Nose Landing Gear (ENLG) for NASA's Space Shuttle orbiters. The ENLG is a proposed orbiter modification developed in-house at NASA's Johnson Space Center (JSC) by a joint government/industry team. It increases the orbiter's nose landing gear (NLG) length, thereby changing the vehicle's angle of attack during rollout, which lowers the aerodynamic forces on the vehicle. This, in combination with a dynamic elevon change, will lower the loads on the orbiter's main landing gear (MLG). The extension is accomplished by adding a telescoping section to the current NLG strut that will be pneumatically extended during NLG deployment.

  7. 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.

  8. MODERNIZATION OF TRACKED VEHICLE RUNNING GEARS

    Directory of Open Access Journals (Sweden)

    V. Tamelo

    2013-01-01

    Full Text Available The paper contains some proposals pertaining  to modernization of tracked vehicle running gears, bogie hydro-pneumatic suspension, methodology  for bench-tests and description of test-bench equipment which is applied for testing bogie hydro-pneumatic suspension. Test results of a hydro-pneumatic spring with parameter stabilization system are given in the paper.The paper presents  description of tracked vehicle running gears with bogie hydro-pneumatic suspension which is equipped with a system for stabilizing a road clearance. Testing results of the gears being part of a test mule are cited in the paper.

  9. 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.)

  10. Influence of gear loss factor on the power loss prediction

    OpenAIRE

    C. M. C. G. Fernandes; P. M. T. Marques; R. C. Martins; J. H. O. Seabra

    2015-01-01

    In order to accurately predict the power loss generated by a meshing gear pair the gear loss factor must be properly evaluated. Several gear loss factor formulations were compared, including the author's approach. A gear loss factor calculated considering the load distribution along the path of contact was implemented. The importance of the gear loss factor in the power loss predictions was put in evidence comparing the predictions with experimental results. It was ...

  11. 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.

  12. 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.

  13. Empirical Prediction of Aircraft Landing Gear Noise

    Science.gov (United States)

    Golub, Robert A. (Technical Monitor); Guo, Yue-Ping

    2005-01-01

    This report documents a semi-empirical/semi-analytical method for landing gear noise prediction. The method is based on scaling laws of the theory of aerodynamic noise generation and correlation of these scaling laws with current available test data. The former gives the method a sound theoretical foundation and the latter quantitatively determines the relations between the parameters of the landing gear assembly and the far field noise, enabling practical predictions of aircraft landing gear noise, both for parametric trends and for absolute noise levels. The prediction model is validated by wind tunnel test data for an isolated Boeing 737 landing gear and by flight data for the Boeing 777 airplane. In both cases, the predictions agree well with data, both in parametric trends and in absolute noise levels.

  14. 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...

  15. Perforated fairings for landing gear noise control

    OpenAIRE

    Boorsma, K.; Zhang, X; Molin, N.

    2008-01-01

    Landing gears of commercial aircraft make an important contribution to total aircraft noise in the approach configuration. Using fairings to shield components from high speed impingement reduces noise. Furthermore, perforating these fairings has been confirmed by flight tests to further enable noise reduction. Following a more fundamental study on the application of perforated fairings, a study has been performed to investigate and optimize the benefits of bleeding air through landing gear fa...

  16. More Electric Landing Gear Actuation Study

    OpenAIRE

    Li, Wei

    2009-01-01

    This report addresses the problem of landing gear actuation system design on more-electric aircraft (MEA). Firstly, information about more-electric aircraft and more-electric actuators was gathered and sorted. Current more-electric landing actuation system applications and researches were also summarized. Then several possible more-electric landing gear actuation concepts were identified. To evaluate these concepts, the case study method has been used. A concept aircraft “MR...

  17. Vibration Control of MR Damper Landing Gear

    OpenAIRE

    Disha Saxena; Harsh Rathore

    2013-01-01

    In the field of Automation, Fuzzy Control Fuzzy control has significant merits which are utilized in intelligent controllers, especially for vibration control systems. This paper is concerned with the application aspects of the developed MR damper for landing gear system, to attenuate the sustained vibrations during the landing phase. Also a comparative study is made on the responses obtained from the MR damper landing gear by utilizing PID and Fuzzy PID controllers.Theory is a well-known tec...

  18. Computational aeroacoustic study of a landing gear

    OpenAIRE

    Khanal, B.; Knowles, K.; Saddington, Alistair J.; Obayashi, S

    2009-01-01

    Computational study of a single wheel landing gear con guration was completed to understand the noise source and it's nature. The ow eld visualisation showed the present of large structural shedding in the wake side of the the landing gear wheel. These large structures were responsible for the low frequency noise. Spectral peaks at frequencies lower than 200 Hz were found to exist from the analysis of the frequency content of the pressure signals at far eld. These low freque...

  19. 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

  20. Polyamide worm gear: manufacturing and performance

    OpenAIRE

    Alexandre Luís Gasparin; Leandro Luís Corso; Eduardo Kirinus Tentardini; Regina Célia Reis Nunes; Maria Madalena Camargo Forte; Ricardo Vinicius Bof de Oliveira

    2012-01-01

    The focus of this paper is to establish a characterisation method for seven polyamide (PA) grades to determine the major material to manufacture an automotive worm gear. The composite properties were measured according to the worm gear loadings: tensile strength, Young's modulus, abrasion and impact resistance. They were also correlated to the PA moisture absorption and its glass fibre (GF) reinforcement. The data from mechanical tests were applied in the finite element analysis (FEA) using t...

  1. Systems and Methods for Implementing Bulk Metallic Glass-Based Strain Wave Gears and Strain Wave Gear Components

    Science.gov (United States)

    Hofmann, Douglas C. (Inventor); Wilcox, Brian (Inventor)

    2016-01-01

    Bulk metallic glass-based strain wave gears and strain wave gear components. In one embodiment, a strain wave gear includes: a wave generator; a flexspline that itself includes a first set of gear teeth; and a circular spline that itself includes a second set of gear teeth; where at least one of the wave generator, the flexspline, and the circular spline, includes a bulk metallic glass-based material.

  2. X-38 Landing Gear Skid Test Report

    Science.gov (United States)

    Gafka, George K.; Daugherty, Robert H.

    2000-01-01

    NASA incorporates skid-equipped landing gear on its series of X-38 flight test vehicles. The X-38 test program is the proving ground for the Crew Return Vehicle (CRV) a gliding parafoil-equipped vehicle designed to land at relatively low speeds. The skid-equipped landing gear is designed to attenuate the vertical landing energy of the vehicle at touchdown using crushable materials within the struts themselves. The vehicle then slides out as the vehicle horizontal energy is dissipated through the skids. A series of tests was conducted at Edwards Airforce Base (EAFB) in an attempt to quantify the drag force produced while "dragging" various X-38 landing gear skids across lakebed regions of varying surface properties. These data were then used to calculate coefficients of friction for each condition. Coefficient of friction information is critical for landing analyses as well as for landing gear load and interface load analysis. The skid specimens included full- and sub-scale V201 (space test vehicle) nose and main gear designs, a V131/V 132 (atmospheric flight test vehicles) main gear skid (actual flight hardware), and a newly modified, full-scale V201 nose -ear skid with substantially increased edge curvature as compared to its original design. Results of the testing are discussed along with comments on the relative importance of various parameters that influence skid stability and other dynamic behavior.

  3. An Overview of Landing Gear Dynamics

    Science.gov (United States)

    Pritchard, Jocelyn

    1999-01-01

    One of the problems facing the aircraft community is landing gear dynamics, especially shimmy and brake-induced vibration. Although neither shimmy nor brake-induced vibrations are usually catastrophic, they can lead to accidents due to excessive wear and shortened life of gear parts and contribute to pilot and passenger discomfort. Recently, NASA has initiated an effort to increase the safety of air travel by reducing the number of accidents by a factor of five in ten years. This safety initiative has spurred an increased interest in improving landing gear design to minimize shimmy and brake-induced vibration that are still largely misunderstood phenomena. In order to increase the understanding of these problems, a literature survey was performed. The major focus of the paper is to summarize work documented from the last ten years to highlight the latest efforts in solving these vibration problems. Older publications are included to understand the longevity of the problem and the findings from earlier researchers. The literature survey revealed a variety of analyses, testing, modeling, and simulation of aircraft landing gear. Experimental validation and characterization of shimmy and brake-induced vibration of aircraft landing gear are also reported. This paper presents an overview of the problem documented in the references together with a history of landing gear dynamic problems and solutions. Based on the assessment of this survey, recommendations of the most critically needed enhancements to the state of the art are given.

  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. Suvremeni pristup liječenju retinopatije nedonoščadi

    OpenAIRE

    Vatavuk, Zoran; Benčić, Goran; Andrijević Derk, Biljana; Mandić, Zdravko

    2008-01-01

    Retinopatija nedonoščadi obuhvaća vazoproliferativne promjene na mrežnici, koje nastaju kao posljedica prijevremenog rođenja, zbog kojeg dolazi do prekida normalnog razvoja krvnih žila mrežnice. U svijetu je ova bolest odgovorna za sljepoću više od 50.000 djece. U posljednjih 50 godina svijet je zabilježio tri velike epidemije retinopatije nedonoščadi, a posljednja epidemija traje još uvijek i obuhvaća zemlje Latinske Amerike i istočne Europe. Studije CRYO-ROP i ETROP pokazale su učinkovitost...

  6. Reconsideration of the temporary ADI and refined exposure assessment for Sunset Yellow FCF (E 110

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Additives and Nutrient Sources added to food (ANS

    2014-07-01

    Full Text Available The Panel on Food Additives and Nutrient Sources added to Food (ANS Panel has previously provided a scientific opinion re-evaluating the safety of Sunset Yellow FCF (E 110 as a food additive in the EU and establishing a temporary acceptable daily intake (ADI of 1 mg/kg bw/day (EFSA ANS Panel, 2009. Following a request by the European Commission, the ANS Panel was asked to assess newly submitted data from a study conducted as a result of the recommendations contained in the 2009 opinion. In addition, EFSA was requested to carry out the refined exposure assessment of Sunset Yellow FCF. The new information assessed comprised an evaluation of the 28-day study report, the data considered by the Joint FAO/WHO Expert Committee on Food Additives (JECFA in its latest evaluation from 2011, and any additional toxicological information that had become available since the completion of the previous evaluation by the ANS Panel. The ANS Panel has considered that the newly submitted data from the 28-day study and the overall available toxicological database on Sunset Yellow FCF provides a basis to revise the established temporary ADI and concluded that, based on the NOAEL of 375 mg/kg bw/day from the long-term feeding study in rats and an uncertainty factor of 100, a new ADI for Sunset Yellow FCF of 4 mg/kg bw/day can be established, in agreement with the latest evaluation by JECFA. Exposure estimates for Sunset Yellow FCF based both on the currently authorised MPLs and reported use levels provided are well below the new ADI of 4 mg/kg bw/day for all population groups. Overall, the Panel concluded that, using data provided by the food industry and Member States, the reported uses and use levels of Sunset Yellow FCF (E 110 would not be of safety concern.

  7. AN ADI GALERKIN METHOD WITH MOVING FINITE ELEMENT SPACES FOR A CLASS OF SECOND-ORDER HYPERBOLIC EQUATIONS

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An alternating-direction implicit (ADI) Galerkin nuthod with moving finite element spaces is formulated for a class of second-order hyperbolic equations in two space variables. A priori H1-error estimate is derived.

  8. Model-Checking Real-Time Properties of an Aircraft Landing Gear System Using Fiacre

    OpenAIRE

    Berthomieu, Bernard; Dal Zilio, Silvano; Fronc, Lukasz

    2014-01-01

    International audience We describe our experience with modeling the landing gear system of an aircraft using the formal specification language Fiacre. Our model takes into account the behavior and timing properties of both the physical parts and the control software of this system. We use this formal model to check safety and real-time properties on the system but also to find a safe bound on the maximal time needed for all gears to be down and locked (assuming the absence of failures). Ou...

  9. Nonlinear parametrically excited vibration and active control of gear pair system with time-varying characteristic

    Institute of Scientific and Technical Information of China (English)

    刘爽; 王进进; 刘金杰; 李雅倩

    2015-01-01

    In the present work, we investigate the nonlinear parametrically excited vibration and active control of a gear pair system involving backlash, time-varying meshing stiffness and static transmission error. Firstly, a gear pair model is established in a strongly nonlinear form, and its nonlinear vibration characteristics are systematically investigated through different approaches. Several complicated phenomena such as period doubling bifurcation, anti period doubling bifurcation and chaos can be observed under the internal parametric excitation. Then, an active compensation controller is designed to suppress the vibration, including the chaos. Finally, the effectiveness of the proposed controller is verified numerically.

  10. DETERMINATION OF TRANSMISSION GEAR RATIO IN MECHANICAL PART OF TRACTOR ELECTRO-MECHANICAL TRANSMISSION

    Directory of Open Access Journals (Sweden)

    Ch. I. Zhdanovich

    2016-01-01

    Full Text Available A methodology has been developed for selection of gear number and transmission gear ratios in mechanical part of a wheel-type tractor with electro-mechanical transmission containing a propulsion asynchronous electric motor with variablefrequency control. The paper proposes to determine a transmission gear ratio on the basis of the following: provision of wheel torque dependence on tractor speed which is the best one for a traction process and during transfer from one gear to the other; provision of nominal operational mode of the electric motor for all tractor operations where it is working for a long period of time; provision of minimum possible number of gears; complete realization of internal combustion engine power on the tractor wheels at limit operational mode of the electric motor. As a characteristic of the asynchronous electric motor with variable-frequency control contains various portions which can be used either completely or partially due to operating conditions, the gear number is determined in the process of transmission gear ration finding but not prior to this. A wheel torque of the tractor with electro-mechanical transmission can be limited according to the following factors: grip of wheel with supporting surface; maximum power of an internal combustion engine which can be transferred to the wheels and a torque which is developed by a propulsion electric motor. It is not proposed to exceed nominal operational mode of the propulsion electric motor for all the operations of the tractor if it is working for a long period of time because in the case of significant excess of the nominal operational mode of the asynchronous electric motor its rather long operation leads to low efficiency and high losses in power, large heat liberation and consequently requires to develop more complicated system for electric motor cooling. An excess of nominal electric motor torque can be justified for short-term operational modes because in this case

  11. Construction of novel Saccharomyces cerevisiae strains for bioethanol active dry yeast (ADY production.

    Directory of Open Access Journals (Sweden)

    Daoqiong Zheng

    Full Text Available The application of active dry yeast (ADY in bioethanol production simplifies operation processes and reduces the risk of bacterial contamination. In the present study, we constructed a novel ADY strain with improved stress tolerance and ethanol fermentation performances under stressful conditions. The industrial Saccharomyces cerevisiae strain ZTW1 showed excellent properties and thus subjected to a modified whole-genome shuffling (WGS process to improve its ethanol titer, proliferation capability, and multiple stress tolerance for ADY production. The best-performing mutant, Z3-86, was obtained after three rounds of WGS, producing 4.4% more ethanol and retaining 2.15-fold higher viability than ZTW1 after drying. Proteomics and physiological analyses indicated that the altered expression patterns of genes involved in protein metabolism, plasma membrane composition, trehalose metabolism, and oxidative responses contribute to the trait improvement of Z3-86. This work not only successfully developed a novel S. cerevisiae mutant for application in commercial bioethanol production, but also enriched the current understanding of how WGS improves the complex traits of microbes.

  12. Pengaruh Kewajiban Karyawan Terhadap Kewajiban Perusahaan Di Lihat Dari Sisi Etika Bisnis Pada PT. Adi Sarana Armada (ASSA) Cabang Medan

    OpenAIRE

    Harahap, Teguh Ardiansyah

    2013-01-01

    This research titled “The effect of employee obligations to liability company in views of bussines ethic at PT. Adi Sarana Armada (ASSA) Chapter Medan”. The purpose of this study is to determine and analyze the effect of employee obligations to liability company in views of bussines ethic at PT. Adi Sarana Armada (ASSA) Chapter Medan. Methods of data analysis using descriptive method and quantitative methods, ie the Simple Linear Regression Analysis. Analyze data using statistical data pr...

  13. 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.

  14. 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

  15. Machinability of Austempered Ductile Iron (ADI) Produced by Integrated Green Technology of Continuous Casting-Heat Treatment Processes

    Science.gov (United States)

    Meena, A.; El Mansori, M.; Ghidossi, P.

    2011-01-01

    This study presents the novel processing technique known as continuous casting-heat treatment processes to produce Austempered Ductile Iron (ADI) which is a new class of ductile iron. ADI is characterized by improved mechanical properties but has low machinability as compared to other cast irons and steel of similar strength. The novel technique is developed by the integration of casting (in die casting) and heat treatment processes in foundry to save cost energy and time. Specimens just after casting were austenitized at 930° C for 90 min and then austempered in fluidized bed at 380° C for 90 and 120 min. Hence, the effect of austempering time on the morphology of retained austenite and mechanical properties of the material were examined and compared with conventionally produced ADI. Drilling tests were then carried out to evaluate the machinability of ADI in terms of cutting forces, chip micro-hardness, chip morphology and surface roughness. The mechanical properties of ADI austempered for 120 min have found to be better as compare to the ADI austempered for 90 min.

  16. Theoretical and experimental studies on dynamics of double-helical gear system supported by journal bearings

    Directory of Open Access Journals (Sweden)

    Minghu Yin

    2016-05-01

    Full Text Available The dynamic behaviour of a double-helical gear system supported by journal bearings is theoretically and experimentally investigated in this study. A bending–torsional–axial coupling model for dynamic analysis of double-helical gear system is developed. Influence of the time-varying mesh stiffness and damping is considered. Oil film stiffness and damping of the supporting journal bearing are supposed to be time-varying, and the time-varying oil film stiffness and damping are predicted by a back propagation neural network, which is optimized by genetic algorithm. A double-helical gear–rotor–journal bearing system test rig is also established to carry out the experimental investigations, such as the dynamic transmission errors of gear pairs. The comparisons between theoretical and experimental results show that the time-varying oil film dynamic coefficients of journal bearings are an important internal excitation. The theoretical model with time-varying oil film stiffness and damping can predict the gear dynamics more accurate than the model with time-invariant oil film stiffness and damping, and the neural network optimized by genetic algorithm can obtain the time-varying oil film stiffness and damping efficiently and accurately for the dynamic analysis of double-helical gear system.

  17. 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.

  18. 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.

  19. Plasma Fairings for Quieting Aircraft Landing Gear Noise Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A major component of airframe noise for commercial transport aircraft is the deployed landing gear. The noise from the gear originates due to complex, unsteady...

  20. Data Fusion Tool for Spiral Bevel Gear Condition Indicator Data

    Science.gov (United States)

    Dempsey, Paula J.; Antolick, Lance J.; Branning, Jeremy S.; Thomas, Josiah

    2014-01-01

    Tests were performed on two spiral bevel gear sets in the NASA Glenn Spiral Bevel Gear Fatigue Test Rig to simulate the fielded failures of spiral bevel gears installed in a helicopter. Gear sets were tested until damage initiated and progressed on two or more gear or pinion teeth. During testing, gear health monitoring data was collected with two different health monitoring systems. Operational parameters were measured with a third data acquisition system. Tooth damage progression was documented with photographs taken at inspection intervals throughout the test. A software tool was developed for fusing the operational data and the vibration based gear condition indicator (CI) data collected from the two health monitoring systems. Results of this study illustrate the benefits of combining the data from all three systems to indicate progression of damage for spiral bevel gears. The tool also enabled evaluation of the effectiveness of each CI with respect to operational conditions and fault mode.

  1. Experimental assessment of low noise landing gear component design

    OpenAIRE

    Dobrzynski, Werner; Chow, Leung Choi; Smith, Malcolm; Boillot, Antoine; Dereure, Olivier; Molin, Nicolas

    2009-01-01

    Landing gear related airframe noise is one of the dominant aircraft noise components at approach. It therefore is essential to particularly reduce landing gear noise. In the European SILENCER project, advanced low noise gears had been designed and tested at full scale. In the current European co-financed project TIMPAN (Technologies to IMProve Airframe Noise) still more advanced low noise design concepts were investigated and noise tested on a ¼ scaled main landing gear model in the German-Du...

  2. CAD SIMULATION & FEM ANALYSIS OF AIRCRAFT LANDING GEAR MECHANISM

    OpenAIRE

    Nilesh W. Nirwan; Dilip G. Gangwani,

    2015-01-01

    Aircraft landing gear supports the entire weight of an aircraft during landing and ground operations. They are attached to primary structural members of the aircraft. The type of gear depends on the aircraft design and its intended use. Most landing gear has wheels to facilitate operation to and from hard surfaces, such as airport runways. Other gear feature skids for this purpose, such as those found on helicopters, balloon gondolas, and in the tail area of some tail dragger airc...

  3. Theoretical analysis on flow characteristics of melt gear pump

    Science.gov (United States)

    Zhao, R. J.; Wang, J. Q.; Kong, F. Y.

    2016-05-01

    The relationship between Geometric parameters and theoretical flow of melt gear pump is revealed, providing a theoretical basis to melt gear pump design. The paper has an analysis of meshing movement of melt gear pump on the condition of four different tooth numbers, stack movement law and flow ripple. The regulation of flow pulsation coefficient is researched by MATLAB software. The modulus formula of melt gear pump is proposed, consistent with actual situation.

  4. Design, Modeling, Application and Analysis of Bevel Gears

    Directory of Open Access Journals (Sweden)

    1 Engr.Rufus Ogbuka Chime ,Mnse , Mnimech

    2016-04-01

    Full Text Available Computer technology has touched all areas of today’s life, impacting how we obtain railway tickets, shop online and receive medical advice from remote location. Computer-based design analysis is nowadays a common activity in most development projects. Traditionally, the design field has been identified with particular end products, e.g., mechanical design, electrical design, ship design. In these fields, design work is largely based on specific techniques to foster certain product characteristics and principles The scope of this work includes, to design, to model the bevel gear, to select gear materials , to detailed factor safety in design and to analysis bevel gears. Gears are toothed elements that transmit rotary motion from one shaft to another. Gears are generally rugged and durable and their power transmission efficiency is as high as 98%. Gears are usually more costly than chains and belts. Bevel gears are gears where the axes of the two shafts intersect and the toothbearing faces of the gears themselves are conically shaped. Bevel gears are most often mounted on shafts that are 90 degrees apart, but can be designed to work at other angles as well. The pitch surface of bevel gears is a cone. Two bevel gears in mesh is known as bevel gearing. In bevel gearing, the pitch cone angles of the pinion and gear are to be determined from the shaft angle, i.e., the angle between the intersecting shafts. The bevel gear has many diverse applications such as locomotives, marine applications, automobiles, printing presses, cooling towers, power plants, steel plants, railway track inspection machines, etc.

  5. Methods for the Gear-Position Decision in AMT

    Institute of Scientific and Technical Information of China (English)

    孙以泽; 熊伟; 姚玉峰

    2003-01-01

    Aimed at defects of the gear-position decision in an automatic mechanical transmission, a method of synthetic shift schedule of 5-speed gear-position is presented, which is based on the fuzzy discernment of the driver intention and the road characteristics. A contrastive experimental analysis between the synthetic gear-position decision method and the traditional gear-position decision method is given by analyzing Santana 2000.

  6. 50 CFR 622.31 - Prohibited gear and methods.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Prohibited gear and methods. 622.31... Management Measures § 622.31 Prohibited gear and methods. In addition to the prohibited gear/methods specified in this section, see §§ 622.33, 622.34, and 622.35 for seasonal/area prohibited gear/methods...

  7. Improving bending stress in spur gears using asymmetric gears and shape optimization

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2010-01-01

    Bending stress plays a significant role in gear design wherein its magnitude is controlled by the nominal bending stress and the stress concentration due to the geometrical shape. The bending stress is indirectly related to shape changes made to the cutting tool. This work shows that the bending...... stress can be reduced significantly by using asymmetric gear teeth and by shape optimizing the gear through changes made to the tool geometry. However, to obtain the largest possible stress reduction a custom tool must be designed depending on the number of teeth, but the stress reductions found...

  8. DESIGN AND ANALYSIS OF A COMPOSITE BEVEL GEAR IN AN AUTOMOBILE DIFFERENTIAL GEAR BOX

    OpenAIRE

    Mr. Rohit Sreekumar *, Prof. T. Jeyapoovan

    2016-01-01

    In automotive Industry,the differential gear plays an important role in power transmission as well as in the handling of the automobile.It transmits torque through three different shafts. This project deals with the design and optimization of the differential gear box through use of composite material. The solid modelling is done by using SOLIDWORKS. Static analysis is performed on the gear using Ni-CR steel, malleable cast iron, aluminium alloy and glass filled polyamide using ANSYS 14.5 The...

  9. Vibration Control of MR Damper Landing Gear

    Directory of Open Access Journals (Sweden)

    Disha Saxena

    2013-03-01

    Full Text Available In the field of Automation, Fuzzy Control Fuzzy control has significant merits which are utilized in intelligent controllers, especially for vibration control systems. This paper is concerned with the application aspects of the developed MR damper for landing gear system, to attenuate the sustained vibrations during the landing phase. Also a comparative study is made on the responses obtained from the MR damper landing gear by utilizing PID and Fuzzy PID controllers.Theory is a well-known technique to acquire the desired response of different non-linear systems.

  10. Measurement of Gear Tooth Dynamic Friction

    Science.gov (United States)

    Rebbechi, Brian; Oswald, Fred B.; Townsend, Dennis P.

    1996-01-01

    Measurements of dynamic friction forces at the gear tooth contact were undertaken using strain gages at the root fillets of two successive teeth. Results are presented from two gear sets over a range of speeds and loads. The results demonstrate that the friction coefficient does not appear to be significantly influenced by the sliding reversal at the pitch point, and that the friction coefficient values found are in accord with those in general use. The friction coefficient was found to increase at low sliding speeds. This agrees with the results of disc machine testing.

  11. CALCULATION OF CONTACT STRESS OF PLASTIC GEARS

    Institute of Scientific and Technical Information of China (English)

    陈其泰

    1995-01-01

    A calculation method of contact problem of plastic gears based on three parameter model of viscoelasticity material is presented. In this calculation method, the influence of temperature upon the property of plastics is considered and an iteration process of temperature-elasticity module-friction coefficient is proposed. From the rolling contact problem of two viscoelastic cylinders with parallel axis, a set of normal-tangential contact coupled integral equations is obtained. Through numerical treatment and normal-tangental iteration, the normal contact stress, tangential stress and contact width of plastic gears are acquired.

  12. 14 CFR 27.477 - Landing gear arrangement.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear arrangement. 27.477 Section 27... AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 27.477 Landing gear arrangement. Sections 27.235, 27.479 through 27.485, and 27.493 apply to landing gear with two wheels aft,...

  13. 14 CFR 25.483 - One-gear landing conditions.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false One-gear landing conditions. 25.483 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.483 One-gear landing conditions. For the one-gear landing conditions, the airplane is assumed to be in the level attitude and...

  14. 14 CFR 29.477 - Landing gear arrangement.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear arrangement. 29.477 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Strength Requirements Ground Loads § 29.477 Landing gear arrangement. Sections 29.235, 29.479 through 29.485, and 29.493 apply to landing gear with two wheels aft,...

  15. Gear cutting tools fundamentals of design and computation

    CERN Document Server

    Radzevich, Stephen P

    2010-01-01

    Presents the DG/K-based method of surface generation, a novel and practical mathematical method for designing gear cutting tools with optimal parameters. This book proposes a scientific classification for the various kinds of the gear machining meshes, discussing optimal designs of gear cutting tools.

  16. 29 CFR 1917.42 - Miscellaneous auxiliary gear.

    Science.gov (United States)

    2010-07-01

    ...) Bridles for handling flush end or box-type pallets shall be designed to prevent disengagement from the... 29 Labor 7 2010-07-01 2010-07-01 false Miscellaneous auxiliary gear. 1917.42 Section 1917.42 Labor... (CONTINUED) MARINE TERMINALS Cargo Handling Gear and Equipment § 1917.42 Miscellaneous auxiliary gear....

  17. Performance of polymer gears reinforced with sisal woven rovings

    Directory of Open Access Journals (Sweden)

    A. Faizur Rahman

    2014-12-01

    Full Text Available Polymer gears find a common place in many industries and applications. In general, carbon fibre and glass fibres are used as reinforcement in polymer gears. This current research focuses on developing and testing the temperature and wear performance of Polyester spur gears reinforced with Sisal Woven Rovings (SWRP . Volume fractions (Vf such as 5% (SWRP/A, 10% (SWRP/B, 15% (SWRP/C and 20% (SWRP/D of gear specimens were prepared and tested for temperature and wear effects. Gears were tested up to 1.4 x 106 cycles. Gear tooth damages are recorded through optical photographs. The result reveals that the temperature and wear performance of SWRP/A and SWRP/B gears were low compared to SWRP/D gears.A small amount of wear damages were observed in SWRP/C gears. No damages were occurred in SWRP/D gears upto 1.4 x 106 cycles and also it was observed that the temperature and wear rate were found to be 15 % and 36 % lesser in SWRP/D gears when compared to SWRP/A gears.

  18. 50 CFR 600.510 - Gear avoidance and disposal.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Gear avoidance and disposal. 600.510 Section 600.510 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Gear avoidance and disposal. (a) Vessel and gear avoidance. (1) FFV's arriving on fishing grounds...

  19. La carnavalización del Archivo en Adiós, Ayacucho de Julio Ortega

    OpenAIRE

    Quiroz Ciriaco, Victor Felipe Segundo

    2014-01-01

    En Adiós Ayacucho (1986/2008), del escritor peruano Julio Ortega, se cuestiona que la ideología patente en la producción textual dominante de la época de la Imposición Colonial (siglo XVI) continúa operando, a fines del siglo XX, en la lógica del discurso antropológico, tercer relato maestro empleado para narrar Latinoamérica. Por ello, planteamos que la obra de Ortega se configura como una variante de las ficciones del Archivo. Además, establecemos que el recorrido narrativo del protagonista...

  20. An average/deprivation/inequality (ADI analysis of chronic disease outcomes and risk factors in Argentina

    Directory of Open Access Journals (Sweden)

    De Maio Fernando G

    2009-06-01

    Full Text Available Abstract Background Recognition of the global economic and epidemiological burden of chronic non-communicable diseases has increased in recent years. However, much of the research on this issue remains focused on individual-level risk factors and neglects the underlying social patterning of risk factors and disease outcomes. Methods Secondary analysis of Argentina's 2005 Encuesta Nacional de Factores de Riesgo (National Risk Factor Survey, N = 41,392 using a novel analytical strategy first proposed by the United Nations Development Programme (UNDP, which we here refer to as the Average/Deprivation/Inequality (ADI framework. The analysis focuses on two risk factors (unhealthy diet and obesity and one related disease outcome (diabetes, a notable health concern in Latin America. Logistic regression is used to examine the interplay between socioeconomic and demographic factors. The ADI analysis then uses the results from the logistic regression to identify the most deprived, the best-off, and the difference between the two ideal types. Results Overall, 19.9% of the sample reported being in poor/fair health, 35.3% reported not eating any fruits or vegetables in five days of the week preceding the interview, 14.7% had a BMI of 30 or greater, and 8.5% indicated that a health professional had told them that they have diabetes or high blood pressure. However, significant variation is hidden by these summary measures. Educational attainment displayed the strongest explanatory power throughout the models, followed by household income, with both factors highlighting the social patterning of risk factors and disease outcomes. As educational attainment and household income increase, the probability of poor health, unhealthy diet, obesity, and diabetes decrease. The analyses also point toward important provincial effects and reinforce the notion that both compositional factors (i.e., characteristics of individuals and contextual factors (i.e., characteristics

  1. Silagem de capim-elefante com a adição de casca de soja

    OpenAIRE

    Lima, Paulo Guataçara da Costa

    2012-01-01

    Resumo: O presente trabalho teve por objetivo, apresentar uma alternativa à confecção de silagem de capim-elefante (Pennisetum purpureum Schumach.), sem se fazer a pré-secagem, quando a planta apresenta grande quantidade de água. O baixo teor de matéria seca no estádio vegetativo dessa forragem é o maior problema no processo fermentativo. O aumento da matéria seca, através da adição da casca de soja, resíduo alimentar barato e de baixo teor de umidade, tem por finalidade controlar as fermenta...

  2. ADI:切分垂直市场新"蛋糕"

    Institute of Scientific and Technical Information of China (English)

    丛秋波

    2006-01-01

    @@ 71岁高龄的Ray Stata先生是美国模拟器件(ADI)公司创始人之一,自1965年创建至1996年,Stata一直担任公司的首席执行官(CEO)和董事会主席.1996年,Ray Stata将首席执行官位置交给了年富力强的Jerald G Fishman,之后他一直担任公司董事会主席至今.

  3. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT XVIII, I--UNDERSTAND ENGINE GEARS AND GEARING PRINCIPLES, II--MACK INTER-AXLE POWER DIVIDER.

    Science.gov (United States)

    Minnesota State Dept. of Education, St. Paul. Div. of Vocational and Technical Education.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF DIESEL ENGINE GEARS AND GEARING PRINCIPLES AND THE OPERATING PRINCIPLES AND MAINTENANCE OF POWER DIVIDERS (GEAR BOXES) USED IN DIESEL ENGINE POWER TRANSMISSION. TOPICS ARE (1) THE PURPOSE OF THE ENGINE GEARS, (2) INSPECTING FOR GEAR FAILURES, (3) INSPECTING FOR SHAFT…

  4. STABILITY AND SUPER CONVERGENCE ANALYSIS OF ADI-FDTD FOR THE 2D MAXWELL EQUATIONS IN A LOSSY MEDIUM

    Institute of Scientific and Technical Information of China (English)

    Gao Liping

    2012-01-01

    Several new energy identities of the two dimensional(2D) Maxwell equations in a lossy medium in the case of the perfectly electric conducting boundary conditions are proposed and proved.These identities show a new kind of energy conservation in the Maxwell system and provide a new energy method to analyze the alternating direction implicit finite difference time domain method for the 2D Maxwell equations (2D-ADI-FDTD).It is proved that 2D-ADI-FDTD is approximately energy conserved,unconditionally stable and second order convergent in the discrete L2 and H1 norms,which implies that 2D-ADI-FDTD is super convergent.By this super convergence,it is simply proved that the error of the divergence of the solution of 2D-ADI-FDTD is second order accurate.It is also proved that the difference scheme of 2D-ADI-FDTD with respect to time t is second order convergent in the discrete H1 norm.Experimental results to confirm the theoretical analysis on stability,convergence and energy conservation are presented.

  5. International

    International Nuclear Information System (INIS)

    This rubric reports on 10 short notes about international economical facts about nuclear power: Electricite de France (EdF) and its assistance and management contracts with Eastern Europe countries (Poland, Hungary, Bulgaria); Transnuclear Inc. company (a 100% Cogema daughter company) acquired the US Vectra Technologies company; the construction of the Khumo nuclear power plant in Northern Korea plays in favour of the reconciliation between Northern and Southern Korea; the delivery of two VVER 1000 Russian reactors to China; the enforcement of the cooperation agreement between Euratom and Argentina; Japan requested for the financing of a Russian fast breeder reactor; Russia has planned to sell a floating barge-type nuclear power plant to Indonesia; the control of the Swedish reactor vessels of Sydkraft AB company committed to Tractebel (Belgium); the renewal of the nuclear cooperation agreement between Swiss and USA; the call for bids from the Turkish TEAS electric power company for the building of the Akkuyu nuclear power plant answered by three candidates: Atomic Energy of Canada Limited (AECL), Westinghouse (US) and the French-German NPI company. (J.S.)

  6. 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.

  7. Computing Contact Stresses In Gear Teeth

    Science.gov (United States)

    Oswald, Fred B.; Somprakit, Paisan; Huston, Ronald L.

    1995-01-01

    Improved method of computing contact stresses in gear teeth accounts for complicating effects like those of static and sliding friction. Provides iterative procedure for determination of contact region and nodal contact forces along with contact stresses. Method based on equations and computational procedure incorporating these effects routinely.

  8. Handcycling : different modes and gear ratios

    NARCIS (Netherlands)

    van der Woude, L H; Bosmans, I; Bervoets, B; Veeger, DirkJan (H. E. J.)

    2001-01-01

    Handrim wheelchair propulsion is a straining form of ambulation. In contrast, arm crank exercise in laboratory settings has shown a higher degree of gross mechanical efficiency and increased levels of peak power output. Moreover, arm crank exercise can be conducted at different gear ratios and in as

  9. 7 CFR 2902.47 - Gear lubricants.

    Science.gov (United States)

    2010-01-01

    ... Gear lubricants. (a) Definition. Products, such as greases or oils, that are designed to reduce... whether or not the product contains any recovered material, in addition to biobased ingredients, and... products with recycled content. Under the Resource Conservation and Recovery Act of 1976, section 6002,...

  10. Automotive gear oil lubricant from soybean oil

    Science.gov (United States)

    The use of lubricants that are based on renewable materials is rapidly increasing. Vegetable oils have good lubricity, wear protection and low volatility which are desired properties for automotive gear lubricant applications. Soybean oil is used widely in the lubricant industry due to its properti...

  11. MODEL PELAYANAN STROKE TERPADU DI RUMAH SAKIT ADI HUSADA UNDAAN WETAN SURABAYA

    Directory of Open Access Journals (Sweden)

    Koosnadi Saputra

    2012-11-01

    Full Text Available Stroke or brain attack is basically brain dysfunction as the effect of disparity on vascular circulation of the brain that caused by various factors. The basic aspect of the brain are influenced by various factors. The basic physiology and psychology aspects of the stroke is essential to understand, especially the correlation to underlying diseases and psychological stress as a social trigger aspect phenomenon. Although stroke could occur at all ages, generally it attacks adult people, and its incidence is increasing at the older age groups. Considering doctor needs to propmtly recognize the symptoms of stroke including its problems, as to manage the problems and to prevent are the most important things to do. The Adi Husada Undaan Wetan Hospital of Surabaya has built the Pelayanan Stroke Terpadu (PST as a system to manage stroke patients which composed of a stroke team specialists who work in prompt responses, prompt treatments and prompt rehabilitation. The PST was developed based on experiences on stroke patient treatment during 12 year period (1 994-2006 in Adi Husada Hospital Surabaya and the data of computerized axial tomography comparing•year 1995 to 2006 (pre-programof the PST condition. Key words:

  12. Comparison between TVD-MacCormack and ADI-type solvers of the shallow water equations

    Science.gov (United States)

    Liang, Dongfang; Falconer, Roger A.; Lin, Binliang

    2006-12-01

    A total variation diminishing (TVD) modification of the MacCormack scheme is developed for simulating shallow water dynamics on a uniform Cartesian grid. Results obtained using conventional and deviatoric forms of the conservative non-linear shallow water equations (SWEs) are compared for cases where the bed has a varying topography. The comparisons demonstrate that the deviatoric form of the SWEs gives more accurate results than the conventional form, in the absence of numerical balancing of the flux-gradient and source terms. A further comparison is undertaken between the TVD-MacCormack model and an alternating direction implicit (ADI) model for cases involving steep-fronted shallow flows. It is demonstrated that the ADI model is unable to predict trans-critical flows correctly, and artificial viscosity has to be introduced to remove spurious oscillations. The TVD-MacCormack model reproduces all flow regimes accurately. Finally, the TVD-MacCormack model is used to predict a laboratory-scale dyke break undertaken at Delft University of Technology. The predictions agree closely with the experimental data, and are in excellent agreement with results from an alternative Godunov-type model.

  13. Holmes-Adie syndrome, autoimmune hepatitis and celiac disease: A case report

    Institute of Scientific and Technical Information of China (English)

    Timea Csak; Aniko Folhoffer; Andrea Horvath; Judit Halász; Csaba Diczházi; Zsuzsa Schaff; Ferenc Szalay

    2006-01-01

    A 35-year-old female patient presented with the following symptoms of Holmes-Adie syndrome: photophobia,enlargement of the left pupil unresponsive to light,Achilles areflexia. The pilocarpine test was positive. No tumor or other neurological abnormality was found. She had a 19-year history of autoimmune hepatitis. Flares up were observed following each 3 deliveries. At age of 31she presented with diarrhea and weight loss. Abdominal tumor was detected by ultrasound. The surgically removed tumor was histologically a benign mesenteric multicystic lymphangioma. Simultaneously, celiac disease was diagnosed. Gluten-free diet resulted in a significant improvement of celiac disease, but not of autoimmune hepatitis. Autonomic neuropathy was proven by standard cardiovascular tests. The patient was a homozygous carrier for HLA DQ2 antigen characteristic for celiac disease and heterozygous for HLA DR3 B8 frequent in autoimmune liver diseases. Our novel observation on association of Holmes-Adie syndrome with autoimmune hepatitis and celiac disease is suggestive for a common immunological background for all three entities present in a patient with mesenteric multicystic lymphangioma.

  14. ADIS16405 IMU 在四旋翼飞行器姿态测量的应用

    Institute of Scientific and Technical Information of China (English)

    冯伟峰

    2013-01-01

      本文针对四旋翼飞行器的姿态测量,利用 ADI 公司的 ADIS16405惯性测量单元(IMU,Inertial measurement unit)测量飞行器的惯性量,然后解算姿态角。本文利用 IMU 采集数据,由嵌入式系统读取并通过串口发送到 PC 机上,在 MATLAB 软件上绘制出采集数据并解算姿态角图像。使用 ADIS16405,使系统具有操作方便,精度高,电路简单的优点。

  15. Initial noise predictions for rudimentary landing gear

    Science.gov (United States)

    Spalart, Philippe R.; Shur, Mikhail L.; Strelets, Mikhail Kh.; Travin, Andrey K.

    2011-08-01

    A four-wheel "rudimentary" landing gear (RLG) truck was designed for public-domain research, with a level of complexity which is manageable in current numerical simulations, and a weak Reynolds-number sensitivity. Experimental measurements of wall-pressure fluctuations are allowing a meaningful test of unsteady simulations with emphasis on noise generation. We present three Detached-Eddy Simulations (DES) using up to 18 million points in the high-order NTS code. The first is incompressible with the model placed in the wind tunnel, as requested for the 2010 workshop on Benchmark problems for Airframe Noise Computations (BANC-I), intended for force and surface-pressure studies. The second and third are at Mach 0.115 and Mach 0.23, with only one wall, a "ceiling" analogous to a wing (but infinite and inviscid), and are used to exercise far-field noise prediction by coupling the Detached-Eddy Simulations and a Ffowcs-Williams/Hawkings calculation. The results include wall-pressure, and far-field-noise intensities and spectra. The wall pressure signals in the three simulations are very similar and, in a comparison published separately, agree well with experiment and other simulations. In the absence of experimental noise data, the attention is focused on internal quality checks, by varying the permeable Ffowcs-Williams/Hawkings calculation surface and then by using only the solid surface. An unexpected finding at these Mach numbers is an apparent strong role for quadrupoles, revealed by a typical deficit of 3 dB in the solid-surface results, relative to the permeable-surface results. The solid-surface approach has variants, related to the presence of the ceiling (a plane of symmetry), which can increase this error further; there is little consensus on the exact configuration of the solid surfaces in the Ffowcs-Williams/Hawkings calculation procedure. Tentative theoretical arguments suggest that a balance somewhat in favor of quadrupoles over dipoles is plausible at Mach

  16. Dynamics of High-Speed Precision Geared Rotor Systems

    Directory of Open Access Journals (Sweden)

    Lim Teik C.

    2014-07-01

    Full Text Available Gears are one of the most widely applied precision machine elements in power transmission systems employed in automotive, aerospace, marine, rail and industrial applications because of their reliability, precision, efficiency and versatility. Fundamentally, gears provide a very practical mechanism to transmit motion and mechanical power between two rotating shafts. However, their performance and accuracy are often hampered by tooth failure, vibrations and whine noise. This is most acute in high-speed, high power density geared rotor systems, which is the primary scope of this paper. The present study focuses on the development of a gear pair mathematical model for use to analyze the dynamics of power transmission systems. The theory includes the gear mesh representation derived from results of the quasi-static tooth contact analysis. This proposed gear mesh theory comprising of transmission error, mesh point, mesh stiffness and line-of-action nonlinear, time-varying parameters can be easily incorporated into a variety of transmission system models ranging from the lumped parameter type to detailed finite element representation. The gear dynamic analysis performed led to the discovery of the out-of-phase gear pair torsion modes that are responsible for much of the mechanical problems seen in gearing applications. The paper concludes with a discussion on effectual design approaches to minimize the influence of gear dynamics and to mitigate gear failure in practical power transmission systems.

  17. CNOOC Geared Up for 2008

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Propped up by soaring international oil prices and its rich offshore oil resources,CNOOC is well positioned to raise its output for 2008 Amid the dark prospects of a global economic downturn,Chinese oil suppliers have been able to sustain global pressure thanks to a stretched domestic oil supply.China National Offshore Oil Corp.(CNOOC),the largest offshore oil and gas producer of China,has

  18. Some characteristics of the design of heads for the cutting of bevel gears with negative curvature of the circular-arc tooth line

    Science.gov (United States)

    Savinov, A. P.; Iastrebov, V. M.

    The principles of the design of the external and internal finishing cutters of heads for the machining of bevel gears with negative curvature of the circular-arc tooth line are examined. The differences between heads for the machining of circular-arc teeth with positive and negative curvatures are discussed. A newly developed design of a head for the machining of bevel gears with negative curvature of the circular-arc tooth is described as an example.

  19. Improving fishing effort descriptors: Modelling engine power and gear-size relations of five European trawl fleets

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Rihan, Dominic; Graham, Norman;

    2011-01-01

    Based on information from an international inventory of gears currently deployed by trawlers in five European countries, the relationship between vessel engine power and trawl size is quantified for different trawl types, trawling techniques and target species. Using multiplicative modelling it i...

  20. Aeroacoustic Analysis of a Simplified Landing Gear

    Science.gov (United States)

    Lockard, David P.; Khorrami, Mehdi, R.; Li, Fei

    2004-01-01

    A hybrid approach is used to investigate the noise generated by a simplified landing gear without small scale parts such as hydraulic lines and fasteners. The Ffowcs Williams and Hawkings equation is used to predict the noise at far-field observer locations from flow data provided by an unsteady computational fluid dynamics calculation. A simulation with 13 million grid points has been completed, and comparisons are made between calculations with different turbulence models. Results indicate that the turbulence model has a profound effect on the levels and character of the unsteadiness. Flow data on solid surfaces and a set of permeable surfaces surrounding the gear have been collected. Noise predictions using the porous surfaces appear to be contaminated by errors caused by large wake fluctuations passing through the surfaces. However, comparisons between predictions using the solid surfaces with the near-field CFD solution are in good agreement giving confidence in the far-field results.

  1. Innovative process chains for crankshafts and gears

    Energy Technology Data Exchange (ETDEWEB)

    Denkena, B.; Becker, J.C.; Kramer, N.; Catoni, F. [Hannover Univ. (DE). Inst. of Production Engineering and Machine Tools (IFW)

    2005-07-01

    Precision forged parts offer a great potential regarding strength but also process chain efficiency. Nevertheless, varying stock allowances call for powerful grinding processes to ensure an economical production. Vitrified bonded CBN tools offer a potential which is not fully used in crankshaft and gear grinding because of process specific limits. The complex geometry of grinding tools used in continuous generating gear grinding usually causes dressing speed ratios far larger than those common for grinding wheels of simple geometry. In this paper the effects of the dressing speed ratio are discussed and general strategies to improve the speed ratio are offered. In path controlled grinding of crankshafts the complex geometry and the varying stiffness of the crankshafts causes differing form and geometrical errors, depending on the crankshaft dimensions and the deviation. In this paper the effects of typical deflections are presented and a general strategy to correct these deviations is discussed. (orig.)

  2. Mathematical and Finite Element Modeling of Micro-Modification for Marine Gear

    Directory of Open Access Journals (Sweden)

    Xiongxi Wu

    2015-01-01

    Full Text Available Based on the computer simulation technique, this paper used the professional gear design software MASTA and finite element software ANSYS combined with the method of gear micro-modification to redesign the gear profile and eventually realized the optimization design of gear micro-modification. Then the gear transmission model of one-level reducer was established to simulate and analyze the contact equivalent stress, transmission error, and meshing impact before and after gear modification. By comparing the simulations results it is found that gear micro-modification can lower meshing impact load, reduce the vibration strength, make gear transmission steady, and improve the gear bearing capacity. By comparing the transmission error curves and meshing impact load curves before and after gear micro-modification, this helps to understand the effects of gear micro-modification on the gear transmission and provides basis references for the future redesign of the marine gears with high strength and long service life.

  3. Graph Models of Automobile Gears - Kinematics

    Directory of Open Access Journals (Sweden)

    Drewniak J.

    2014-08-01

    Full Text Available In the present paper, kinematical analysis of an automotive gear is described. Versatile graph based methods have been utilized for this purpose. An application of mixed, contour and bond graphs gives the same results. It allows the detection of possible mistakes as well as a deeper insight into the designed artifact. The graphs can also be used for further analyses which will be published in a separate document

  4. Shared Memory Parallelization of an Implicit ADI-type CFD Code

    Science.gov (United States)

    Hauser, Th.; Huang, P. G.

    1999-01-01

    A parallelization study designed for ADI-type algorithms is presented using the OpenMP specification for shared-memory multiprocessor programming. Details of optimizations specifically addressed to cache-based computer architectures are described and performance measurements for the single and multiprocessor implementation are summarized. The paper demonstrates that optimization of memory access on a cache-based computer architecture controls the performance of the computational algorithm. A hybrid MPI/OpenMP approach is proposed for clusters of shared memory machines to further enhance the parallel performance. The method is applied to develop a new LES/DNS code, named LESTool. A preliminary DNS calculation of a fully developed channel flow at a Reynolds number of 180, Re(sub tau) = 180, has shown good agreement with existing data.

  5. Pengaruh Kapabilitas terhadap Keunggulan Kompetitif dan Dampaknya terhadap Kinerja Perusahaan pada PT Adi Cipta, Makassar

    Directory of Open Access Journals (Sweden)

    Dyah Budiastuti

    2011-05-01

    Full Text Available As a company which implements differentiation strategy, PT. Adi Cipta has achieved competitive advantage in using capabilities through implementing organization culture and quality management. But, for about last 5 years, the company’s performance seems to be stagnant and having no significant improvement. This research aims to analyze the effect of capability, which is Organization Culture and Quality Management, towards the Competitive Advantage and its effect to the company’s performance. Data are taken from observation result, questionnaire, and interview with company’s holder and the decision maker, which then be analyzed with regression method. The research result shows that Organization Culture and Quality Management affect on Competitive Advantage, which affects to the company’s performance. 

  6. US-VISIT Identity Matching Algorithm Evaluation Program: ADIS Algorithm Evaluation Project Plan Update

    Energy Technology Data Exchange (ETDEWEB)

    Grant, C W; Lenderman, J S; Gansemer, J D

    2011-02-24

    This document is an update to the 'ADIS Algorithm Evaluation Project Plan' specified in the Statement of Work for the US-VISIT Identity Matching Algorithm Evaluation Program, as deliverable II.D.1. The original plan was delivered in August 2010. This document modifies the plan to reflect modified deliverables reflecting delays in obtaining a database refresh. This document describes the revised schedule of the program deliverables. The detailed description of the processes used, the statistical analysis processes and the results of the statistical analysis will be described fully in the program deliverables. The US-VISIT Identity Matching Algorithm Evaluation Program is work performed by Lawrence Livermore National Laboratory (LLNL) under IAA HSHQVT-07-X-00002 P00004 from the Department of Homeland Security (DHS).

  7. Accelerator test of an improved Angle Detecting Inclined Sensor (ADIS) prototype with beams of 78Kr and fragments

    Science.gov (United States)

    Connell, J. J.; Lopate, C.; McLaughlin, K. R.

    2016-11-01

    The measurement of cosmic rays and Solar energetic particles in space is basic to our understanding of the Galaxy, the Sun, phenomena in the heliosphere and the emerging field of space weather. For these reasons, cosmic ray instruments are common on both scientific spacecraft and operational spacecraft such as weather satellites. Cosmic rays and Solar energetic particles include ions over the full range of elements found in the Solar System. High-resolution measurements of the elemental and isotopic composition require the angle of incidence of these energetic ions be determined to correct for pathlength variation in detectors within an instrument. The Angle Detecting Inclined Sensor (ADIS) system is a simple detector configuration used to determine the angle of incidence of heavy ions in space instruments. ADIS replaces complex position sensing detectors (PSDs) with a system of simple, reliable and robust detectors inclined at an angle to the instrument axis. An ADIS instrument thus offers significant advantages in mass, power, telemetry and cost. In February 2008 an improved ADIS prototype was tested with a 150 MeV/u 78Kr beam at the National Superconducting Cyclotron Laboratory's (NSCL) Coupled Cyclotron Facility (CCF). This demonstrated a charge resolution of σ 0.3 e at Kr (Z=36), an exceptional charge resolution for such a simple instrument system.

  8. X-38 Landing Gear qualification testing

    Science.gov (United States)

    Urgoiti, Eduardo

    2003-09-01

    The Landing Gear System for the X-38 demonstration vehicle has been developed considering future application to the CRV vehicle. It consists of three legs in a typical aeroplane configuration with two main and one nose legs. They are retracted during ascent, in orbit and re-entry phases and are released near the ground by pyrotechnic-nuts and deployed by preloaded springs and gravity. This gear has been designed to allow landing in unprepared plain fields limiting the accelerations on the spacecraft at touch down, through expendable damping cartridges and skids. During 2002 the test campaign of the X-38 Landing Gear has been completed at Sener. Three different types of tests have been performed: Functional deployment tests, Static load tests and vibration tests. This paper discusses the objectives of the tests and how they are achieved with a description of the mechanisms involved and their predicted performances. The different types of tests and results are described together with the major events and lessons learned during their performance.

  9. 14 CFR 23.729 - Landing gear extension and retraction system.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear extension and retraction... Design and Construction Landing Gear § 23.729 Landing gear extension and retraction system. (a) General. For airplanes with retractable landing gear, the following apply: (1) Each landing gear...

  10. A Lightweight Model for Gear Mesh Dynamics Incorporating Variable Mesh Stiffness

    Directory of Open Access Journals (Sweden)

    Fokas Nikolaos

    2015-01-01

    Full Text Available Variable stiffness of the gear tooth mesh for a pair of spur gears is computed using an accurate lightweight mathematical formulation. This is used to simulate gear dynamic behavior. Gear eigenfrequencies are calculated for the SDOF system and correlated with gear physical properties and the effect of stiffness variation during a mesh cycle is studied.

  11. Displaceable Spur Gear Torque Controlled Driver and Method

    Science.gov (United States)

    Cook, Joseph S., Jr. (Inventor)

    1996-01-01

    Methods and apparatus are provided for a torque driver including a laterally displaceable gear support member to carry an output spur gear. A biasing assembly biases the output spur gear into engagement with a pinion to which is applied an input torque greater than a desired output torque limit for a threaded fastener such as a nut or screw. A coiled output linkage connects the output spur gear with a 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. A gauged selector mechanism is provided to laterally displace multiple driven members for fasteners arranged in differing configurations. The torque limit is selectably adjustable and may be different for fasteners within the same fastener configuration.

  12. Handcycling: different modes and gear ratios.

    Science.gov (United States)

    van der Woude, L H; Bosmans, I; Bervoets, B; Veeger, H E

    2000-01-01

    Handrim wheelchair propulsion is a straining form of ambulation. In contrast, arm crank exercise in laboratory settings has shown a higher degree of gross mechanical efficiency and increased levels of peak power output. Moreover, arm crank exercise can be conducted at different gear ratios and in asynchronic or synchronic mode. Although tricycle crank exercise or handcycling has become increasingly popular for recreational use, sports and outdoor wheeling over the last decade, today little is known about the cardiopulmonary strain in handcycling. The physiological and subjective responses during handcycling were evaluated in a group of 12 male non-wheelchair users (age 24.6 +/- 2.7 yr; body weight 73.7 +/- 9.7 kg). During an incremental submaximal exercise test on a motor driven treadmill (velocity: 1.8 ms-1; an incremental slope of 1% per 3 min; 0-3%; mean power output of the subject group varied between 7.6 +/- 1.6 W and 47.5 +/- 6.2 W), effects of asynchronic and synchronic crank settings and three different gear ratios (1:0.42, 1:0.59, 1:0.74 (or 24, 36 and 44 rpm)) were evaluated in a random testing sequence. Significantly lower levels of mean oxygen uptake, ventilation, relative heart rate and oxygen uptake were seen during synchronic arm use and for the lighter gear ratios (i.e. higher movement frequency; 44 rpm). Subjective local perceived discomfort showed similar trends. Conversely, gross mechanical efficiency appeared higher for these conditions. The need for strong medio-lateral stabilizing muscle effort during asynchronic arm use (to ensure a proper wheeling direction as well as simultaneous power transfer to the cranks) and the effective use of the trunk in this subject group may explain the advantage of synchronic arm use. Whether this advantage is consolidated among wheelchair confined individuals needs further study. Apart from the important effects of a shift in force--velocity characteristics of the contracting muscles with varying gear ratios

  13. DESIGN IMPROVEMENT OF THE LOCOMOTIVE RUNNING GEARS

    Directory of Open Access Journals (Sweden)

    S. V. Myamlin

    2013-09-01

    Full Text Available Purpose. To determine the dynamic qualities of the mainline freight locomotives characterizing the safe motion in tangent and curved track sections at all operational speeds, one needs a whole set of studies, which includes a selection of the design scheme, development of the corresponding mathematical model of the locomotive spatial fluctuations, construction of the computer calculation program, conducting of the theoretical and then experimental studies of the new designs. In this case, one should compare the results with existing designs. One of the necessary conditions for the qualitative improvement of the traction rolling stock is to define the parameters of its running gears. Among the issues related to this problem, an important place is occupied by the task of determining the locomotive dynamic properties on the stage of projection, taking into account the selected technical solutions in the running gear design. Methodology. The mathematical modeling studies are carried out by the numerical integration method of the dynamic loading for the mainline locomotive using the software package «Dynamics of Rail Vehicles » («DYNRAIL». Findings. As a result of research for the improvement of locomotive running gear design it can be seen that the creation of the modern locomotive requires from engineers and scientists the realization of scientific and technical solutions. The solutions enhancing design speed with simultaneous improvement of the traction, braking and dynamic qualities to provide a simple and reliable design, especially the running gear, reducing the costs for maintenance and repair, low initial cost and operating costs for the whole service life, high traction force when starting, which is as close as possible to the ultimate force of adhesion, the ability to work in multiple traction mode and sufficient design speed. Practical Value. The generalization of theoretical, scientific and methodological, experimental studies aimed

  14. HEALTH MONITORING OF ELECTRICAL ACTUATORS FOR LANDING GEARS

    OpenAIRE

    Phillips, Paul

    2012-01-01

    There are numerous benefits associated with replacing hydraulic actuators with electrical counterparts as part of an all electric landing gear including reduced consumption of non-propulsive engine power, reduced weight, reduced cost and the elimination of hydraulic systems. The development of health monitoring systems to support the introduction of electrical actuation systems into landing gears will aid in guaranteeing reliability and to optimise landing gear maintenance activ...

  15. Prediction of Landing Gear Noise Reduction and Comparison to Measurements

    Science.gov (United States)

    Lopes, Leonard V.

    2010-01-01

    Noise continues to be an ongoing problem for existing aircraft in flight and is projected to be a concern for next generation designs. During landing, when the engines are operating at reduced power, the noise from the airframe, of which landing gear noise is an important part, is equal to the engine noise. There are several methods of predicting landing gear noise, but none have been applied to predict the change in noise due to a change in landing gear design. The current effort uses the Landing Gear Model and Acoustic Prediction (LGMAP) code, developed at The Pennsylvania State University to predict the noise from landing gear. These predictions include the influence of noise reduction concepts on the landing gear noise. LGMAP is compared to wind tunnel experiments of a 6.3%-scale Boeing 777 main gear performed in the Quiet Flow Facility (QFF) at NASA Langley. The geometries tested in the QFF include the landing gear with and without a toboggan fairing and the door. It is shown that LGMAP is able to predict the noise directives and spectra from the model-scale test for the baseline configuration as accurately as current gear prediction methods. However, LGMAP is also able to predict the difference in noise caused by the toboggan fairing and by removing the landing gear door. LGMAP is also compared to far-field ground-based flush-mounted microphone measurements from the 2005 Quiet Technology Demonstrator 2 (QTD 2) flight test. These comparisons include a Boeing 777-300ER with and without a toboggan fairing that demonstrate that LGMAP can be applied to full-scale flyover measurements. LGMAP predictions of the noise generated by the nose gear on the main gear measurements are also shown.

  16. ANALYTICAL WEIGHT ESTIMATION OF UNCONVENTIONAL LANDING GEAR DESIGNS

    OpenAIRE

    Parés Prat, Andreu; Borhani Coca, Dario; Munjulury, Raghu Chaitanya; Berry, Patrick

    2015-01-01

    Landing gear weight calculations can be carried out using statistical or analytical methods. Statistical methods were used in the past and offered quick group weights, however, they are not capable of computing with accuracy the weight of unconventional landing gears which have special geometries and performances. In this work, landing gear weight is computed using analytical methods. The procedure established by Kraus and Wille is acquired as a baseline so as to create a program able to deal...

  17. Tool Gear: Infrastructure for Building Parallel Programming Tools

    Energy Technology Data Exchange (ETDEWEB)

    May, J M; Gyllenhaal, J

    2002-12-09

    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.

  18. Finite Element Residual Stress Analysis of Planetary Gear Tooth

    OpenAIRE

    Jungang Wang; Yong Wang; Zhipu Huo

    2013-01-01

    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 in...

  19. STUDY ON WEAR AND DESTRUCTION OF HOB IN GEAR HOBBING

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The wear and destruction appearances of hobs are researched. The reasons of the wear and destruction of hobare analyzed. And the influence of the change of the hobbing force and the hobbing temperature on the wear and destruc-tion of hob in gear hobbing is also analyzed. In gear hobbing, the main wear mechanisms are adhesion and ploughingwhen cutting the 20CrMnTi gear using W 18Cr4V high-speed steel hob.

  20. Influence of material and gear parameters on the safety of gearing in metallurgical industry

    Directory of Open Access Journals (Sweden)

    S. Medvecká - Beňová

    2015-01-01

    Full Text Available This paper deals with the appropriate choice of parameters to obtain the desired level of safety of gears in a gearbox to drive the conveyor in the metallurgical industry under increased load. Steel with surface hardness up to 350 HBW, or heat treated steel with hardness of 500 - 650 HBW are used. As a final heat treatment are used surface hardening, cementation and hardening, nitridation. Good properties of heat-treated steels are at the correct thickness of the heat-treated layer of the tooth. Results are presented for dual-ratio gearbox with spur gears from operation of an integrated steel company.

  1. Offset Compound Gear Inline Two-Speed Drive

    Science.gov (United States)

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

    2014-01-01

    A two-speed transmission having an input shaft and an output shaft, the transmission being capable of transitioning between fixed ratios, the high-range ratio being direct 1:1 and the low-range ratio being about 2:1. The transmission is a simple lightweight, yet robust, configuration utilizing only two gear meshes, being comprised of an input gear, a cluster gear, and an output gear. The transmission is controlled with a clutch and a sprag and with the input and output shafts turning in the same direction.

  2. The theory and practice of worm gear drives

    CERN Document Server

    Dudás, Ilés

    2005-01-01

    Worm gears are special gears that resemble screws, and can be used to drive other gears. Worm gears, enable two non-touching shafts in a machine to mesh (join) together. This publication, unique in that it combines both theoretical and practical design aspects, including the latest results of research and development, provides detailed treatment of the theory and production of worm drives, as well as the overarching subject of production geometry of helicoidal surfaces.Included are mathematical models for a number of practical applications; a description of dressing equipment r

  3. Turbine Engine with Differential Gear Driven Fan and Compressor

    Science.gov (United States)

    Suciu, Gabriel L. (Inventor); Pagluica, Gino J. (Inventor); Duong, Loc Quang (Inventor); Portlock, Lawrence E. (Inventor)

    2013-01-01

    A gas turbine engine provides a differential gear system coupling the turbine to the bypass fan and the compressor. In this manner, the power/speed split between the bypass fan and the compressor can be optimized under all conditions. In the example shown, the turbine drives a sun gear, which drives a planet carrier and a ring gear in a differential manner. One of the planet carrier and the ring gear is coupled to the bypass fan, while the other is coupled to the compressor.

  4. Design, Load Analysis and Optimization of Compound Epicyclic Gear Trains

    OpenAIRE

    Syed Ibrahim Dilawer

    2013-01-01

    - Gears in the Epicyclic gear trains are one of the most critical components in the mechanical power transmission system in which failure of one gear will affect the whole transmission system, thus it is very necessary to determine the causes of failure in an attempt to reduce them. The different modes of failure of gears and their possible remedies to avoid the failure are mentioned in J.R. Davis (2005) [17], Khurmi & Gupta (2006) [19], P. Kannaiah (2006) [18] [20] as bending failure (load f...

  5. EFFECT OF GEAR WIDTH AND HELIX ANGLE ON FACTOR OF DYNAMIC LOAD OF DOUBLE CIRCULAR ARC HELICAL GEARING

    Institute of Scientific and Technical Information of China (English)

    Wu Baolin

    2004-01-01

    Based on theory of mechanical dynamics, meshing characteristic as well as the dynamic model of double circular arc helical gearing, an analysis approach and a computer program have been developed for studying the state of dynamic load and factor of dynamic load of the gearing, the changing situation of dynamic load and dynamic load factor vs some affecting factors such as gear width, helix angle and accuracy grade etc are investigated. A series of conclusions are obtained: ①With the increasing in the values of gear width, the dynamic load factor appears slow decreasing tendency in most region of gear width. ② When the accuracy grades of the gearing are improved, the values of dynamic load factor decrease. ③ The value of dynamic load factor appears a decreasing tendency with the increasing of value of helix angle at the same ratio of critical rotational speed.

  6. DYNAMIC MODELLING OF BAR-GEAR MIXED MULTIBODY SYSTEMS USING A SPECIFIC FINITE ELEMENT METHOD

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A new dynamic model for mixed, flexible bar and gear multibody systems is developed based on a specific finite element method, and a new gear-element is proposed. The gear-element can take into account the time variant stiffness, the gear errors and mass unbalance. The model for geared multibody systems can couple the gear meshing and the flexibility of all contained components. The kinematic and dynamic analyses of the geared multibody systems are expounded and illustrated on an example composed of three gears, two bars and one slider.

  7. Topological Expression Model of Satellite Gear Mechanism

    Institute of Scientific and Technical Information of China (English)

    Yang Ping

    2005-01-01

    By investigation of the topological characteristics of the kinematic structure of Satellite Gear Mechanism (SGM) with graph theory, the graph model of SGM is analyzed, and a topological expression model between input and output of SGM is established based on systematic design point. Meanwhile, the mathematical expression for SGM is deduced by integrating matrix theory and graph theory; thus, the topological characteristics of the kinematic structure of SGM can be converted into a matrix model, and the topological design problem of SGM into a matrix operation problem. In addition, a brief discussion about the measures for identification of isomorphism of the graph mode is made.

  8. 14 CFR 25.477 - Landing gear arrangement.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Landing gear arrangement. 25.477 Section 25.477 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Ground Loads § 25.477 Landing gear...

  9. Potential for Landing Gear Noise Reduction on Advanced Aircraft Configurations

    Science.gov (United States)

    Thomas, Russell H.; Nickol, Craig L.; Burley, Casey L.; Guo, Yueping

    2016-01-01

    The potential of significantly reducing aircraft landing gear noise is explored for aircraft configurations with engines installed above the wings or the fuselage. An innovative concept is studied that does not alter the main gear assembly itself but does shorten the main strut and integrates the gear in pods whose interior surfaces are treated with acoustic liner. The concept is meant to achieve maximum noise reduction so that main landing gears can be eliminated as a major source of airframe noise. By applying this concept to an aircraft configuration with 2025 entry-into-service technology levels, it is shown that compared to noise levels of current technology, the main gear noise can be reduced by 10 EPNL dB, bringing the main gear noise close to a floor established by other components such as the nose gear. The assessment of the noise reduction potential accounts for design features for the advanced aircraft configuration and includes the effects of local flow velocity in and around the pods, gear noise reflection from the airframe, and reflection and attenuation from acoustic liner treatment on pod surfaces and doors. A technical roadmap for maturing this concept is discussed, and the possible drag increase at cruise due to the addition of the pods is identified as a challenge, which needs to be quantified and minimized possibly with the combination of detailed design and application of drag reduction technologies.

  10. Survey gear calibration independent of spatial fish distribution

    DEFF Research Database (Denmark)

    Lewy, Peter; Nielsen, J. Rasmus; Hovgård, Holger

    2004-01-01

    Trawl surveys provide important information for evaluation of relative stock abundance fluctuations over time. Therefore, when survey gears or vessels are changed, it is important to compare the efficiency and selectivity of old and new gears and vessels. A method for estimation of conversion fac...

  11. 29 CFR 1918.62 - Miscellaneous auxiliary gear.

    Science.gov (United States)

    2010-07-01

    ... box-type pallets shall be designed to prevent disengagement from the pallet under load. (5) Pallets... 29 Labor 7 2010-07-01 2010-07-01 false Miscellaneous auxiliary gear. 1918.62 Section 1918.62 Labor... (CONTINUED) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Cargo Handling Gear and Equipment Other Than...

  12. 50 CFR 635.21 - Gear operation and deployment restrictions.

    Science.gov (United States)

    2010-10-01

    ... at 50 CFR 600.105(c). (5) The operator of a vessel required to be permitted under this part and that... or bottom longline gear onboard and that have been issued, or are required to have, a limited access... this paragraph (b), a vessel using or having onboard in the Atlantic Ocean any unauthorized gear...

  13. 50 CFR 622.46 - Prevention of gear conflicts.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Prevention of gear conflicts. 622.46 Section 622.46 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Management Measures § 622.46 Prevention of gear conflicts. (a) No person may knowingly place in the Gulf...

  14. 50 CFR 654.25 - Prevention of gear conflicts.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 8 2010-10-01 2010-10-01 false Prevention of gear conflicts. 654.25 Section 654.25 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND... Measures § 654.25 Prevention of gear conflicts. (a) No person may knowingly place in the management...

  15. 33 CFR 164.39 - Steering gear: Foreign tankers.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Steering gear: Foreign tankers... (CONTINUED) PORTS AND WATERWAYS SAFETY NAVIGATION SAFETY REGULATIONS § 164.39 Steering gear: Foreign tankers. (a) This section applies to each foreign tanker of 10,000 gross tons or more, except a public...

  16. 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.

  17. Actively Controlled Landing Gear for Aircraft Vibration Reduction

    Science.gov (United States)

    Horta, Lucas G.; Daugherty, Robert H.; Martinson, Veloria J.

    1999-01-01

    Concepts for long-range air travel are characterized by airframe designs with long, slender, relatively flexible fuselages. One aspect often overlooked is ground induced vibration of these aircraft. This paper presents an analytical and experimental study of reducing ground-induced aircraft vibration loads using actively controlled landing gears. A facility has been developed to test various active landing gear control concepts and their performance. The facility uses a NAVY A6-intruder landing gear fitted with an auxiliary hydraulic supply electronically controlled by servo valves. An analytical model of the gear is presented including modifications to actuate the gear externally and test data is used to validate the model. The control design is described and closed-loop test and analysis comparisons are presented.

  18. 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.)

  19. On-line tribochemical strengthening of gear surface

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It has been found that under favorable friction conditions some antiwear elements inlubricating additives can permeate into subsurface of metal which can strengthens the friction sur-faces and improves anti-wear capacity of frication pairs. It is in many ways similar to chemical heattreatment. A new concept, technology of on-line strengthening, was logically put forward. Based oncurrent gear surface treatment technology, the on-line strengthen of gear surface is proposed. Itsdesign method is established. Based on it, the on-line strengthen of gear is achieved on CL-100gear test machine. A new method is put forward for strengthen treatment of gear surface. Andthree kinds of surface film were suggested.

  20. Dynamic Analysis of Geared Rotors by Finite Elements

    Science.gov (United States)

    Kahraman, A.; Ozguven, H. Nevzat; Houser, D. R.; Zakrajsek, J. J.

    1992-01-01

    A finite element model of a geared rotor system on flexible bearings has been developed. The model includes the rotary inertia of on shaft elements, the axial loading on shafts, flexibility and damping of bearings, material damping of shafts and the stiffness and the damping of gear mesh. The coupling between the torsional and transverse vibrations of gears were considered in the model. A constant mesh stiffness was assumed. The analysis procedure can be used for forced vibration analysis geared rotors by calculating the critical speeds and determining the response of any point on the shafts to mass unbalances, geometric eccentricities of gears, and displacement transmission error excitation at the mesh point. The dynamic mesh forces due to these excitations can also be calculated. The model has been applied to several systems for the demonstration of its accuracy and for studying the effect of bearing compliances on system dynamics.

  1. 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.

  2. Development of a high-performance magnetic gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Andersen, Torben Ole; Jørgensen, Frank Thorleif;

    2005-01-01

    is to be installed because of a low natural torsion spring constant. The analyzed gear was also constructed in practice in order to validate the analysis and predict the efficiency. The measured torque from the magnetic gear was only 16 N-m reduced by the large end-effects. A systematic analysis of the 1055...... components in the magnetic gear is also performed in order to figure out why the efficiency for the actual construction was only 81 %. A large magnetic 1055 component originated in the bearings, where an unplanned extra bearing was necessary due to mechanical problems. Without the losses of magnetic origin...... in the bearings and jess end-effects caused by relative ly short stack, an impressive efficiency estimated at 96% can be obtained. Comparison with c1assical mechanical gears has shown that the magnetic gear has a bette r efficiency and a comparable torque per volume density. Finally, it is concluded...

  3. Two dimensional model of a permanent magnet spur gear

    DEFF Research Database (Denmark)

    Jørgensen, Frank Thorleif; Andersen, Torben Ole; Rasmussen, Peter Omand

    2005-01-01

    is to be installed because of a low natural torsion spring constant. The analyzed gear was also constructed in practice in order to validate the analysis and predict the efficiency. The measured torque from the magnetic gear was only 16 N/spl middot/m reduced by the large end-effects. A systematic analysis...... of the loss components in the magnetic gear is also performed in order to figure out why the efficiency for the actual construction was only 81%. A large magnetic loss component originated in the bearings, where an unplanned extra bearing was necessary due to mechanical problems. Without the losses...... of magnetic origin in the bearings and less end-effects caused by relatively short stack, an impressive efficiency estimated at 96% can be obtained. Comparison with classical mechanical gears has shown that the magnetic gear has a better efficiency and a comparable torque per volume density. Finally...

  4. An ADI extrapolated Crank-Nicolson orthogonal spline collocation method for nonlinear reaction-diffusion systems: a computational study

    CERN Document Server

    Fernandes, Ryan I

    2012-01-01

    An alternating direction implicit (ADI) orthogonal spline collocation (OSC) method is described for the approximate solution of a class of nonlinear reaction-diffusion systems. Its efficacy is demonstrated on the solution of well-known examples of such systems, specifically the Brusselator, Gray-Scott, Gierer-Meinhardt and Schnakenberg models, and comparisons are made with other numerical techniques considered in the literature. The new ADI method is based on an extrapolated Crank-Nicolson OSC method and is algebraically linear. It is efficient, requiring at each time level only $O({\\cal N})$ operations where ${\\cal N}$ is the number of unknowns. Moreover,it is shown to produce approximations which are of optimal global accuracy in various norms, and to possess superconvergence properties.

  5. Bebida com adição de soro de leite e fibra alimentar prebiótica

    Directory of Open Access Journals (Sweden)

    Mirela Guedes Bosi

    2013-03-01

    Full Text Available O objetivo deste trabalho foi avaliar a aceitação sensorial de bebida não fermentada, com adição de inulina e polpa de acerola. Seis formulações foram desenvolvidas, com adição de 0, 20, 40, 60, 80 e 100% de soro. O pH do soro foi 6,59, e a acidez de 0,103% de ácido lático. Utilizou-se a escala hedônica de nove pontos no teste de aceitação. As médias hedônicas das amostras com 0, 20 e 40% de soro não diferiram significativamente e variaram entre 6 e 8 pontos. As bebidas desenvolvidas com até 60% de soro são alternativas interessantes para o aproveitamento desse subproduto em laticínios.

  6. High-order compact ADI method using predictor-corrector scheme for 2D complex Ginzburg-Landau equation

    Science.gov (United States)

    Shokri, Ali; Afshari, Fatemeh

    2015-12-01

    In this article, a high-order compact alternating direction implicit (HOC-ADI) finite difference scheme is applied to numerical solution of the complex Ginzburg-Landau (GL) equation in two spatial dimensions with periodical boundary conditions. The GL equation has been used as a mathematical model for various pattern formation systems in mechanics, physics, and chemistry. The proposed HOC-ADI method has fourth-order accuracy in space and second-order accuracy in time. To avoid solving the nonlinear system and to increase the accuracy and efficiency of the method, we proposed the predictor-corrector scheme. Validation of the present numerical solutions has been conducted by comparing with the exact and other methods results and evidenced a good agreement.

  7. Hybrid foundry patterns of bevel gears

    Directory of Open Access Journals (Sweden)

    Budzik G.

    2007-01-01

    Full Text Available Possibilities of making hybrid foundry patterns of bevel gears for investment casting process are presented. Rapid prototyping of gears with complex tooth forms is possible with the use of modern methods. One of such methods is the stereo-lithography, where a pattern is obtained as a result of resin curing with laser beam. Patterns of that type are applicable in precision casting. Removing of stereo-lithographic pattern from foundry mould requires use of high temperatures. Resin burning would generate significant amounts of harmful gases. In case of a solid stereo-lithographic pattern, the pressure created during gas burning may cause the mould to crack. A gas volume reduction may be achieved by using patterns of honeycomb structure. However, this technique causes a significant worsening of accuracy of stereo-lithographic patterns in respect of their dimensions and shape. In cooperation with WSK PZL Rzeszów, the Machine Design Department of Rzeszow University of Technology carried out research on the design of hybrid stereo-lithographic patterns. Hybrid pattern consists of a section made by stereo-lithographic process and a section made of casting wax. The latter material is used for stereo-lithographic pattern filling and for mould gating system. The hybrid pattern process consists of two stages: wax melting and then the burn-out of stereolithographic pattern. Use of hybrid patterns reduces the costs of production of stereolithographic patterns. High dimensional accuracy remains preserved in this process.

  8. The design and analysis of single flank transmission error testor for loaded gears

    Science.gov (United States)

    Houser, D. R.; Bassett, D. E.

    1985-01-01

    Due to geometrical imperfections in gears and finite tooth stiffnesses, the motion transmitted from an input gear shaft to an output gear shaft will not have conjugate action. In order to strengthen the understanding of transmission error and to verify mathematical models of gear transmission error, a test stand that will measure the transmission error of a gear pair at operating loads, but at reduced speeds would be desirable. This document describes the design and development of a loaded transmission error tester. For a gear box with a gear ratio of one, few tooth meshing combinations will occur during a single test. In order to observe the effects of different tooth mesh combinations and to increase the ability to load test gear pairs with higher gear ratios, the system was designed around a gear box with a gear ratio of two.

  9. Reliability Based Optimum Design of a Gear Box

    Directory of Open Access Journals (Sweden)

    D.Madhusekhar

    2014-10-01

    Full Text Available The gear box represents an important mechanical sub system. In machine tools, the propose of a gear box is to provide a series of useful output speeds so that the machining operation can be carried out at its most optimum operating conditions high spindle speeds with low feed rate for roughing operations. An important aspect in the design of machine tool transmission is to keep the cost and volume of the gear box to a minimum. The probabilistic approach to design has been considered to be more rational compared to the conventional design approach based on the factor of safety. The existence of uncertainties in either engineering simulations or manufacturing processes calls for a reliability-based design optimization (RBDO model for robust and cost-effective designs. In the present work a three shaft four speed gear box is 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. A FORTRAN program has been developed to calculate the mean values of face widths of gears for the minimum mass of gear box. By changing the probability of failure of system variations in the face widths are studied. The reliability based optimum design results are compared with those obtained by deterministic optimum design. The minimum mass of the gear box is increase as the specified values of the reliability is increased.

  10. POD/DEIM Nonlinear model order reduction of an ADI implicit shallow water equations model

    CERN Document Server

    Stefanescu, Razvan

    2012-01-01

    In the present paper we consider a 2-D shallow-water equations (SWE) model on a $\\beta$-plane solved using an alternating direction fully implicit (ADI) finite-difference scheme on a rectangular domain. The scheme was shown to be unconditionally stable for the linearized equations. The discretization yields a number of nonlinear systems of algebraic equations. We then use a proper orthogonal decomposition (POD) to reduce the dimension of the SWE model. Due to the model nonlinearities, the computational complexity of the reduced model still depends on the number of variables of the full shallow - water equations model. By employing the discrete empirical interpolation method (DEIM) we reduce the computational complexity of the reduced order model due to its depending on the nonlinear full dimension model and regain the full model reduction expected from the POD model. To emphasize the CPU gain in performance due to use of POD/DEIM, we also propose testing an explicit Euler finite difference scheme (EE) as an a...

  11. Microstructure and Mechanical Properties of ADI Depending on Austenitization Methods and Parameters

    Directory of Open Access Journals (Sweden)

    T. Giętka

    2012-04-01

    Full Text Available Ductile iron was quenched using two-variant isothermal transformation. The first treatment variant consisted of one-phase austenitization at a temperature t = 830, 860 or 900 C, cooling down to an isothermal transformation temperature of 300 or 400 C and holding from 8 to 64 minutes. The second treatment variant consisted of two-phase austenitization. Cast iron was austenitizied at a tem- perature t = 950 C and cooled down to a supercritical temperature t ’ = 900, 860 or 830 C. Isothermal transformation was conducted under the same conditions as those applied to the first variant. Ferrite cast iron was quenched isothermally. Basic strength (Rp0.2, Rm and plastic (A5 properties as well as matrix microstructure and hardness were examined.As a result of heat treatment, the following ADI grades were obtained: EN-GJS-800-8, EN-GJS-1200-2 and EN-GJS-1400-1 in accordance with PN–EN 1564:2000 having plasticity of 1.5÷4 times more than minimum requirements specified in the standard.

  12. The studies of mechanical properties and structure of ADI as function of austempering parameters

    Directory of Open Access Journals (Sweden)

    A. Krzyńska

    2010-10-01

    Full Text Available The results of study of ductile iron austempered using different parameters of austempering are presented. The aim of the investigations was to look closer into mechanical properties of this very attractive cast material. The experiment was carried out with commercial EN-GJS-500-7 grade ductile iron. The specimens were first solution heat treated 1 hour in 910oC and then isothermally quenched for different time in molten tin of different temperature. The mechanical properties heat treated specimens were tested using tensile test machine to evaluate Rp,0.2, Rm and A10. Moreover Brinell hardness tests were carried out for structure investigation conventional light microscopy only was used. It was discovered, that low yield strength ADI obtained for short time quenching at 275oC exhibited high strengthening effect while tensile strained. So it was concluded that this had to by cause by large amount of untransformed austenite, which FCC lattice providing large number of glide systems.

  13. Influence of process parameters on the properties of austempered ductile iron (ADI examined with the use of data mining methods

    Directory of Open Access Journals (Sweden)

    D. Wilk-Kołodziejczyk

    2016-10-01

    Full Text Available The article presents opportunities offered by the data mining analysis as applied to studies of the effect of process parameters on the mechanical properties of ADI. The applied methods of regression trees and cluster analysis allow for the detection of relationships between parameters and also allow determination of strength and form of the impact of different factors. The results of this study allow the creation of knowledge bases for systems supporting the decision-making process in technology.

  14. 3-D ADI-FDTD modeling of GPR backscatter from complex targets for the training of artificial neural networks

    Science.gov (United States)

    Sassen, D. S.; Everett, M. E.

    2007-12-01

    Artificial neural networks can provide approximate solutions to ground-penetrating radar (GPR) problems in cases where real time performance is needed. Examples include discrimination of landmines or UXO's, and in circumstances that require a high number of successive forward problems, for example inversion or imaging. The training of neural networks to work within even a limited range of targets and electromagnetic properties requires a large set of successive examples generated from numerical methods such as finite difference time domain (FDTD). The traditional FDTD technique suffers from numerical dispersion unless time steps are kept below the Courant stability limit. The accurate modeling of electromagnetic scattering by complex targets require a refined grid, subgrids, or conformal grids that can significantly increase computation time, making neural network training inefficient. A relatively recent FDTD technique, ADI-FDTD, uses implicit equations that help to cancel numerical dispersion and allow for unconditionally stable modeling of EM propagation and therefore is not bound by the Courant stability limit. The technique is especially efficient for the accurate modeling of complex targets. Our ADI-FDTD code includes the ability to refine the model grid and to implement a conformal gridding to improve model accuracy without effecting the overall computation time. We will explore the tradeoff in computation time and accuracy in modeling the GPR backscatter of various targets using both the ADI-FDTD technique and the traditional FDTD technique for the purpose of neural network training.

  15. Unveiling the Mechanism of Arginine Transport through AdiC with Molecular Dynamics Simulations: The Guiding Role of Aromatic Residues

    Science.gov (United States)

    Krammer, Eva-Maria; Ghaddar, Kassem; André, Bruno

    2016-01-01

    Commensal and pathogenic enteric bacteria have developed several systems to adapt to proton leakage into the cytoplasm resulting from extreme acidic conditions. One such system involves arginine uptake followed by export of the decarboxylated product agmatine, carried out by the arginine/agmatine antiporter (AdiC), which thus works as a virtual proton pump. Here, using classical and targeted molecular dynamics, we investigated at the atomic level the mechanism of arginine transport through AdiC of E. coli. Overall, our MD simulation data clearly demonstrate that global rearrangements of several transmembrane segments are necessary but not sufficient for achieving transitions between structural states along the arginine translocation pathway. In particular, local structural changes, namely rotameric conversions of two aromatic residues, are needed to regulate access to both the outward- and inward-facing states. Our simulations have also enabled identification of a few residues, overwhelmingly aromatic, which are essential to guiding arginine in the course of its translocation. Most of them belong to gating elements whose coordinated motions contribute to the alternating access mechanism. Their conservation in all known E. coli acid resistance antiporters suggests that the transport mechanisms of these systems share common features. Last but not least, knowledge of the functional properties of AdiC can advance our understanding of the members of the amino acid-carbocation-polyamine superfamily, notably in eukaryotic cells. PMID:27482712

  16. Identification of a Non-Linear Landing Gear Model Using Nature-Inspired Optimization

    Directory of Open Access Journals (Sweden)

    Felipe A.C. Viana

    2008-01-01

    Full Text Available This work deals with the application of a nature-inspired optimization technique to solve an inverse problem represented by the identification of an aircraft landing gear model. The model is described in terms of the landing gear geometry, internal volumes and areas, shock absorber travel, tire type, and gas and oil characteristics of the shock absorber. The solution to this inverse problem can be obtained by using classical gradient-based optimization methods. However, this is a difficult task due to the existence of local minima in the design space and the requirement of an initial guess. These aspects have motivated the authors to explore a nature-inspired approach using a method known as LifeCycle Model. In the present formulation two nature-based methods, namely the Genetic Algorithms and the Particle Swarm Optimization were used. An optimization problem is formulated in which the objective function represents the difference between the measured characteristics of the system and its model counterpart. The polytropic coefficient of the gas and the damping parameter of the shock absorber are assumed as being unknown: they are considered as design variables. As an illustration, experimental drop test data, obtained under zero horizontal speed, were used in the non-linear landing gear model updating of a small aircraft.

  17. Increased Fidelity in Prediction Methods For Landing Gear Noise

    Science.gov (United States)

    Lopes, Leonard V.; Brentner, Kenneth S.; Morris, Philip J.; Lockhard, David P.

    2006-01-01

    An aeroacoustic prediction scheme has been developed for landing gear noise. The method is designed to handle the complex landing gear geometry of current and future aircraft. The gear is represented by a collection of subassemblies and simple components that are modeled using acoustic elements. These acoustic elements are generic, but generate noise representative of the physical components on a landing gear. The method sums the noise radiation from each component of the undercarriage in isolation accounting for interference with adjacent components through an estimate of the local upstream and downstream flows and turbulence intensities. The acoustic calculations are made in the code LGMAP, which computes the sound pressure levels at various observer locations. The method can calculate the noise from the undercarriage in isolation or installed on an aircraft for both main and nose landing gear. Comparisons with wind tunnel and flight data are used to initially calibrate the method, then it may be used to predict the noise of any landing gear. In this paper, noise predictions are compared with wind tunnel data for model landing gears of various scales and levels of fidelity, as well as with flight data on fullscale undercarriages. The present agreement between the calculations and measurements suggests the method has promise for future application in the prediction of airframe noise.

  18. A study on the automated design system for gear

    International Nuclear Information System (INIS)

    A computer aided design system for spur, helical, bevel and worm gears by using AutoCAD system and its AutoLISP computer language was newly developed in this study. Two methods are available for a designer to draw a gear. The first method needs the gear design parameters such as pressure, module, number of tooth, shaft angle, velocity, materials, etc. When the gear design parameters are inputted, a gear is drawn in AutoCAD system and maximum allowable power and shaft diameter are calculated additionally. The second method calculates all dimensions and gear design parameters to draw a gear when the information such as transmission, reduction ratio, rpm, materials and pressure are inputted. The system includes four programs. Each program is composed of a data input module, a database module, a strength calculation module, a drawing module, a text module and a drawing edit module. In conclusion, the CAD system would be widely used in companies to find the geometric data and manufacturing course

  19. DESIGN OF NONCIRCULAR GEARS WITH DISCONTINUOUS PITCH CURVE

    Institute of Scientific and Technical Information of China (English)

    ZHANG Rui; WU Xutang

    2006-01-01

    When the noncircular gear pair is applied to the continuously variable transmission (CVT)with gear, the transmission ratio function is discontinuous. In accordance with this unique characteristic, a new approach to design and analyze noncircular gears with discontinuous pitch curve is proposed. The design courses of various noncircular gear pairs with discontinuous pitch curve are unified based on the numerical algorithm of spline fitting and "fairing boundary condition".According to the particularity of discontinuous pitch curve, the rules and procedures for teeth distribution are recommended. It is explained in detail why the undercut is formed and how to manage the undercut based on meshing principle. In addition, the calculation formulas for each tooth profile segment are also derived. If the tooth profile data are calculated, the measurement and the incision process for noncircular gear can be conducted and the CAD simulation can be achieved easily. To ensure the continuity of the transmission, the transmission interference of the tooth which is located at ratio of gear pair is obtained. The case study shows that this approach is successful and opens up a new way for the design ofnoncircular gear.

  20. 14 CFR 27.501 - Ground loading conditions: landing gear with skids.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground loading conditions: landing gear... § 27.501 Ground loading conditions: landing gear with skids. (a) General. Rotorcraft with landing gear...) The gear in its most critically deflected position for the landing condition being considered; and...

  1. 14 CFR 29.501 - Ground loading conditions: landing gear with skids.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground loading conditions: landing gear... § 29.501 Ground loading conditions: landing gear with skids. (a) General. Rotorcraft with landing gear...) The gear in its most critically deflected position for the landing condition being considered; and...

  2. If the Gear Fits, Spin It!: Embodied Education and in-Game Assessments

    NARCIS (Netherlands)

    Johnson-Glenberg, M.C.; Birchfield, D.; Megowan-Romanowicz, C.; Snow, E.L.

    2015-01-01

    Two embodied gears games were created. Better learners should use fewer gear switches to reflect their knowledge. Twenty–three 7th graders, playing as dyads, used gestures to manipulate virtual gears. The Kinect sensor tracked arm-spinning movements and switched gear diameters. Knowledge tests were

  3. 50 CFR Table 19 to Part 679 - Seabird Avoidance Gear Codes

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Seabird Avoidance Gear Codes 19 Table 19... ALASKA Pt. 679, Table 19 Table 19 to Part 679—Seabird Avoidance Gear Codes VESSEL LOGBOOK CODE SEABIRD AVOIDANCE GEAR OR METHOD. 1 Paired Streamer Lines: Used during deployment of hook-and-line gear to...

  4. Evaluation of Gear Condition Indicator Performance on Rotorcraft Fleet

    Science.gov (United States)

    Antolick, Lance J.; Branning, Jeremy S.; Wade, Daniel R.; Dempsey, Paula J.

    2010-01-01

    The U.S. Army is currently expanding its fleet of Health Usage Monitoring Systems (HUMS) equipped aircraft at significant rates, to now include over 1,000 rotorcraft. Two different on-board HUMS, the Honeywell Modern Signal Processing Unit (MSPU) and the Goodrich Integrated Vehicle Health Management System (IVHMS), are collecting vibration health data on aircraft that include the Apache, Blackhawk, Chinook, and Kiowa Warrior. The objective of this paper is to recommend the most effective gear condition indicators for fleet use based on both a theoretical foundation and field data. Gear diagnostics with better performance will be recommended based on both a theoretical foundation and results of in-fleet use. In order to evaluate the gear condition indicator performance on rotorcraft fleets, results of more than five years of health monitoring for gear faults in the entire HUMS equipped Army helicopter fleet will be presented. More than ten examples of gear faults indicated by the gear CI have been compiled and each reviewed for accuracy. False alarms indications will also be discussed. Performance data from test rigs and seeded fault tests will also be presented. The results of the fleet analysis will be discussed, and a performance metric assigned to each of the competing algorithms. Gear fault diagnostic algorithms that are compliant with ADS-79A will be recommended for future use and development. The performance of gear algorithms used in the commercial units and the effectiveness of the gear CI as a fault identifier will be assessed using the criteria outlined in the standards in ADS-79A-HDBK, an Army handbook that outlines the conversion from Reliability Centered Maintenance to the On-Condition status of Condition Based Maintenance.

  5. 飞利浦GoGear MUSE

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    当价格成为选择苹果最痛苦的纠结时,其实还有一个腕级的品牌可供选择——飞利浦。从2008年进入国内,已经有包括GoGearSA28、Mix、SA075等在内的一大批数码播放产品脱颖而出。个性与差异化是飞利浦GoGear系列播放器的特质。关于MUSE,早在今年4月的国内经销商大会上已经被躁光,并被飞利浦官方评价为“最牛使用体验”。真相是什么呢?。

  6. Technology Innovation of Power Transmission Gearing in Aviation

    Science.gov (United States)

    Handschuh, Robert F.

    2009-01-01

    An overview of rotary wing evolution and innovations over the last 20 years was presented. This overview is provided from a drive system perspective. Examples of technology innovations that have changed and advanced drive systems of rotary wing vehicles will be provided. These innovations include full 6-axis CNC gear manufacture, face gear development to aerospace standards, health and usage monitoring, and gear geometry and bearing improvements. Also, an overview of current state-of-the-art activities being conducted at NASA Glenn is presented with a short look to fixed and rotary wing aircraft and systems needed for the future.

  7. 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.

  8. Reliability Based Optimum Design of a Gear Box

    OpenAIRE

    D.MADHUSEKHAR; DR.K. MADHAVA REDDY

    2014-01-01

    The gear box represents an important mechanical sub system. In machine tools, the propose of a gear box is to provide a series of useful output speeds so that the machining operation can be carried out at its most optimum operating conditions high spindle speeds with low feed rate for roughing operations. An important aspect in the design of machine tool transmission is to keep the cost and volume of the gear box to a minimum. The probabilistic approach to design has been considered to be mor...

  9. Engagement of Metal Debris into a 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.

  10. Computer Synthesis Approaches of Hyperboloid Gear Drives with Linear Contact

    Directory of Open Access Journals (Sweden)

    Abadjiev Valentin

    2014-09-01

    Full Text Available The computer design has improved forming different type software for scientific researches in the field of gearing theory as well as performing an adequate scientific support of the gear drives manufacture. Here are attached computer programs that are based on mathematical models as a result of scientific researches. The modern gear transmissions require the construction of new mathematical approaches to their geometric, technological and strength analysis. The process of optimization, synthesis and design is based on adequate iteration procedures to find out an optimal solution by varying definite parameters.

  11. Epicyclic Gear Train Solution Techniques with Application to Tandem Bicycling

    OpenAIRE

    Corey, Christopher A.

    2003-01-01

    This thesis presents a unification of kinematic and force-based methods for the design and analysis of planetary gear trains along with a discussion of potential applications in tandem biking. Specifically, this thesis will provide a simple solution technique for the general case of a two-degree of freedom (2DOF) planetary gear train along with new graphical design aids. It will also address the use of epicyclic gear trains as a power coupling in a tandem bike. In the current literature, p...

  12. Dynamics of gears and CVT in hybrid electric-powered vehicles; Dynamik von Getriebe und CVT beim Hybridfahrzeug

    Energy Technology Data Exchange (ETDEWEB)

    Maier, S.K.

    2006-07-01

    Calculation of the dynamics and acoustics of the gears of an electric-powered hybrid vehicle with CVT, internal combustion engine and electric motor/generator on the basi of the available construction data is a technological challenge. A method is presented by which vibrations of the bearing forces are simulated, and gear noise is identified in the form of noise levels, noise maps and spectrograms. The vibration characteristics of the gears are calculated in a single multibody system model for several gear tooth systems, the CVT level and the induction of vibrations in the engine. High accuracy of the calculations is obtained with detailed mechanical models of all toothmeshings and chain contacts. Important elements of the noise transmission chain from source to ear are calculated. The noisiness and non-noisiness of various construction variants are identified to be caused by steady and transient operating conditions of the hybrid vehicle. The results indicate noise levels for real driving situations which also comprise acceleration processes up to maximum speed. (orig.)

  13. DESIGN AND TEST RESULTS FOR MULTIPLE-CONTACT GEAR OF «BELARUS»-TRACTOR TRANSMISSION

    OpenAIRE

    V. Supin

    2012-01-01

    Gearing with high contact ratio (HCR) has other properties than gearing formed with a standard original profile. The gearing is characterized by increased loading capacity. The paper presents a boundary element method (BEM) which is applied to solve a problem pertaining to stress concentration at the tooth root. Gear-box casing with multiple-contact gear has remained in series production. Results of the investigations have been realized in the experimental gearbox of  the «Belarus-1523» tract...

  14. 50 CFR 654.6 - Vessel and gear identification.

    Science.gov (United States)

    2010-10-01

    ... legible and in good repair and ensure that no part of the fishing vessel, its rigging, fishing gear, or... is required to be marked is illegal and may be disposed of in any appropriate manner by the...

  15. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    Directory of Open Access Journals (Sweden)

    Soňa Benešová

    2013-09-01

    Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

  16. OPTIMIZATION OF HEATING OF GEAR WHEEL USING NUMERICAL MODELING

    Directory of Open Access Journals (Sweden)

    Sona Benesova

    2013-05-01

    Full Text Available Successful heat treating and carburizing of gear wheels for wind turbine gear boxes requires that plastic deformation in the wheel is minimized. Numerical modeling using the DEFORM software was aimed at exploring the effects of the base, on which the gear wheel rests during heating, on the heating process. Homogeneous heating was assumed. It was found that the base heats up more quickly than the workpiece. It is the consequence of the base's shape and volume. As a result, the base expands and slides against the wheel, predominantly at the first heating stage. Later on, it prevents the gear wheel from expanding, causing plastic deformation in the wheel. The findings were used for designing new heating schedules to minimize these undesirable interactions and to reduce the plastic deformation to a negligible magnitude. In addition, this paper presents an example of a practical use of numerical modeling in the DEFORM software.

  17. Enhanced Prediction of Gear Tooth Surface Fatigue Life Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Sentient will develop an enhanced prediction of gear tooth surface fatigue life with rigorous analysis of the tribological phenomena that contribute to pitting...

  18. Research on meshing theory of noninvolute beveloid gears

    Institute of Scientific and Technical Information of China (English)

    李瑰贤; 温建民; 李笑; 刘福利; 刘宇

    2003-01-01

    A mathematical model has been developed using the space engagement theory and the differential ge-ometry for the line contact of noninvolute beveloid gears with intersecting axes with their tooth profile equationsand engagement equations established for the first time and their meshing theory analysed. It can be seen fromthe fact that the tooth profile equation finally derived is no longer a standard involute helicoid and standard invo-lute beveloid gears with intersecting axes have no way to satisfy the line contact requirement. However, the non-invdute beveloid gears derived in this paper satisfy the line contact requirement very well. All these work willinevitably facilitate further investigations into gear tooth generation, stiffness, backlash and efficiency of trans-mission.

  19. Plasma Fairings for Quieting Aircraft Landing Gear Noise Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Phase II SBIR project deals with the design, development, and testing of a "Plasma Fairing" to reduce noise on the Gulfstream G550 landing gear. The plasma...

  20. Experimental Measurements of Belt Gears in Newly Developed Device

    Directory of Open Access Journals (Sweden)

    Jozef Mascenik

    2016-05-01

    Full Text Available The paper deals with the alternative of determination of state of the belt gear. To realize themeasurements a newly developed device was designed for measurement and diagnostics of the belt gears. The main task is to detect the V-belt slip expressed by the coefficient of elastic creep and of specific slip with a measuring device. The measurements regarding can be performed if input revolutions of the electric motor and torque of the belt gear are constant whereas the tensioning force of the belt gear changes. It is also possible to perform the measurement if the input revolutions of the electric motor and the tensioning forces are constant and the torque changes.

  1. Coefficient of friction of a starved lubricated spur gear pair

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huaiju; Zhu, Caichao; Sun, Zhangdong; Zhang, Yuanyuan; Song, Chaosheng [Chongqing University, Chongqing (China)

    2016-05-15

    The frictional power loss issue of gear pairs becomes an important concern in both industry and academia due to the requirement of the energy saving and the improvement of power density of gear drives. A thermal starved elastohydrodynamic lubrication model is developed to study the tribological performance of a spur gear pair under starved lubrication conditions. The contact pressure, the film thickness, the temperature rise, the frictional power loss, as well as the coefficient of friction are evaluated by considering the variation of the curvature radius, the sliding/rolling motion, and the load distribution of gear tooth within the meshing period. Effects of lubrication starvation condition, load and speed on the coefficient of friction are studied.

  2. Effect of solid particles on gear tooth failure

    Institute of Scientific and Technical Information of China (English)

    Abdelouahab BOUCHIREB; Mohamed Rafik SARI

    2015-01-01

    The failure of spur gears operating in highly contaminated media was studied. In fact, the effect of the presence of solid particles in gear mechanisms during surface tooth contact was observed. It is shown that the solid contaminants lead to significant wear in the first few operating cycles, in zones with a high rate of sliding. The scanning electron microscopy (SEM) images show clearly that the wear is more significant for a dry contact in the presence of larger size particles. Indeed, the presence of contaminants leads to an increase in friction, and therefore raises the temperature and the vibration levels when the operation of gear mechanism becomes very severe especially for a dry contact under the effect of larger size particles. On the other hand, we have tried to obtain a better understanding and a good description of wear debris distributions in gear mechanisms by using unimodal, single distribution models (Weibull and three-parameter Weibull).

  3. Prediction of Landing Gear Loads Using Machine Learning Techniques

    OpenAIRE

    Cross, Elizabeth; Worden, Keith; Sartor, Pia N; Southern, Paul

    2012-01-01

    This work aims to establish if significant correlations exist between flight parameters recorded on production aircraft and the loads induced in the landing gear by employing accurate nonlinear regression models developed using machine learning techniques. The mathematical modelling approach used in the development of the regression model employs both classical Multi-Layer Perceptron (MLP) and Bayesian MLP neural networks. The MLP neural networks in this work were developed using landing gear...

  4. Aircraf landing gear design in respect of pavement design

    OpenAIRE

    Fabre, C.; ALBIN, A; Balay, Jean Maurice

    2009-01-01

    This paper considers the close relationship between aircraft landing gear (LG) and pavement design in respect of airfield pavement compatibility. In pavement design and analysis, we usually deal with pavement structures, materials and design thickness procedure but rarely aircraft LG design This paper emphasizes key drivers, which must be considered for new aircraft LG design to achieve aircraft pavement compatibility. Several parameters such as number & size of wheels, type of gear, brakes, ...

  5. A400M landing gear, loads measurement evaluation

    OpenAIRE

    Rodríguez Juncosa, David

    2008-01-01

    Two A400M aircraft landing gears have been instrumented. The experience obtained with the first aircraft led some modifications to the second aircraft instrumentation. The project consists in studying the behaviour of the second aircraft landing gear loads measurements , as well as comparison with those of the first aircraft. The analysis of this comparison will lead to a proposal for an improvement of the measurement method (instrumentation, loading cases, etc).

  6. Magnetorheological landing gear: 2. Validation using experimental data

    OpenAIRE

    Batterbee, D.C.; N.D. Sims; STANWAY, R.; Rennison, M.

    2007-01-01

    Aircraft landing gears are subjected to a wide range of excitation conditions with conflicting damping requirements. A novel solution to this problem is to implement semi-active damping using magnetorheological (MR) fluids. In part 1 of this contribution, a methodology was developed that enables the geometry of a flow mode MR valve to be optimized within the constraints of an existing passive landing gear. The device was designed to be optimal in terms of its impact performance, which was dem...

  7. Aeroacoustic control of landing gear noise using perforated fairings

    OpenAIRE

    Boorsma, Koen

    2008-01-01

    A study was performed to investigate and optimize the application of perforated fairings for landing gear noise control. The sparse knowledge about this new subject has necessitated a more fundamental study involving a basic fairing-strut configuration, followed by wind tunnel tests on a simplified landing gear configuration incorporating perforated fairings. For the basic configuration, various exchangeable perforated half-cylindrical shells shrouding a circular cylinder we...

  8. Adaptive Landing Gear: Optimum Control Strategy and Potential for Improvement

    OpenAIRE

    Grzegorz Mikułowski; Łukasz Jankowski

    2009-01-01

    An adaptive landing gear is a landing gear (LG) capable of active adaptation to particular landing conditions by means of controlled hydraulic force. The objective of the adaptive control is to mitigate the peak force transferred to the aircraft structure during touch-down, and thus to limit the structural fatigue factor. This paper investigates the ultimate limits for improvement due to various strategies of active control. Five strategies are proposed and investigated numerically using a~va...

  9. Hydrostatic self-locking bevel differential gear; Hydrostatisch selbstsperrendes Kegelraddifferentialgetriebe

    Energy Technology Data Exchange (ETDEWEB)

    Kalmbach, K.

    2001-07-01

    The product range of the rail vehicle industry comprises the construction of railroad material for long-distance and short-distance transport. This includes, for example, locomotives and cars, subway, light railway and tramway cars as well as rail vehicle equipment. The development of the industry is determined by the demand for transport services and government actions for the extension of railways and procurement of suitable vehicle types. In contrast to road vehicles, differential gears are only used in a negligible percentage of rail vehicles. Primarily in the short-distance rail transport sector, the demand for differential gears is growing due to increased drive power, smaller wheel diameters, lower vehicle mass with higher load capacity, the introduction of low-floor technology as well as the requirement of employing ever more quiet vehicles. In hydrostatic self-locking differential gears, oil is supplied to the gears within the differential gearbox. They only rotate relative to each other when the differential gear performs a compensation movement. In this case, oil is transported in the tooth space to the meshing of the gears, where it is displaced due to the meshing and must drain through tight gaps. The pressure generated by this process acts against the compensation movement of the gear, and the drive torque is transmitted to the wheel that has the higher friction. The achievable locking torque is linearly dependent on the differential speed of the drive wheel. This locking effect is achieved without wear-prone components and works automatically without active external intervention. The design space required corresponds to that of conventional differential gears, as the locking effect is integrated in the existing design. (orig.)

  10. An Artificial Intelligence Approach for Gears Diagnostics in AUVs

    OpenAIRE

    Graciliano Nicolás Marichal; María Lourdes Del Castillo; Jesús López; Isidro Padrón; Mariano Artés

    2016-01-01

    In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles), where the usage of polymer gears in the vehicle transmission is frequent. Few st...

  11. QUALITY CONTROL ON THE AUSTENITIC-BAINITIC DUCTILE IRON GEAR

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    By reasonable casting, spheroidizing , inoculating and heat treating processes to control cupola metallurgy and the lipuid iron chemical compositions, a new kind of austenitic-bainitic ductile iron which can substitute for 20CrMnTi carburizing steel is studied. The gears made by the cast iron are high in quality,low in weight and the production cost is greatly reduced. The mechanical properties of the gear, including wear resistance, fatigue resistance, durability and others, can be greatly improved.

  12. Darwin-industrien i højt gear

    DEFF Research Database (Denmark)

    2008-01-01

    Darwin-industrien i højt gear. Næste år bliver et 'Darwin-år' - både tilhængere og kritikere gør sig klar. Udgivelsesdato: 12. december......Darwin-industrien i højt gear. Næste år bliver et 'Darwin-år' - både tilhængere og kritikere gør sig klar. Udgivelsesdato: 12. december...

  13. A Landing Gear Noise Reduction Study Based on Computational Simulations

    Science.gov (United States)

    Khorrami, Mehdi R.; Lockard, David P.

    2006-01-01

    Landing gear is one of the more prominent airframe noise sources. Techniques that diminish gear noise and suppress its radiation to the ground are highly desirable. Using a hybrid computational approach, this paper investigates the noise reduction potential of devices added to a simplified main landing gear model without small scale geometric details. The Ffowcs Williams and Hawkings equation is used to predict the noise at far-field observer locations from surface pressure data provided by unsteady CFD calculations. Because of the simplified nature of the model, most of the flow unsteadiness is restricted to low frequencies. The wheels, gear boxes, and oleo appear to be the primary sources of unsteadiness at these frequencies. The addition of fairings around the gear boxes and wheels, and the attachment of a splitter plate on the downstream side of the oleo significantly reduces the noise over a wide range of frequencies, but a dramatic increase in noise is observed at one frequency. The increased flow velocities, a consequence of the more streamlined bodies, appear to generate extra unsteadiness around other parts giving rise to the additional noise. Nonetheless, the calculations demonstrate the capability of the devices to improve overall landing gear noise.

  14. Fault Feature Analysis of a Cracked Gear Coupled Rotor System

    Directory of Open Access Journals (Sweden)

    Hui Ma

    2014-01-01

    Full Text Available Considering the misalignment of gear root circle and base circle and accurate transition curve, an improved mesh stiffness model for healthy gear is proposed, and it is validated by comparison with the finite element method. On the basis of the improved method, a mesh stiffness model for a cracked gear pair is built. Then a finite element model of a cracked gear coupled rotor system in a one-stage reduction gear box is established. The effects of crack depth, width, initial position, and crack propagation direction on gear mesh stiffness, fault features in time domain and frequency domain, and statistical indicators are investigated. Moreover, fault features are also validated by experiment. The results show that the improved mesh stiffness model is more accurate than the traditional mesh stiffness model. When the tooth root crack appears, distinct impulses are found in time domain vibration responses, and sidebands appear in frequency domain. Amplitudes of all the statistical indicators ascend gradually with the growth of crack depth and width, decrease with the increasing crack initial position angle, and firstly increase and then decrease with the growth of propagation direction angle.

  15. Effects of Planetary Gear Ratio on Mean Service Life

    Science.gov (United States)

    Savage, M.; Rubadeux, K. L.; Coe, H. H.

    1996-01-01

    Planetary gear transmissions are compact, high-power speed reductions which use parallel load paths. The range of possible reduction ratios is bounded from below and above by limits on the relative size of the planet gears. For a single plane transmission, the planet gear has no size at a ratio of two. As the ratio increases, so does the size of the planets relative to the sizes of the sun and ring. Which ratio is best for a planetary reduction can be resolved by studying a series of optimal designs. In this series, each design is obtained by maximizing the service life for a planetary with a fixed size, gear ratio, input speed power and materials. The planetary gear reduction service life is modeled as a function of the two-parameter Weibull distributed service lives of the bearings and gears in the reduction. Planet bearing life strongly influences the optimal reduction lives which point to an optimal planetary reduction ratio in the neighborhood of four to five.

  16. Continued Evaluation of Gear Condition Indicator Performance on Rotorcraft Fleet

    Science.gov (United States)

    Delgado, Irebert R.; Dempsey, Paula J.; Antolick, Lance J.; Wade, Daniel R.

    2013-01-01

    This paper details analyses of condition indicator performance for the helicopter nose gearbox within the U.S. Army's Condition-Based Maintenance Program. Ten nose gearbox data sets underwent two specific analyses. A mean condition indicator level analysis was performed where condition indicator performance was based on a 'batting average' measured before and after part replacement. Two specific condition indicators, Diagnostic Algorithm 1 and Sideband Index, were found to perform well for the data sets studied. A condition indicator versus gear wear analysis was also performed, where gear wear photographs and descriptions from Army tear-down analyses were categorized based on ANSI/AGMA 1010-E95 standards. Seven nose gearbox data sets were analyzed and correlated with condition indicators Diagnostic Algorithm 1 and Sideband Index. Both were found to be most responsive to gear wear cases of micropitting and spalling. Input pinion nose gear box condition indicators were found to be more responsive to part replacement during overhaul than their corresponding output gear nose gear box condition indicators.

  17. Surface Fatigue Life of High Temperature Gear Materials

    Science.gov (United States)

    Townsend, Dennis P.

    1994-01-01

    Three high temperature gear materials were evaluated using spur gear surface fatigue tests. These materials were, VASCO max 350, VASCO matrix 2, and nitralloy N and were evaluated for possible use in high temperature gear applications. The fatigue life of the three high temperature gear materials were compared with the life of the standard AISI 9310 aircraft gear material. Surface fatigue tests were conducted at a lubricant inlet temperature of 321 K (120 F), a lubricant outlet temperature of 350 K (170 F), a maximum Hertz stress of 1.71 GPa (248 ksi), a speed of 10,000 rpm, and with a synthetic paraffinic lubricant. The life of the nitralloy N was approximately the same as the AISI 9310, the life of the VASCO max 350 was much less than the AISI 9310 while the life of the VASCO matrix 2 was several times the life of the AISI 9310. The VASCO max 350 also showed very low fracture toughness with approximately half of the gears failed by tooth fracture through the fatigue spall. The VASCO matrix 2 had approximately 10-percent fracture failure through the fatigue spalls indicating moderate to good fracture toughness.

  18. [The problem of cancer in the work of Władysław Kopaczewski (1886-1953)].

    Science.gov (United States)

    Daszkiewicz, P

    1994-01-01

    Having left Lódź in 1906 Władysław Kopaczewski (1886-1953) studied physics, chemistry and biology at Swiss universities. In 1911 he moved to France where he conducted research in coloidal chemistry simultaneously obtaining a physician's diploma and an MD. During 42 years he spent in France he was dealing with biological systems physics, doing research in medicine, nutritive chemistry and cosmetology. He created an original conception of cancer disease. His theory allowed him to provide the theoretical bases of the cancer physics and to suggest a diagnositic method to direct the search for means of the cancer therapy. PMID:11624929

  19. Fatores associados à adição de sal à refeição pronta

    Directory of Open Access Journals (Sweden)

    Raquel da Silva Assunção de Castro

    2014-05-01

    Full Text Available O objetivo desta pesquisa foi investigar se existem diferenças na adição de sal à refeição pronta entre homens e mulheres. Foram incluídos 47.557 indivíduos de 18 a 64 anos, participantes do sistema de Vigilância de Fatores de Risco e Proteção para Doenças Crônicas por Inquérito Telefônico, das 26 capitais e Distrito Federal, em 2006. As diferenças entre homens e mulheres foram analisadas pelo teste do qui-quadrado e as magnitudes da associação estimadas pelo Odds Ratio obtido por meio da regressão logística múltipla. A prevalência da adição de sal à refeição pronta foi 8,3%, sendo maior entre homens (9,8% vs 6,9%, p < 0,01. Após ajustes, a adição de sal à refeição pronta foi maior em indivíduos com a autoavaliação de saúde regular e ruim, relato de doença cardiovascular e que residiam na região Norte do Brasil. Indivíduos hipertensos relataram adicionar menos sal à refeição pronta. A escolaridade não foi associada à adição de sal. Homens adicionam mais sal à refeição pronta do que mulheres. Políticas públicas de saúde voltadas para a redução da ingestão de sal pela população devem levar em consideração a diferença de gênero no uso discricionário de sal e nos fatores que favorecem essas diferenças.

  20. Minimizing tooth bending stress in spur gears with simplified shapes of fillet and tool shape determination

    DEFF Research Database (Denmark)

    Pedersen, Niels Leergaard

    2015-01-01

    is then used to find the cutting tool (the gear envelope) that can create this optimized gear shape.A simple but sufficiently flexible root parameterization is applied and emphasis is put on the importance of separating the shape parameterization from the finite element analysis of stresses. Large improvements......The strength of a gear is typically defined relative to durability (pitting) and load capacity (tooth-breakage). Tooth-breakage is controlled by the root shape and this gear part can be designed because there is no contact between gear pairs here. The shape of gears is generally defined...... by different standards, with the ISO standard probably being the most common one. Gears are manufactured using two principally different tools: rack tools and gear tools. In this work, the bending stress of involute teeth is minimized by shape optimization made directly on the final gear. This optimized shape...

  1. Aerodynamics of a Gulfstream G550 Nose Landing Gear Model

    Science.gov (United States)

    Neuhart, Dan H.; Khorrami, Mehdi R.; Choudhari, Meelan M.

    2009-01-01

    In this paper we discuss detailed steady and unsteady aerodynamic measurements of a Gulfstream G550 nose landing gear model. The quarter-scale, high-fidelity model includes part of the lower fuselage and the gear cavity. The full model configuration allowed for removal of various gear components (e.g. light cluster, steering mechanism, hydraulic lines, etc.) in order to document their effects on the local flow field. The measurements were conducted at a Reynolds number of 7.3 x 10(exp 4) based on the shock strut (piston) diameter and a freestream Mach number of 0.166. Additional data were also collected at lower Mach numbers of 0.12 and 0.145 and correspondingly lower Reynolds numbers. The boundary layer on the piston was tripped to enable turbulent flow separation, so as to better mimic the conditions encountered during flight. Steady surface pressures were gathered from an extensive number of static ports on the wheels, door, fuselage, and within the gear cavity. To better understand the resultant flow interactions between gear components, surface pressure fluctuations were collected via sixteen dynamic pressure sensors strategically placed on various subcomponents of the gear. Fifteen of the transducers were flush mounted on the gear surface at fixed locations, while the remaining one was a mobile transducer that could be placed at numerous varying locations. The measured surface pressure spectra are mainly broadband in nature, lacking any local peaks associated with coherent vortex shedding. This finding is in agreement with off-surface flow measurements using PIV that revealed the flow field to be a collection of separated shear layers without any dominant vortex shedding processes.

  2. Parametric Analysis of the End Face Engagement Worm Gear

    Institute of Scientific and Technical Information of China (English)

    DENG Xingqiao; WANG Jueling; WANG Jinge; CHEN Shouan; YANG Jie

    2015-01-01

    A novel specific type of worm drive, so-called end face engagement worm gear(EFEWD), is originally presented to minimize or overcome the gear backlash. Different factors, including the three different types, contact curves, tooth profile, lubrication angle and the induced normal curvature are taken into account to investigate the meshing characteristics and create the profile of a novel specific type of worm drive through mathematical models and theoretical analysis. The tooth of the worm wheel is very specific with the sine-shaped tooth which is located at the alveolus of the worm and the tooth profile of a worm is generated by the meshing movement of the worm wheel with the sine-shaped tooth, but just the end face of the worm(with three different typical meshing types) is adapted to meshing, and therefore an extraordinary manufacturing methods is used to generate the profile of the end face engagement worm. The research results indicates that the bearing contacts of the generated conjugate hourglass worm gear set are in line contacts, with certain advantages of no-backlash, high precision and high operating efficiency over other gears and gear systems besides the end face engagement worm gear drive may improve bearing contact, reduce the level of transmission errors and lessen the sensitivity to errors of alignment. Also, the end face engagement worm can be easily made with superior meshing and lubrication performance compared with the conventional techniques. In particular, the meshing and lubrication performance of the end face engagement worm gear by using the end face to meshing can be increased over 10% and 7%, respectively. This investigate is expect to provide a new insight on the design of the future no-backlash worm drive for industry.

  3. 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

  4. Improvement in Abrasion Wear Resistance and Microstructural Changes with Deep Cryogenic Treatment of Austempered Ductile Cast Iron (ADI)

    Science.gov (United States)

    Šolić, Sanja; Godec, Matjaž; Schauperl, Zdravko; Donik, Črtomir

    2016-10-01

    The application of a deep cryogenic treatment during the heat-treatment processes for different types of steels has demonstrated a significant influence on their mechanical and tribological properties. A great deal of research was conducted on steels, as well as on other kinds of materials, such as hard metal, gray cast iron, aluminum, aluminum alloys, etc., but not on austempered ductile iron (ADI). In this research the influence of a deep cryogenic treatment on the microstructure and abrasive wear resistance of austempered ductile iron was investigated. The ductile cast iron was austempered at the upper ausferritic temperature, deep cryogenically treated, and afterwards tempered at two different temperatures. The abrasion wear resistance was tested using the standard ASTM G65 method. The microstructure was characterized using optical microscopy, field-emission scanning electron microscopy, electron back-scattered diffraction, and X-ray diffraction in order to define the microstructural changes that influenced the properties of the ADI. The obtained results show that the deep cryogenic treatment, in combination with different tempering temperatures, affects the matrix microstructure of the austempered ductile iron, which leads to an increase in both the abrasion wear resistance and the hardness.

  5. Influência da adição de pectina e farelo de soja sobre a digestibilidade aparente de nutrientes, em eqüinos

    Directory of Open Access Journals (Sweden)

    Gabriel Jorge Carneiro de Oliveira

    2002-06-01

    Full Text Available O trabalho foi conduzido com o objetivo de avaliar a influência da adição de pectina e farelo de soja sobre a digestibilidade aparente de nutrientes, em eqüinos. Foi utilizado um delineamento inteiramente casualizado em esquema fatorial 4x2, sendo qautro níveis de pectina (0, 1, 2 e 3% da MS do feno de coastcross consumido e a adição ou não de farelo de soja, totalizando oito tratamentos, com quatro repetições. As variáveis estudadas foram os coeficientes de digestibilidade aparente da matéria seca (CDAMS, proteína bruta (CDAPB, fibra em detergente neutro (CDAFDN, fibra em detergente ácido (CDAFDA, hemicelulose (CDAHEM, energia bruta (CDAEB e a energia digestível (ED. A adição de pectina não afetou o CDAMS, CDAFDN, CDAFDA, CDAEB e nem a ED; porém melhorou o CDAPB, no nível de 1,25%, e o CDAHEM, em todos os níveis utilizados. Concluiu-se que a adição de 1,25% de pectina à dieta melhorou a digestibilidade aparente da PB e a adição de 3% de pectina proporcionou a melhor digestibilidade aparente da hemicelulose. A adição de farelo de soja à dieta, com o intuito de aumentar o aproveitamento da fibra bruta dos alimentos como fonte de energia, não é aconselhavel, uma vez que não houve melhora da digestibilidade aparente da FDN e da FDA.

  6. One Approach to the Synthesis, Design and Manufacture of Hyperboloid Gear Sets With Face Mating Gears. Part 1: Basic Theoretical and Cad Experience

    Directory of Open Access Journals (Sweden)

    Abadjiev Valentin

    2016-06-01

    Full Text Available Hyperboloid gear drives with face mating gears are used to transform rotations between shafts with non-parallel and non-intersecting axes. A special case of these transmissions are Spiroid and Helicon gear drives. The classical gear drives of this type are the Archimedean ones. The objective of this study are hyperboloid gear drives with face meshing, when the pinion possesses threads of conic convolute, Archimedean and involute types, or the pinion has threads of cylindrical convolute, Archimedean and involute types. For simplicity, all three types transmis- sions with face mating gears and a conic pinion are titled Spiroid and all three types transmissions with face mating gears and a cylindrical pinion are titled Helicon.

  7. 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.

  8. Kinematic synthesis of bevel-gear-type robotic wrist mechanisms

    Science.gov (United States)

    Lin, Chen-Chou

    Bevel-gear-type robotic wrist mechanisms are commonly used in industry. The reasons for their popularity are that they are compact, light-weight, and relatively inexpensive. However, there are singularities in their workspace, which substantially degrade their manipulative performance. The objective of this research is to develop an atlas of three-degree-of-freedom bevel-gear-type wrist mechanisms, and through dimensional synthesis to improve their kinematic performance. The dissertation contains two major parts: the first is structural analysis and synthesis, the other is kinematic analysis and dimensional synthesis. To synthesize the kinematic structures of bevel-gear-type wrist mechanisms, the kinematic structures are separated from their functional considerations. All kinematic structures which satisfy the mobility condition are enumerated in an unbiased, systematic manner. Then the bevel-gear-type wrist mechanisms are identified by applying the functional requirements. Structural analysis shows that a three-degree-of-freedom wrist mechanism usually consists of non-fractionated, two degree-of-freedom epicyclic gear train jointed with the base link. Therefore, the structural synthesis can be simplified into a problem of examining the atlas of non-fractionated, two-degree-of-freedom epicyclic gear trains. The resulting bevel-gear-type wrist mechanism has been categorized and evaluated. It is shown that three-degree-of-freedom, four-jointed wrist mechanisms are promising for further improving the kinematic performance. It is found that a spherical planetary gear train is necessarily imbedded in a three-degree-of-freedom, four-jointed wrist mechanism. Therefore, to study the workspace and singularity problems of three-degree-of-freedom four-jointed spherical wrist mechanisms, we have to study the trajectories of spherical planetary gear trains. The parametric equations of the trajectories and some useful geometric properties for the analysis and synthesis of

  9. Vibration Propagation of Gear Dynamics in a Gear-Bearing-Housing System Using Mathematical Modeling and Finite Element Analysis

    Science.gov (United States)

    Parker, Robert G.; Guo, Yi; Eritenel, Tugan; Ericson, Tristan M.

    2012-01-01

    Vibration and noise caused by gear dynamics at the meshing teeth propagate through power transmission components to the surrounding environment. This study is devoted to developing computational tools to investigate the vibro-acoustic propagation of gear dynamics through a gearbox using different bearings. Detailed finite element/contact mechanics and boundary element models of the gear/bearing/housing system are established to compute the system vibration and noise propagation. Both vibration and acoustic models are validated by experiments including the vibration modal testing and sound field measurements. The effectiveness of each bearing type to disrupt vibration propagation is speed-dependent. Housing plays an important role in noise radiation .It, however, has limited effects on gear dynamics. Bearings are critical components in drivetrains. Accurate modeling of rolling element bearings is essential to assess vibration and noise of drivetrain systems. This study also seeks to fully describe the vibro-acoustic propagation of gear dynamics through a power-transmission system using rolling element and fluid film wave bearings. Fluid film wave bearings, which have higher damping than rolling element bearings, could offer an energy dissipation mechanism that reduces the gearbox noise. The effectiveness of each bearing type to disrupt vibration propagation in explored using multi-body computational models. These models include gears, shafts, rolling element and fluid film wave bearings, and the housing. Radiated noise is mapped from the gearbox surface to surrounding environment. The effectiveness of rolling element and fluid film wave bearings in breaking the vibro-acoustic propagation path from the gear to the housing is investigated.

  10. Aeroacoustic Evaluation of Flap and Landing Gear Noise Reduction Concepts

    Science.gov (United States)

    Khorrami, Mehdi R.; Humphreys, William M., Jr.; Lockard, David P.; Ravetta, Patricio A.

    2014-01-01

    Aeroacoustic measurements for a semi-span, 18% scale, high-fidelity Gulfstream aircraft model are presented. The model was used as a test bed to conduct detailed studies of flap and main landing gear noise sources and to determine the effectiveness of numerous noise mitigation concepts. Using a traversing microphone array in the flyover direction, an extensive set of acoustic data was obtained in the NASA Langley Research Center 14- by 22-Foot Subsonic Tunnel with the facility in the acoustically treated open-wall (jet) mode. Most of the information was acquired with the model in a landing configuration with the flap deflected 39 deg and the main landing gear alternately installed and removed. Data were obtained at Mach numbers of 0.16, 0.20, and 0.24 over directivity angles between 56 deg and 116 deg, with 90 deg representing the overhead direction. Measured acoustic spectra showed that several of the tested flap noise reduction concepts decrease the sound pressure levels by 2 - 4 dB over the entire frequency range at all directivity angles. Slightly lower levels of noise reduction from the main landing gear were obtained through the simultaneous application of various gear devices. Measured aerodynamic forces indicated that the tested gear/flap noise abatement technologies have a negligible impact on the aerodynamic performance of the aircraft model.

  11. Gear Mesh Loss-of-Lubrication Experiments and Analytical Simulation

    Science.gov (United States)

    Handschuh, Robert F.; Polly, Joseph; Morales, Wilfredo

    2011-01-01

    An experimental program to determine the loss-of-lubrication (LOL) characteristics of spur gears in an aerospace simulation test facility has been completed. Tests were conducted using two different emergency lubricant types: (1) an oil mist system (two different misted lubricants) and (2) a grease injection system (two different grease types). Tests were conducted using a NASA Glenn test facility normally used for conducting contact fatigue. Tests were run at rotational speeds up to 10000 rpm using two different gear designs and two different gear materials. For the tests conducted using an air-oil misting system, a minimum lubricant injection rate was determined to permit the gear mesh to operate without failure for at least 1 hr. The tests allowed an elevated steady state temperature to be established. A basic 2-D heat transfer simulation has been developed to investigate temperatures of a simulated gear as a function of frictional behavior. The friction (heat generation source) between the meshing surfaces is related to the position in the meshing cycle, the load applied, and the amount of lubricant in the contact. Experimental conditions will be compared to those from the 2-D simulation.

  12. Materials and lubrication for gear and bearing surfaces in uhv

    International Nuclear Information System (INIS)

    During design and construction of the SLAC polarized LEED (PLEED) system, a search was made for a dependable gear, bearing, and lubrication system for the computer-controlled Faraday cup used to measure diffracted beams. Components must be nonmagnetic, bakeable to 2500C, and at room temperature must operate at pressures in the 10-9 to 10-10 Pa range. A test system was constructed which incorporated a meshed pair of dissimilar pitch diameter spur gears, one of which was confined to (by bushings) and rotated on a fixed shaft, while the other gear was driven by a commercial rotary motion feedthrough which was rotated by a servo motor driven in sine fashion with a direction reversal every six turns and peak speeds of 50 rpm. The criterion for a successful pair was approx. 105 turns, the life rating for the feedthrough. Pairs had actual turn counts from less than 1 to 91,000. Materials for gears included stainless steel, beryllium copper, and aluminum alloys. Lubricants used singly and in concert were MoS2, WS2, Ag, hard chrome, and a MoS2-graphite-sodium silicate mixture. The successful gear pair was Ag-plated Al alloy and MoS2-graphite-sodium silicate-coated Be-Cu. Subsequent performance in the PLEED system after repeated bakeouts will also be discussed

  13. Detailed modeling of gear losses; Detaillierte Modellierung von Getriebeverlusten

    Energy Technology Data Exchange (ETDEWEB)

    Schlegel, Clemens [Schlegel Simulation GmbH, Freising (Germany); Hoesl, Andreas [BMW AG, Muenchen (Germany); Diel, Sergej [Hochschule Landshut (Germany)

    2011-07-01

    The torque losses of gears are an important part of the total losses of today's vehicle drive trains. From measurements it is known that transmission loss factors strongly vary over the operating range of a transmission (torque and rpm). This variation is due to the interaction of the losses of the individual transmission components such as bearings, gear et cetera. Since the emission regulations for vehicles are becoming more restrictive, the targeted reduction of losses in the design phase of a transmission already is highly desirable. The projections of losses helps to save costs (for example, for measurements). It accelerates the development and allows to investigate a series of drive concepts in a short time. In this paper, detailed semi-analytical loss models of the most common gear components are compiled from the literature and manufacturer's documents and implemented in a library of simulation models in the modeling language Modelica. This library contains models for radial seals, rotary joints, planetary gears, bearings of different designs, lubrication systems and lubrication oils. With this library, the loss of vehicle transmissions are calculated for any operating point (gear, torque, rpm, temperature). The results for a 7-speed dual-clutch gearbox are in good agreement with measurements.

  14. Pinion tooth surface generation strategy of spiral bevel gears

    Science.gov (United States)

    Liu, Guanglei; Fan, Hongwei

    2012-07-01

    Aviation spiral bevel gears are often generated by spiral generated modified (SGM) roll method. In this style, pinion tooth surface modified generation strategy has an important influence on the meshing and contact performances. For the optimal contact pattern and transmission error function, local synthesis is applied to obtain the machine-tool settings of pinion. For digitized machine, four tooth surface generation styles of pinion are proposed. For every style, tooth contact analysis (TCA) is applied to obtain contact pattern and transmission error function. For the difference between TCA transmission error function and design objective curve, the degree of symmetry and agreement are defined and the corresponding sub-objective functions are established. Linear weighted combination method is applied to get an equivalent objective function to evaluate the shape of transmission error function. The computer programs for the process above are developed to analyze the meshing performances of the four pinion tooth surface generation styles for a pair of aviation spiral bevel gears with 38/43 teeth numbers. The four analytical results are compared with each other and show that the incomplete modified roll is optimal for this gear pair. This study is an expansion to generation strategy of spiral bevel gears, and offers new alternatives to computer numerical control (CNC) manufacture of spiral bevel gears.

  15. Hybrid Gear Preliminary Results-Application of Composites to Dynamic Mechanical Components

    Science.gov (United States)

    Handschuh, Robert F.; Roberts Gary D.; Sinnamon, R.; Stringer, David B.; Dykas, Brian D.; Kohlman, Lee W.

    2012-01-01

    Composite spur gears were fabricated and then tested at NASA Glenn Research Center. The composite material served as the web of the gear between the gear teeth and a metallic hub for mounting to the torque-applying shaft. The composite web was bonded only to the inner and outer hexagonal features that were machined from an initially all-metallic aerospace quality spur gear. The Hybrid Gear was tested against an all-steel gear and against a mating Hybrid Gear. As a result of the composite to metal fabrication process used, the concentricity of the gears were reduced from their initial high-precision value. Regardless of the concentricity error, the hybrid gears operated successfully for over 300 million cycles at 10000 rpm and 490 in.*lbs torque. Although the design was not optimized for weight, the composite gears were found to be 20% lighter than the all-steel gears. Free vibration modes and vibration/noise tests were also conduct to compare the vibration and damping characteristic of the Hybrid Gear to all-steel gears. The initial results indicate that this type of hybrid design may have a dramatic effect on drive system weight without sacrificing strength.

  16. Dynamic hypoxic zones in Lake Erie compress fish habitat, altering vulnerability to fishing gears

    Science.gov (United States)

    Kraus, Richard T.; Knight, Carey T.; Farmer, Troy M.; Gorman, Ann Marie; Collingsworth, Paris D.; Warren, Glenn J.; Kocovsky, Patrick M.; Conroy, Joseph D.

    2015-01-01

    Seasonal degradation of aquatic habitats from hypoxia occurs in numerous freshwater and coastal marine systems and can result in direct mortality or displacement of fish. Yet, fishery landings from these systems are frequently unresponsive to changes in the severity and extent of hypoxia, and population-scale effects have been difficult to measure except in extreme hypoxic conditions with hypoxia-sensitive species. We investigated fine-scale temporal and spatial variability in dissolved oxygen in Lake Erie as it related to fish distribution and catch efficiencies of both active (bottom trawls) and passive (trap nets) fishing gears. Temperature and dissolved oxygen loggers placed near the edge of the hypolimnion exhibited much higher than expected variability. Hypoxic episodes of variable durations were frequently punctuated by periods of normoxia, consistent with high-frequency internal waves. High-resolution interpolations of water quality and hydroacoustic surveys suggest that fish habitat is compressed during hypoxic episodes, resulting in higher fish densities near the edges of hypoxia. At fixed locations with passive commercial fishing gear, catches with the highest values occurred when bottom waters were hypoxic for intermediate proportions of time. Proximity to hypoxia explained significant variation in bottom trawl catches, with higher catch rates near the edge of hypoxia. These results emphasize how hypoxia may elevate catch rates in various types of fishing gears, leading to a lack of association between indices of hypoxia and fishery landings. Increased catch rates of fish at the edges of hypoxia have important implications for stock assessment models that assume catchability is spatially homogeneous.

  17. Interrelationship between autism diagnostic observation schedule-generic (ADOS-G), autism diagnostic interview-revised (ADI-R), and the diagnostic and statistical manual of mental disorders (DSM-IV-TR) classification in children and adolescents with mental retardation

    NARCIS (Netherlands)

    de Bildt, A; Sytema, S; Ketelaars, C; Kraijer, D; Mulder, E; Volkmar, F; Minderaa, R

    2004-01-01

    The interrelationship between the Autism Diagnostic Interview-Revised (ADI-R), Autism Diagnostic Observation Schedule-Generic (ADOS-G) and clinical classification was studied in 184 children and adolescents with Mental Retardation (MR). The agreement between the ADI-R and ADOS-G was fair, with a sub

  18. Coupled AXIAL-LATERAL-TORSIONAL Dynamics of a ROTOR-BEARING System Geared by Spur Bevel Gears

    Science.gov (United States)

    LI, M.; HU, H. Y.; JIANG, P. L.; YU, L.

    2002-07-01

    The coupled lateral-torsional dynamics of parallel rotor-bearing systems has been intensively investigated. However, little attention has been paid to the analysis of coupled vibrations of angled rotor-bearing systems so that the torsional and the lateral vibrations of those systems are usually analyzed separately. In this paper, the coupled axial-lateral-torsional dynamics of a rotor-bearing system geared by bevel gears is studied. The meshing of two spur bevel gears is analyzed on the basis of a pair of virtual cylindrical gears, and thereafter the constraint condition describing the relationship between the generalized displacements of bevel gears is derived under some assumptions. The coupled dynamic model is established by using Lagrange's equation under this constraint condition. The numerical results of a number of case studies show that the critical speeds of the coupled model are different from those of the uncoupled model both in values and modes, and the threshold speed of stability is fairly less than that of the uncoupled model. The effects of system parameters, such as the pitch cone angles, on the coupling behavior are also discussed.

  19. Adaptive Landing Gear: Optimum Control Strategy and Potential for Improvement

    Directory of Open Access Journals (Sweden)

    Grzegorz Mikułowski

    2009-01-01

    Full Text Available An adaptive landing gear is a landing gear (LG capable of active adaptation to particular landing conditions by means of controlled hydraulic force. The objective of the adaptive control is to mitigate the peak force transferred to the aircraft structure during touch-down, and thus to limit the structural fatigue factor. This paper investigates the ultimate limits for improvement due to various strategies of active control. Five strategies are proposed and investigated numerically using a~validated model of a real, passive landing gear as a reference. Potential for improvement is estimated statistically in terms of the mean and median (significant peak strut forces as well as in terms of the extended safe sinking velocity range. Three control strategies are verified experimentally using a laboratory test stand.

  20. On the modelling of spur and helical gear dynamic behaviour

    CERN Document Server

    Velex, Philippe

    2012-01-01

    This chapter is aimed at introducing the fundamentals of spur and helical gear dynamics. Using three-dimensional lumped models and a thin-slice approach for mesh elasticity, the general equations of motion for single-stage spur or helical gears are presented. Some particular cases including the classic one degree-of-freedom model are examined in order to introduce and illustrate the basic phenomena. The interest of the concept of transmission errors is analysed and a number of practical considerations are deduced. Emphasis is deliberately placed on analytical results which, although approximate, allow a clearer understanding of gear dynamics than that provided by extensive numerical simulations. Some extensions towards continuous models are presented.

  1. A new procedure for calculating contact stresses in gear teeth

    Science.gov (United States)

    Somprakit, Paisan; Huston, Ronald L.

    1991-01-01

    A numerical procedure for evaluating and monitoring contact stresses in meshing gear teeth is discussed. The procedure is intended to extend the range of applicability and to improve the accuracy of gear contact stress analysis. The procedure is based upon fundamental solution from the theory of elasticity. It is an iterative numerical procedure. The method is believed to have distinct advantages over the classical Hertz method, the finite-element method, and over existing approaches with the boundary element method. Unlike many classical contact stress analyses, friction effects and sliding are included. Slipping and sticking in the contact region are studied. Several examples are discussed. The results are in agreement with classical results. Applications are presented for spur gears.

  2. An Experimental Study of Fretting of Gear Teeth

    Science.gov (United States)

    Krantz, Timothy L.

    2008-01-01

    Experiments were conducted to study fretting of gears. The gears were made from case-carburized AISI 9310 alloy to match the material of a flight actuator gearbox of interest. The objective of the testing was to produce damage representative of that observed on flight hardware. The following correlations and observations were noted. The amplitude of dithering motion very strongly influenced the type and magnitude of damage. Sliding amounts on the order of 30% of the width of the line contact were judged to most readily produce fretting damage. There was observed an incubation period on the order of tens-of-thousands of cycles, and the incubation period was influenced by surface roughness, torque, and the motion extent. Fretting damage could be produced for any of the torques tested, and the severity of damage increased slightly with torque. Gear teeth having surface roughness of 0.7-0.8 micrometer were somewhat more resistant to fretting than were smoother surfaces.

  3. Adaptive Wavelet Transform Method to Identify Cracks in Gears

    Directory of Open Access Journals (Sweden)

    Ales Belsak

    2010-01-01

    Full Text Available Many damages and faults can cause problems in gear unit operation. A crack in the tooth root is probably the least desirable among them. It often leads to failure of gear unit operation. By monitoring vibrations, it is possible to determine the presence of a crack. Signals are, however, very noisy. This makes it difficult to define properties of individual components. Wavelet analysis is an effective tool for analysing signals and for defining properties. In this paper, a denoising method based on wavelet analysis, which takes prior information about impulse probability density into consideration, is used to identify transient information from vibration signals of a gear unit with a fatigue crack in the tooth root.

  4. CYLINDIRICAL SPUR GEARS DESIGN BASED ON ARTIFICIAL NEURAL NETWORKS

    Directory of Open Access Journals (Sweden)

    İhsan TOKTAŞ

    2007-03-01

    Full Text Available In this study, testing and training data sets of Artificial Neural Networks(ANNs models have been produced by employing analytical design calculations of cylindrical spur gears. In the input layer, the constraints and requirement values of cylindrical spur gears are used while at the output layer the modules (e.g. the bending and contact stress and the number of tooths are used. These data have been presented to train a multi layered, single directed, hierarchically connected ANNs using Scaled Conjugate Gradient (SCG and Levenberg-Marquardt (LM Back Propagation algorithms with the logistic sigmoid transfer function. The outcomes demonstrated that, the ANN based model have been very successful and the testing data produced very low level of errors. It has been shown that, the ANN based mechanism may be used in the design of cylindrical spur gears instead of analytical calculations.

  5. Contact and Bending Durability Calculation for Spiral-Bevel Gears

    Science.gov (United States)

    Vijayakar, Sandeep

    2016-01-01

    The objective of this project is to extend the capabilities of the gear contact analysis solver Calyx, and associated packages Transmission3D, HypoidFaceMilled, HypoidFaceHobbed. A calculation process for the surface durability was implemented using the Dowson-Higginson correlation for fluid film thickness. Comparisons to failure data from NASA's Spiral Bevel Gear Fatigue rig were carried out. A bending fatigue calculation has been implemented that allows the use of the stress-life calculation at each individual fillet point. The gears in the NASA test rig did not exhibit any bending fatigue failure, so the bending fatigue calculations are presented in this report by using significantly lowered strength numbers.

  6. The application of elastohydrodynamic lubrication in gear tooth contacts.

    Science.gov (United States)

    Townsend, D. P.

    1972-01-01

    It is shown that in the early stages of design, scoring and fatigue failure of gear contact surfaces can be prevented by the following means: improving load capacity with the aid of tip relief, or by improved surface finish; by giving special care to the location and application of the lubricant in high-speed or high-load gear applications; by determining the thickness of the elastohydrodynamic film from an analysis for the worst temperature, speed, and load conditions, and selecting the appropriate lubricant from this analysis; by using an additive in the case of frequent repeated startup and shutdown conditions; by taking the expected temperature, speed, and load in the selection of an extreme pressure additive; and by systematically testing any new transmission or gear box design.

  7. Geared-elevator flutter study. [transonic flutter characteristics of empennage

    Science.gov (United States)

    Ruhlin, C. L.; Doggett, R. V., Jr.; Gregory, R. A.

    1976-01-01

    The paper describes an experimental and analytical study of the transonic flutter characteristics of an empennage flutter model having an all-movable horizontal tail with a geared elevator. Two configurations were flutter tested: one with a geared elevator and one with a locked elevator with the model cantilever-mounted on a sting in the wind tunnel. The geared-elevator configuration fluttered experimentally at about 20% higher dynamic pressures than the locked-elevator configuration. The experimental flutter boundary was nearly flat at transonic speeds for both configurations. It was found that an analysis which treated the elevator as a discrete surface predicted flutter dynamic pressure levels better than analyses which treated the stabilizer and elevator as a warped surface. Warped-surface methods, however, predicted more closely the experimental flutter frequencies and Mach number trends.

  8. Eddy current pulsed thermography for fatigue evaluation of gear

    Science.gov (United States)

    Tian, Gui Yun; Yin, Aijun; Gao, Bin; Zhang, Jishan; Shaw, Brian

    2014-02-01

    The pulsed eddy current (PEC) technique generates responses over a wide range of frequencies, containing more spectral coverage than traditional eddy current inspection. Eddy current pulsed thermography (ECPT), a newly developed non-destructive testing (NDT) technique, has advantages such as rapid inspection of a large area within a short time, high spatial resolution, high sensitivity and stand-off measurement distance. This paper investigates ECPT for the evaluation of gear fatigue tests. The paper proposes a statistical method based on single channel blind source separation to extract details of gear fatigue. The discussion of transient thermal distribution and patterns of fatigue contact surfaces as well as the non-contact surfaces have been reported. In addition, the measurement for gears with different cycles of fatigue tests by ECPTand the comparison results between ECPT with magnetic Barkhausen noise (MBN) have been evaluated. The comparison shows the competitive capability of ECPT in fatigue evaluation.

  9. Unsteady Simulation of a Landing-Gear Flow Field

    Science.gov (United States)

    Li, Fei; Khorrami, Mehdi R.; Malik, Mujeeb R.

    2002-01-01

    This paper presents results of an unsteady Reynolds-averaged Navier-Stokes simulation of a landing-gear flow field. The geometry of the four-wheel landing gear assembly consists of several of the fine details including the oleo-strut, two diagonal struts, a door, yokes/pin and a flat-plate simulating the wing surface. The computational results, obtained by using 13.3 million grid points, are presented with an emphasis on the characteristics of the unsteadiness ensuing from different parts of the landing-gear assembly, including vortex shedding patterns and frequencies of dominant oscillations. The results show that the presence of the diagonal struts and the door significantly influence the flow field. Owing to the induced asymmetry, vortices are shed only from one of the rear wheels and not the other. Present computations also capture streamwise vortices originating from the upstream corners of the door.

  10. Geometric and Meshing Properties of Conjugate Curves for Gear Transmission

    Directory of Open Access Journals (Sweden)

    Dong Liang

    2014-01-01

    Full Text Available Conjugate curves have been put forward previously by authors for gear transmission. Compared with traditional conjugate surfaces, the conjugate curves have more flexibility and diversity in aspects of gear design and generation. To further extend its application in power transmission, the geometric and meshing properties of conjugate curves are discussed in this paper. Firstly, general principle descriptions of conjugate curves for arbitrary axial position are introduced. Secondly, geometric analysis of conjugate curves is carried out based on differential geometry including tangent and normal in arbitrary contact direction, characteristic point, and curvature relationships. Then, meshing properties of conjugate curves are further revealed. According to a given plane or spatial curve, the uniqueness of conjugated curve under different contact angle conditions is discussed. Meshing commonality of conjugate curves is also demonstrated in terms of a class of spiral curves contacting in the given direction for various gear axes. Finally, a conclusive summary of this study is given.

  11. KINEMATICAL CLASSIFICATION OF GEARINGTYPES AND PROOF OF TWO THEOREMS OF GEARING

    Institute of Scientific and Technical Information of China (English)

    张文祥; 方跃法

    1996-01-01

    The equations determining a resultant screw of two given screws are applied to thestudies on gearing and meshing theories. A kinematical classification is proposed and meanwhileproof is given to the First Theorem of Gearing and Willis Theorem.

  12. Elderly Adi Women of Arunachal Pradesh: "Living Encyclopedias" and Cultural Refugia in Biodiversity Conservation of the Eastern Himalaya, India

    Science.gov (United States)

    Singh, Ranjay K.; Rallen, Orik; Padung, Egul

    2013-09-01

    Elderly women of a particular socioecological system are considered to be "living encyclopedias" in biocultural knowledge systems. These women play a pivotal role in retaining and passing on biodiversity-related traditional knowledge to the next generations. Unfortunately the fast changing sociocultural values and the impact of modernity have rendered their knowledge somewhat less valuable and they are being treated as "cultural refugia." Our study on the importance of these women in the conservation of indigenous biodiversity was conducted in 14 randomly selected villages dominated by the Adi tribe of East Siang District, Arunachal Pradesh (northeast India). Data were collected from 531 women (381 elderly and 150 young to middle aged) during 2003-2008 using conventional social science methods and participatory rural appraisal. One innovative method, namely "recipe contest," was devised to mobilize Adi women of each village in order to energies them and explore their knowledge relating to traditional foods, ethnomedicines, and conservation of indigenous biodiversity. Results indicated that 55 plant species are being used by elderly Adi women in their food systems, while 34 plant species are integral parts of ethnomedicinal practices. These women identified different plant species found under multistory canopies of community forests. Elderly women were particularly skilled in preparing traditional foods including beverages and held significantly greater knowledge of indigenous plants than younger women. Lifelong experiences and cultural diversity were found to influence the significance of biodiversity use and conservation. The conservation of biodiversity occurs in three different habitats: jhum lands (shifting cultivation), Morang forest (community managed forests), and home gardens. The knowledge and practice of elderly women about habitats and multistory vegetations, regenerative techniques, selective harvesting, and cultivation practices contribute

  13. Rational and affordable concepts of Landing Gear for small reentry vehicle demonstrators

    OpenAIRE

    Fioriti, Marco; Cardile, Diego; Viola, Nicole; Chiesa, Sergio

    2012-01-01

    The paper proposes an innovative solution for landing gear of small space vehicles, in particular of technological demonstrators of reentry space vehicles. After explaining why small space vehicles can benefit from landing gears, the work investigates a solution, which avoids the use of fluidic systems and minimizes constraints on the whole vehicle, thus limiting cost raising and making the installation of the landing gear easier on vehicles that originally did not envisage landing gears

  14. Testing a wheeled landing gear system for the TH-57 helicopter.

    OpenAIRE

    Heckman, Nancy L.

    1992-01-01

    Using the main gear from a Cessna 182 and the nose gear from a Grumman AAI-B, (patent pending) a comparison with the skid gear currently installed on the TH-57 helicopters was conducted. The initial comparison was done using a structural analysis program, GIFTS, to simultaneously analyze and compare the gear systems. Experimental data was used to verify program results. Experimental testing was conducted for further code validation and analysis of each system's advantages and disadvantages. W...

  15. Aerodynamic Measurements in a Wind Tunnel on Scale Models of a 777 Main Landing Gear

    OpenAIRE

    Ringshia, Aditya K

    2006-01-01

    Aerodynamic measurements were taken over models of the Boeing 777 high fidelity isolated landing gear in the 6- by 6-foot Virginia Tech Stability Wind Tunnel (VT-SWT) at a free-stream Mach number of 0.16. Noise control devices (NCD) were developed at Virginia Tech [9] to reduce noise by shielding gear components, reducing wake interactions and by streamlining the flow around certain landing gear components. Aerodynamic measurements were performed to understand the flow over the landing gear a...

  16. PITTING OF TOOTH FLANKS OF CROSSED HELICAL GEARS MADE OF SINTERED STEEL

    OpenAIRE

    Miltenović, Đorđe; Tica, Milan; Miltenović, Aleksandar; Banić, Milan; Živković, Srđan; Mišković, Žarko

    2015-01-01

    Crossed helical gears are used in cars and in many household appliances. The trend towards increased comfort in motor vehicles has led to the utilisation of more than a hundred servo-drives in luxury class automobiles. Important advantages of crossed helical gears are their easy and inexpensive design, low noise performance and high gear ratio that can be realised in one step. Sintered steel is a material with very favourable properties for the manufacture of crossed helical gears. High deman...

  17. DETERMINATION OF TRANSMISSION GEAR RATIO IN MECHANICAL PART OF TRACTOR ELECTRO-MECHANICAL TRANSMISSION

    OpenAIRE

    Ch. I. Zhdanovich; N. V. Kalinin

    2016-01-01

    A methodology has been developed for selection of gear number and transmission gear ratios in mechanical part of a wheel-type tractor with electro-mechanical transmission containing a propulsion asynchronous electric motor with variablefrequency control. The paper proposes to determine a transmission gear ratio on the basis of the following: provision of wheel torque dependence on tractor speed which is the best one for a traction process and during transfer from one gear to the other; provis...

  18. Modal Analysis of Worm and Worm Gear Based on ANSYS Workbench

    Directory of Open Access Journals (Sweden)

    Liu Yichang

    2015-01-01

    Full Text Available To establish the three-dimensional model of the worm and worm gear by using SolidWorks. On the worm and worm gear modal analysis is carried out by using finite element analysis software ANSYS Workbench. Obtain the first 6 order natural frequency and vibration mode characteristics of worm and worm gear. Modal analysis laid the foundation for further study on dynamics analysis, Also for the worm and worm gear structure optimization design provides a reference.

  19. Numerical Analysis and Demonstration: Transmission Shaft Influence on Meshing Vibration in Driving and Driven Gears

    OpenAIRE

    Xu Jinli; Su Xingyi; Peng Bo

    2015-01-01

    The variable axial transmission system composed of universal joint transmission shafts and a gear pair has been applied in many engineering fields. In the design of a drive system, the dynamics of the gear pair have been studied in detail. However few have paid attention to the effect on the system modal characteristics of the gear pair, arising from the universal joint transmission shafts. This work establishes a torsional vibration mathematical model of the transmission shaft, driving gear,...

  20. Selection and Simulation of Electric Steering Gear Control System

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2013-06-01

    Full Text Available For the electric steering gear control systems, the principle of the system is introduced. Specific model and parameters are selected to deduce the optimal combination of control system and choices method of the steering system model is determined. The transfer function of motor according to the parameters is achieved and simulation results are gained based on MATLAB. Simulation results show that this method can meet the performance requirements of electric steering gear, the control method is simple and easy to work to achieve.

  1. Estimation of fatigue damage of airplane landing gear

    Institute of Scientific and Technical Information of China (English)

    LIU Ke-ge; YAN Chu-liang; ZHANG Shu-ming

    2006-01-01

    Taking the main landing gears of fighter and transport airplanes as examples,the fatigue life was estimated by means of the Miner's rule and from the spectrum of the real measurements.The computed results show that the landing damage to the fighter and transport airplanes is 75% and 60% of the total damage,and the damage caused by the landing stroke is 40% of the landing-gear damage.The fatigue damage properties can provide important information for reliable designing and the structural optimization.

  2. Subsynchronous instability of a geared centrifugal compressor of overhung design

    Science.gov (United States)

    Hudson, J. H.; Wittman, L. J.

    1980-01-01

    The original design analysis and shop test data are presented for a three stage (poster) air compressor with impellers mounted on the extensions of a twin pinion gear, and driven by an 8000 hp synchronous motor. Also included are field test data, subsequent rotor dynamics analysis, modifications, and final rotor behavior. A subsynchronous instability existed on a geared, overhung rotor. State-of-the-art rotor dynamics analysis techniques provided a reasonable analytical model of the rotor. A bearing modification arrived at analytically eliminated the instability.

  3. Fabrication of micro gear wheels by micropowder injection molding

    Institute of Scientific and Technical Information of China (English)

    Haiqing Yin; Xuanhui Qu; Chengchang Jia

    2008-01-01

    The micropowder injection molding technology was investigated to fabricate the microsized gear wheels on a conventional injection molding machine. The feedstock comprised of carbonyl ferrum powder and a wax-based thermoplastic binder. Microinjection molding was fulfilled at about 423 K under 100 MPa. The heating system was applied to the die to improve the fluidity of the feedstock and subsequently the cooling system was used to enhance the strength of the green compacts after injection by decreasing the temperature of the die. The gear wheels were realized successfully with their addendum circle diameter ranging from 800 to 200 m and with the center hole as small as 60 μtm.

  4. Procedure for the automatic mesh generation of innovative gear teeth

    Directory of Open Access Journals (Sweden)

    Radicella Andrea Chiaramonte

    2016-01-01

    Full Text Available After having described gear wheels with teeth having the two sides constituted by different involutes and their importance in engineering applications, we stress the need for an efficient procedure for the automatic mesh generation of innovative gear teeth. First, we describe the procedure for the subdivision of the tooth profile in the various possible cases, then we show the method for creating the subdivision mesh, defined by two series of curves called meridians and parallels. Finally, we describe how the above procedure for automatic mesh generation is able to solve specific cases that may arise when dealing with teeth having the two sides constituted by different involutes.

  5. 77 FR 67261 - Airworthiness Directives; Aeronautical Accessories, Inc., High Landing Gear Forward Crosstube...

    Science.gov (United States)

    2012-11-09

    ... Accessories, Inc., High Landing Gear Forward Crosstube Assembly AGENCY: Federal Aviation Administration (FAA... Accessories, Inc. (AAI) high landing gear forward crosstube assemblies (crosstubes) installed on Agusta S.p.A..., collapse of the landing gear, and subsequent loss of control of the helicopter. DATES: This AD is...

  6. 76 FR 472 - Harmonization of Airworthiness Standards for Transport Category Airplanes-Landing Gear Retracting...

    Science.gov (United States)

    2011-01-05

    ... Airworthiness Standards for Transport Category Airplanes--Landing Gear Retracting Mechanisms and Pilot... transport category airplanes on landing gear retracting mechanisms and the pilot compartment view. This... in a stalling maneuver, and would add an additional requirement to keep the landing gear and doors...

  7. 77 FR 1614 - Harmonization of Airworthiness Standards for Transport Category Airplanes-Landing Gear Retracting...

    Science.gov (United States)

    2012-01-11

    ... Register on January 5, 2011 (76 FR 472). The NPRM proposed to amend the standards for landing gear... Transport Category Airplanes--Landing Gear Retracting Mechanisms and Pilot Compartment View AGENCY: Federal... the airworthiness standards for transport category airplanes on landing gear retracting mechanisms...

  8. 14 CFR 29.497 - Ground loading conditions: landing gear with tail wheels.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground loading conditions: landing gear... Requirements Ground Loads § 29.497 Ground loading conditions: landing gear with tail wheels. (a) General. Rotorcraft with landing gear with two wheels forward and one wheel aft of the center of gravity must...

  9. 14 CFR 27.549 - Fuselage, landing gear, and rotor pylon structures.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuselage, landing gear, and rotor pylon... Requirements § 27.549 Fuselage, landing gear, and rotor pylon structures. (a) Each fuselage, landing gear, and... accelerated flight and landing conditions, including engine torque. (Secs. 604, 605, 72 Stat. 778, 49...

  10. 77 FR 5420 - Airworthiness Directives; Aeronautical Accessories Inc. High Landing Gear Aft Crosstube Assembly

    Science.gov (United States)

    2012-02-03

    ... Accessories Inc. High Landing Gear Aft Crosstube Assembly AGENCY: Federal Aviation Administration (FAA), DOT... (AD) for the Aeronautical Accessories Inc. (AAI) High Landing Gear Aft Crosstube Assembly (aft... proposed actions are intended to prevent failure of a crosstube, collapse of the landing gear,...

  11. 77 FR 37768 - Airworthiness Directives; Aeronautical Accessories, Inc., High Landing Gear Aft Crosstube Assembly

    Science.gov (United States)

    2012-06-25

    ... Accessories, Inc., High Landing Gear Aft Crosstube Assembly AGENCY: Federal Aviation Administration (FAA), DOT... Accessories, Inc. (AAI), High Landing Gear Aft Crosstube Assembly (aft crosstube) installed on certain Bell... failure of a crosstube, collapse of the landing gear, and subsequent loss of control of the...

  12. 14 CFR 27.497 - Ground loading conditions: landing gear with tail wheels.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Ground loading conditions: landing gear... Requirements Ground Loads § 27.497 Ground loading conditions: landing gear with tail wheels. (a) General. Rotorcraft with landing gear with two wheels forward, and one wheel aft, of the center of gravity must...

  13. LUBRICATION BASIS THEORY OF WORM PAIR AND TEMPERATURE DISTRIBUTION ON WORM GEAR SURFACE

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The lubrication basis theory of worm pair is given. The lubrication state of worm gear is analyzed. It is found that the temperature distribution on the tooth surface of worm gear is closely related with the lubrication state and that the temperature on the tooth surface of worm gear is consistent with the characteristic term of mesh and motion of worm pair.

  14. Servosystem with an undulatory reducing gear. [servomotor control by armature circuit

    Science.gov (United States)

    Romashchenko, A. I.; Samoylenko, V. A.; Grishin, I. A.; Tatarchuk, Y. S.

    1974-01-01

    The development of a potentiometric servosystem is described that has a dc microservomotor, which is the built in drive of an undulatory reducing gear. The operation of the system and the structural design of the undulatory reducing gear are elaborated. Results are presented from analyzing some tests of various types of undulatory reducing gear generators.

  15. Motor Integrated Permanent Magnet Gear with a Wide Torque-Speed Range

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Matzen, Torben N.; Jahns, T. M.;

    2009-01-01

    This paper present a new motor integrated permanent magnet gear with a wide torque-speed range. In the paper a 35 kW permanent magnet motor with a base speed of 4000 rpm and a top speed of 14000 rpm is integrated into a permanent magnetic gear with a gearing ratio of 8.67. The design process of t...

  16. Calculation method of sliding ratios for conjugate-curve gear pair and its application

    Institute of Scientific and Technical Information of China (English)

    梁栋; 陈兵奎; 高艳娥

    2015-01-01

    The calculation method of sliding ratios for conjugate-curve gear pair, generated based on the theory of conjugate curves, is proposed. The theoretical model of conjugate-curve gear drive is briefly introduced. The general calculation formulas of sliding ratios are developed according to the conjugate curves. The applications to the circular arc gears based on conjugate curves and the novel involute-helix gears are studied. A comparison on the sliding coefficient with the conventional corresponding gear drive is also carried out. The influences of gear parameters such as spiral parameter, gear ratio and modulus on the sliding ratios of gear drive are discussed. Brief description of manufacturing method for conjugate-curve gear pair is given. The research results show that the sliding ratios of gear pair become smaller with the increase of spiral parameter and gear ratio, respectively. And it will be greater with the increase of modulus for the tooth profiles. The meshing characteristics of conjugate-curve gears are further reflected and the optimization design of tooth profiles with high performance may be obtained.

  17. 76 FR 50180 - Proposed Information Collection; Comment Request; Northwest Region Gear Identification Requirements

    Science.gov (United States)

    2011-08-12

    ... management programs depends significantly on regulatory compliance. The requirements that fishing gear be marked are essential to facilitate enforcement. The ability to link fishing gear to the vessel owner or... concerning damage, loss, and civil proceedings. The regulations specify fishing gear must be marked with...

  18. Generation of spiral bevel gears with zero kinematical errors and computer aided tooth contact analysis

    Science.gov (United States)

    Litvin, F. L.; Tsung, W. J.; Coy, J. J.; Heine, C.

    1986-01-01

    Kinematic errors in spiral bevel gears are a major source of noise and vibrations in transmissions. A method for the generation of Gleason's spiral bevel gears which provides conjugated gear tooth surfaces and an improved bearing contact was developed. A computer program for the simulation of meshing, misalignment, and bearing contact was written.

  19. On the Transmission Noise of Machine Gears and an Effective Solution

    Institute of Scientific and Technical Information of China (English)

    WANG Mei

    2009-01-01

    Noise pollution has become one of the world's three major pollutions. In modem industrial enterprises, the noise from gear transmission is an important source of pollution. In this paper, we first analyse the noise of a gear transmission system. Then, through repairing the margin of gear, using shaving processing, shaving cutter grind- ing to present an effective solution.

  20. An electronic control for an electrohydraulic active control landing gear for the F-4 aircraft

    Science.gov (United States)

    Ross, I.

    1982-01-01

    A controller for an electrohydraulic active control landing gear was developed for the F-4 aircraft. A controller was modified for this application. Simulation results indicate that during landing and rollout over repaired bomb craters the active gear effects a force reduction, relative to the passive gear, or approximately 70%.

  1. TRANSMISSION MOMENTARY EFFICIENCY BASED ON THE D'ALEMBERT-LAGRANGE EQUATION FOR INVOLUTES GEARS

    Institute of Scientific and Technical Information of China (English)

    Liang Yi; Lai Changying

    2004-01-01

    The D'Alembert-Lagrange equation is introduced and used to derive the formulas of momentary efficiency for external gearing of standard involutes spur gears.The gearings with correct and increased center distance are discussed.The momentary efficiency formula is calculated and analyzed using software Matlab.The derived formula of momentary efficiency is also compared with the traditional formula.

  2. Discurso de Carlos Matus en la presentación de Adiós, Señor Presidente

    Directory of Open Access Journals (Sweden)

    Carlos Matus

    2014-01-01

    Full Text Available El texto que reproducimos en este artículo fue escrito y leído por Carlos Matus en la primera presentación del libro Adiós, Señor Presidente realizada en 1987, en Venezuela. Matus describe los problemas de los gobiernos de América Latina de aquellos años para abor- dar la brecha creciente entre la capacidad de gobierno y la complejidad de los sistemas socia- les, que exige teorías, técnicas, sistemas y métodos para desarrollar proyectos de gobierno en los que la gobernabilidad del sistema no sea más baja que la magnitud de los problemas. Este documento fue recuperado del fondo Mario Testa, perteneciente al Centro de Documentación e Investigación Pensar en Salud (CEDOPS del Instituto de Salud Colectiva de la Universidad Nacional de Lanús.

  3. Low-rank plus sparse decomposition for exoplanet detection in direct-imaging ADI sequences. The LLSG algorithm

    CERN Document Server

    Gonzalez, C A Gomez; Absil, P -A; Van Droogenbroeck, M; Mawet, D; Surdej, J

    2016-01-01

    Data processing constitutes a critical component of high-contrast exoplanet imaging. Its role is almost as important as the choice of a coronagraph or a wavefront control system, and it is intertwined with the chosen observing strategy. Among the data processing techniques for angular differential imaging (ADI), the most recent is the family of principal component analysis (PCA) based algorithms. PCA serves, in this case, as a subspace projection technique for constructing a reference point spread function (PSF) that can be subtracted from the science data for boosting the detectability of potential companions present in the data. Unfortunately, when building this reference PSF from the science data itself, PCA comes with certain limitations such as the sensitivity of the lower dimensional orthogonal subspace to non-Gaussian noise. Inspired by recent advances in machine learning algorithms such as robust PCA, we aim to propose a localized subspace projection technique that surpasses current PCA-based post-pro...

  4. Autism Diagnostic Interview-Revised (ADI-R) Algorithms for Toddlers and Young Preschoolers : Application in a Non-US Sample of 1,104 Children

    NARCIS (Netherlands)

    de Bildt, Annelies; Sytema, Sjoerd; Zander, Eric; Bölte, Sven; Sturm, Harald; Yirmiya, Nurit; Yaari, Maya; Charman, Tony; Salomone, Erica; LeCouteur, Ann; Green, Jonathan; Bedia, Ricardo Canal; Primo, Patricia García; van Daalen, Emma; de Jonge, Maretha V.; Guðmundsdóttir, Emilía; Jóhannsdóttir, Sigurrós; Raleva, Marija; Boskovska, Meri; Rogé, Bernadette; Baduel, Sophie; Moilanen, Irma; Yliherva, Anneli; Buitelaar, Jan; Oosterling, Iris J.

    2015-01-01

    The current study aimed to investigate the Autism Diagnostic Interview-Revised (ADI-R) algorithms for toddlers and young preschoolers (Kim and Lord, J Autism Dev Disord 42(1):82–93, 2012) in a non-US sample from ten sites in nine countries (n = 1,104). The construct validity indicated a good fit of

  5. Autism Diagnostic Interview-Revised (ADI-R) Algorithms for Toddlers and Young Preschoolers: Application in a Non-US Sample of 1,104 Children

    NARCIS (Netherlands)

    Bildt, A. de; Sytema, S.; Zander, E.; Bolte, S.; Sturm, H.; Yirmiya, N.; Yaari, M.; Charman, T.; Salomone, E.; LeCouteur, A.; Green, J.; Bedia, R.C.; Primo, P.G.; Daalen, E. van; Jonge, M.V. de; Guethmundsdottir, E.; Johannsdottir, S.; Raleva, M.; Boskovska, M.; Roge, B.; Baduel, S.; Moilanen, I.; Yliherva, A.; Buitelaar, J.; Oosterling, I.J.

    2015-01-01

    The current study aimed to investigate the Autism Diagnostic Interview-Revised (ADI-R) algorithms for toddlers and young preschoolers (Kim and Lord, J Autism Dev Disord 42(1):82-93, 2012) in a non-US sample from ten sites in nine countries (n = 1,104). The construct validity indicated a good fit of

  6. Autism Diagnostic Interview-Revised (ADI-R) Algorithms for Toddlers and Young Preschoolers : Application in a Non-US Sample of 1,104 Children

    NARCIS (Netherlands)

    de Bildt, Annelies; Sytema, Sjoerd; Zander, Eric; Bolte, Sven; Sturm, Harald; Yirmiya, Nurit; Yaari, Maya; Charman, Tony; Salomone, Erica; LeCouteur, Ann; Green, Jonathan; Canal Bedia, Ricardo; Primo, Patricia Garcia; van Daalen, Emma; de Jonge, Maretha V.; Gudmundsdottir, Emilia; Johannsdottir, Sigurros; Raleva, Marija; Boskovska, Meri; Roge, Bernadette; Baduel, Sophie; Moilanen, Irma; Yliherva, Anneli; Buitelaar, Jan; Oosterling, Iris J.

    2015-01-01

    The current study aimed to investigate the Autism Diagnostic Interview-Revised (ADI-R) algorithms for toddlers and young preschoolers (Kim and Lord, J Autism Dev Disord 42(1):82-93, 2012) in a non-US sample from ten sites in nine countries (n = 1,104). The construct validity indicated a good fit of

  7. Natural convection in a differentially heated rectangular layer solved by an A.D.I. method coupled with compact Hermitian methods of 0<2>-0<4> order

    Energy Technology Data Exchange (ETDEWEB)

    Boussaid, M. [Institut National de Genie Mecanique, Boumerdes (Algeria); Bouhadef, M. [Algiers Univ. (Algeria). Faculte des Sciences

    1993-12-31

    We study in this article the classical problem of the differentially heated rectangular layer by an O(2)-O(4) order difference method, which is ADI coupled with compact Hermitian method with off-center convection terms, in order to obtain very high Rayleigh numbers (approximately 10 E +11) and for various elongation and tilting layers. (Authors). 8 refs., 7 figs.

  8. Force Analysis of a New Coaxial Counter Rotating Cycloid Pin Gear Transmission%新型同轴对转摆线针轮传动的受力分析

    Institute of Scientific and Technical Information of China (English)

    何小萍; 许立新

    2015-01-01

    在论述新型同轴对转摆线针轮行星传动原理的基础上,建立了内外输出针齿壳、摆线轮的受力模型,分析了摆线轮与针齿之间、摆线轮与柱销之间以及摆线轮与曲柄之间的受力情况. 在此基础上,运用Matlab软件编程并求解,着重分析了转臂曲柄对摆线轮作用力的曲线随输入轴转动的变化规律. 为进一步研究新型同轴对转摆线针轮行星传动参数、结构设计以及强度计算等提供了理论依据.%On the basis of discussing the principle of new coaxial counter rotating cycloid pin gear planetary transmission, the stress model of the internal and external output pin tooth shell and the cycloid gear is established and force conditions of the cycloid gear and the pin gear, the cycloid gear and the column, the cycloid gear and the crank are analyzed in this paper. On this basis, the Matlab software is used to program and solve, and the force curve of the jib crank to the cycloid gear is analyzed emphatically. So a theoretical basis is provided to further study the new coaxial counter rotating cycloid pin gear planetary transmission parameters, structural design and strength calculation.

  9. Scientific Opinion on the reconsideration of the ADI and a refined exposure assessment of β-apo-8?-carotenal (E 160e

    Directory of Open Access Journals (Sweden)

    EFSA Panel on Food Additives and Nutrient Sources added to food (ANS

    2014-01-01

    Full Text Available The Panel on Food Additives and Nutrient Sources added to Food (ANS has previously provided a scientific opinion re-evaluating the safety of β-apo-8′-carotenal (E 160e as a food additive in the EU and establishing an acceptable daily intake (ADI of 0.05 mg/kg body weight (bw/day (EFSA ANS Panel, 2012. Following a request by the European Commission, the ANS Panel was asked to consider newly submitted information on the interpretation of the 13-week study in rats used as a basis to establish the ADI, to clarify its impact on that ADI and to carry out the refined exposure assessment of β-apo-8′-carotenal. The new information comprised an evaluation of all of the original kidney section slides from the 13-week toxicological study under improved visualisation conditions. The ANS Panel has considered that the supplementary information provided by the Commission and the present toxicological database on β-apo-8′-carotenal provides a basis to revise the established ADI and concluded that, based on the NOAEL of 30 mg/kg bw/day from the 13-week study in rats and an uncertainty factor of 100, a new ADI for β-apo-8′-carotenal of 0.3 mg/kg bw/day can be established. The Panel concluded that using data provided by the food industry, which are based only on a limited number of regulated categories, the reported uses and use levels of β-apo-8’-carotenal (E 160e would not be of safety concern.

  10. Adição de óleo e lipase sobre a biodigestão anaeróbia de dejetos suínos

    Directory of Open Access Journals (Sweden)

    João Paulo Rodrigues

    2014-03-01

    Full Text Available O objetivo do trabalho foi verificar a eficiência da co-digestão anaeróbia dos dejetos suínos com crescentes níveis de adição de óleo de descarte e lipase. Foram testadas quatro doses de óleos (8, 12, 16 e 20g kg-1 de substrato e 3 doses de lipase (1, 2 e 3g kg-1 de substrato. Os parâmetros avaliados foram: redução de sólidos totais (ST, sólidos voláteis (SV e número mais provável (NMP de coliformes totais (CT e termotolerantes (CTT, além do pH, demanda química de oxigênio (DQO, produção e potenciais de produção de biogás. Os resultados demonstraram que houve influência das adições de óleo e lipase sobre as reduções de ST SV e pH do efluente, seguindo um modelo de predição linear e decrescente. As reduções do NMP de CT e CTT foram mais elevadas nos tratamentos com maior adição de óleo e lipase. A produção de biogás apresentou uma correlação negativa com as adições de lipase, sendo que estas proporcionaram efeito linear decrescente sobre os potenciais de produção de biogás/kg de dejeto, ST e SV adicionado. As adições de óleo e lipase não proporcionam efeitos favoráveis sobre as produções de biogás.

  11. 14 CFR 125.187 - Landing gear: Aural warning device.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Landing gear: Aural warning device. 125.187 Section 125.187 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS CERTIFICATION AND OPERATIONS: AIRPLANES HAVING...

  12. Retraction Assembly for Space Shuttle Extended Nose Landing Gear

    Science.gov (United States)

    Files, Bradley S.; Nicholson, Leonard S. (Technical Monitor)

    2000-01-01

    As part of a project to encourage the use of shape memory alloy actuators for space actuators, this mechanism uses a nitinol ribbon to provide the necessary motion to help retract the proposed extended nose landing gear (ENLG) for the space shuttle. Initial proof-of-concept design of the ENLG did not include the ability to retract the gear automatically. One proposed actuator for this purpose was designed at Johnson Space Center and uses resistive heating to rotate the ribbon around a cylinder. This rotation then allows the assembly to pull down a wedge that is used to hold the landing gear strut in place, thus returning the landing gear to its previous height before extension. The presentation will follow the design of this assembly from working with the nitinol ribbon to providing mechanical connections and allowing minimal friction for motion of three wraps around a cylinder. Also to be presented is preliminary work on design of a shape memory alloy gripper, a design project to demonstrate uses of NiTi.

  13. Innovative Anti Crash Absorber for a Crashworthy Landing Gear

    Science.gov (United States)

    Guida, Michele; Marulo, Francesco; Montesarchio, Bruno; Bruno, Massimiliano

    2014-06-01

    This paper defines an innovative concept to anti-crash absorber in composite material to be integrated on the landing gear as an energy-absorbing device in crash conditions to absorb the impact energy. A composite cylinder tube in carbon fiber material is installed coaxially to the shock absorber cylinder and, in an emergency landing gear condition, collapses in order to enhance the energy absorption performance of the landing system. This mechanism has been developed as an alternative solution to a high-pressure chamber installed on the Agusta A129 CBT helicopter, which can be considered dangerous when the helicopter operates in hard and/or crash landing. The characteristics of the anti-crash device are presented and the structural layout of a crashworthy landing gear adopting the developed additional energy absorbing stage is outlined. Experimental and numerical results relevant to the material characterization and the force peaks evaluation of the system development are reported. The anti-crash prototype was designed, analysed, optimized, made and finally the potential performances of a landing gear with the additional anti-crash absorber system are tested by drop test and then correlated with a similar test without the anti-crash system, showing that appreciable energy absorbing capabilities and efficiencies can be obtained in crash conditions.

  14. 14 CFR 121.289 - Landing gear: Aural warning device.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Landing gear: Aural warning device. 121.289 Section 121.289 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR COMPENSATION OR HIRE: CERTIFICATION AND OPERATIONS OPERATING REQUIREMENTS: DOMESTIC, FLAG,...

  15. 50 CFR 622.6 - Vessel and gear identification.

    Science.gov (United States)

    2010-10-01

    ... § 622.4(a)(2)(vi); a vessel in the commercial Caribbean reef fish fishery fishing with traps; and a... legible and in good repair and must ensure that no part of the fishing vessel, its rigging, fishing gear..., or buoy is required to be marked is illegal and may be disposed of in any appropriate manner by...

  16. Risk assessment of soils identified on firefighter turnout gear.

    Science.gov (United States)

    Easter, Elizabeth; Lander, Deborah; Huston, Tabitha

    2016-09-01

    The purpose of this research was to identify the composition of soils on firefighter turnout gear and to determine the dermal exposure risks associated with the soils. Nine used Nomex hoods from the Philadelphia fire department were analyzed for the presence of trace metals and seven sets of used turnout gear were analyzed for semi-volatile organics. Turnout gear samples were removed from areas of the gear known to have high levels of dermal absorption including the collar, armpit, wrist, and crotch areas, from either the outer shell or thermal liner layers. The following compounds were detected: polycyclic aromatic hydrocarbons (PAHs), phthalate plasticizers, and polybrominated diphenyl ether flame retardants (PBDEs). A screening risk assessment was conducted by converting the measured concentrations to an estimated dermally absorbed dose based on estimates for the permeation coefficient (Kp) and an assumed firefighting exposure scenario. Benzo(a) pyrene had the highest dermal exposure risk based on carcinogenic effects and PBDE-99 had the highest dermal exposure risk based on non-carcinogenic effects. For the metals, arsenic had the highest dermal exposure risk for the use hoods. PMID:27027971

  17. Development of three-axis inkjet printer for gear sensors

    Science.gov (United States)

    Iba, Daisuke; Rodriguez Lopez, Ricardo; Kamimoto, Takahiro; Nakamura, Morimasa; Miura, Nanako; Iizuka, Takashi; Masuda, Arata; Moriwaki, Ichiro; Sone, Akira

    2016-04-01

    The long-term objective of our research is to develop sensor systems for detection of gear failure signs. As a very first step, this paper proposes a new method to create sensors directly printed on gears by a printer and conductive ink, and shows the printing system configuration and the procedure of sensor development. The developing printer system is a laser sintering system consisting of a laser and CNC machinery. The laser is able to synthesize micro conductive patterns, and introduced to the CNC machinery as a tool. In order to synthesize sensors on gears, we first design the micro-circuit pattern on a gear through the use of 3D-CAD, and create a program (G-code) for the CNC machinery by CAM. This paper shows initial experiments with the laser sintering process in order to obtain the optimal parameters for the laser setting. This new method proposed here may provide a new manufacturing process for mechanical parts, which have an additional functionality to detect failure, and possible improvements include creating more economical and sustainable systems.

  18. 50 CFR 648.51 - Gear and crew restrictions.

    Science.gov (United States)

    2010-10-01

    ... the dredge bottom. No more than triple linking shall be used in or on the dredge bottom portion and... strengtheners, ropes, lines, or chafing gear, on the top of a trawl net, except that one splitting strap and one bull rope (if present), consisting of line and rope no more than 3 inches (7.62 cm) in diameter, may...

  19. Study of an NC system of machining crown gears

    Science.gov (United States)

    Xu, Xiaogang; Wang, Huaqing; Yan, Jian; Gao, Shenyou

    2005-12-01

    Crown gear couplings are usually used in metallurgy and steel rolling equipments, which is manufactured by duplicating processing in common. The method makes the manipulator work hard, and the efficiency is low. The machining precision is limited to the shape of the mold and it is difficult to control the movement of machines table. This work stated an NC system to use hobbing machine. It consists of an industrial control computer, grating sensor, servo- motor and its driver source, servo driver card and other I/O equipments of inputting and outputting. The grating sensor was installed in the axial direction to trace the instantaneous position of gob rest. The radial movement of the machine table was controlled by a servomotor. When the computer captures the axial signal, this system controls the machine table by moving ahead or backwards according to the calculated value of interpolation theory. Thus, two dimensions (axial and radial) associated movement was realized while the crown gear was processed. The feature of the system is that a grating sensor used in the axial direction replaces the servomotor. By making a little change in the mechanism of the machine, NC can be implement and its redesign cost is very low. The design software has an interpolation function for a circular arc and line. The system has been used on a Y1380 gear hobbing machine, and the correlative software of machining crown gear has been designed as well. Satisfactory results have been obtained, showing facility and reliability in practical operation.

  20. The additon of screws and the axodes of gear pairs

    Institute of Scientific and Technical Information of China (English)

    张文祥

    2001-01-01

    In the light of screw addition, the distribution of instantaneous axes along the common perpendicular of the two screws is determined and all possible sorts of axodes are derived cinematically with the pitch of the relative-motion screw in the gear pair as the basis and the transmission ratio i as an independent variable.

  1. Marine Hydrokinetic Power Take-Off Using Magnetic Gearing

    OpenAIRE

    Bird, Jonathan Z.

    2014-01-01

    This paper reviews different power take-off approaches for rotary based marine hydrokinetic power generation. The technology for wind power generation is used as a guide. A discussion on the potential benefits of utilizing magnetic gearing is presented. University of North Carolina at Chapel Hill. Coastal Studies Institute

  2. Motor Integrated Permanent Magnet Gear in a Battery Electrical Vehicle

    DEFF Research Database (Denmark)

    Frandsen, Tommy; Mathe, Laszlo; Berg, Nick Ilsø;

    2015-01-01

    This paper presents the physical construction and test results of two new demonstrators of a Motor Integrated Permanent Magnet Gear (MIPMG), which is a second version of an already tested demonstrator. The demonstrators will be used as traction units for a Battery Electrical Vehicle (BEV) and the...... used as traction unit in urban traffic....

  3. LOADING OF MECHANICAL TRANSMISSION OF TROLLEYBUS TRACTION DRIVING GEAR

    Directory of Open Access Journals (Sweden)

    A. I. Safonov

    2009-01-01

    Full Text Available The paper analyzes factors that determine dynamic loads of mechanical transmission of trolleybus traction driving gear. The paper proposes a methodology for determination of calculative moments of loading transmission elements. Results of the research are analyzed and recommendations on  dynamic reduction of trolleybus transmission are given in the paper. 

  4. The additon of screws and the axodes of gear pairs

    Institute of Scientific and Technical Information of China (English)

    ZHANG Wen-xiang

    2001-01-01

    In the light of screw addition, the distribution of instantaneous axes along the common perpendicular of the two screws is determined and all possible sorts of axodes are derived cinematically with the pitch of the relative-motio n screw in the gear pair as the basis and the transmission ratio i as an inde pendent variable.

  5. 50 CFR 300.108 - Vessel and gear identification.

    Science.gov (United States)

    2010-10-01

    ... harvesting vessel is engaged (as described at 33 CFR part 81). (c) Gear identification. (1) The operator of... contrast to the background and must be permanently affixed to the harvesting vessel in block roman alphabet letters and arabic numerals at least 1 m in height for harvesting vessels over 20 m in length, and...

  6. Generation and tooth contact analysis of spiral bevel gears with predesigned parabolic functions of transmission errors

    Science.gov (United States)

    Litvin, Faydor L.; Lee, Hong-Tao

    1989-01-01

    A new approach for determination of machine-tool settings for spiral bevel gears is proposed. The proposed settings provide a predesigned parabolic function of transmission errors and the desired location and orientation of the bearing contact. The predesigned parabolic function of transmission errors is able to absorb piece-wise linear functions of transmission errors that are caused by the gear misalignment and reduce gear noise. The gears are face-milled by head cutters with conical surfaces or surfaces of revolution. A computer program for simulation of meshing, bearing contact and determination of transmission errors for misaligned gear has been developed.

  7. DESIGN AND TEST RESULTS FOR MULTIPLE-CONTACT GEAR OF «BELARUS»-TRACTOR TRANSMISSION

    Directory of Open Access Journals (Sweden)

    V. Supin

    2012-01-01

    Full Text Available Gearing with high contact ratio (HCR has other properties than gearing formed with a standard original profile. The gearing is characterized by increased loading capacity. The paper presents a boundary element method (BEM which is applied to solve a problem pertaining to stress concentration at the tooth root. Gear-box casing with multiple-contact gear has remained in series production. Results of the investigations have been realized in the experimental gearbox of  the «Belarus-1523» tractor.

  8. One Approach to the Synthesis, Design and Manufacture of Hyperboloid Gear Sets with Face Mating Gears. Part 2: Review of Practical Realization

    Science.gov (United States)

    Abadjiev, Valentin; Abadjieva, Emilia

    2016-09-01

    Hyperboloid gear drives with face mating gears are used to transform rotations between shafts with non-parallel and non-intersecting axes. A special case of these transmissions are Spiroid1 and Helicon gear drives. The classical gear drives of this type are Archimedean ones. The objective of this study are hyperboloid gear drives with face meshing, when the pinion has threads of conic convolute, Archimedean and involute types, or the pinion has threads of cylindrical convolute, Archimedean and involute types. For simplicity, all three type transmissions with face mating gears and a conic pinion are titled Spiroid and all three type trans- missions with face mating gears and a cylindrical pinion are titled Helicon. Principles of the mathematical modelling of tooth contact synthesis are discussed in Part 1: Basic theoretical and CAD experience of this study. The second part of this article is a brief overview of the innovations and inventions created in this field at the Institute of Mechanics - Bulgarian Academy of Sciences in the last three decades. This study is also dedicated on elaboration of the specialized face gear sets for implementation into bio-robot hand. It is based on the application of 3D software technology, using 3D print for the realization of the physical models of the gear drives.

  9. One Approach to the Synthesis, Design and Manufacture of Hyperboloid Gear Sets With Face Mating Gears. Part 1: Basic Theoretical and Cad Experience

    Science.gov (United States)

    Abadjiev, Valentin; Abadjieva, Emilia

    2016-06-01

    Hyperboloid gear drives with face mating gears are used to transform rotations between shafts with non-parallel and non-intersecting axes. A special case of these transmissions are Spiroid and Helicon gear drives. The classical gear drives of this type are the Archimedean ones. The objective of this study are hyperboloid gear drives with face meshing, when the pinion possesses threads of conic convolute, Archimedean and involute types, or the pinion has threads of cylindrical convolute, Archimedean and involute types. For simplicity, all three types transmis- sions with face mating gears and a conic pinion are titled Spiroid and all three types transmissions with face mating gears and a cylindrical pinion are titled Helicon. Principles of the mathematical modelling of tooth contact synthesis are discussed in this study. The presented research shows that the synthesis is realized by application of two mathematical models: pitch contact point and mesh region models. Two approaches for synthesis of the gear drives in accordance with Olivier's principles are illustrated. The algorithms and computer programs for optimization synthesis and design of the studied hyperboloid gear drives are presented.

  10. One Approach to the Synthesis, Design and Manufacture of Hyperboloid Gear Sets with Face Mating Gears. Part 2: Review of Practical Realization

    Directory of Open Access Journals (Sweden)

    Abadjiev Valentin

    2016-09-01

    Full Text Available Hyperboloid gear drives with face mating gears are used to transform rotations between shafts with non-parallel and non-intersecting axes. A special case of these transmissions are Spiroid1 and Helicon gear drives. The classical gear drives of this type are Archimedean ones. The objective of this study are hyperboloid gear drives with face meshing, when the pinion has threads of conic convolute, Archimedean and involute types, or the pinion has threads of cylindrical convolute, Archimedean and involute types. For simplicity, all three type transmissions with face mating gears and a conic pinion are titled Spiroid and all three type trans- missions with face mating gears and a cylindrical pinion are titled Helicon. Principles of the mathematical modelling of tooth contact synthesis are discussed in Part 1: Basic theoretical and CAD experience of this study. The second part of this article is a brief overview of the innovations and inventions created in this field at the Institute of Mechanics – Bulgarian Academy of Sciences in the last three decades. This study is also dedicated on elaboration of the specialized face gear sets for implementation into bio-robot hand. It is based on the application of 3D software technology, using 3D print for the realization of the physical models of the gear drives.

  11. Mathematical models of grinding manufacture and tooth contact analysis of spherical gears

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The spherical gear is a gear-driven mechanism with two degrees of freedom (DOF), which can transfer spatial motion and power. Grinding machining of the spherical gear is performed with a plate grinding wheel by using generating method, and based on mathematical model of the plate grinding wheel, the mathematical model of the spherical gear is set up. And then, the meshing model of a spherical gear pair is developed and the tooth contact analysis (TCA) of the spherical gear pairs is performed. After that, the position of a contact point on teeth surfaces of the spherical gear pair can be solved by using a nonlinear solver. Finally, the paths of contact points on teeth surfaces of the spherical gear are studied: Since every tooth of the spherical gear is diverse, the contact paths of the meshing of the spherical gear pair are complex and multiform. These are very useful to further investigations on transmission theory and practical applications of spherical gear pairs.

  12. Quantitative analysis on the non-similarity of thermal deformation of the gear

    Science.gov (United States)

    Li, Guihua; Fei, Yetai; Ma, Xiushui; Fei, Wen

    2008-12-01

    Gears as common machine elements are deformed when its temperature varies. One direct result is that the tooth shape of meshing gear is changed. Using the theory of heat and elastic mechanics, the involute cylindrical gear is taken for example. Calculation makes it clear that the total profile of gear after thermal deformation is different from the shape before thermal deformation. That is named non-similarity, and the non-similarity error is given. For proving the non-similarity existed in thermal deformation of Gear, a four-dimension equipment is adopted for experiment, which is able to realize rotated motion and rectilinear motion. The experimental result also shows that the non-similarity does exist in thermal deformation of involute cylindrical gear. Shared a common theory, the non-similarity is existed in the circular gear.

  13. Surface Fatigue Lives of Case-Carburized Gears With an Improved Surface Finish

    Science.gov (United States)

    Krantz, T. L.; Alanou, M. P.; Evans, H. P.; Snidle, R. W.; Krantz, T. L. (Technical Monitor)

    2000-01-01

    Previous research provides qualitative evidence that an improved surface finish can increase the surface fatigue lives of gears. To quantify the influence of surface roughness on life, a set of AISI 93 10 steel gears was provided with a nearmirror finish by superfinishing. The effects of the superfinishing on the quality of the gear tooth surfaces were determined using data from metrology, profilometry, and interferometric microscope inspections. The superfinishing reduced the roughness average by about a factor of 5. The superfinished gears were subjected to surface fatigue testing at 1.71 -GPa (248-ksi) Hertz contact stress, and the data were compared with the NASA Glenn gear fatigue data base. The lives of gears with superfinished teeth were about four times greater compared with the lives of gears with ground teeth but with otherwise similar quality.

  14. Estimating seabed pressure from demersal trawls, seines, and dredges based on gear design and dimensions

    DEFF Research Database (Denmark)

    Eigaard, Ole Ritzau; Bastardie, Francois; Breen, Mike;

    2016-01-01

    This study assesses the seabed pressure of towed fishing gears and models the physical impact (area and depth of seabed penetration) from trip-based information of vessel size, gear type, and catch. Traditionally fishing pressures are calculated top-down by making use of large-scale statistics......'s impact. An industry-based survey covering 13 countries provided the basis for estimating the relative impact-area contributions from individual gear components, whereas sediment penetration was estimated based on a literature review. For each gear group, a vessel size–gear size relationship was estimated...... to enable the prediction of gear footprint area and sediment penetration from vessel size. Application of these relationships with average vessel sizes and towing speeds provided hourly swept-area estimates by métier. Scottish seining has the largest overall gear footprint of ∼1.6 km2 h−1 of which 0.08 km2...

  15. 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.

  16. Izbrannye voprosy matematičeskoj fiziki i p-adičeskogo analiza

    OpenAIRE

    2015-01-01

    This volume presents papers on modern trends in mathematical physics, including equations of mathematical physics, mathematical problems of quantum theory, and ▫$p$▫-adic mathematical physics. The volume also contains selected contributions to The Third International Conference on ▫$p$▫-adic Mathematical Physics: From Planck Scale Physics to Complex Systems and Biology (October 1-6, 2007, Moscow, Steklov Institute of Mathematics, Russian Academy of Sciences). The volume is addressed to scient...

  17. Analysis and correction of the machining errors of small plastic helical gears by ball-end milling

    Institute of Scientific and Technical Information of China (English)

    Gao Sande; Huang Loulin; and Han Baoling

    2012-01-01

    Many small-size precise plastic helical involutes gears are used in electrical appliances to transmit rotary movements con- tinuously and smoothly. Ball-end milling is an effective method for trial manufacture or small batch production of this type of gear, but the precision of the gear is usually low. In this research, the main sources of the errors of the gear, machining errors of the tooth profile and trace of the gear obtained were analyzed. The correction amounts for these errors are then determined by using a CNC gear tester. They are used to generate a new 3D-CAD model for gear machining with better nrecision.

  18. Vehicle transmission gear 2009; Getriebe in Fahrzeugen 2009

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    Within the VDI Conference 'Vehicle Transmission Gears' at 30th June to 1st May, 2009 in Friedrichshafen (Federal Republic of Germany), the following lectures were held: (1) Production site Germany - Home in trend (B.O. Braun); (2) Luk CVT Technology - Efficiency, comfort, dynamics (A. Teubert); (3) The new BMW eight-speed automatic gear (J. Kretschmer); (4) Influence of transmission concept and design on simulated fuel consumption in official customer driving cycles (A. Schmidt); (5) GETRAG PowerShift {sup registered} - Extended driving functionalities due to controllable double clutch (A. Pawlenka); (6) New efficient transmission strategy in automatic transmission in the city bus (H. Nolzen); (7) Electronic controllers for gears: decision about design concepts und applied technologies on the basis of the place of installation in vehicles (P. Bertelshofer); (8) Coupled systems based on magnetorheological fluids (D. Gueth); (9) Investigation of setting losses of diaphragm springs in dry-running couplings according to given conditions (P. Merkel); (10) Influence of material properties and heat balance on the tribologic behaviour of dry-running friction couplings (C. Spaeth); (11) A contribution to massively transformed components of gears for the reduction of consumption and resources saving (G. Quintenz); (12) An economic production of transmission shafts by means of near netshape transformation also in the area of commercial vehicles (E. Rauschnabel); (13) Potentials and transformation of design and process optimization in the serial production using hypoid interlocking as an example (A. Dietrich); (14) Development of automated manual transmission (Se-il Song); (15) Integration of new functions to GETRAG PowerShift {sup registered} Transmissions of transversal, transaxle powertrains (I. Steinberg); (16) Automatedmanual transmission - The forgotten concept for the future? (B.-R. Hoehn); (17) A new back-torque limiter for high power motorcycles

  19. Investigation about crack propagation paths in thin rim gears

    Directory of Open Access Journals (Sweden)

    F. Curà

    2014-10-01

    Full Text Available Crack propagation in gears is a problem related not only to the life of the components, but also to the concept of failsafe design. Fail safe design means to design a component in order that, if a failure occurs, this may cause a “safe failure”. This aspect is very important above all in aerospace industry. As a matter of fact, in aerospace application, the need of reducing weight brings to produce gears with very thick rim and web. Considering thin rim gears, when a crack is nucleated near the tooth root, it may propagate through the tooth (causing the loss of the entire tooth or a portion of it or the propagation may follow a path across the wheel diameter (causing the projection of big parts of the gear that may break the gearbox and may cause serious damage to the aircraft. The first failure mode is define as “failsafe failure” and the second one as “catastrophic failure” and of course has to be avoided. Designers need to have robust design criteria in order to predict crack propagation paths and to avoid catastrophic failures. In literature, few works are present concerning this topic, in particular related to the effect of geometrical parameters that may affect the crack propagation. In this work a numerical analysis about crack propagation in gears with respect to the backup ratio (ratio between tooth height and rim thickness, initial crack position and shape has been done by means of the Extended FEM (XFEM technique, realizing 3D models. XFEM 3D is a relatively new technique consisting in enriching traditional finite elements with more complex shape functions; in this way it is possible to propagate crack also between mesh nodes and to have mesh independent results. Aim of this paper is to highlight the crack propagation path in order to give to designers an high confident design criterion, related to the gear geometry. In particular, the effect of both rim thickness and orientation of the initial crack have been considered

  20. Effect of two synthetic lubricants on life of AISI 9310 spur gears

    Science.gov (United States)

    Townsend, Dennis P.; Shimski, John

    1991-01-01

    Spur-gear fatigue tests were conducted with two lubricants using a single lot of consumable-electrode vacuum-melted (CVM) AISI 9310 spur gears. The gears were case carburized and hardened to Rockwell C60. The gear pitch diameter was 8.89 cm. The lot of gears was divided into two groups, each of which was tested with a different lubricant. The test lubricants can be classified as synthetic polyol-ester-based lubricants. One lubricant was 30 percent more viscous that the other. Both lubricants have similar pressure viscosity coefficients. Test conditions included a bulk gear temperature of 350 K, a maximum Hertz stress of 1.71 GPa at the pitch line, and a speed of 10,000 rpm. The surface fatigue life of gears tested with one lubricant was approximately 2.4 times that for gears tested with the other lubricant. The lubricant with the 30 percent higher viscosity gave a calculated elastohydrodynamic (EHD) film thickness that was 20 percent higher than the other lubricant. This increased EHD film thickness is the most probable reason for the improvement in surface fatigue life of gears tested with this lubricant over gears tested with the less viscous lubricant.

  1. A method for variable pressure load estimation in spur and helical gear pumps

    Science.gov (United States)

    Battarra, M.; Mucchi, E.

    2016-08-01

    A systematic procedure is proposed to determine variable excitation loads coming from pressure evolution inside tooth spaces in external gear pumps. Pressure force and torque are estimated with respect to the angular position of the gears, taking into account the phenomena that occur during the meshing course. In particular, the paper proposes a general methodology aiming at determining pressure force and torque components along the three coordinate axes and suitable to be applied on both spur and helical gear configuration. Firstly, the method to calculate pressure loads acting on a single tooth space during a complete revolution is given, then the total pressure force and torque loading each gear is obtained. Particular attention is addressed on the description of the helical gear scenario. As an example, the method is applied to a tandem gear pump, characterized by the presence of two stages, one with spur gears and one with helical gears. An experimentally assessed model to calculate the pressure ripple inside the tandem pump is described and the proposed procedure for pressure load estimation is applied. Eventually, the pressure loads estimated with the present procedure are compared with other estimation methods already described in the literature. The comparison shows that the present methodology is able to describe a wider range of phenomena involved in the meshing evolution and to determine all the pressure force and torque components applied to helical gears. The method gives suitable results to study the balancing and the dynamic behavior of gear pumps.

  2. 50 CFR Table 20 to Part 679 - Seabird Avoidance Gear Requirements for Vessels, based on Area, Gear, and Vessel Type. (See § 679...

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Seabird Avoidance Gear Requirements for Vessels, based on Area, Gear, and Vessel Type. (See § 679.24(e) for complete seabird avoidance program...) FISHERIES OF THE EXCLUSIVE ECONOMIC ZONE OFF ALASKA Pt. 679, Table 20 Table 20 to Part 679—Seabird...

  3. Topological modeling of a one stage spur gear transmission

    Science.gov (United States)

    Miladi Chaabane, Mariem; Plateaux, Régis; Choley, Jean-Yves; Karra, Chafik; Riviere, Alain; Haddar, Mohamed

    2014-09-01

    Finding a basis of unification for the modeling of mechatronic systems is the search subject of several works. This paper is a part of a general research designed to the application of topology as a new approach for the modeling of mechatronic systems. Particularly, the modeling of a one stage spur gear transmission using a topological approach is tackled. This approach is based on the concepts of topological collections and transformations and implemented using the MGS(modeling of general systems) language. The topological collections are used to specify the interconnection laws of the one stage spur gear transmission and the transformations are used to specify the local behavior laws of its different components. In order to validate this approach, simulation results are presented and compared with those obtained with MODELICA language using Dymola solver. Since good results are achieved, this approach might be used as a basis of unification for the modeling of mechatronic systems.

  4. Suitability of Alternative Lubricants for Automotive Gear Applications

    Directory of Open Access Journals (Sweden)

    Amit Suhane

    2014-03-01

    Full Text Available Rising environmental concerns due to the problems associated with conventional mineral lubricants has renewed interest in usage of alternative resources. Various attempts have been made to explore the possibilities of utilizing vegetable oils for range of applications. Properties like excellent viscosity features, higher biodegradability, lower toxicity, better renewability & natural lubricity etc shows its potential as lubricants inspite of certain technical problems. Critical issues like lower oxidation stability , poor cold temperature properties affects the performance of vegetable oils and restricts its application to limited range . Gear oils are the hidden workhorses of automotive applications. This article highlights the suitability of various vegetable oils for lubricant formulation as an alternative in automotive gearing applications.

  5. Global behavior of gear system using mixed cell mapping

    Institute of Scientific and Technical Information of China (English)

    SHEN; Yunwen; LIU; Mengjun; DONG; Haijun

    2004-01-01

    In some mechanical nonlinear systems, the transient motion will be undergoing a very long process and the attractor-basin boundaries are so complicated that some difficulties occur in analyzing the system global behavior. To solve this problem a mixed cell mapping method based on the point mapping and the principle of simple cell mapping is developed. The algorithm of the mixed cell mapping is studied. A dynamic model of a gear pair is established with the backlash, damping, transmission error and the time-varying stiffness taken into consideration. The global behaviors of this system are analyzed. The coexistence of the system attractors and the respective attractor-basin of each attractor with different parameters are obtained, thus laying a theoretical basis for improvement of the dynamic behaviors of gear system.

  6. Prediction of Fatigue Life of Gear Subjected to Varying Loads

    Directory of Open Access Journals (Sweden)

    D. Hanumanna

    1998-07-01

    Full Text Available Structural members and components of a vehicle during service are subjected to varying loads which are random in nature. For structural members subjected to loads of constant amplitude, it is possible to describe the load with explicit mathematical relationship, and thereby, the life span can be estimated. Whereas, for structural members subjected to varying loads with time, there is no satisfactory method to estimate their life span. This paper describes a method for the estimation of life span of a gear in the gear box of a fighting vehicle subjected to fluctuating loads. For this purpose, it is assumed that the load spectrum corresponds to Gaussian (normal distribution, and the life has been worked out by applying linear cumulative damage theory.

  7. Photonic polarization gears for ultra-sensitive angular measurements

    CERN Document Server

    D'Ambrosio, V; Del Re, L; Slussarenko, S; Li, Y; Kwek, L C; Marrucci, L; Walborn, S P; Aolita, L; Sciarrino, F

    2013-01-01

    A key aim in metrology is to find new physical methods for enhancing measurement precision. In this respect, quantum metrology bears great promise, but is unlikely to become practical in the near future. Its ideas can nevertheless provide inspiration for classical methods of immediate value. Here, we demonstrate the generation of NOON-like photonic states of m quanta of angular momentum, with m as high as 100, in a setup that acts as a photonic gear, converting a mechanical rotation of angle {\\theta} into an amplified rotation of the optical polarization by the angle m{\\theta}. Exploiting this effect, we demonstrate angular measurements with a precision comparable to that of the optimal quantum strategy with m photons, but robust to photon losses. The high gear ratio m translates into a similar sensitivity enhancement of optical non-contact angular measurements, boosting the current state-of-the-art by almost two orders of magnitude.

  8. Achievements of Study Concerning Worm Face Gear Made in Romania

    Directory of Open Access Journals (Sweden)

    Vasile Boloş

    2010-12-01

    Full Text Available Worm face gears are a relatively new category of gear failure in 50 years in the USA. They are composed of a conical or cylindrical worm to engage the front wheel of a conical or flat. Geometric configuration to ensure a great contact ratio and lubrication between the flanks favorable conditions which allow their implementation of hardened steel, gray iron, bronze. Also they will produce big rapport of transmission in a single stage. Originally conceived by Illinois Tool Works Company Chicago they were taken and developed at the Institute of Mechanical Izhevsk (Russia. Experimental and theoretical developments were made in Britain, Germany, Hungary, Poland, Bulgaria and Romania. In the present paper is highlighted the concerns and the achievements of researchers from Romania in the period 1980-2009.

  9. 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

  10. A Tooth Flank Crowning Method by Applying a Novel Crossed Angle Function Between the Hob Cutter and Work Gear in the Gear Hobbing Process

    Directory of Open Access Journals (Sweden)

    Wu Yu-Ren

    2016-01-01

    Full Text Available In this paper, a novel longitudinal tooth flank crowning method is proposed by setting the crossed angle between the hob cutter and work gear as a linear function of hob’s traverse feed movement in the gear hobbing process. However, this method makes twisted tooth flanks on the hobbed work gear. Therefore, a variable pressure angle hob cutter is applied to obtain an anti-twist tooth flank of hobbed work gear. A computer simulation example is performed to verify the superiority of the proposed novel hobbing method by comparing topographies of the crowned work gear surfaces hobbed by a standard hob cutter and a variable pressure angle hob cutter.

  11. Adição de plasma seminal ao sêmen descongelado e taxa de prenhez de ovelhas inseminadas em tempo fixo

    OpenAIRE

    O.R. Prado; G.M. Bastos; A.L.G. Monteiro; B.B. Saab; S. Gilaverte; C.C. Pierobom; F. Hentz; L.H.S. Martins; C.J.A. Silva; G.S. Dranca; T.S.S. Stivari; G. Cerqueira

    2013-01-01

    Avaliou-se o efeito da adição de plasma seminal ovino ao sêmen descongelado sobre a taxa de prenhez de ovelhas em rebanho comercial. Cento e setenta e quatro ovelhas cruza Texel foram distribuídas em quatro tratamentos: T1) inseminação artificial cervical (IAC) com sêmen descongelado (SD) diluído em solução tampão fosfato salino (PBS); T2) IAC com SD e adição de plasma seminal ovino; T3) grupo-controle I: IAC com sêmen fresco diluído em PBS; T4) grupo-controle II: inseminação artificial por l...

  12. Stochastic Production and Heterogeneous Risk Preferences: Commercial Fishers’ Gear Choices

    OpenAIRE

    Eggert, Håkan; Tveterås, Ragnar

    2001-01-01

    As long as total effort cannot be completely controlled, a more thorough understanding of fishers’ supply response decisions will be beneficial for fishery managers. In this paper, we present a model of fishers’ gear choice, which is empirically estimated on a panel of Swedish demersal trawlers. The approach allows for heterogeneity both in production technology and in risk preferences. Stochastic revenue functions with fixed effects are estimated and used to predict expected revenue and stan...

  13. Landing Gear Aerodynamic Noise Prediction Using Building-Cube Method

    OpenAIRE

    Daisuke Sasaki; Deguchi Akihito; Hiroshi Onda; Kazuhiro Nakahashi

    2012-01-01

    Landing gear noise prediction method is developed using Building-Cube Method (BCM). The BCM is a multiblock-structured Cartesian mesh flow solver, which aims to enable practical large-scale computation. The computational domain is composed of assemblage of various sizes of building blocks where small blocks are used to capture flow features in detail. Because of Cartesian-based mesh, easy and fast mesh generation for complicated geometries is achieved. The airframe noise is predicted through ...

  14. Bifurcation Analysis of a Nose Landing Gear System

    OpenAIRE

    Tartaruga, Irene; Lowenberg, Mark H.; Cooper, Jonathan E; Sartor, Pia N; Lemmens, Yves

    2016-01-01

    A methodology is proposed to enable the bifurcation analysis of a multi-body nose landing gear (NLG) model by coupling AUTO, a continuation software, to LMS Virtual.Lab Motion, a multi-body software. The approach uses a Singular Value Decomposition (or High Order Singular Value Decomposition) based technique to enable the computation of the stability bounds (e.g. the onset of shimmy) in a very efficient manner. Sensitivity and uncertainty analyses are performed to determine the influence of v...

  15. Numerical continuation applied to landing gear mechanism analysis

    OpenAIRE

    Knowles, J.; Krauskopf, B; Lowenberg, MH

    2010-01-01

    A method of investigating quasi-static mechanisms is presented and applied to an overcentre mechanism and to a nose landing gear mechanism. The method uses static equilibrium equations along with equations describing the geometric constraints in the mechanism. In the spirit of bifurcation analysis, solutions to these steady-state equations are then continued numerically in parameters of interest. Results obtained from the bifurcation method agree with the equivalent results obtained from two ...

  16. STOCHASTIC PRODUCTION AND HETEROGENEOUS RISK PREFERENCES: COMMERCIAL FISHERS' GEAR CHOICE

    OpenAIRE

    Eggert, Hakan; Tveteras, Ragnar

    2001-01-01

    As long as total effort cannot be completely controlled, a more thorough understanding of fishers' supply response decisions will be beneficial for fisheries managers. In this paper, we present a model of fishers' gear choice, which is empirically estimated on a panel of Swedish demersal trawlers. The approach allows for heterogeneity both in production technology and in risk preferences. Stochastic revenue functions with fixed effects are estimated and used to predict expected revenue and st...

  17. Nonlinear Predictive Control of Semi-Active Landing Gear System

    OpenAIRE

    Wu, Dongsu; Gu, Hongbin; Liu, Hui

    2010-01-01

    The application of model predictive control and constructive nonlinear control methodology to semi-active landing gear system is studied in this paper. A unified shock absorber mathematical model incorporates solenoid valve’s electromechanical and magnetic dynamics is built to facilitate simulation and controller design. Then we propose a hierarchical control structure to deal with the high nonlinearity. A dual mode model predictive controller as an outer loop controller is developed to gen...

  18. Tietohallinnon prosessien kehityssuunnitelma COBIT-viitekehysmallilla. CASE: Moventas Gears Oy

    OpenAIRE

    Lähteenmäki, Pasi

    2014-01-01

    Moventas Gears Oy (Moventas) on yksi maailman johtavista teollisuus- ja tuulivoimaturbiini vaihteiden valmistajista. Yhtiö valmistaa voimansiirtoratkaisuja tuulivoima-, sellu-, paperi- ja kaivosteollisuudelle. Moventaksella on noin 900 työntekijää 13 eri maassa sekä maailmanlaajuinen yhteistyökumppaniverkosto. Opinnäytetyön tavoite oli kehittää Moventaksen tietohallinnon prosesseja COBIT viitekehyksen avulla. Tietohallinnon prosessien kehittämisellä on tarkoitus selkeyttää toimintata...

  19. Use of Protective Gear in Bird Flu Outbreak Response

    Centers for Disease Control (CDC) Podcasts

    2008-12-29

    CDC's Dr. Oliver Morgan discusses how the use of masks and other protective gear impacted whether workers dealing with an outbreak of bird flu in England became sick. The paper is published in the January 2009 issue of CDC’s journal, Emerging Infectious Diseases.  Created: 12/29/2008 by Emerging Infectious Diseases.   Date Released: 12/29/2008.

  20. 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.

  1. Model Based Incipient Fault Detection for Gear Drives

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper presents the method of model based incipient fault detection for gear drives,this method is based on parity space method. It can generate the robust residual that is maximally sensitive to the fault caused by the change of the parameters. The example of simulation shows the application of the method, and the residual waves have different characteristics due to different parameter changes; one can detect and isolate the fault based on the different characteristics.

  2. Wearable high-tech gear for homeland security personnel

    Science.gov (United States)

    Venkateswarlu, Ronda; Hui Wei, Choo; Li Lian, Ngiam; Lim, E. T.; Zhu, Zijian; Yang, Mingjiang

    2006-05-01

    Recent homeland security problems in various countries indicate that fixed surveillance systems at important places are not adequate enough. As the security threats take new dimensions in future, mobile smart security personnel wearing high-tech gear will form the basic infrastructure. See first, listen first, detect first, track first, communicate first with peers, assess the threat and coordinate with security head-quarters are the functions of high-tech gear. This paper proposes a high-tech gear involving (i) hands-free and obtrusion-free textile-based wearable microphone array to capture users voice and interface with body-worn computer, (ii) microphone arrays embedded in textiles to listen and record others voices from a distance, (iii) miniature cameras embedded in the shirt to provide the user with omni vision (iv) wireless personal display as GUI hidden in textile or natural glasses, (v) GPS and body area network for positional awareness for information in the form of text or textile integrated, (vi) reconfigurable HW/SW for all the above functions configured in the form of a usual belt. The main focus of this paper is how to configure the high-tech gear with all these sophisticated functions to disappear into the natural wearables of the user giving him normal look in the public. This project is sponsored by Defence Science & Technology Agency, Ministry of Defence, Singapore. This paper covers multi-discipline technologies at system level, hence not possible to go into details of any subsystem. The main objective of this paper is to share our thoughts and get feedback. Progress and some critical design issues are discussed in this paper.

  3. Teaching Planetary Gear Trains with the Aid of Nomographs

    OpenAIRE

    Essam Lauibi Esmail

    2013-01-01

    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...

  4. VERIFICATION OF GEAR DYNAMIC MODEL IN DIFFERENT OPERATING CONDITIONS

    Directory of Open Access Journals (Sweden)

    Grzegorz PERUŃ

    2014-09-01

    Full Text Available The article presents the results of verification of the drive system dynamic model with gear. Tests were carried out on the real object in different operating conditions. For the same assumed conditions were also carried out simulation studies. Comparison of the results obtained from those two series of tests helped determine the suitability of the model and verify the possibility of replacing experimental research by simulations with use of dynamic model.

  5. Road failure caused by landslide in north Ethiopia: A case study from Dedebit - Adi-Remets road segment

    Science.gov (United States)

    Fisseha, Shimeles; Mewa, Getnet

    2016-06-01

    Landslide represents one of the main constraints for the development of road infrastructures in many parts of Ethiopia. While rugged topography, intra-sedimentary clay horizons, thick talus deposits at the foot of hills and wide spread tectonic fissures and faults account for the prominent inducing factors, heavy monsoon rainfall is the most common triggering factor for the majority of road failures caused by landslides. We present the results of geoelectrical investigation of a landslide that caused a severe damage to the Dedebit-Adi-Remets segment of the recently built highway that transects the high relief and mountainous region of Tigray, northern Ethiopia. Vertical Electrical Sounding (VES) measurements were taken at twelve points, systematically distributed to cover the affected area. The resulting geo-electric sections revealed that the shallow subsurface is composed of four distinct geo-electric layers. The corresponding major lithological successions, from top to bottom, are: unconsolidated conglomeratic layer, moist silty clay, moderately weathered and fractured basaltic rock and a possibly saturated portion of the basalt. Major discontinuities, indications of structural weak zones, have also been inferred based on abrupt vertical shift in geo-electrical layer boundaries between neighboring soundings. Based on the main findings, the road failure in the study area appears to be caused by a downslope movement of the subgrade composed of top unconsolidated sediment soaked with water from heavy rain. The location of the probable slip plane could be the inclined interface between the conductive clayey soil and the underlying resistive weathered basalt.

  6. Simulation of X-38 Landing Scenarios With Landing Gear Failures

    Science.gov (United States)

    Fasanella, Edwin L.; Lyle, Karen H.; Pritchard, Jocelyn I.; Stockwell, Alan E.

    2000-01-01

    Abnormal landing scenarios of the X-38 prototype Crew Rescue Vehicle (CRV) were modeled for three different cases involving non-deployment of landing gear with an explicit dynamic nonlinear finite element code, MSC/DYTRAN. The goal of this research was to develop models to predict the probability of crew injuries. The initial velocity conditions for the X-38 with chute deployed were 10 ft/s vertical and 57 ft/s longitudinal velocity. An MSC/NASTRAN structural model was supplied by JSC and was converted to a dynamic MSC/DYTRAN model. The MSC/NASTRAN model did not include seats or floor structure; thus, the acceleration of a lumped-mass attached to the bulkhead near each assumed occupant location was used to determine injury risk for each occupant. The worst case for injury was nondeployment of all gears. The mildest case was nondeployment of one main gear. Although a probability for minor injury was predicted for all cases, it is expected that the addition of energy-absorbing floor structure and seats would greatly diminish the probability of injury.

  7. An Artificial Intelligence Approach for Gears Diagnostics in AUVs

    Directory of Open Access Journals (Sweden)

    Graciliano Nicolás Marichal

    2016-04-01

    Full Text Available In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles, where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised. Furthermore, techniques based on several paradigms of the Artificial Intelligence (Neural Networks, Fuzzy systems and Genetic Algorithms have been applied altogether in order to design an efficient fault diagnostic system. A hybrid Genetic Neuro-Fuzzy system has been developed, where it is possible, at the final stage of the learning process, to express the fault diagnostic system as a set of fuzzy rules. Several trials have been carried out and satisfactory results have been achieved.

  8. Effects of parameters on rotational fine blanking of helical gears

    Institute of Scientific and Technical Information of China (English)

    杨珊; 宋燕利; 张梅

    2014-01-01

    The application of fine blanking to the manufacturing of helical gears directly from a strip has been restricted due to the traditional linear cutting stroke of the punch and die. In this work, rotational fine blanking which combined the linear and rotational motion of punch and counterpunch was applied for the forming of helical gears. A three-dimensional (3D) rigid-plastic finite element model was developed on the DEFORM-3D platform. By finite element simulation and analysis, the influences of key parameters on the punch load and cut surface were investigated. It is shown that:1) with increasing the counterforce or helical angle, the punch load and the depth of die roll increase;2) with increasing blank holder force, the punch load increases while the depth of die roll decreases;3) V-ring indenter facilitates an improvement in the quality. The results of this research reveal the deformation mechanism of rotational fine blanking of helical gears, and provide valuable guidelines for further experimental studies.

  9. Study of lubricant jet flow phenomena in spur gears

    Science.gov (United States)

    Akin, L. S.; Townsend, D. P.; Mross, J. J.

    1974-01-01

    Lubricant jet flow impingement and penetration depth into a gear tooth space were measured at 4920 and 2560 rpm using a 8.89 cm (3.5 inch) pitch diameter 8 pitch spur gear at oil pressures from 70,000 to 410,000 n/sqm (10 psi to 60 psi). A high speed motion picture camera was used with xenon and high speed stroboscopic lights to slow down and stop the motion of the oil jet. An analytical model was developed for the vectorial impingement dept and for the impingement depth with tooth space windage effects included. The windage effects for oil drop size greater than .0076 cm (.003 inches). The analytical impingement dept compared favorably with experimental results above an oil jet pressure of 70,000 n/sqm (10psi). There was further penetration into the tooth space after impingement, but much of this oil was thrown out of the tooth space without further contacting the gear teeth.

  10. An Artificial Intelligence Approach for Gears Diagnostics in AUVs.

    Science.gov (United States)

    Marichal, Graciliano Nicolás; Del Castillo, María Lourdes; López, Jesús; Padrón, Isidro; Artés, Mariano

    2016-01-01

    In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles), where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised. Furthermore, techniques based on several paradigms of the Artificial Intelligence (Neural Networks, Fuzzy systems and Genetic Algorithms) have been applied altogether in order to design an efficient fault diagnostic system. A hybrid Genetic Neuro-Fuzzy system has been developed, where it is possible, at the final stage of the learning process, to express the fault diagnostic system as a set of fuzzy rules. Several trials have been carried out and satisfactory results have been achieved. PMID:27077868

  11. Numerical Simulation of Oil Jet Lubrication for High Speed Gears

    Directory of Open Access Journals (Sweden)

    Tommaso Fondelli

    2015-01-01

    Full Text Available The Geared Turbofan technology is one of the most promising engine configurations to significantly reduce the specific fuel consumption. In this architecture, a power epicyclical gearbox is interposed between the fan and the low pressure spool. Thanks to the gearbox, fan and low pressure spool can turn at different speed, leading to higher engine bypass ratio. Therefore the gearbox efficiency becomes a key parameter for such technology. Further improvement of efficiency can be achieved developing a physical understanding of fluid dynamic losses within the transmission system. These losses are mainly related to viscous effects and they are directly connected to the lubrication method. In this work, the oil injection losses have been studied by means of CFD simulations. A numerical study of a single oil jet impinging on a single high speed gear has been carried out using the VOF method. The aim of this analysis is to evaluate the resistant torque due to the oil jet lubrication, correlating the torque data with the oil-gear interaction phases. URANS calculations have been performed using an adaptive meshing approach, as a way of significantly reducing the simulation costs. A global sensitivity analysis of adopted models has been carried out and a numerical setup has been defined.

  12. Multiobjective gear shifting optimization considering a known driving cycle

    Directory of Open Access Journals (Sweden)

    Fabio Mazzariol Santiciolli

    2015-07-01

    Full Text Available The reduction of the fuel consumption of the vehicles driven by combustion engines is a target of the automakers, governments and drivers. The literature asserts that the adjustment of the driver behavior results in a substantial fuel economy. Specifically, the gear shifting is one aspect of the driver behavior that can be changed by the use of support systems installed in the vehicle that indicate the right moment that the gear must be shifted. The interested community is focused on the development of the algorithms that are implemented in these support systems. These algorithms must be able to arbitrate between two antagonistic objective functions simultaneously: the maximization of the performance and the fuel economy. Thus, this paper demonstrates that it is possible to calculate the trade-off threshold between performance and fuel economy of a vehicle by means of the multiobjective optimization of the gear shifting considering a known driving cycle. To reach this objective, it is created a dynamic model of an automobile base on the literature data; the optimization algorithm implemented is Non-dominated Sorting Genetic Algorithm - II and the driving cycle used is described by the standards ABNT NBR6601:2012 and FTP-72.

  13. An Artificial Intelligence Approach for Gears Diagnostics in AUVs

    Science.gov (United States)

    Marichal, Graciliano Nicolás; Del Castillo, María Lourdes; López, Jesús; Padrón, Isidro; Artés, Mariano

    2016-01-01

    In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles), where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised. Furthermore, techniques based on several paradigms of the Artificial Intelligence (Neural Networks, Fuzzy systems and Genetic Algorithms) have been applied altogether in order to design an efficient fault diagnostic system. A hybrid Genetic Neuro-Fuzzy system has been developed, where it is possible, at the final stage of the learning process, to express the fault diagnostic system as a set of fuzzy rules. Several trials have been carried out and satisfactory results have been achieved. PMID:27077868

  14. An Artificial Intelligence Approach for Gears Diagnostics in AUVs.

    Science.gov (United States)

    Marichal, Graciliano Nicolás; Del Castillo, María Lourdes; López, Jesús; Padrón, Isidro; Artés, Mariano

    2016-04-12

    In this paper, an intelligent scheme for detecting incipient defects in spur gears is presented. In fact, the study has been undertaken to determine these defects in a single propeller system of a small-sized unmanned helicopter. It is important to remark that although the study focused on this particular system, the obtained results could be extended to other systems known as AUVs (Autonomous Unmanned Vehicles), where the usage of polymer gears in the vehicle transmission is frequent. Few studies have been carried out on these kinds of gears. In this paper, an experimental platform has been adapted for the study and several samples have been prepared. Moreover, several vibration signals have been measured and their time-frequency characteristics have been taken as inputs to the diagnostic system. In fact, a diagnostic system based on an artificial intelligence strategy has been devised. Furthermore, techniques based on several paradigms of the Artificial Intelligence (Neural Networks, Fuzzy systems and Genetic Algorithms) have been applied altogether in order to design an efficient fault diagnostic system. A hybrid Genetic Neuro-Fuzzy system has been developed, where it is possible, at the final stage of the learning process, to express the fault diagnostic system as a set of fuzzy rules. Several trials have been carried out and satisfactory results have been achieved.

  15. 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.

  16. Autism Diagnostic Interview-Revised (ADI-R) Algorithms for Toddlers and Young Preschoolers: Application in a Non-US Sample of 1,104 Children

    Science.gov (United States)

    de Bildt, Annelies; Sytema, Sjoerd; Zander, Eric; Bölte, Sven; Sturm, Harald; Yirmiya, Nurit; Yaari, Maya; Charman, Tony; Salomone, Erica; LeCouteur, Ann; Green, Jonathan; Bedia, Ricardo Canal; Primo, Patricia García; van Daalen, Emma; de Jonge, Maretha V.; Guðmundsdóttir, Emilía; Jóhannsdóttir, Sigurrós; Raleva, Marija; Boskovska, Meri; Rogé, Bernadette; Baduel, Sophie; Moilanen, Irma; Yliherva, Anneli; Buitelaar, Jan; Oosterling, Iris J.

    2015-01-01

    The current study aimed to investigate the Autism Diagnostic Interview-Revised (ADI-R) algorithms for toddlers and young preschoolers (Kim and Lord, "J Autism Dev Disord" 42(1):82-93, 2012) in a non-US sample from ten sites in nine countries (n = 1,104). The construct validity indicated a good fit of the algorithms. The diagnostic…

  17. International theme for seaside event.

    Science.gov (United States)

    Adie, Kate; Whitehorn, Will

    2014-05-01

    The organisers of this month's HefmA 2014 annual conference and exhibition promise delegates "the opportunity to hear international perspectives on the current issues facing the worldwide 'family' of health estates and facilities professionals". Conference speakers will include a US-based consultant architect discussing 'a transformational change programme which has achieved up to threefold greater throughput using the existing footprint in a US Emergency Department'; the assistant director, Facilities Services, at Health Facilities Scotland, focusing on HFS's work to ensure high training standards and succession planning, former BBC war correspondent, Kate Adie, describing some of the 'extraordinary experiences' of an eventful career, and Will Whitehorn, a former search-and-rescue helicopter crewman, who later became president of 'the world's first commercial spaceline', Virgin Galactic, giving his view on technology's impact in business. PMID:24930186

  18. Integrating Condition Indicators and Usage Parameters for Improved Spiral Bevel Gear Health Monitoring

    Science.gov (United States)

    Dempsey, Paula J.; Handschuh, Robert F.; Delgado, Irebert, R.

    2013-01-01

    The objective of this study was to illustrate the importance of combining Health Usage Monitoring Systems (HUMS) data with usage monitoring system data when detecting rotorcraft transmission health. Three gear sets were tested in the NASA Glenn Spiral Bevel Gear Fatigue Rig. Damage was initiated and progressed on the gear and pinion teeth. Damage progression was measured by debris generation and documented with inspection photos at varying torque values. A contact fatigue analysis was applied to the gear design indicating the effect temperature, load and reliability had on gear life. Results of this study illustrated the benefits of combining HUMS data and actual usage data to indicate progression of damage for spiral bevel gears.

  19. Determination Of The Wear Fault In Spur Gear System Using Statistical Process Control Method

    Directory of Open Access Journals (Sweden)

    Sinan Maraş

    2014-01-01

    Full Text Available Vibration analysis is one of the early warning methods widely used in obtaining information about faults occurring on the machine elements and structures. In this method, gear fault detection can be performed by analyzing of the vibration test results using signal processing, artificial intelligence and statistical analysis methods. The objective of this study is detection the existence of wear by examining changes in the vibrations of spur gears due to wear faults in statistical process control carts. In this study, artificial wear was created on the surfaces of spur gears in order to be examined in gears test rig. Then, these gears were attached and vibrations data were recorded by operating the system at various loading and number of cycles conditions. Detection of fault was demonstrated by analyzing undeformed and worn gears data in statistical process control carts by means of real-time experimental studies.

  20. Gear inspection and reconstruction based on laser metrology and computer algorithms

    Science.gov (United States)

    Torres Contreras, Ignacio; Muñoz Rodríguez, J. Apolinar; Garnica Campos, Guillermo

    2009-09-01

    An automatic technique for gear reconstruction is presented. In this technique, the gear modeling is performed by means of an approximation network. To carry it out, a vision system is implemented based on laser metrology. The approximation network is performed based on the gear pattern. To perform the contouring, the gear is scanned by a laser line. This process involves image processing of a laser line pattern. The network performs the gear modeling without measurements on the optical setup. In this manner, errors of the measurement are not added to the computational model. Thus, the setup performance and accuracy are improved. To describe the accuracy a mean square of error is calculated using data provided by the network and data given by a contact method. This technique is tested with real gears and its experimental results are presented.

  1. Bearing and gearing systems for rotary piston engines. Lager- und Getriebeanordnung einer Rotationskolbenmaschine

    Energy Technology Data Exchange (ETDEWEB)

    Eiermann, D.

    1991-03-14

    The proposed bearing and gearing system for rotary piston engines is provided with a trochoidal liner and triangular piston which is controlled by a synchromesh gear consisting of ring gear and pinion. The ring gear toothing is worked from the piston bore by shaping or broaching a depth of teeth which corresponds to the depth of the bore. A second, concentric bore inside the piston bore reaches from off the synchromesh gear to the ring gear and truncates the toothing of the latter. The stubs which are left hold the shell of the eccentric bearing. Cooling ducts are formed by the spaces in between. Since the bearing shell rests on the tooth stubs alone, the heat transfer from piston to eccentric bearing is considerably reduced.

  2. Confrontation of ordinary and special-type chain gear-toothing

    Energy Technology Data Exchange (ETDEWEB)

    Dolipski, M.

    1985-12-01

    A comparison between normal and special-type chain gear toothing illustrates the advantages of the latter: Smooth meshing of the horizontal links; better load distribution on the driving shaft and less excitation of vibrations; lower impact loads avoiding additional loads on the chain links and pockets; smaller amplitudes of the dynamic loads on the chain; frictional connection of the horizontal links at the pocket bottom in addition to the interloading with the teeth; gradual reduction of the tensile force in the chain links during rotation; minimum loads on the driving gear teeth reducing the hazard of tooth fracture; low wear on the gear teeth; better performance. Specific-type chain gear toothing is recommended for driving gear. This has the additional advantage of preventing chain link jamming during running-in, thus prolonging the life of driving gears.

  3. 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.

  4. Analysis of dynamic capacity of low-contact-ratio spur gears using Lundberg-Palmgren theory

    Science.gov (United States)

    Coy, J. J.

    1975-01-01

    A concise mathematical model is developed for surface fatigue life of low-contact-ratio spur gears. The expected fatigue life of the pinion, gear, or gear sets may be calculated from the model. An equation for the dynamic capacity of the gear set was also derived in terms of the transmitted tangential tooth load which will give a 10-percent fatigue life of one million pinion revolutions. The theoretical life was compared with experimental data for a set of VAR AISI 9310 gears operating at a Hertz stress of 1.71X10 to the 9th power newtons per square meter (248,000 psi) and 10 000 revolutions per minute. Good agreement was obtained between the experimental and theoretical surface fatigue life of the gears.

  5. Gearsketch: An Adaptive Drawing-Based Learning Environment for the Gears Domain

    Science.gov (United States)

    Leenaars, Frank A.; Joolingen, Wouter R.; Gijlers, Hannie; Bollen, Lars

    2014-01-01

    GearSketch is a learning environment for the gears domain, aimed at students in the final years of primary school. It is designed for use with a touchscreen device and is based on ideas from drawing-based learning and research on cognitive tutors. At the heart of GearSketch is a domain model that is used to transform learners' strokes into…

  6. Bifurcation analysis of a coupled nose-landing-gear-fuselage system

    OpenAIRE

    Terkovics, Nándor; Neild, Simon; Lowenberg, Mark; Krauskopf, Bernd

    2014-01-01

    Under certain conditions during takeoff and landing, pilots may sometimes experience vibrations in the cockpit. Because the cockpit is located right above the nose landing gear, which is known to potentially be prone to self-excited vibrations at certain velocities, an explanation for those vibrations might be oscillations of the landing gear feeding into the fuselage. However, the fuselage dynamics itself may also influence the dynamics of the landing gear, meaning that the coupling must be ...

  7. THE CALCULATION OF THE STRESS-STRAIN STATE OF THE FRONT LANDING GEAR TRANSPORT AIRCRAFT

    OpenAIRE

    Trubachev, Sergei Ivanovych; Alekseychuk, Olga Mykolaivna

    2014-01-01

    The modeling and calculation object is the front rack of landing gear of the aircraft. To solve the problem of determining the stress-strain state of the front rack landing gear an analytical methods are inefficient due to complex geometry, so it is advisable to apply numerical simulation. The calculation of landing gear structural elements by finite element method was implemented with using the complex software ANSYS, which allows with a high degree of accuracy to determine the characteristi...

  8. Computational analysis of the effect of bogie inclination angle on landing gear noise

    OpenAIRE

    van Mierlo, K.J.; Takeda, K.; Peers, E.

    2010-01-01

    Airframe noise and in particular main landing gear noise is a major noise source during the approach phase. Wind tunnel tests have shown a strong relationship between the inclination angle of the bogie and the noise radiation of a main landing gear. Using Computational Fluid Dynamics, this paper investigates the flow features around three different configurations of a simplified four wheel main landing gear. The three configurations consist of a horizontal, 10 degree toe up and 10 degree t...

  9. Computer Aided Design and Stress Analysis of Nose Landing Gear Barrel (NLGB)

    OpenAIRE

    Sanjay Kumar Sardiwal; D. Harika Chowdary

    2015-01-01

    During the conceptual design phase of aircraft the integration of undercarriage system is very important and it is often difficult to achieve on the first time. The nose wheel landing gear preferred configurations for light naval trainer aircraft. The main objective of this project is to improve the static strength criteria and fatigue life of Nose Landing Gear Barrel considered. The investigations includes preliminary design layout for Nose Landing Gear Barrel and initial sizing ...

  10. Bifurcation analysis of nose landing gear shimmy with lateral and longitudinal bending

    OpenAIRE

    Thota, P; Krauskopf, B; Lowenberg, MH

    2009-01-01

    We develop and study a model of an aircraft nose landing gear with torsional, lateral and longitudinal degrees of freedom. The corresponding three modes are coupled in a nonlinear fashion via the geometry of the landing gear in the presence of a nonzero rake angle, as well as via the nonlinear tyre forces. Their interplay may lead to different types of shimmy oscillations as a function of the forward velocity and the vertical force on the landing gear. Methods from nonlinear dynamics, especia...

  11. Vibration Attenuation of Magnetorheological Landing Gear System with Human Simulated Intelligent Control

    OpenAIRE

    X. M. Dong; Xiong, G. W.

    2013-01-01

    Due to the short duration of impulsive impact of an aircraft during touchdown, a traditional landing gear can only achieve limited performance. In this study, a magnetorheological (MR) absorber is incorporated into a landing gear system; an intelligent control algorithm, a human simulated intelligent control (HSIC), is proposed to adaptively tune the MR absorber. First, a two degree-of-freedom (DOF) dynamic model of a landing gear system featuring an MR absorber is constructed. The control mo...

  12. Enhancing the Precision of Timing Gear Used in Automobile by Making Use of Azotizing Deformation

    Directory of Open Access Journals (Sweden)

    Wei Yangang

    2016-01-01

    Full Text Available Statistic analysis about the effect of heat treatment deformation on tooth profile deviation distribution of the timing gear used in automobile is done with mathematical statistics. Based on the research on the effect of the heat treatment deformation on tooth profile deviation, helical deviation and common normal length etc, the processing measure, tolerance and correcting quantity before and after azotizing treatment can be adjusted to optimize the gear process and to enhance processing precision of the gear.

  13. Faults Analysis and Diagnosis of DR J-460 Dish Centrifugal Separator's Helical Gear

    Institute of Scientific and Technical Information of China (English)

    MA Xiao-jian; GAN Xue-hui

    2004-01-01

    The main faults of dish centrifugal separator's helical gear are described in this paper. In order to diagnose the DR J-460 dish centrifugal separator correctly, the vibration is tested with a helical gear under both normal and abnormal conditions. After comparing several general methods of the gear's fault feature extraction, a new convenient and effective method is presented on the basis of analyzing the vibration spectrum under different rotary velocities.

  14. Damage types of crossed helical gears with wheels from sintered steel

    OpenAIRE

    Miltenović A.; Predki W.

    2011-01-01

    Sintered steel appears to be a very effective material for wheels in crossed helical gears. High demands are set on gears made from sintered steel regarding wear, fretting, tooth fracture and pitting load capacity. This report shows results of iron-based sintered material Fe1.5Cr0.2Mo in case of crossed helical gears concerning wear resistance and other damage types under different speed, torque and lubricants. As material variants, samples with additional treatment, such as pyrohydroly...

  15. The Impact of Analog and Bang-Bang Steering Gear Control on Ship's Fuel Economy

    DEFF Research Database (Denmark)

    Nørtoft Thomsen, J. C.; Blanke, Mogens; Reid, R. E.;

    1982-01-01

    The latest years have shown considerable efforts towards improving steering generated propulsion losses of ships by the introduction of various sophisticated control algorithms in the autopilots. However, little previous attention has been given to the steering gear control loop, although it is...... found to be at least equally important regarding steering performance and fuel economy. The paper presents a comprehensive survey of steering gear principles commonly used, including relevant details of three analog steering gear servo principles, which have outperformed conventional designs. Control...

  16. Load capacity of hardened gear wheels machined with cubic boron nitride (CBN wedges

    Directory of Open Access Journals (Sweden)

    R. Talar

    2013-07-01

    Full Text Available The paper presents the results of exploitation examination of gear wheels with hardened bearing surface. The gears under investigation have been finish machined by the method elaborated by the author, with a tool possessing wedges made of CBN (cubic boron nitride. The symptoms of tooth surface wear having arisen during operation on the test rig with power loop. Assessment of the gear wheels’ capacity of carrying loads under EHL (ElastoHydrodynamic Lubrication conditions has been performed.

  17. Ecological indicators and gear-based management of Algarve coastal fisheries

    OpenAIRE

    Conduto, Telma Lúcia Pereira dos Santos Coelho

    2007-01-01

    Dissertação mest., Aquacultura e Pescas, Universidade do Algarve, 2007 A number of ecological indicators were used to study the impact of fishing gear on the Algarve marine ecosystem. Catch composition, species richness, diversity, mean length, trophic level, percentage of mature and optimum sized fish and percentage of megaspawners were determined for the fish catches of each gear type. Four types of static gears (gill nets, trammel nets, bottom longline and semi-pelagic longline) with di...

  18. Aeroacoustic characterization of scaled canonical nose landing gear configurations

    Science.gov (United States)

    Zawodny, Nikolas S.

    Aircraft noise is a critical issue in the commercial airline industry. Airframe noise is a subcomponent of aircraft noise and is generally dominant over jet engine noise during approach conditions, which can lead to high community impact. Landing gears have been identified as major components of airframe noise during landing configurations for commercial aircraft. They are perhaps the least understood contributors to airframe noise due to complex flow patterns associated with intricate gear component geometries. Nose landing gear in particular have received much attention in recent years, exhibiting acoustic signatures on the order of the main landing gear assembly of an aircraft, while simultaneously being more amenable to scaled wind tunnel testing. In order to characterize the acoustic signature of a complex geometry such as a nose landing gear, it is important to isolate, study, and understand the acoustic contributions of individual component geometries. The purpose of this dissertation is to develop a correlation between the complex flow field nature and far-field acoustic signature of a nose landing gear sub-system. The model under investigation is a 1/2-scale shock-strut cylinder coupled with an adjustable torque link apparatus. This geometry was chosen due to its fundamental importance and implementation across a wide span of commercial aircraft. The fluid dynamic (surface pressure and stereoscopic particle image velocimety) and aeroacoustic (far-field microphone and phased array) experiments were performed in the University of Florida Aeroacoustic Flow Facility. The experimental data compare favorably with the results of a numerical simulation using PowerFLOW, a lattice-Boltzmann solver developed by the Exa Corporation. The far-field acoustic results of this dissertation have shown non-uniform scaling behavior as a function of frequency for the different model configurations tested. For frequencies that appropriately satisfied the condition of acoustic

  19. Adição de plasma seminal ao sêmen descongelado e taxa de prenhez de ovelhas inseminadas em tempo fixo

    Directory of Open Access Journals (Sweden)

    O.R. Prado

    2013-02-01

    Full Text Available Avaliou-se o efeito da adição de plasma seminal ovino ao sêmen descongelado sobre a taxa de prenhez de ovelhas em rebanho comercial. Cento e setenta e quatro ovelhas cruza Texel foram distribuídas em quatro tratamentos: T1 inseminação artificial cervical (IAC com sêmen descongelado (SD diluído em solução tampão fosfato salino (PBS; T2 IAC com SD e adição de plasma seminal ovino; T3 grupo-controle I: IAC com sêmen fresco diluído em PBS; T4 grupo-controle II: inseminação artificial por laparoscopia com SD diluído em PBS. Para indução de cio, utilizaram-se esponjas impregnadas com acetato de medroxiprogesterona (MAP por 12 dias, com aplicação intramuscular de 400 UI de eCG (Novormon® e de 37,5µg de cloprostenol sódico (Sincrocio®, no dia da retirada das esponjas. O aparecimento de cio foi monitorado com rufiões vasectomizados a partir da retirada das esponjas até a inseminação artificial em tempo fixo - 54 a 60 horas. A taxa de prenhez do tratamento com adição de plasma seminal ao sêmen descongelado (7,0% não diferiu (P>0,05 do tratamento sem adição de plasma (4,3%, entretanto foi menor (P<0,05 se comparada à taxa de prenhez dos grupos-controle I inseminação via cervical superficial com sêmen fresco diluído (50,0% e II inseminação via laparoscopia com sêmen descongelado (39,4%. A inseminação artificial por via cervical superficial com adição de plasma seminal ao sêmen descongelado não elevou o percentual de prenhez em valores que justifiquem a indicação desta biotecnologia em rebanhos comerciais de ovinos.

  20. Generation of noncircular gears for variable motion of the crank-slider mechanism

    Science.gov (United States)

    Niculescu, M.; Andrei, L.; Cristescu, A.

    2016-08-01

    The paper proposes a modified kinematics for the crank-slider mechanism of a nails machine. The variable rotational motion of the driven gear allows to slow down the velocity of the slider in the head forming phase and increases the period for the forming forces to be applied, improving the quality of the final product. The noncircular gears are designed based on a hybrid function for the gear transmission ratio whose parameters enable multiple variations of the noncircular driven gears and crack-slider mechanism kinematics, respectively. The AutoCAD graphical and programming facilities are used (i) to analyse and optimize the slider-crank mechanism output functions, in correlation with the predefined noncircular gears transmission ratio, (ii) to generate the noncircular centrodes using the kinematics hypothesis, (iii) to generate the variable geometry of the gear teeth profiles, based on the rolling method, and (iv) to produce the gears solid virtual models. The study highlights the benefits/limits that the noncircular gears transmission ratio defining hybrid functions have on both crank-slider mechanism kinematics and gears geometry.

  1. Precise modeling of arc tooth face-gear with transition curve

    Institute of Scientific and Technical Information of China (English)

    Cui Yanmei; Fang Zongde; Su Jinzhan; Feng Xianzhang; Peng Xianlong

    2013-01-01

    A fabrication method is adopted for which an imaginary gear simultaneously realizes conjugated meshing with an arc tooth cylindrical gear and an arc tooth face-gear. The cutter fillet and tooth crest edge form the tooth root fillet of the gear, and the linear tooth surface equation of the imaginary gear and the position vector of the curvature center of the cutter fillet are constructed with certain cutter inclination to deduce a working arc tooth surface equation. The tooth root fillet equation of the arc tooth face-gear is derived from the meshing geometry and kinematics. A numer-ically controlled machining model of the arc tooth face-gear is established through the transforma-tion of adjustment parameters from the cutter-tilt milling machine to a common multi-axis NC machine. Motion parameters of each movement axis of the NC machine are acquired. A processing example is presented to verify the precision of the fabrication method in processing the arc tooth face-gear. The method provides a theoretical and tentative basis for the analysis of tooth surface contact stress, tooth root bending stress and dynamics. A hobbing test is conducted to demonstrate the good meshing condition of the arc tooth face-gear pair.

  2. Performance-based gear metrology kinematic, transmission, error computation and diagnosis

    CERN Document Server

    Mark, William D

    2012-01-01

    A mathematically rigorous explanation of how manufacturing deviations and damage on the working surfaces of gear teeth cause transmission-error contributions to vibration excitations Some gear-tooth working-surface manufacturing deviations of significant amplitude cause negligible vibration excitation and noise, yet others of minuscule amplitude are a source of significant vibration excitation and noise.   Presently available computer-numerically-controlled dedicated gear metrology equipment can measure such error patterns on a gear in a few hours in sufficient detail to enable

  3. Research on the Comprehensive Demodulation of Gear Tooth Crack Early Fault

    Institute of Scientific and Technical Information of China (English)

    CUI Lingli; DING Fang; GAO Lixin; ZHANG Jianyu

    2006-01-01

    The component of gear vibration signal is very complex, when a localized tooth defect such as a tooth crack is present, the engagement of the cracked tooth will induce an impulsive change with comparatively low energy to the gear mesh signal and the background noise. This paper presents a new comprehensive demodulation method which combined with amplitude envelop demodulation and phase demodulation to extract gear crack early fault. A mathematical model of gear vibration signal contain crack fault is put forward. Simulation results based on this model show that the new comprehensive demodulation method is more effective in finding fault and judging fault level then conventional single amplitude demodulation at present.

  4. Development of a high accurate gear measuring machine based on laser interferometry

    Science.gov (United States)

    Lin, Hu; Xue, Zi; Yang, Guoliang; Huang, Yao; Wang, Heyan

    2015-02-01

    Gear measuring machine is a specialized device for gear profile, helix or pitch measurement. The classic method for gear measurement and the conventional gear measuring machine are introduced. In this gear measuring machine, the Abbe errors arisen from the angle error of guideways hold a great weight in affection of profile measurement error. For minimize of the Abbe error, a laser measuring system is applied to develop a high accurate gear measuring machine. In this laser measuring system, two cube-corner reflectors are placed close to the tip of probe, a laser beam from laser head is splited along two paths, one is arranged tangent to the base circle of gear for the measurement of profile and pitch, another is arranged parallel to the gear axis for the measurement of helix, both laser measurement performed with a resolution of 0.3nm. This approach not only improves the accuracy of length measurement but minimize the Abbe offset directly. The configuration of this improved measuring machine is illustrated in detail. The measurements are performed automatically, and all the measurement signals from guide rails, rotary table, probe and laser measuring system are obtained synchronously. Software collects all the data for further calculation and evaluation. The first measurements for a gear involute artifact and a helix artifact are carried out, the results are shown and analyzed as well.

  5. On the Influence of Force Distribution and Boundary Condition on Helical Gear Stiffness

    Directory of Open Access Journals (Sweden)

    Niels Leergaard Pedersen

    2015-07-01

    Full Text Available The gear stiffness has a direct influence on the dynamic response of transmission systems that include a gear box, the stiffness also controls the load distribution among the teeth in mesh. The stiffness of a gear tooth varies non-linearly as the contact line with the meshing gear tooth moves along the surface of the tooth and the resulting meshing stiffness also includes discontinuities. The stiffness estimation for helical gears can only be done using full 3D analysis contrary to spur gears where 2D often suffice. Besides the usual gear geometry defined by standards two factors are found to have a large influence on the stiffness. These two factors are the rim thickness included in the stiffness calculation and the contact zone size. In the contact zone the distribution of the load is also shown to be important. Simple possible simplifications in relation to the contact load distribution are presented. The gear stiffness is found using the elastic energy of the loaded tooth. In the finite element calculation the true gear tooth root profile is applied.

  6. Determination of Geometrical Parameters for Semi-Rolling Bevel Precessional Gears With Straight Teeth

    Science.gov (United States)

    Syzrantsev, V.; Syzrantseva, K.; Milanovic, M.; Pazyak, A.

    2016-08-01

    The aim of this paper is to analyse the semi-rolling bevel precessional gear with straight teeth. The given method of cutting pinion and gear teeth significantly simplifies its manufacture technology. Authors have given a system of equations to study the analysis of generating pinion tooth surfaces and geometry of meshing for semi-rolling bevel precessional gear with straight teeth. A computer program was developed to enable implement formulas provided in the paper. By using this program authors obtained contact lines on the pinion tooth surface and number of tooth pairs in gears mesh.

  7. Ángulos de conos primitivos y relación de transmisión virtual en engranajes cónicos. // Pitch angles and gear ratio of virtual cylindrical gear on bevel gears.

    Directory of Open Access Journals (Sweden)

    E. Mirabet Lemos

    2007-09-01

    Full Text Available En el presente trabajo se realiza la deducción de expresiones generales para el cálculo de los semi-conos primitivos de los engranajescónicos. Para dicha deducción se realiza un análisis geométrico mediante el empleo de cuatro paralelogramos rectangulares. Lasexpresiones determinadas pueden ser aplicadas a engranajes cónicos con un ángulo cualquiera entre sus ejes.Palabras claves: Engranajes cónicos, conos primitivos, relación de transmisión.________________________________________________________________________________AbstractsIn the present work, general relations for the calculation of pitch angles of bevel gears and gear ration of virtual cylindrical gearare given. For the mathematical processing is carried out a geometric analysis by means of four rectangular parallelograms. Thefound expressions can be applied to bevel gears with any shaft angles.Key words: Bevel gear, pith angles, virtual ratio of transmission.

  8. Cinza de palha de cana-de-açúcar como adição mineral em fibrocimento

    Directory of Open Access Journals (Sweden)

    Michelle S. Rodrigues

    2013-12-01

    Full Text Available O Brasil é o maior produtor mundial de cana-de-açúcar e sua indústria sucroalcooleira gera grande quantidade de resíduos líquidos e sólidos, dentre eles a palha da cana-de-açúcar. Com o objetivo de agregar valor a este resíduo produziu-se, neste trabalho, cinza de palha de cana-de-açúcar por meio da queima controlada a 700 °C e se avaliou sua aplicação como adição mineral em compósitos de fibrocimento. A cinza foi caracterizada pelas técnicas de fluorescência de raios X, difração de raios X, granulometria a laser e superfície específica. Nos compósitos foram avaliadas as propriedades de absorção de água, porosidade aparente, massa específica aparente, módulo de ruptura, energia específica, módulo de elasticidade e limite de proporcionalidade. A caracterização das cinzas indicou superfície específica e porosidade elevadas, além de apresentar um halo de amorficidade no seu difratograma. Compósitos produzidos com as cinzas mostraram características físicas e mecânicas similares àquelas do controle o que viabiliza a substituição parcial do cimento Portland por esse tipo de cinzas.

  9. Development of a tanks line for waxing landing gear parts

    OpenAIRE

    Calvo Narvaez, Felix; Rodríguez Monroy, Carlos

    2012-01-01

    The aim of this article is to define the technical specifications and to design the implementation of a line of tanks that would be used in the process of waxing and de-waxing large pieces. As it is based in a real case, it is also analyzed the process of dismantling the former installation that supported these functions. The origin of this project is due to a new rating for the maintenance of landing gears which makes the previous waxing line that was prepared to work on smaller aircraft?s p...

  10. Plasmonic rack-and-pinion gear with chiral metasurface

    Science.gov (United States)

    Gorodetski, Yuri; Karabchevsky, Alina

    2016-04-01

    The effect of circularly polarized beaming excited by traveling surface plasmons, via chiral metasurface is experimentally studied. Here we show that the propagation direction of the plasmonic wave, evanescently excited on the thin gold film affects the handedness of the scattered beam polarization. Nanostructured metasurface leads to excitation of localized plasmonic modes whose relative spatial orientation induces overall spin-orbit interaction. This effect is analogical to the rack-and-pinion gear: the rotational motion into the linear motion converter. From the practical point of view, the observed effect can be utilized in integrated optical circuits for communication systems, cyber security and sensing.

  11. Experimental Evaluation of a Motor Integrated Permanent Magnet Gear

    DEFF Research Database (Denmark)

    Rasmussen, Peter Omand; Frandsen, Tommy; Jensen, Kasper Køtter;

    2011-01-01

    This paper presents test results of a new motor integrated permanent magnet gear and clarifies a path for future optimizations. The prototype, which fabrication also is described, is initially targeting electrical traction for vehicles. Basic measured parameters in form of back-emf, stall torque...... by a non optimal diameter/length aspect ratio. The torque density is superior, the copper losses is only a fraction of the copper losses in other traction motors. With the proposed aspects to reduce the rotational losses is it believed that the unit has a great potential....

  12. Fuzzy fault tree analysis of roller oscillating tooth gear drive

    Institute of Scientific and Technical Information of China (English)

    李瑰贤; 杨伟君; 张欣; 李笑; 刘福利

    2002-01-01

    Conventional fault tree and reliability analysis do not reflect the characteristics of basic events asnon-stationary and ergodic process. To overcome these drawbacks, theory of fuzzy sets is employed to run faulttree analysis(FTA) of roller oscillating tooth gear drive( ROTGD), the relative frequencies of basic events areconsidered as symmetrical normal fuzzy numbers, from the logical relationship between different events in thefault tree and fuzzy operators AND and OR, fuzzy probability of top event is solved. Finally, an example is giv-en to demonstrate a real ROTGD system.

  13. EFFECT OF FRICTIONAL FORCE ON GEARING CONTACT FATIGUE STRENGTH

    Institute of Scientific and Technical Information of China (English)

    Ql Xiumei; GAO Chuangkuan

    2007-01-01

    The model for computing frictional coefficient between two teeth faces at the state of mixed elastohydrodynamic lubrication is established. And then more than 80 sets of numerical calculations and six sets of disc fatigue tests are completed. The results show that when the film thickness ratio λ<1.6, frictional coefficient μ is drastically decreased as λ rises; Thereafter it decreases smoothly until λ=4.5. When λ>4.5, however, it goes up again with λ, which indicates that the excessive film thickness ratio will deteriorate gearing contact fatigue strength. At the end, the formulae for determining the frictional coefficients are formed.

  14. Research on Gear Shifting Process without Disengaging Clutch for a Parallel Hybrid Electric Vehicle Equipped with AMT

    Directory of Open Access Journals (Sweden)

    Hui-Long Yu

    2014-01-01

    Full Text Available Dynamic models of a single-shaft parallel hybrid electric vehicle (HEV equipped with automated mechanical transmission (AMT were described in different working stages during a gear shifting process without disengaging clutch. Parameters affecting the gear shifting time, components life, and gear shifting jerk in different transient states during a gear shifting process were deeply analyzed. The mathematical models considering the detailed synchronizer working process which can explain the gear shifting failure, long time gear shifting, and frequent synchronizer failure phenomenon in HEV were derived. Dynamic coordinated control strategy of the engine, motor, and actuators in different transient states considering the detailed working stages of synchronizer in a gear shifting process of a HEV is for the first time innovatively proposed according to the state of art references. Bench test and real road test results show that the proposed control strategy can improve the gear shifting quality in all its evaluation indexes significantly.

  15. Life test failure of harmonic gears in a Two-axis Gimbal for the Mars Reconnaissance Orbiter Spacecraft

    Science.gov (United States)

    Johnson, Michael R.; Gehling, Russ; Head, Ray

    2006-01-01

    This paper will present a process for increasing the stiffness of harmonic gear assemblies and recommend a maximum stiffness point that, if exceeded, compromises the reliability of the gear components for long life applications.

  16. 77 FR 27663 - Airworthiness Directives; Aeronautical Accessories, Inc. High Landing Gear Forward Crosstube...

    Science.gov (United States)

    2012-05-11

    ... Accessories, Inc. High Landing Gear Forward Crosstube Assembly AGENCY: Federal Aviation Administration (FAA... directive (AD) for Aeronautical Accessories, Inc. (AAI) high landing gear forward crosstube assemblies... crosstubes. The proposed actions are intended to prevent failure of a crosstube, collapse of the landing...

  17. Computing Surface Coordinates Of Face-Milled Spiral-Bevel Gear Teeth

    Science.gov (United States)

    Handschuh, Robert F.; Litvin, Faydor L.

    1995-01-01

    Surface coordinates of face-milled spiral-bevel gear teeth computed by method involving numerical solution of governing equations. Needed to generate mathematical models of tooth surfaces for use in finite-element analyses of stresses, strains, and vibrations in meshing spiral-bevel gears.

  18. A NEW GENERATING METHOD FOR THE MACHINING OF A CYLINDRICAL GEAR WITH SYMMETRIC ARCUATE TOOTH TRACE

    Institute of Scientific and Technical Information of China (English)

    马振群; 龚堰珏; 王小椿

    2004-01-01

    Objective To introduce a new generating method for the machining of a cylindrical gear with symmetric arcuate tooth trace. Methods Adopting this method, the key problems of mismatch control and manufacturing of symmetric arcuate tooth trace gears are solved by using suitable cutter tilt and a new generating method with double-edge gear-wheel cutter. The machining principle is analyzed and the mathematical model of generating motion is established. Then the tooth flank equation and differential geometrical parameters are discussed. Results The minim alteration of cutter tilt will make the contact flank area change so as to satisfy the special requirements. It is easy to realize the tip relief of gearing by altering coefficients of every moving axis. Because the tooth has the arc shape, the symmetrical arcuate cylindrical gears have higher overall strength and it is easy to perform the flank grinding for high precision. Conclusion This new generating method has higher productivity. It is easy to get a perfect contact zone and fully give play to the potential bearing capacity of the gears. The symmetrical arcuate cylindrical gears can be used in highly durable and heavy duty gearing applications.

  19. Relationship between gear ratio and 10-s sprint cycling on an air-braked ergometer.

    Science.gov (United States)

    Barnett, C; Jenkins, D G; Mackinnon, L T

    1996-01-01

    This investigation examined the relationship between gear ratio and peak and mean power outputs (PPO and MPO) and peak cadence (PC) during a 10-s all-out sprint on a multi-geared air-braked cycle ergometer. Ten physically active men [mean age 21.0 years (SEM 0.7)] performed in random order six 10-s sprints (15-min rest between each sprint) on two occasions (48 h apart) in six different gear ratios; flywheel revolutions per pedal crank revolution (FR/PCR) ranged between 5.22 and 11.61. The PPO, MPO, and PC were recorded from each sprint. Of the six gear ratios tested, a gear ratio eliciting 8.87 FR/PCR elicited the highest PPO for the initial test session; the PPO output of 1274 W was significantly greater (P gears. Analysis of data from the second test session revealed no statistically significant difference in PPO between gear ratios eliciting 8.00, 8.87, and 10.06 FR/PCR. The PPO from these three ratios were significantly greater (P gear ratio maximising PPO was 120 rpm. Analysis of PC data revealed a significant decrease (P < 0.05) as the number of FR/PCR increased. PMID:8925824

  20. 46 CFR 97.15-3 - Steering gear, whistle, and means of communication.

    Science.gov (United States)

    2010-10-01

    ... MISCELLANEOUS VESSELS OPERATIONS Tests, Drills, and Inspections § 97.15-3 Steering gear, whistle, and means of communication. (a) On all vessels making a voyage of more than 48 hours' duration, the entire steering gear, the whistle, and the means of communication between the bridge or pilothouse and the engineroom shall...

  1. 46 CFR 196.15-3 - Steering gear, whistle, and means of communication.

    Science.gov (United States)

    2010-10-01

    ... RESEARCH VESSELS OPERATIONS Test, Drills, and Inspections § 196.15-3 Steering gear, whistle, and means of communication. (a) On all vessels making a voyage of more than 48 hours duration, the entire steering gear, the whistle, and the means of communication between the bridge or pilothouse and engineroom shall be...

  2. An experimental and theoretical study of the dynamic behavior of double-helical gear sets

    Science.gov (United States)

    Kang, M. R.; Kahraman, A.

    2015-08-01

    In this study, dynamic behavior of a double-helical gear pair is investigated both experimentally and theoretically. In the experimental side, a new double-helical test set-up consisting of a test machine and test specimens is developed for operating a double-helical gear pair under realistic torque and speed ranges. A test gear pair formed by novel three-piece double-helical gears is developed to allow adjustable right-to-left stagger angles. A measurement system to capture three-dimensional vibratory motions and dynamic motion transmission error under high-speed conditions is implemented. A test matrix that included various combinations of key system parameters is executed under realistic torque values within a wide speed range to establish a database. In view of this experimental data, a linear, time-invariant dynamic model of double-helical gear pair systems including shafts and bearing supports is proposed, also allowing for any stagger angle between the right and left sides of a double-helical gear pair through proper definition of phasing between the two gear mesh excitations. Direct comparisons to measurements are presented to demonstrate the accuracy of the proposed model in predicting three-dimensional gear vibrations. The right-to-left stagger angle is shown to be the most critical parameter impacting dynamic response.

  3. EQUIDISTANT TOOTH GENERATION ON NONCYLINDRICAL SURFACES FOR TWO-PARAMETER GEARING

    Directory of Open Access Journals (Sweden)

    Yuriy GUTSALENKO,

    2011-11-01

    Full Text Available The questions of design research of noncylindrical tooth surfaces for two-parameter gearing on example of bevel gears with constant normal pitch forgearing variators are been considered. Engineering is based on the special applied development of the mathematical theory of multiparametric mappings of space.

  4. THE APPLICATION OF UNIVERSAL CNC MACHINE TOOL FOR SPUR GEARS MANUFACTURING

    Directory of Open Access Journals (Sweden)

    Leszek Skoczylas

    2013-09-01

    Full Text Available The article introduces two variants of making spur gears by using universal CNC machine tools with universal shank cutter. The measurement of the chosen parameters of geometric structures of gear tooth surface were carried out as well as their comparison was made.

  5. Finish machining of hardened gears wheels using cubic boron nitride (CBN inserts

    Directory of Open Access Journals (Sweden)

    R. Talar

    2012-04-01

    Full Text Available The paper presents some results of investigation of finish machining of hardened bearing surfaces of cylindrical gear wheels. Finish machining has been performed with wedges of defined geometry made of CBN. The presented investigation results are related mainly to the wear processes of the cutting wedges. Additional results of quality examination of finish machined gear wheels have been presented, too.

  6. Development and validation of a new reference cylindrical gear for pitch measurement

    DEFF Research Database (Denmark)

    Malberg, Maria Pia Sammartini; De Chiffre, Leonardo

    2000-01-01

    A new type of master gear, the Gauge Block Gear (GBG), was developed for the performance verification of coordinate measuring machines (CMMs), for the specific task of pitch and chordal tooth thickness measurement. Its main characteristic is the replacement of the teeth with gauge blocks, in order...

  7. 50 CFR 660.231 - Limited entry fixed gear sablefish primary fishery.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Limited entry fixed gear sablefish primary... primary fishery. This section applies to the sablefish primary season for the limited entry fixed gear... sablefish primary season north of 36° N. lat. is governed by routine management measures imposed...

  8. A Study on Contact Fatigue Performance of Nitrided and TiN Coated Gears

    Directory of Open Access Journals (Sweden)

    Hongbin Xu

    2013-01-01

    Full Text Available This paper discusses the effects of TiN coating on gear contact fatigue performance through contact fatigue experiment and gear rig test. The results reveal that the deposition on gears with hard coating TiN could provide the subsurface protection and improve the contact fatigue life, and the contact fatigue strength of nitrided+TiN coated 32Cr2MoV is 1557 MPa at survival probability of 99%, 284 MPa higher than that of nitrided 32Cr2MoV. Although TiN coating on the the edge of the meshing zone wore out, there is no obvious pitting at the site and the rest of meshed zone of TiN coated gear keeps well without pittings and wear grooves, which is opposite to nitrided gears with pittings and peeling off. TiN coating is dense and smooth with lower surface roughness, and it wraps up the gear tooth so that the gear surface no longer contacts with lubricant and prevents the cracks initiation, prolonging the contact fatigue life of gears.

  9. Rational Design of Spur Gears Directed to Increase Efficiency and Decrease Loss by Friction

    Directory of Open Access Journals (Sweden)

    Gonzalo González Rey

    2010-10-01

    Full Text Available External parallel-axis cylindrical gears are considered as very efficient means for transmitting mechanical power, but for requirements of maximum efficiency in the current machines and equipments a precision in the procedures of calculation of power losses is necessary. In this sense, the Technical Report ISO / TR 14179-1:2001 offers formulas with empirical and theoretical bases to evaluate the gear efficiency considering gear mesh losses, windage and churning losses, and losses by bearings and seals. In particular, this article presents some results derived from a study of ISO/TR 14179-1:2001 and mathematical models described the interrelation of gear geometry, working parameters and efficiency. The results offer solution to the problem of increasing gear efficiency through a convenient relationship between the load, speed and rational gear geometry. Finally, through multiple regression a new formulation was estimated for the calculation of gear efficiency as a function of the load density, module, speed, gear ration and number of pinion teeth.

  10. Numerical simulation of the anti-shock performance of a gear case

    Institute of Scientific and Technical Information of China (English)

    YAO Xiong-liang; ZHOU Qi-xin; ZHANG A-man; FENG Lin-han

    2008-01-01

    Both sea battles and testing of ship in underwater explosions reveal unacceptably poor anti-shock performance of important shipboard equipment. Anti-shock performance of shipboard equipment is a significant factor determining fighting strength and survivability. The anti-shock performance of a shipboard gear case based on BV043/85 was investigated using numerical simulation. A geometric model of the gear case was built using MDT software and meshed in HyperMesh software, and then the finite element model of the gear case was formed. Using ABAQUS software, the anti-shock performance of the gear case was simulated. First, shock response of typical regions of gear case was determined. Next, some generalizations were made about the anti-shock performance of the gear case by analyzing the Mises stress of typical regions varied with shock inputs. Third, weak regions were determined from simulation results. The threshold values of shock resistance of the gear case at different impulse widths were obtained through interpolating the numerical simulation results selected from the most dangerous spot. This research provides a basis for further optimization of the design of gear cases.

  11. 29 CFR Appendix III to Part 1918 - The Mechanics of Conventional Cargo Gear (Non-mandatory)

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false The Mechanics of Conventional Cargo Gear (Non-mandatory.... 1918, App. III Appendix III to Part 1918—The Mechanics of Conventional Cargo Gear (Non-mandatory) Note: This appendix is non-mandatory and provides an explanation of the mechanics in the correct spotting...

  12. Research on Gear-broken Fault Diagnosis in a Tank Gearbox

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A fault diagnosis method of working position gear in a tank gearbox is put forward based on simulating the fault of working position gear in an actual tank, extracting the envelope of vibration signal by Hilbert transformation amplitude demodulation method, and zooming the low-frequency band to envelope signal.

  13. An Investigation on the Suitability of Abrasive Waterjet Cutting for Hybrid Manufacturing of Gears in Automotive Industry

    OpenAIRE

    Babashov, Vusal; Mammadova, Gunel

    2015-01-01

    Gears are components in mechanical assemblies used for transmitting power and motion. Gear form cutting (broaching, milling) and gear generating (shaping and hobbing) are two of the main gear manufacturing methods. Usually production involves three stages: (i) soft machining, (ii) heat treatment, and (iii) hard machining. Limitations introduced by conventional methods can be listed as follows: - In machining difficult to cut materials, high cost of specialized cutting tools, high cutting tool...

  14. 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...

  15. A computer solution for the dynamic load, lubricant film thickness and surface temperatures in spiral bevel gears

    Science.gov (United States)

    Chao, H. C.; Cheng, H. S.

    1987-01-01

    A complete analysis of spiral bevel gear sets is presented. The gear profile is described by the movements of the cutting tools. The contact patterns of the rigid body gears are investigated. The tooth dynamic force is studied by combining the effects of variable teeth meshing stiffness, speed, damping, and bearing stiffness. The lubrication performance is also accomplished by including the effects of the lubricant viscosity, ambient temperature, and gear speed. A set of numerical results is also presented.

  16. Cardan gear mechanism versus slider-crank mechanism in pumps and engines

    Energy Technology Data Exchange (ETDEWEB)

    Karhula, J.

    2008-07-01

    In machine design we always want to save space, save energy and produce as much power as possible. We can often reduce accelerations, inertial loads and energy consumption by changing construction. In this study the old cardan gear mechanism (hypocycloid mechanism) has been compared with the conventional slider-crank mechanism in air pumps and four-stroke engines. Comprehensive Newtonian dynamics has been derived for the both mechanisms. First the slidercrank and the cardan gear machines have been studied as lossless systems. Then the friction losses have been added to the calculations. The calculation results show that the cardan gear machines can be more efficient than the slider-crank machines. The smooth running, low mass inertia, high pressures and small frictional power losses make the cardan gear machines clearly better than the slider-crank machines. The dynamic tooth loads of the original cardan gear construction do not rise very high when the tooth clearances are kept tight. On the other hand the half-size crank length causes high bearing forces in the cardan gear machines. The friction losses of the cardan gear machines are generally quite small. The mechanical efficiencies are much higher in the cardan gear machines than in the slider-crank machines in normal use. Crankshaft torques and power needs are smaller in the cardan gear air pumps than in the equal slider-crank air pumps. The mean crankshaft torque and the mean output power are higher in the cardan gear four-stroke engines than in the slider-crank four-stroke engines in normal use. The cardan gear mechanism is at its best, when we want to build a pump or an engine with a long connecting rod (approx 5.crank length) and a thin piston (approx 1.5.crank length) rotating at high angular velocity and intermittently high angular acceleration. The cardan gear machines can be designed also as slide constructions without gears. Suitable applications of the cardan gear machines are three-cylinder half

  17. Dynamic response of large increased pressure wind tunnel rotor-gear coupling system with parallel misalignment

    Institute of Scientific and Technical Information of China (English)

    DONG Guo-qing; CUI Ya-hui; WANG Zhong-ren; LIU Zhan-sheng; SHEN Ji-quan

    2008-01-01

    To study the misalignment of gear coupling, this paper analyzed the distortion of the tooth of gear coupling on the base of gear coupling's motion under parallel misalignment, and derived the specific expression of additive radial force, which produced by the rotor' torque. The motion differential equations of the large in-creased pressure wind tunnel rotor-gear coupling system were derived by the finite element method. Newmark integral method was applied to calculate the dynamic response of the system with parallel misalignment. The nu-merical results show that: under the effect of additive radial force, the static misalignment can arouse 2X fre-quency component lateral vibration; the dynamic misalignment can arouse2X,4X,6X multiple frequency compo-nents lateral vibration. The 2X frequency component is obvious. The additive radial force of the gear coupling can arouse lateral vibration with even multiple frequency components.

  18. Modeling and Validation of a Navy A6-Intruder Actively Controlled Landing Gear System

    Science.gov (United States)

    Horta, Lucas G.; Daugherty, Robert H.; Martinson, Veloria J.

    1999-01-01

    Concepts for long-range air travel are characterized by airframe designs with long, slender, relatively flexible fuselages. One aspect often overlooked is ground-induced vibration of these aircraft. This paper presents an analytical and experimental study of reducing ground-induced aircraft vibration loads by using actively controlled landing gear. A facility has been developed to test various active landing gear control concepts and their performance, The facility uses a Navy A6 Intruder landing gear fitted with an auxiliary hydraulic supply electronically controlled by servo valves. An analytical model of the gear is presented, including modifications to actuate the gear externally, and test data are used to validate the model. The control design is described and closed-loop test and analysis comparisons are presented.

  19. Near-net shape manufacturing of miniature spur gears by wire spark erosion machining

    CERN Document Server

    Gupta, Kapil

    2016-01-01

    This work describes an experimental investigation with the aim to evaluate and establish wire spark erosion machining (WSEM) as a viable alternative for high quality miniature gear manufacturing. External spur type miniature brass (ASTM 858) gears with 12 teeth, 9.8 mm outside diameter and 5 mm face width were manufactured by WSEM. The research work was accomplished in four distinct experimental stages viz., preliminary, pilot, main and confirmation. The aim, scope and findings of each stage are progressively presented and discussed. In essence, the investigation found that it was possible to manufacture miniature gears to high quality by using WSEM. Gears up to DIN 5 quality with a good surface finish (1.2 µm average roughness) and satisfactory surface integrity were achieved. The results suggest that WSEM should be considered a viable alternative to conventional miniature gear manufacturing techniques and that in some instances it may even be superior. This work will prove useful to researchers and profess...

  20. Volume calculation of the spur gear billet for cold precision forging with average circle method

    Institute of Scientific and Technical Information of China (English)

    Wangjun Cheng; Chengzhong Chi; Yongzhen Wang; Peng Lin; Wei Liang; Chen Li

    2014-01-01

    Forging spur gears are widely used in the driving system of mining machinery and equipment due to their higher strength and dimensional accuracy. For the purpose of precisely calculating the volume of cylindrical spur gear billet in cold precision forging, a new theoretical method named average circle method was put forward. With this method, a series of gear billet volumes were calculated. Comparing with the accurate three-dimensional modeling method, the accuracy of average circle method by theoretical calculation was estimated and the maximum relative error of average circle method was less than 1.5%, which was in good agreement with the experimental results. Relative errors of the calculated and the experimental for obtaining the gear billet volumes with reference circle method are larger than those of the average circle method. It shows that average circle method possesses a higher calculation accuracy than reference circle method (traditional method), which should be worth popularizing widely in calculation of spur gear billet volume.