WorldWideScience

Sample records for hydraulic motor driven

  1. Model predictive control of servo motor driven constant pump hydraulic system in injection molding process based on neurodynamic optimization

    Institute of Scientific and Technical Information of China (English)

    Yong-gang PENG; Jun WANG; Wei WEI

    2014-01-01

    In view of the high energy consumption and low response speed of the traditional hydraulic system for an injection molding machine, a servo motor driven constant pump hydraulic system is designed for a precision injection molding process, which uses a servo motor, a constant pump, and a pressure sensor, instead of a common motor, a constant pump, a pressure pro-portion valve, and a flow proportion valve. A model predictive control strategy based on neurodynamic optimization is proposed to control this new hydraulic system in the injection molding process. Simulation results showed that this control method has good control precision and quick response.

  2. FOUR WHEELS DRIVEN INDEPENDENTLY BY ONE PUMP DRIVING FOUR HYDRAULIC MOTORS

    Institute of Scientific and Technical Information of China (English)

    Wu Baolin; Qiu Lihua; Wang Zhanlin

    2005-01-01

    An improved Narendra model reference adaptive control (MRAC) scheme is proposed to research one variable displacement pump driving four hydraulic variable displacement motors. This approach not only ensures the underdamped and unstable system be global uniform asymptotic stability, but also has good robustness in these aspects of modeling uncertainty, pressure fluctuation of constant pressure network, and disturbance from external load, which also upgrades the rapidity of system response so as to make controlled system with nicer dynamic quality. The scheme of one pump driving four motors can meet the demand on off-road mobility of engineering vehicles and armored cars. A proof of stability about improved Narendra MRAC scheme is also given.

  3. A new linear type hydraulic motor

    Science.gov (United States)

    Jiang, Dong; Zhang, Tong; Li, Wenhua; Chen, Xinyang

    2017-08-01

    This paper proposes the design of liner type hydraulic motor on the base of inner curved radial piston hydraulic motor. The hydraulic cylinders of the new type motor are in the straight line which will improve the utilization of the axial space and different out power can be supplied by changes the number of cylinders. In this paper, the structure and working principle of the liner type hydraulic motor is introduced.

  4. Gravity-Driven Hydraulic Fractures

    Science.gov (United States)

    Germanovich, L. N.; Garagash, D.; Murdoch, L. C.; Robinowitz, M.

    2014-12-01

    This study is motived by a new method for disposing of nuclear waste by injecting it as a dense slurry into a hydraulic fracture that grows downward to great enough depth to permanently isolate the waste. Disposing of nuclear waste using gravity-driven hydraulic fractures is mechanically similar to the upward growth of dikes filled with low density magma. A fundamental question in both applications is how the injected fluid controls the propagation dynamics and fracture geometry (depth and breadth) in three dimensions. Analog experiments in gelatin [e.g., Heimpel and Olson, 1994; Taisne and Tait, 2009] show that fracture breadth (the short horizontal dimension) remains nearly stationary when the process in the fracture "head" (where breadth is controlled) is dominated by solid toughness, whereas viscous fluid dissipation is dominant in the fracture tail. We model propagation of the resulting gravity-driven (buoyant or sinking), finger-like fracture of stationary breadth with slowly varying opening along the crack length. The elastic response to fluid loading in a horizontal cross-section is local and can be treated similar to the classical Perkins-Kern-Nordgren (PKN) model of hydraulic fracturing. The propagation condition for a finger-like crack is based on balancing the global energy release rate due to a unit crack extension with the rock fracture toughness. It allows us to relate the net fluid pressure at the tip to the fracture breadth and rock toughness. Unlike the PKN fracture, where breadth is known a priori, the final breadth of a finger-like fracture is a result of processes in the fracture head. Because the head is much more open than the tail, viscous pressure drop in the head can be neglected leading to a 3D analog of Weertman's hydrostatic pulse. This requires relaxing the local elasticity assumption of the PKN model in the fracture head. As a result, we resolve the breadth, and then match the viscosity-dominated tail with the 3-D, toughness

  5. Light-driven molecular motors

    OpenAIRE

    van Delden, RA; FERINGA, BL; Kuzmany, H.; Fink, J.; Mehring, M.; Roth, S.

    2004-01-01

    Molecular motors can be defined as molecules that are able to convert any type of energy input (a fuel) into controlled motion. These systems can be categorized into linear and rotary motors, depending on the motion induced. This brief account will discuss the state of affairs of the research on light-driven rotary molecular motors.

  6. Measurement and evaluation of static characteristics of rotary hydraulic motor

    Directory of Open Access Journals (Sweden)

    Hružík Lumír

    2014-03-01

    Full Text Available The paper describes experimental equipment for measurement of static characteristics of rotary hydraulic motor. It is possible to measure flow, pressure, temperature, speed and torque by means of this equipment. It deals with measurement of static characteristics of a gear rotary hydraulic motor. Mineral oil is used as hydraulic liquid in this case. Flow, torque and speed characteristics are evaluated from measured parameters. Measured mechanical-hydraulic, flow and total efficiencies of the rotary hydraulic motor are adduced in the paper. It is possible to diagnose technical conditions of the hydraulic motor (eventually to recommend its exchange from the experimental measurements.

  7. Hydraulic Motor Driving Variable-Pitch System for Wind Turbine

    Directory of Open Access Journals (Sweden)

    Ye HUANG

    2013-11-01

    Full Text Available The present hydraulic variable-pitch mechanism of wind turbine uses three hydraulic cylinders to drive three crank and connecting rod mechanisms respectively; the blades are moved with the cranks. The hydraulic variable-pitch mechanism has complex structure, occupies a lot of space and its maintenance is trouble. In order to make up for the shortcomings of hydraulic cylinder variable-pitch system, the present hydraulic variable-pitch mechanism should be changed as follows: hydraulic motors are used to drive gears; gears drive blades; the electro-hydraulic proportional valves are used to control hydraulic motors. The hydraulic control part and electrical control part of variable-pitch system is redesigned. The new variable-pitch system is called hydraulic motor driving variable-pitch system. The new variable-pitch system meets the control requirements of blade pitch, makes the structure simple and its application effect is perfect.    

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

    Science.gov (United States)

    Yu, Hongying; Luo, Changjie; Wang, Huimin

    2012-07-01

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

  9. Hydraulically Driven Grips For Hot Tensile Specimens

    Science.gov (United States)

    Bird, R. Keith; Johnson, George W.

    1994-01-01

    Pair of grips for tensile and compressive test specimens operate at temperatures up to 1,500 degrees F. Grips include wedges holding specimen inside furnace, where heated to uniform temperature. Hydraulic pistons drive wedges, causing them to exert clamping force. Hydraulic pistons and hydraulic fluid remain outside furnace, at room temperature. Cooling water flows through parts of grips to reduce heat transferred to external components. Advantages over older devices for gripping specimens in high-temperature tests; no need to drill holes in specimens, maintains constant gripping force on specimens, and heated to same temperature as that of specimen without risk of heating hydraulic fluid and acuator components.

  10. Investigation of Valve Plate in Water Hydraulic Axial Piston Motor

    Institute of Scientific and Technical Information of China (English)

    聂松林; 李壮云; 等

    2002-01-01

    This paper has introduced the developments of water hydraulic axial piston equipments.According to the effects of physicochemical properties of water on water hydraulic components,a novel valve plate for water hydraulic axial motor has been put forward,whose moment exerted by the fluid field between valve plate and bearing plate is balanced entirely.The material screening experiment of valve plate is done on the test rig.Through numerical simulation the effects of some geometry parameters on the performance of water hydraulic motor have been studied.The silencing grooves on the valve plate in water hydraulic motor can reduce the pressure shock and the occurrence of cavitation effectively.It is evident that the appropriate structure should change the wear status between matching paris and reduces the wear and specific pressure of the matching pairs.The specimen with the new type valve plate is used in a tool system.

  11. Piezoelectric Torsional Vibration Driven Motor

    Science.gov (United States)

    2000-10-29

    20 which can provide large amplitude rotational motion with a high torque. 21 Piezoelectric ultrasonic motors have been developed using traveling...Motor for High Torque", T. S. Glenn, W.G. Hagwood, SPIE Volume 3041, 4 1997. These piezoelectric ultrasonic motors are of limited application

  12. Robust control of a hydraulically driven flexible arm

    Institute of Scientific and Technical Information of China (English)

    Guang LI; Khajepour AMIR

    2004-01-01

    A new robust controller is proposed to regulate both flexural vibrations and rigid body motion of a hydraulically driven flexible arm. The controller combines backstepping control and sliding mode to arrive at a controller capable of dealing with a nonlinear system with uncertainties. The sliding mode technique is used to achieve an asymptotic joint angle and vibration regulation in the presence of payload uncertainty by providing a virtual torque input at the joint while the backstepping technique is used to regulate the spool position of a hydraulic valve to provide the required torque. It is shown that there is no chatter in the hydraulic valve, which results in smoother operation of the system.

  13. Motor-Driven Giant Magnetostrictive Actuator

    DEFF Research Database (Denmark)

    Zhang, Lihui; Xia, Yongming; Lu, Kaiyuan

    2015-01-01

    to produce the desired magnetic field when an output strain should be maintained. The GMA does not produce any mechanical power in this condition, but constant power is being consumed by the excitation coil. This paper presents a new type of motor-driven GMA (MDGMA), which works in a coil-free driven manner...

  14. Development of an electrically driven molecular motor.

    Science.gov (United States)

    Murphy, Colin J; Sykes, E Charles H

    2014-10-01

    For molecules to be used as components in molecular machinery, methods are required that couple individual molecules to external energy sources in order to selectively excite motion in a given direction. While significant progress has been made in the construction of synthetic molecular motors powered by light and by chemical reactions, there are few experimental examples of electrically driven molecular motors. To this end, we pioneered the use of a new, stable and tunable molecular rotor system based on surface-bound thioethers to comprehensively study many aspects of molecular rotation. As biological molecular motors often operate at interfaces, our synthetic system is especially amenable to microscopic interrogation as compared to solution-based systems. Using scanning tunneling microscopy (STM) and density functional theory, we studied the rotation of surface-bound thioethers, which can be induced either thermally or by electrons from the STM tip in a two-terminal setup. Moreover, the temperature and electron flux can be adjusted to allow each rotational event to be monitored at the molecular scale in real time. This work culminated in the first experimental demonstration of a single-molecule electric motor, where the electrically driven rotation of a butyl methyl sulfide molecule adsorbed on a copper surface could be directionally biased. The direction and rate of the rotation are related to the chirality of both the molecule and the STM tip (which serves as the electrode), illustrating the importance of the symmetry of the metal contacts in atomic-scale electrical devices. Copyright © 2014 The Chemical Society of Japan and Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Phenomenon of methane driven caused by hydraulic fracturing in methane-bearing coal seams

    Institute of Scientific and Technical Information of China (English)

    Huang Bingxiang; Cheng Qingying; Chen Shuliang

    2016-01-01

    The methane concentration of the return current will always be enhanced to a certain degree when hydraulic fracturing with bedding drilling is implemented to a gassy coal seam in an underground coal mine. The methane in coal seam is driven out by hydraulic fracturing. Thus, the phenomenon is named as methane driven effect of hydraulic fracturing. After deep-hole hydraulic fracturing at the tunneling face of the gassy coal seam, the coal methane content exhibits a‘low-high-low”distribution along exca-vation direction in the following advancing process, verifying the existence of methane driven caused by hydraulic fracturing in methane-bearing coal seam. Hydraulic fracturing causes the change of pore-water and methane pressure in surrounding coal. The uneven distribution of the pore pressure forms a pore pressure gradient. The free methane migrates from the position of high pore (methane) pressure to the position of low pore (methane) pressure. The methane pressure gradient is the fundamental driving force for methane-driven coal seam hydraulic fracturing. The uneven hydraulic crack propagation and the effect of time (as some processes need time to complete and are not completed instantaneously) will result in uneven methane driven. Therefore, an even hydraulic fracturing technique should be used to avoid the negative effects of methane driven; on the other hand, by taking fully advantage of methane driven, two technologies are presented.

  16. From the Kinetic Energy Recovery System to the Thermo-Hydraulic Hybrid Motor Vehicle

    Science.gov (United States)

    Cristescu, Corneliu; Drumea, Petrin; Guta, Dragos; Dumitrescu, Catalin

    2011-12-01

    The paper presents some theoretical and experimental results obtained by the Hydraulics and Pneumatics Research Institute INOE 2000-IHP with its partners, regarding the creating of one hydraulic system able to recovering the kinetic energy of the motor vehicles, in the braking phases, and use this recovered energy in the starting and accelerating phases. Also, in the article is presented a testing stand, which was especially designed for testing the hydraulic system for recovery the kinetic energy. Through mounting of the kinetic energy recovering hydraulic system, on one motor vehicle, this vehicle became a thermo-hydraulic hybrid vehicle. Therefore, the dynamic behavior was analyzed for the whole hybrid motor vehicle, which includes the energy recovery system. The theoretical and experimental results demonstrate the possible performances of the hybrid vehicle and that the kinetic energy recovery hydraulic systems are good means to increase energy efficiency of the road motor vehicles and to decrease of the fuel consumption.

  17. Control of rotor function in light-driven molecular motors

    NARCIS (Netherlands)

    Lubbe, Anouk S.; Ruangsupapichat, Nopporn; Caroli, Giuseppe; Feringa, Ben L.

    2011-01-01

    A study is presented on the control of rotary motion of an appending rotor unit in a light-driven molecular motor. Two new light driven molecular motors were synthesized that contain aryl groups connected to the stereogenic centers. The aryl groups behave as bidirectional free rotors in three of the

  18. Light-driven rotary molecular motors : an ultrafast optical study

    NARCIS (Netherlands)

    Augulis, Ramunas; Klok, Martin; Loosdrecht, Paul H.M. van; Feringa, Bernard

    2009-01-01

    Molecular rotary motors, though common in nature, were first synthesized rather recently. One of the most promising categories of light-driven rotary molecular motors which allow for optical control is based on helical overcrowded alkenes. In this category of motors, the rotation of the motor’s roto

  19. Design and Optimization of Fast Switching Valves for Large Scale Digital Hydraulic Motors

    DEFF Research Database (Denmark)

    Roemer, Daniel Beck

    of seat valves suitable for large scale digital hydraulic motors and detailed analysis methods for the pressure chambers of such machines. In addition, modeling methods of seat valves within this field have been developed, and a design method utilizing these models including optimization of subdomains has......The present thesis is on the design, analysis and optimization of fast switching valves for digital hydraulic motors with high power ratings. The need for such high power motors origins in the potential use of hydrostatic transmissions in wind turbine drive trains, as digital hydraulic machines...... have been shown to improve the overall efficiency and efficient operation range compared to traditional hydraulic machines. Digital hydraulic motors uses electronically controlled independent seat valves connected to the pressure chambers, which must be fast acting and exhibit low pressure losses...

  20. Continuous rotary motor electro-hydraulic servo system based on the improved repetitive controller

    Institute of Scientific and Technical Information of China (English)

    WANG Xiao-jing; JIANG ji-hai; LI Shang-yi

    2010-01-01

    In order to suppress the periodic interference of the continuous rotary electro-hydraulic servo motor,this paper makes the motor tracking the periodic signals with high accuracy,and improves the influence of friction interference to the performance of continuous rotary electro-hydraulic servo motor.The mathematic model of the electro-hydraulic position servo system of the continuous rotary motor was established,and the compound control method was adopted based on the repetitive control,feed forward and PID to suppress the friction interference.Through the simulation,the result confirms that the compound control method decreases the tracking error of the system,increases the robust performance of the system and improves the performance of the continuous rotary electro-hydraulic servo motor.

  1. Thermal hydraulics of accelerator driven system windowless targets

    Directory of Open Access Journals (Sweden)

    Bruno ePanella

    2015-07-01

    Full Text Available The study of the fluid dynamics of the windowless spallation target of an Accelerator Driven System (ADS is presented. Several target mockup configurations have been investigated: the first one was a symmetrical target, that was made by two concentric cylinders, the other configurations are not symmetrical. In the experiments water has been used as hydraulic equivalent to lead-bismuth eutectic fluid. The experiments have been carried out at room temperature and flow rate up to 24 kg/s. The fluid velocity components have been measured by an ultrasound technique. The velocity field of the liquid within the target region either for the approximately axial-symmetrical configuration or for the not symmetrical ones as a function of the flow rate and the initial liquid level is presented. A comparison of experimental data with the prediction of the finite volume FLUENT code is also presented. Moreover the results of a 2D-3D numerical analysis that investigates the effect on the steady state thermal and flow fields due to the insertion of guide vanes in the windowless target unit of the EFIT project ADS nuclear reactor are presented, by analysing both the cold flow case (absence of power generation and the hot flow case (nominal power generation inside the target unit.

  2. Statistical investigation of hydraulic driven circular interpolation motions

    Indian Academy of Sciences (India)

    Ahmet Murat Pinar; Abdulkadir Gullu; Sezai Taskin

    2012-10-01

    In this study, a twin-axis gantry has been structured to examine hydraulic driven positioning skills of the curvilinear motions based on ISO 230-4 standard entitled ‘Circular tests for numerically controlled machine tools’. The system is controlled by a path and position control module of a PLC device. As a result of the experiments conducted based on the full factorial design, the effects of piston diameter, feed rate, radius and their two-way interactions on the circularity error are determined through analysis of variance. Accordingly, minimum circularity error is obtained with the piston diameter of 63 mm, inertia load of 12.5 kg, radius of 5 mm and feed rate of 50 mm/min as 0.345 mm. Circularity error increases with the increase of inertia load, radius and feed rate, and declines with the increase of piston diameter. Lastly, piston diameter has the greatest effect on the circularity error change and followed by radius, feed rate, piston diameter–radius, radius–feed rate, piston diameter-feed-rate, inertia load, piston diameter–inertia load, and inertia load–radius factors and interactions.

  3. Singular perturbation approach for control of hydraulically driven flexible manipulator

    Institute of Scientific and Technical Information of China (English)

    LI Guang; WU Min

    2005-01-01

    The hydraulic flexible manipulator system is divided into two parts: flexible arm dynamics and hydraulic servomechanism, a driving Jacobian is derived to connect these two parts. Taking hydraulic actuator force as virtual input, a singular perturbed composite model is formulated and used to design composite controllers for the flexible link, in which the slow subsystem controller dominates the trajectory tracking, and then a fast controller is designed to damp out the vibration of the flexible structure. Moreover, the backstepping technique is applied to regulate the spool position of a hydraulic valve to provide the required force. Simulation results are provided to show the effectiveness of the presented approach.

  4. EXPERIMENTAL RESEARCH FOCUSED ON YIELDS OF LINEARE HYDRAULIC MOTORS USED TO DRIVE THE BOTTOM PUMPS

    Directory of Open Access Journals (Sweden)

    Petre SĂVULESCU

    2011-07-01

    Full Text Available This paper presents the authors’s concerns for determining the functional parameters and its yieldsfor a linear hydraulic engine with double effect. Functional parameters are determined both at unloadedrunning and loaded running of the linear hydraulic motor. The yields was determined on loaded running.

  5. EXPERIMENTAL RESEARCH FOCUSED ON YIELDS OF LINEARE HYDRAULIC MOTORS USED TO DRIVE THE BOTTOM PUMPS

    OpenAIRE

    Petre SĂVULESCU

    2011-01-01

    This paper presents the authors’s concerns for determining the functional parameters and its yieldsfor a linear hydraulic engine with double effect. Functional parameters are determined both at unloadedrunning and loaded running of the linear hydraulic motor. The yields was determined on loaded running.

  6. Submerged electricity generation plane with marine current-driven motors

    Science.gov (United States)

    Dehlsen, James G.P.; Dehlsen, James B.; Fleming, Alexander

    2014-07-01

    An underwater apparatus for generating electric power from ocean currents and deep water tides. A submersible platform including two or more power pods, each having a rotor with fixed-pitch blades, with drivetrains housed in pressure vessels that are connected by a transverse structure providing buoyancy, which can be a wing depressor, hydrofoil, truss, or faired tube. The platform is connected to anchors on the seafloor by forward mooring lines and a vertical mooring line that restricts the depth of the device in the water column. The platform operates using passive, rather than active, depth control. The wing depressor, along with rotor drag loads, ensures the platform seeks the desired operational current velocity. The rotors are directly coupled to a hydraulic pump that drives at least one constant-speed hydraulic-motor generator set and enables hydraulic braking. A fluidic bearing decouples non-torque rotor loads to the main shaft driving the hydraulic pumps.

  7. Submerged electricity generation plane with marine current-driven motors

    Energy Technology Data Exchange (ETDEWEB)

    Dehlsen, James G.P.; Dehlsen, James B.; Fleming, Alexander

    2014-07-01

    An underwater apparatus for generating electric power from ocean currents and deep water tides. A submersible platform including two or more power pods, each having a rotor with fixed-pitch blades, with drivetrains housed in pressure vessels that are connected by a transverse structure providing buoyancy, which can be a wing depressor, hydrofoil, truss, or faired tube. The platform is connected to anchors on the seafloor by forward mooring lines and a vertical mooring line that restricts the depth of the device in the water column. The platform operates using passive, rather than active, depth control. The wing depressor, along with rotor drag loads, ensures the platform seeks the desired operational current velocity. The rotors are directly coupled to a hydraulic pump that drives at least one constant-speed hydraulic-motor generator set and enables hydraulic braking. A fluidic bearing decouples non-torque rotor loads to the main shaft driving the hydraulic pumps.

  8. Light-driven altitudinal molecular motors on surfaces

    NARCIS (Netherlands)

    London, Gabor; Carroll, Gregory T.; Fernández Landaluce, Tatiana; Pollard, Michael M.; Rudolf, Petra; Feringa, Ben L.

    2009-01-01

    A Cu(I)-catalyzed 1,3-dipolar cycloaddition was used to construct a monolayer of an altitudinal molecular motor on quartz and silicon substrates, which represents the fastest light-driven molecular motor, to date, grafted to a solid surface.

  9. Light-Driven Rotary Molecular Motors on Gold Nanoparticles

    NARCIS (Netherlands)

    Pollard, Michael M.; ter Wiel, Matthijs K. J.; van Delden, Richard A.; Vicario, Javier; Koumura, Nagatoshi; van den Brom, Coenraad R.; Meetsma, Auke; Feringa, Ben L.

    2008-01-01

    We report the synthesis of unidirectional light-driven rotary molecular motors based oil chiral overcrowded alkenes and their immobilisation on the surface of gold nanoparticles through two anchors. Using a combination of (1)H and (13)C NMR, UV/Vis and CD spectroscopy, we show that these motors pres

  10. Coincident switch closing reduces error in motor-driven timer

    Science.gov (United States)

    Rich, S.

    1964-01-01

    To cut the lag-lead in motor-driven timing devices, the timing circuit has been extended to include a second switch. This is actuated in time with the first but driven directly at a speed x times faster than the first.

  11. Optimum Design of a Moving Coil Actuator for Fast-Switching Valves in Digital Hydraulic Pumps and Motors

    DEFF Research Database (Denmark)

    Roemer, Daniel Beck; Bech, Michael Møller; Johansen, Per

    2015-01-01

    Fast-switching seat valves suitable for digital hydraulic pumps and motors utilize direct electromagnetic actuators, which must exhibit superior transient performance to allow efficient operation of the fluid power pump/motor. A moving coil actuator resulting in a minimum valve switching time.......5 bar at 600 L/min flow rate, enabling efficient operation of digital hydraulic pumps and motors....

  12. Unidirectional light-driven molecular motors based on overcrowded alkenes.

    Science.gov (United States)

    Cnossen, Arjen; Browne, Wesley R; Feringa, Ben L

    2014-01-01

    Over the last two decades, interest in nanotechnology has led to the design and synthesis of a toolbox of nanoscale versions of macroscopic devices and components. In molecular nanotechnology, linear motors based on rotaxanes and rotary motors based on overcrowded alkenes are particularly promising for performing work at the nanoscale. In this chapter, progress on light-driven molecular motors based on overcrowded alkenes is reviewed. Both the so-called first and second generation molecular motors are discussed, as well as their potential applications.

  13. NEW PUNCHING MACHINE DRIVEN BY LINEAR INDUCTION MOTOR

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The research and application of the punching machine driven by a linear induction motor(LIM)are introducedThe fundamental principle,construction,performance and application are describedComparing this new model machine with its traditional form,the LIM driven punching machine has many great advantages,such as,simple construction,small size and mass,low production cost,short production time,easy to control,low noise and considerable energy saving

  14. Hydraulics.

    Science.gov (United States)

    Decker, Robert L.; Kirby, Klane

    This curriculum guide contains a course in hydraulics to train entry-level workers for automotive mechanics and other fields that utilize hydraulics. The module contains 14 instructional units that cover the following topics: (1) introduction to hydraulics; (2) fundamentals of hydraulics; (3) reservoirs; (4) lines, fittings, and couplers; (5)…

  15. A HIGH VELOCITY FEED UNIT DRIVEN BY LINEAR MOTOR

    Institute of Scientific and Technical Information of China (English)

    Zhang Bolin; Chen Yanji; Li Zhiying

    2000-01-01

    In order to realize high speed machining,the special requirements for feed transmission system of the CNC machine tool have to be satisfied.A high velocity feed unit driven by a induction linear motor is developed.The compositions of the high velocity CNC feed unit and main problems in the unit design are discussed.

  16. Tuning the Rotation Rate of Light-Driven Molecular Motors

    NARCIS (Netherlands)

    Bauer, Jurica; Hou, Lili; Kistemaker, Jos C. M.; Feringa, Bernard

    2014-01-01

    Overcrowded alkenes are among the most promising artificial mol. motors because of their ability to undergo repetitive light-driven unidirectional rotary motion around the central C=C bond. The exceptional features of these mols. render them highly useful for a no. of applications in nanotechnol. Ma

  17. Motor-driven compressor-condenser group for cooling cycles

    Energy Technology Data Exchange (ETDEWEB)

    Giuffrida, G.G.

    1984-07-17

    A motor-driven compressor condenser group for equipment actuating cooling-cycles, such as for example cooling apparatuses and heat pumps, enclosed in a single container. The cooling fluid of the heat-exchanger connected to the condenser passing to and from the container is to be used in domestic cooling systems to heat water.

  18. The Dynamic test of Novel Punch Driven by Linear Motor

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The key character of punch is its impulsion. For the novel punch driven by linear motor, the computer-aided test system is used. Its frequency performance is calculated by the identification method according to the dynamic demarcation. This dynamic test system presented here can be applied in the sample machines under development and performance test of finished products.

  19. 46 CFR 111.97-5 - Electric and hydraulic power supply.

    Science.gov (United States)

    2010-10-01

    ... by one or more motor-driven hydraulic pumps that can operate from the final source of the emergency lighting and power system. (d) The motor-driven hydraulic pumps must automatically maintain the accumulator... 46 Shipping 4 2010-10-01 2010-10-01 false Electric and hydraulic power supply. 111.97-5...

  20. Backstepping Adaptive Controller of Electro-Hydraulic Servo System of Continuous Rotary Motor

    Institute of Scientific and Technical Information of China (English)

    XiaoJing Wang; ChangFu Xian; CaoLei Wan; JinBao Zhao; LiWei Xiu; AnCai Yu

    2014-01-01

    In order to consider the influence of the continuous rotary motor electro-hydraulic servo system parameters change on its performance, the design method of backstepping adaptive controller is put forward. The mathematical model of electro-hydraulic servo system of continuous rotary motor is established, and the whole system is decomposed into several lower order subsystems, and the virtual control signal is designed for each subsystem from the final subsystem with motor angular displacement to the subsystem with system control input voltage. Based on Lyapunov method and the backstepping theory, an adaptive backstepping controller is designed with the changed parameters adaptive law. It is proved that the system reaches the global asymptotic stability, and the system tracking error asymptotically tends to zero. The simulation results show that the backstepping adaptive controller based on the adaptive law of the changed parameters can improve the performance of continuous rotary motor, and the proposed control strategy is feasible.

  1. An evaluation of a hubless inducer and a full flow hydraulic turbine driven inducer boost pump

    Science.gov (United States)

    Lindley, B. K.; Martinson, A. R.

    1971-01-01

    The purpose of the study was to compare the performance of several configurations of hubless inducers with a hydrodynamically similar conventional inducer and to demonstrate the performance of a full flow hydraulic turbine driven inducer boost pump using these inducers. A boost pump of this type consists of an inducer connected to a hydraulic turbine with a high speed rotor located in between. All the flow passes through the inducer, rotor, and hydraulic turbine, then into the main pump. The rotor, which is attached to the main pump shaft, provides the input power to drive the hydraulic turbine which, in turn, drives the inducer. The inducer, rotating at a lower speed, develops the necessary head to prevent rotor cavitation. The rotor speed is consistent with present main engine liquid hydrogen pump designs and the overall boost pump head rise is sufficient to provide adequate main pump suction head. This system would have the potential for operating at lower liquid hydrogen tank pressures.

  2. Mixing and entrainment in hydraulically driven stratified sill flows

    DEFF Research Database (Denmark)

    Nielsen, Morten Holtegaard; Pratt, Larry; Helfrich, Karl

    2004-01-01

    that the reduced gravity model systematically underestimates inertia and overestimates buoyancy. These differences are quantified by shape coefficients that measure the vertical non-uniformities of the density and horizontal velocity that arise, in part, by incomplete mixing of entrained mass and momentum over...... model. Self-similarity is not observed in the numerically generated flow, but the observed critical section continues to lie upstream of the location predicted by the reduced gravity model. The factors influencing this result are explored.......The investigation involves the hydraulic behaviour of a dense layer of fluid flowing over an obstacle and subject to entrainment of mass and momentum from a dynamically inactive (but possibly moving) overlying fluid. An approach based on the use of reduced gravity, shallow-water theory with a cross...

  3. Mixing and entrainment in hydraulically driven stratified sill flows

    Science.gov (United States)

    Holtegaard Nielsen, Morten; Pratt, Larry; Helfrich, Karl

    2004-09-01

    The investigation involves the hydraulic behaviour of a dense layer of fluid flowing over an obstacle and subject to entrainment of mass and momentum from a dynamically inactive (but possibly moving) overlying fluid. An approach based on the use of reduced gravity, shallow-water theory with a cross-interface entrainment velocity is compared with numerical simulations based on a model with continuously varying stratification and velocity. The locations of critical flow (hydraulic control) in the continuous model are estimated by observing the direction of propagation of small-amplitude long-wave disturbances introduced into the flow field. Although some of the trends predicted by the shallow-water model are observed in the continuous model, the agreement between the interface profiles and the position of critical flow is quantitatively poor. A reformulation of the equations governing the continuous flow suggests that the reduced gravity model systematically underestimates inertia and overestimates buoyancy. These differences are quantified by shape coefficients that measure the vertical non-uniformities of the density and horizontal velocity that arise, in part, by incomplete mixing of entrained mass and momentum over the lower-layer depth. Under conditions of self-similarity (as in Wood's similarity solution) the shape coefficients are constant and the formulation determines a new criterion for and location of critical flow. This location generally lies upstream of the critical section predicted by the reduced-gravity model. Self-similarity is not observed in the numerically generated flow, but the observed critical section continues to lie upstream of the location predicted by the reduced gravity model. The factors influencing this result are explored.

  4. A New Type of Continuously Variable Displacement Mechanism Used for Hydraulic Motors

    Institute of Scientific and Technical Information of China (English)

    LI Yong; SHI Guang-lin; CHEN Zhao-neng

    2007-01-01

    A continuously variable displacement mechanism, which is composed of a hydraulic control valve with mechanical-positional feedback to camshaft, was designed for changing the displacement of traditional camshaft connecting-rod low speed high torque (LSHT) hydraulic motor continuously. The new type of continuously variable displacement mechanism is simple and easy to be made. The structure and principle of a continuously variable displacement mechanism was introduced. The mathematic model of the continuously variable displacement mechanism was set up and its static and dynamic characteristics were analyzed with the help of computer simulation. It can be seen that the cam ring on camshaft of the traditional LSHT hydraulic motor can stop at any position between minimum and maximum eccentricity, according to an input fluid pressure signal. And it can also stay anywhere stably through self-adjusting. Besides, it can work stabilized when load impact or oil leakage exists.

  5. Hydraulic Yaw System for Wind Turbines with New Compact Hydraulic Motor Principle

    DEFF Research Database (Denmark)

    Sørensen, Rasmus Mørk; Hansen, Michael Rygaard; Mouritsen, Ole Ø.

    2011-01-01

    is based on leakage flow. The most critical gaps in the motor, across the end faces of the rotor, are investigated both by a fluid structural interaction simulation model and by experimental prototype tests. The simulation model is the basis for the motor design and the manufacturing tolerances...... volumes is minimizing the deflections, the measured gap height is around ℎ = 10?m and the volumetric efficiency of the motor is around ?v = 0.85. By decreasing the initial gaps from the manufacturing process, this volumetric efficiency can be further increased....

  6. Motor-Driven Bacterial Flagella and Buckling Instabilities

    CERN Document Server

    Vogel, Reinhard

    2012-01-01

    Many types of bacteria swim by rotating a bundle of helical filaments also called flagella. Each filament is driven by a rotary motor and a very flexible hook transmits the motor torque to the filament. We model it by discretizing Kirchhoff's elastic-rod theory and develop a coarse-grained approach for driving the helical filament by a motor torque. A rotating flagellum generates a thrust force, which pushes the cell body forward and which increases with the motor torque. We fix the rotating flagellum in space and show that it buckles under the thrust force at a critical motor torque. Buckling becomes visible as a supercritical Hopf bifurcation in the thrust force. A second buckling transition occurs at an even higher motor torque. We attach the flagellum to a spherical cell body and also observe the first buckling transition during locomotion. By changing the size of the cell body, we vary the necessary thrust force and thereby obtain a characteristic relation between the critical thrust force and motor torq...

  7. Intracellular transport driven by cytoskeletal motors: General mechanisms and defects

    CERN Document Server

    Appert-Rolland, Cecile; Santen, Ludger

    2015-01-01

    Cells are strongly out-of-equilibrium systems driven by continuous energy supply. They carry out many vital functions requiring active transport of various ingredients and organelles, some being small, others being large. The cytoskeleton, composed of three types of filaments, determines the shape of the cell and plays a role in cell motion. It also serves as a road network for the so-called cytoskeletal motors. These molecules can attach to a cytoskeletal filament, perform directed motion, possibly carrying along some cargo, and then detach. It is a central issue to understand how intracellular transport driven by molecular motors is regulated, in particular because its breakdown is one of the signatures of some neuronal diseases like the Alzheimer. We give a survey of the current knowledge on microtubule based intracellular transport. We first review some biological facts obtained from experiments, and present some modeling attempts based on cellular automata. We start with background knowledge on the origi...

  8. A cycloidal wobble motor driven by shape memory alloy wires

    Science.gov (United States)

    Hwang, Donghyun; Higuchi, Toshiro

    2014-05-01

    A cycloidal wobble motor driven by shape memory alloy (SMA) wires is proposed. In realizing a motor driving mechanism well known as a type of reduction system, a cycloidal gear mechanism is utilized. It facilitates the achievement of bidirectional continuous rotation with high-torque capability, based on its high efficiency and high reduction ratio. The applied driving mechanism consists of a pin/roller based annular gear as a wobbler, a cycloidal disc as a rotor, and crankshafts to guide the eccentric wobbling motion. The wobbling motion of the annular gear is generated by sequential activation of radially phase-symmetrically placed SMA wires. Consequently the cycloidal disc is rotated by rolling contact based cycloidal gearing between the wobbler and the rotor. In designing the proposed motor, thermomechanical characterization of an SMA wire biased by extension springs is experimentally performed. Then, a simplified geometric model for the motor is devised to conduct theoretical assessment of design parametric effects on structural features and working performance. With consideration of the results from parametric analysis, a functional prototype three-phase motor is fabricated to carry out experimental verification of working performance. The observed experimental results including output torque, rotational speed, bidirectional positioning characteristic, etc obviously demonstrate the practical applicability and potentiality of the wobble motor.

  9. A Hydraulic Motor-Alternator System for Ocean-Submersible Vehicles

    Science.gov (United States)

    Aintablian, Harry O.; Valdez, Thomas I.; Jones, Jack A.

    2012-01-01

    An ocean-submersible vehicle has been developed at JPL that moves back and forth between sea level and a depth of a few hundred meters. A liquid volumetric change at a pressure of 70 bars is created by means of thermal phase change. During vehicle ascent, the phase-change material (PCM) is melted by the circulation of warm water and thus pressure is increased. During vehicle descent, the PCM is cooled resulting in reduced pressure. This pressure change is used to generate electric power by means of a hydraulic pump that drives a permanent magnet (PM) alternator. The output energy of the alternator is stored in a rechargeable battery that powers an on-board computer, instrumentation and other peripherals.The focus of this paper is the performance evaluation of a specific hydraulic motor-alternator system. Experimental and theoretical efficiency data of the hydraulic motor and the alternator are presented. The results are used to evaluate the optimization of the hydraulic motor-alternator system. The integrated submersible vehicle was successfully operated in the Pacific Ocean near Hawaii. A brief overview of the actual test results is presented.

  10. What we learn from surveillance testing of standby turbine driven and motor driven pumps

    Energy Technology Data Exchange (ETDEWEB)

    Christie, B.

    1996-12-01

    This paper describes a comparison of the performance information collected by the author and the respective system engineers from five standby turbine driven pumps at four commercial nuclear electric generating units in the United States and from two standby motor driven pumps at two of these generating units. Information was collected from surveillance testing and from Non-Test actuations. Most of the performance information (97%) came from surveillance testing. {open_quotes}Conditional Probabilities{close_quotes} of the pumps ability to respond to a random demand were calculated for each of the seven standby pumps and compared to the historical record of the Non-Test actuations. It appears that the Conditional Probabilities are comparable to the rate of success for Non-Test actuations. The Conditional Probabilities of the standby motor driven pumps (approximately 99%) are better than the Conditional Probabilities of the standby turbine driven pumps (82%-96% range). Recommendations were made to improve the Conditional Probabilities of the standby turbine driven pumps.

  11. IEMDC IN-LINE ELECTRIC MOTOR DRIVEN COMPRESSOR

    Energy Technology Data Exchange (ETDEWEB)

    Michael J. Crowley; Prem N. Bansal

    2004-10-01

    This report contains the final project summary and deliverables required by the award for the development of an In-line Electric Motor Driven Compressor (IEMDC). Extensive work was undertaken during the course of the project to develop the motor and the compressor section of the IEMDC unit. Multiple design iterations were performed to design an electric motor for operation in a natural gas environment and to successfully integrate the motor with a compressor. During the project execution, many challenges were successfully overcome in order to achieve the project goals and to maintain the system design integrity. Some of the challenges included limiting the magnitude of the compressor aerodynamic loading for appropriate sizing of the magnetic bearings, achieving a compact motor rotor size to meet the rotor dynamic requirements of API standards, devising a motor cooling scheme using high pressure natural gas, minimizing the impact of cooling on system efficiency, and balancing the system thrust loads for the magnetic thrust bearing. Design methods that were used on the project included validated state-of-the-art techniques such as finite element analysis and computational fluid dynamics along with the combined expertise of both Curtiss-Wright Electro-Mechanical Corporation and Dresser-Rand Company. One of the most significant areas of work undertaken on the project was the development of the unit configuration for the system. Determining the configuration of the unit was a significant step in achieving integration of the electric motor into a totally enclosed compression system. Product review of the IEMDC unit configuration was performed during the course of the development process; this led to an alternate design configuration. The alternate configuration is a modular design with the electric motor and compressor section each being primarily contained in its own pressure containing case. This new concept resolved the previous conflict between the aerodynamic flow

  12. Catch bond mechanism in Dynein motor driven collective transport

    CERN Document Server

    Nair, Anil; Mitra, Mithun K; Muhuri, Sudipto; Chaudhuri, Abhishek

    2016-01-01

    Recent experiments have demonstrated that dynein motor exhibits catch bonding behaviour, in which the unbinding rate of a single dynein decreases with increasing force, for a certain range of force. Motivated by these experiments, we propose a model for catch bonding in dynein using a threshold force bond deformation (TFBD) model wherein catch bonding sets in beyond a critical applied load force. We study the effect of catch bonding on unidirectional transport properties of cellular cargo carried by multiple dynein motors within the framework of this model. We find catch bonding can result in dramatic changes in the transport properties, which are in sharp contrast to kinesin driven unidirectional transport, where catch bonding is absent. We predict that, under certain conditions, the average velocity of the cellular cargo can actually increase as applied load is increased. We characterize the transport properties in terms of a velocity profile phase plot in the parameter space of the catch bond strength and ...

  13. stepping motor - hydraulic motor servo drives for an nc milling machine

    African Journals Online (AJOL)

    Dr Obe

    ω = rotational speed of stepping motor. kL = System ... existing production batch sizes and .... Each pulse fed to the motor causes ... constant angle called "the step ..... (ii) Feedrate: This was found to bear a linear relationship with the pulse rate.

  14. Facile assembly of light-driven molecular motors onto a solid surface.

    Science.gov (United States)

    Chen, Jiawen; Chen, Kuang-Yen; Carroll, Gregory T; Feringa, Ben L

    2014-10-28

    In order to improve the rotary motion of surface assembled light-driven molecular motors, tetra-acid-functionalized motors were bound to an amine-coated quartz surface without prior activation of the acid groups. In contrast to earlier bipodal motors, the tetravalent motor showed no significant reduction in the rotation speed when attached to a surface.

  15. Facile assembly of light-driven molecular motors onto a solid surface

    NARCIS (Netherlands)

    Chen, Jiawen; Chen, Kuang-Yen; Carroll, Gregory T; Feringa, Ben L

    2014-01-01

    In order to improve the rotary motion of surface assembled light-driven molecular motors, tetra-acid-functionalized motors were bound to an amine-coated quartz surface without prior activation of the acid groups. In contrast to earlier bipodal motors, the tetravalent motor showed no significant redu

  16. Periodic thermodynamics of laser-driven molecular motor

    Institute of Scientific and Technical Information of China (English)

    Li Dan; Zheng Wen-Wei; Wang Zhi-Song

    2008-01-01

    Operation of a laser-driven nano-motor inevitably generates a non-trivial amount of heat,which can possibly lead to instability or even hinder the motor's continual running.This work quantitatively examines the overheating problem for a recently proposed laser-operated molecular locomotive.We present a single-molecule cooling theory,in which molecular details of the locomotive system are explicitly treated.This theory is able to quantitatively predict cooling efficiency for various candidates of molecular systems for the locomotive,and also suggests concrete strategies for improving the locomotive's cooling.It is found that water environment is able to cool the hot locomotive down to room temperature within 100 picoseconds after photon absorption.This cooling time is a few orders of magnitude shorter than the typical time for laser operation,effectively preventing any overheating for the nano-locomotive.However,when the cooling is less effective in non-aqueous environment,residual heat may build up.A continuous running of the motor will then lead to a periodic thermodynamics,which is a common character of many laser-operated nano-devices.

  17. Electric Field Driven Torque in Biological Rotary Motors

    CERN Document Server

    Miller,, John H; Maric, Sladjana; Infante, Hans L; Claycomb, James R

    2013-01-01

    Ion driven rotary motors, such as Fo-ATP synthase (Fo) and the bacterial flagellar motor, act much like a battery-powered electric motor. They convert energy from ions as they move from high to low potential across a membrane into torque and rotary motion. Here we propose a mechanism whereby electric fields, emanating from channels in one or more stators, act on asymmetric charge distributions due to protonated and deprotonated sites in the rotor and drive it to rotate. The model predicts an ideal scaling law between torque and ion motive force, which can be hindered by mitochondrial mutations. The rotor of Fo drives the gamma-subunit to rotate within the ATP-producing complex (F1), working against an opposing torque that rises and falls periodically with angular position. Drawing an analogy with Brownian motion of a particle in a tilted washboard potential, we compute the highly nonlinear ATP production rate vs. proton motive force (pmf), showing a minimum pmf needed to drive ATP production with important me...

  18. LUBRICATION FILM FORMATION MECHANISM OF SLIPPER PAIRS IN LOW SPEED HIGH TORQUE HYDRAULIC MOTORS

    Institute of Scientific and Technical Information of China (English)

    LI Yong; SHI Guanglin; CHEN Zhaoneng

    2007-01-01

    Pressure-flow analytical formulas of lubrication film of slipper pairs on camshaft connecting rod type low speed high torque (LSHT) hydraulic motors are put forward. The bottom surface of slipper pairs is rectangle, and the effect of squeeze flow and pressure differential flow is considered. The dynamic process of lubrication film formation through squeezing is numerically studied by computer simulation. Effects of supply pressure, initial lubrication film thickness, velocity damping coefficient, loading impact and gravity, etc are studied. Advantages of novel slipper pairs with large oil cavity area are pointed out.

  19. The Development of Water Hydraulic Transmission and Water Hydraulic Axial Piston Pump (Motor)%水压传动及柱塞泵(马达)的现状和发展

    Institute of Scientific and Technical Information of China (English)

    聂松林; 张铁华; 李壮云

    2000-01-01

    介绍了国内外水压传动技术及其水压轴向柱塞泵(马达)的设计制造和发展。%Introduces the developments of Water Hydraulic transmission and Water Hydraulic Axial Piston Pump (Motor). The challenges for designing water hydraulic components and analyzed.

  20. Blade-shaped (PKN) Hydraulic Fracture Driven By A Turbulent Fluid In An Impermeable Rock

    CERN Document Server

    Zolfaghari, Navid; Bunger, Andrew P

    2016-01-01

    High flow rate, water-driven hydraulic fractures are more common now than ever in the oil and gas industry. Although the fractures are small, the high injection rate and low viscosity of the water, lead to high Reynolds numbers and potentially turbulence in the fracture. Here we present a semi-analytical solution for a blade-shaped (PKN) geometry hydraulic fracture driven by a turbulent fluid in the limit of zero fluid leak-off to the formation. We model the turbulence in the PKN fracture using the Gaukler-Manning-Strickler parametrization, which relates the the flow rate of the water to the pressure gradient along the fracture. The key parameter in this relation is the Darcy-Weisbach friction factor for the roughness of the crack wall. Coupling this turbulence parametrization with conservation of mass allows us to write a nonlinear pde for the crack width as a function of space and time. By way of a similarity ansatz, we obtain a semi-analytical solution using an orthogonal polynomial series. Embedding the a...

  1. Long-Stroke Nanopositioning Stage Driven by Piezoelectric Motor

    Directory of Open Access Journals (Sweden)

    Yong Wang

    2014-01-01

    Full Text Available This paper reported a biaxial nanopositioning stage single-driven by piezoelectric motor. The employed piezoelectric motor can perform two different driving modes, namely, AC drive mode to drive in long-stroke and at high-speed and DC scanning mode with the high-resolution of several nanometers, which satisfies the requirements of both long-stroke and nanoresolution. To compensate for the effects of the variable friction force and some unpredictable disturbances, a novel backward error compensation (BEC positioning control method integrated of the two driving modes and a double closed-loop PID controller system are proposed to obtain a high-accuracy positional motion. The experiment results demonstrate that the nanopositioning stage with large travel range of 300 mm × 300 mm has a fine speed characteristic and resolution is 5 nm. In the experiments of different travels up to 15 mm, calibrated by a commercial laser vibrometer, the positioning accuracy is proved within 55 nm in x-axis and 40 nm in y-axis with standard deviation less than 40 nm in x-axis and 30 nm in y-axis and the final position locking can be limited to 10 nm, meeting the requirements of micromanipulation technology.

  2. Static Analysis of High-Performance Fixed Fluid Power Drive with a Single Positive-Displacement Hydraulic Motor

    Directory of Open Access Journals (Sweden)

    O. F. Nikitin

    2015-01-01

    Full Text Available The article deals with the static calculations in designing a high-performance fixed fluid power drive with a single positive-displacement hydraulic motor. Designing is aimed at using a drive that is under development and yet unavailable to find and record the minimum of calculations and maximum of existing hydraulic units that enable clear and unambiguous performance, taking into consideration an available assortment of hydraulic units of hydraulic drives, to have the best efficiency.The specified power (power, moment and kinematics (linear velocity or angular velocity of rotation parameters of the output element of hydraulic motor determine the main output parameters of the hydraulic drive and the useful power of the hydraulic drive under development. The value of the overall efficiency of the hydraulic drive enables us to judge the efficiency of high-performance fixed fluid power drive.The energy analysis of a diagram of the high-performance fixed fluid power drive shows that its high efficiency is achieved when the flow rate of fluid flowing into each cylinder and the magnitude of the feed pump unit (pump are as nearly as possible.The paper considers the ways of determining the geometric parameters of working hydromotors (effective working area or working volume, which allow a selection of the pumping unit parameters. It discusses the ways to improve hydraulic drive efficiency. Using the principle of holding constant conductivity allows us to specify the values of the pressure losses in the hydraulic units used in noncatalog modes. In case of no exact matching between the parameters of existing hydraulic power modes and a proposed characteristics of the pump unit, the nearest to the expected characteristics is taken as a working version.All of the steps allow us to create the high-performance fixed fluid power drive capable of operating at the required power and kinematic parameters with high efficiency.

  3. A seismic vertical vibrator driven by linear synchronous motors

    NARCIS (Netherlands)

    Noorlandt, R.P.; Drijkoningen, G.G.; Dams, J.; Jenneskens, R.

    2015-01-01

    A linear synchronous motor (LSM) is an electric motor that can produce large controllable forces and is therefore suitable as a driving engine for a seismic vibrator. This motor consists of two independent elements, a magnet track and a coil track, allowing practically unlimited motor displacements.

  4. Method of Sum of Power Losses as a Way for Determining the ki Coefficients of Energy Losses in Hydraulic Motor

    Directory of Open Access Journals (Sweden)

    Maczyszyn A.

    2016-04-01

    Full Text Available This paper shows application of the method of sum of power losses to determining energy losses which occur in hydraulic rotary motor in situation when not all laboratory data are at one’s disposal or when no use is made of data contained in catalogue charts. The method makes it possible to determine the coefficients, ki, of energy losses occurring in the motor. The method of sum of power losses is based on the approach proposed by Z. Paszota, in the papers [3 ÷ 9]. It consists in adding power flow of energy losses occurring in the motor to power flow output and comparing the sum to the power flow input. Application of the method is exemplified by using a A6VM hydraulic motor.

  5. Forming-Precision-Driven Structure Design of Hydraulic Press:Methodology and Case Study

    Institute of Scientific and Technical Information of China (English)

    李艳聪; 张连洪; 何柏岩; 陈永亮; 张淳

    2015-01-01

    The structure stiffness of presses has great effects on the forming precision of workpieces, especially in near-net or net shape forming. Conventionally the stiffness specification of presses is empirically determined, re-sulting in poor designs with insufficient or over sufficient stiffness of press structures. In this paper, an approach for the structure design of hydraulic presses is proposed, which is forming-precision-driven and can make presses cost-effective by lightweight optimization. The approach consists of five steps:(1)the determination of the press stiff-ness specification in terms of the forming precision requirement of workpieces;(2)the conceptual design of the press structures according to the stiffness and workspace specifications, and the structure configuration of the press;(3)the prototype design of the press structures by equivalently converting the conceptual design to proto-types;(4)the selection of key structure parameters by sensitivity analysis of the prototype design; and(5)the opti-mization of the prototype design. The approach is demonstrated and validated through a case study of the structure design of a 100 MN hydraulic press.

  6. Bench-mark solution for a penny-shaped hydraulic fracture driven by a thinning fluid

    CERN Document Server

    Linkov, Aleksandr

    2015-01-01

    The paper presents a solution for axisymmetric propagation of a penny-shaped crack driven by a thinning fluid. The solution to the accuracy of four significant digits, at least, is obtained on the basis of the modified formulation of hydraulic fracture problem by employing the particle velocity, rather than conventionally used flux. This serves to properly organize iterations in the opening after reducing the problem to the self-similar form. Numerical results obtained show relatively small dependence of self-similar quantities (fracture radius, propagation speed, opening, particle velocity, pressure, flux) on the behavior index of a thinning fluid. The results provide bench marks for the accuracy control of truly 3D simulators and they serve for assigning an apparent viscosity when simulating the action of a thinning fluid by replacing it with an equivalent Newtonian fluid.

  7. Continuous Energy Improvement in Motor Driven Systems - A Guidebook for Industry

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert A. McCoy and John G. Douglass

    2014-02-01

    This guidebook provides a step-by-step approach to developing a motor system energy-improvement action plan. An action plan includes which motors should be repaired or replaced with higher efficiency models, recommendations on maintaining a spares inventory, and discussion of improvements in maintenance practices. The guidebook is the successor to DOE’s 1997 Energy Management for Motor Driven Systems. It builds on its predecessor publication by including topics such as power transmission systems and matching driven equipment to process requirements in addition to motors.

  8. Position Control of Motor Drive Systems: A Data Driven Approach

    Directory of Open Access Journals (Sweden)

    Hossein Parastvand

    2015-08-01

    Full Text Available This paper presents a new model free approach to the design of robust PID controller for the position control of electrical machines, such as induction motor, synchronous motor and DC motor faced to un-modeled dynamics. It is illustrated that knowing the frequency response data is sufficient to calculate the family of robust PID controllers that satisfy -norm on the complementary sensitivity function. The usefulness of the proposed approach is demonstrated through simulation on an induction motor drive system.

  9. Hydraulic engines in armoured conveyors; Motores hidraulicos en los transportadores blindados

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez Fernandez, N.; Fernandez Equibar, J.L. [Hullera Vasco-Leones, S.A., Leon (Spain)

    1994-05-01

    The Sociedad Anonima Hullera Vasco-Leonesa (HVL) coal mining company in Spain is exploiting a deposit of large subvertical seams which are characterised by being highly tectonised. A very important part of the work of exploitation is developed in the depths of the mine with the aid of secondary ventilation. In the near future, which will characterise itself with the opening of the `New Mine`, this type of work will come to have a significant relevance in underground mining technology. The limitations of space and the presence of methane necessitate, as for many years, the use of pneumatic moving shields, with the great inconveniences which derive from them: reduced energy efficiency, and elevated production of dust and noise. For this HVL seek to introduce in a conventional working, at the bottom of the mine, a system of armoured conveyors driven by hydraulic units, which besides reducing and/or eliminating the problems referred to above serve, as in the past, to extend hydraulic energy into other parts of mining activity. In order to initiate the proposed investigation a pilot project will be partially financed by Ocicarbon. 5 figs.

  10. Motor-Driven (Passive) Cycling: A Potential Physical Inactivity Countermeasure?

    Science.gov (United States)

    Peterman, James E; Wright, Kenneth P; Melanson, Edward L; Kram, Rodger; Byrnes, William C

    2016-09-01

    We have previously shown that motor-driven (passive) stationary cycling elevates energy expenditure (EE). This study aimed to quantify how acute passive cycling affects glucose and insulin responses to an oral glucose tolerance test (OGTT) and basic cognition compared with sitting and moderate-intensity active cycling. Twenty-four physically inactive healthy males completed three trials in randomized order involving 30-min conditions of sitting, passive cycling, and moderate-intensity cycling. During each condition, EE was measured, and participants performed cognitive tests. After each condition, a 2-h OGTT was performed. EE was significantly higher during the cycling conditions compared with sitting (1.36 ± 0.58 and 6.50 ± 1.73 kcal·min greater than sitting for passive and moderate-intensity, respectively). A significant correlation was found between body fat percentage and postsitting OGTT 2-h postplasma glucose (r = 0.30, P < 0.05); thus, participants were divided into lean (n = 11) and nonlean (n = 13) groups. In the nonlean group, compared with sitting, passive cycling lowered 2-h postplasma glucose (7.7 ± 1.3 vs 6.9 ± 1.6 mmol·L, respectively, P < 0.05), and the Matsuda whole-body insulin sensitivity index (WBISI) was higher (2.74 ± 0.86 vs 3.36 ± 1.08, P < 0.05). In addition, passive and moderate-intensity cycling had similar beneficial effects on 2-h postplasma glucose and WBISI. Cognitive performance did not significantly differ between the sitting and passive cycling conditions. Two-hour postplasma glucose was lower and WBISI after acute passive cycling was higher in nonlean participants. Given that and the increase in EE without changes in cognitive performance, we propose passive cycling as a promising intervention to counteract some of the deleterious effects of prolonged sitting in the workplace.

  11. Unidirectional Light-Driven Molecular Motors Based on Overcrowded Alkenes

    NARCIS (Netherlands)

    Cnossen, Arjen; Browne, Wesley R.; Feringa, Ben L.; Credi, Alberto; Silvi, Serena; Venturi, Margherita

    2014-01-01

    Over the last two decades, interest in nanotechnology has led to the design and synthesis of a toolbox of nanoscale versions of macroscopic devices and components. In molecular nanotechnology, linear motors based on rotaxanes and rotary motors based on overcrowded alkenes are particularly promising

  12. Hydraulics and pneumatics

    CERN Document Server

    Parr, Andrew

    2006-01-01

    Nearly all industrial processes require objects to be moved, manipulated or subjected to some sort of force. This is frequently accomplished by means of electrical equipment (such as motors or solenoids), or via devices driven by air (pneumatics) or liquids (hydraulics).This book has been written by a process control engineer as a guide to the operation of hydraulic and pneumatic systems for all engineers and technicians who wish to have an insight into the components and operation of such a system.This second edition has been fully updated to include all recent developments su

  13. Study on the ride comfort of vehicles driven by in-wheel motors

    Directory of Open Access Journals (Sweden)

    Liqiang Jin

    2016-02-01

    Full Text Available Vehicles driven by in-wheel motors have received more and more attention. However, due to the introduction of in-wheel motors, the ratio between unsprung and sprung mass is increased. In this article, to study the influence of this change on ride comfort of vehicles driven by in-wheel motors, an 11 degrees of freedom of vehicle ride comfort model will be presented and studied with MATLAB/Simulink. Then, road tests will be conducted to corroborate the simulation results. It can be obtained that the vehicle ride comfort becomes poor with the increasing unsprung mass. Finally, semi-active air-suspension proportional–integral–derivative control system will be proposed to improve the vehicle ride comfort. Through the simulation results, one can come to a conclusion that the proportional–integral–derivative control system for air suspension is feasible and effective to improve the ride comfort of the vehicles driven by in-wheel motors.

  14. IEMDC -IN-LINE ELECTRIC MOTOR DRIVEN COMPRESSOR

    Energy Technology Data Exchange (ETDEWEB)

    Michael J. Crowley; Prem N. Bansal; John E. Tessaro

    2004-01-01

    Dresser-Rand completed the preliminary aerodynamic flowpath of the volute and inlet design for the compressor section. This has resulted in considerable progress being made on the development of the compressor section and ultimately towards the successful integration of the IEMDC System design. Significant effort was put forth in the design of aerodynamic components which resulted in a design that meets the limits of aerodynamically induced radial forces previously established. Substantial effort has begun on the mechanical design of the compressor pressure containing case and other internal components. These efforts show progression towards the successful integration of a centrifugal compressor and variable speed electric motor ventilated by the process gas. All efforts continue to confirm the feasibility of the IEMDC system design. During the third quarter reporting period, the focus was to further refine the motor design and to ensure that the IEMDC rotor system supported on magnetic bearing is in compliance with the critical speed and vibration requirements of the API standards 617 and 541. Consequently specification to design magnetic bearings was developed and an RFQ to three magnetic bearing suppliers was issued. Considerable work was also performed to complete preliminary reports on some of the deliverable tasks under phase 1.0. These include specification for the VFD, RFQ for the magnetic bearings, and preliminary write-up for motor instrumentation and control schematic. In order to estimate motor efficiency at various operating points, plots of calculated motor losses, and motor cooling gas flow rates were also prepared. Preliminary evaluations of motor support concepts were performed via FEA to determine modal frequencies. Presentation was made at DOE Morgantown on August 12, 2003 to provide project status update. Preparations for the IEMDC motor-compressor presentation, at the GMRC conference in Salt Lake City to be held on October 5, 2003, were also

  15. Investigation of Valve Plate in Water Hydraulic Axial Piston Motor%水压轴向柱塞马达配流盘的研究

    Institute of Scientific and Technical Information of China (English)

    聂松林; 李壮云; 杨曙东

    2002-01-01

    This paper has introduced the developments of water hydraulic axial piston equipments. According to the effects of physicochemical properties of water on water hydraulic components, a novel valve plate for water hydraulic axial motor has been put forward, whose moment exerted by the fluid field between valve plate and bearing plate is balanced entirely. The material screening experiment of valve plate is done on the test rig. Through numerical simulation the effects of some geometry parameters on the performance of water hydraulic motor have been studied. The silencing grooves on the valve plate in water hydraulic motor can reduce the pressure shock and the occurrence of cavitation effectively. It is evident that the appropriate structure should change the wear status between matching pairs and reduces the wear and specific pressure of the matching pairs. The specimen with the new type valve plate is used in a tool system.

  16. Fault degradation assessment of water hydraulic motor by impulse vibration signal with Wavelet Packet Analysis and Kolmogorov Smirnov Test

    Science.gov (United States)

    Chen, H. X.; Chua, Patrick S. K.; Lim, G. H.

    2008-10-01

    The machinery fault diagnosis is important for improving reliability and performance of systems. Many methods such as Time Synchronous Average (TSA), Fast Fourier Transform (FFT)-based spectrum analysis and short-time Fourier transform (STFT) have been applied in fault diagnosis and condition monitoring of mechanical system. The above methods analyze the signal in frequency domain with low resolution, which is not suitable for non-stationary vibration signal. The Kolmogorov-Smirnov (KS) test is a simple and precise technique in vibration signal analysis for machinery fault diagnosis. It has limited use and advantage to analyze the vibration signal with higher noise directly. In this paper, a new method for the fault degradation assessment of the water hydraulic motor is proposed based on Wavelet Packet Analysis (WPA) and KS test to analyze the impulsive energy of the vibration signal, which is used to detect the piston condition of water hydraulic motor. WPA is used to analyze the impulsive vibration signal from the casing of the water hydraulic motor to obtain the impulsive energy. The impulsive energy of the vibration signal can be obtained by the multi-decomposition based on Wavelet Packet Transform (WPT) and used as feature values to assess the fault degradation of the pistons. The kurtosis of the impulsive energy in the reconstructed signal from the Wavelet Packet coefficients is used to extract the feature values of the impulse energy by calculating the coefficients of the WPT multi-decomposition. The KS test is used to compare the kurtosis of the impulse energy of the vibration signal statistically under the different piston conditions. The results show the applicability and effectiveness of the proposed method to assess the fault degradation of the pistons in the water hydraulic motor.

  17. Design of single-phase driven screw-thread-type ultrasonic motor

    Science.gov (United States)

    Chang, Lien-Kai; Tsai, Mi-Ching

    2016-05-01

    Most screw-thread-type ultrasonic motors are designed to be two-phase driven. This paper aims to present a novel single phase driven design that generates the required wobble motion, thus significantly simplifying the driving circuit of the ultrasonic motor. The proposed single-phase driven screw-thread-type ultrasonic motor works with two orthogonal bending modes generated by an asymmetric stator design. The novel stator design can improve the vibration displacement and further enhance the performance of the single phase driven motor. The vibration characteristics of the asymmetric stator structure were analyzed by ANSYS finite element analysis software. Based on the design and analysis processes, a prototype of the desired screw-thread-type ultrasonic motor was fabricated and tested. When the operating voltage is 200 Vpp, the obtained main characteristics of the proposed motor are as follows: the working frequency is between 28.3 and 29.5 kHz; the maximum no-load velocity is approximately 4.1 mm s-1; and the thrust force is 1.6 N.

  18. Fluid driven fracture mechanics in highly anisotropic shale: a laboratory study with application to hydraulic fracturing

    Science.gov (United States)

    Gehne, Stephan; Benson, Philip; Koor, Nick; Enfield, Mark

    2017-04-01

    The finding of considerable volumes of hydrocarbon resources within tight sedimentary rock formations in the UK led to focused attention on the fundamental fracture properties of low permeability rock types and hydraulic fracturing. Despite much research in these fields, there remains a scarcity of available experimental data concerning the fracture mechanics of fluid driven fracturing and the fracture properties of anisotropic, low permeability rock types. In this study, hydraulic fracturing is simulated in a controlled laboratory environment to track fracture nucleation (location) and propagation (velocity) in space and time and assess how environmental factors and rock properties influence the fracture process and the developing fracture network. Here we report data on employing fluid overpressure to generate a permeable network of micro tensile fractures in a highly anisotropic shale ( 50% P-wave velocity anisotropy). Experiments are carried out in a triaxial deformation apparatus using cylindrical samples. The bedding planes are orientated either parallel or normal to the major principal stress direction (σ1). A newly developed technique, using a steel guide arrangement to direct pressurised fluid into a sealed section of an axially drilled conduit, allows the pore fluid to contact the rock directly and to initiate tensile fractures from the pre-defined zone inside the sample. Acoustic Emission location is used to record and map the nucleation and development of the micro-fracture network. Indirect tensile strength measurements at atmospheric pressure show a high tensile strength anisotropy ( 60%) of the shale. Depending on the relative bedding orientation within the stress field, we find that fluid induced fractures in the sample propagate in two of the three principal fracture orientations: Divider and Short-Transverse. The fracture progresses parallel to the bedding plane (Short-Transverse orientation) if the bedding plane is aligned (parallel) with the

  19. Thermally driven molecular linear motors - A molecular dynamics study

    DEFF Research Database (Denmark)

    Zambrano, Harvey A; Walther, Jens Honore; Jaffe, Richard Lawrence

    2009-01-01

    We conduct molecular dynamics simulations of a molecular linear motor consisting of coaxial carbon nanotubes with a long outer carbon nanotube confining and guiding the motion of an inner short, capsule-like nanotube. The simulations indicate that the motion of the capsule can be controlled...

  20. Mechanical properties of organelles driven by microtubule-dependent molecular motors in living cells.

    Directory of Open Access Journals (Sweden)

    Luciana Bruno

    Full Text Available The organization of the cytoplasm is regulated by molecular motors which transport organelles and other cargoes along cytoskeleton tracks. Melanophores have pigment organelles or melanosomes that move along microtubules toward their minus and plus end by the action of cytoplasmic dynein and kinesin-2, respectively. In this work, we used single particle tracking to characterize the mechanical properties of motor-driven organelles during transport along microtubules. We tracked organelles with high temporal and spatial resolutions and characterized their dynamics perpendicular to the cytoskeleton track. The quantitative analysis of these data showed that the dynamics is due to a spring-like interaction between melanosomes and microtubules in a viscoelastic microenvironment. A model based on a generalized Langevin equation explained these observations and predicted that the stiffness measured for the motor complex acting as a linker between organelles and microtubules is ∼ one order smaller than that determined for motor proteins in vitro. This result suggests that other biomolecules involved in the interaction between motors and organelles contribute to the mechanical properties of the motor complex. We hypothesise that the high flexibility observed for the motor linker may be required to improve the efficiency of the transport driven by multiple copies of motor molecules.

  1. Research on Hybrid Input Mechanical Press Driven by Two Motors

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Given the speed requirements of a mechanical press slider, a differential gear train is adopted instead of the belt and gear drive of a general mechanical press. Two electric motors are used to drive the differential gear train with hybrid input. Based on the working principle of a differential gear train, the angular speed equations and the power distribution equations of the input-output system are established. By controlling the angular speeds of the two motors, the slider can move at different speeds. Taken a JH23-100 type mechanical press as example, the driving system is designed and the power of two motors determined. The simulated results show that the highest slider speed in the mechanical press approaches 39 mm/s only at the forging-punching stage, far less than the 232 mm/s of a general JH23-100 type mechanical press. This provides a new scheme to realize low-speed forging-punching technology from a mechanical press.

  2. A Motor-Driven Mechanism for Cell-Length Sensing

    Directory of Open Access Journals (Sweden)

    Ida Rishal

    2012-06-01

    Full Text Available Size homeostasis is fundamental in cell biology, but it is not clear how large cells such as neurons can assess their own size or length. We examined a role for molecular motors in intracellular length sensing. Computational simulations suggest that spatial information can be encoded by the frequency of an oscillating retrograde signal arising from a composite negative feedback loop between bidirectional motor-dependent signals. The model predicts that decreasing either or both anterograde or retrograde signals should increase cell length, and this prediction was confirmed upon application of siRNAs for specific kinesin and/or dynein heavy chains in adult sensory neurons. Heterozygous dynein heavy chain 1 mutant sensory neurons also exhibited increased lengths both in vitro and during embryonic development. Moreover, similar length increases were observed in mouse embryonic fibroblasts upon partial downregulation of dynein heavy chain 1. Thus, molecular motors critically influence cell-length sensing and growth control.

  3. Research on Power Recycling Test Method of Integrative Hydraulic Pump and Motor%联体泵马达功率回收试验方法研究

    Institute of Scientific and Technical Information of China (English)

    郭刘洋; 刘俊; 唐守生; 郭杨浏

    2013-01-01

    The experimental method for the integrative hydraulic pump and motor was researched. The power recycling theory of hydraulic pump was analyzed. According to character of the integrative hydraulic pump and motor,the test method for the integrative hydraulic pump and motor power recycling was defined. The formula to calculate volumetric efficiency was deduced. The power recycling test result is assist to analyze volumetric efficiency,meanwhile,to verify the fundamental performance of the integrative hydraulic pump and motor. Additionally,the test result proves that the integrative hydraulic pump and motor power recycling test method is feasible.%  针对联体泵马达的试验方法进行研究,分析液压泵的功率回收试验原理,根据联体泵马达的结构特点,确定了联体泵马达功率回收试验方法,并推导出容积效率计算公式;通过功率回收试验,对联体泵马达的容积效率进行了测试,验证了泵马达的基本性能,也证实了功率回收方法的有效性和可行性。

  4. Computational Design of a Family of Light-Driven Rotary Molecular Motors with Improved Quantum Efficiency.

    Science.gov (United States)

    Nikiforov, Alexander; Gamez, Jose A; Thiel, Walter; Filatov, Michael

    2016-01-07

    Two new light-driven molecular rotary motors based on the N-alkylated indanylidene benzopyrrole frameworks are proposed and studied using quantum chemical calculations and nonadiabatic molecular dynamics simulations. These new motors perform pure axial rotation, and the photochemical steps of the rotary cycle are dominated by the fast bond-length-alternation motion that enables ultrafast access to the S1/S0 intersection. The new motors are predicted to display a quantum efficiency higher than that of the currently available synthetic all-hydrocarbon motors. Remarkably, the quantum efficiency is not governed by the topography (peaked versus sloped) of the minimum-energy conical intersection, whereas the S1 decay time depends on the topography as well as on the energy of the intersection relative to the S1 minimum. It is the axial chirality (helicity), rather than the point chirality, that controls the sense of rotation of the motor.

  5. Development of a data-driven forecasting tool for hydraulically fractured, horizontal wells in tight-gas sands

    Science.gov (United States)

    Kulga, B.; Artun, E.; Ertekin, T.

    2017-06-01

    Tight-gas sand reservoirs are considered to be one of the major unconventional resources. Due to the strong heterogeneity and very low permeability of the formation, and the complexity of well trajectories with multiple hydraulic fractures; there are challenges associated with performance forecasting and optimum exploitation of these resources using conventional modeling approaches. In this study, it is aimed to develop a data-driven forecasting tool for tight-gas sands, which are based on artificial neural networks that can complement the physics-driven modeling approach, namely numerical-simulation models. The tool is designed to predict the horizontal-well performance as a proxy to the numerical model, once the initial conditions, operational parameters, reservoir/hydraulic-fracture characteristics are provided. The data-driven model, that the forecasting tool is based on, is validated with blind cases by estimating the cumulative gas production after 10 years with an average error of 3.2%. A graphical-user-interface application is developed that allows the practicing engineer to use the developed tool in a practical manner by visualizing estimated performance for a given reservoir within a fraction of a second. Practicality of the tool is demonstrated with a case study for the Williams Fork Formation by assessing the performance of various well designs and by incorporating known uncertainties through Monte Carlo simulation. P10, P50 and P90 estimates of the horizontal-well performance are quickly obtained within acceptable accuracy levels.

  6. Kinetic analysis of the rotation rate of light-driven unidirectional molecular motors

    NARCIS (Netherlands)

    Klok, Martin; Browne, Wesley R.; Feringa, Ben L.

    2009-01-01

    The combination of a photochemical and a thermal equilibrium in overcrowded alkenes, which is the basis for unidirectional rotation of light-driven molecular rotary motors, is analysed in relation to the actual average rotation rates of such structures. Experimental parameters such as temperature, c

  7. Increased speed of rotation for the smallest light-driven molecular motor

    NARCIS (Netherlands)

    ter Wiel, MKJ; van Delden, RA; Meetsma, A; Feringa, BL; Delden, Richard A. van; Feringa, Bernard

    2003-01-01

    In this paper we present the smallest artificial light-driven molecular motor consisting of only 28 carbon and 24 hydrogen atoms. The concept of controlling directionality of rotary movement at the molecular level by introduction of a stereogenic center next to the central olefinic bond of a sterica

  8. Fine tuning of the rotary motion by structural modification in light-driven unidirectional molecular motors

    NARCIS (Netherlands)

    Vicario, J; Walko, M; Meetsma, A; Feringa, Ben L.

    2006-01-01

    The introduction of bulky substituents at the stereogenic center of light-driven second-generation molecular motors results in an acceleration of the speed of rotation. This is due to a more strained structure with elongated C=C bonds and a higher energy level of the ground state relative to the tra

  9. Near-field optically driven Brownian motors (Conference Presentation)

    Science.gov (United States)

    Wu, Shao-Hua; Huang, Ningfeng; Jaquay, Eric; Povinelli, Michelle L.

    2016-09-01

    Brownian ratchets are of fundamental interest in fields from statistical physics to molecular motors. The realization of Brownian ratchets in engineered systems opens up the potential to harness thermal energy for directed motion, with applications in transport and sorting of nanoparticles. Implementations based on optical traps provide a high degree of tunability along with precise spatiotemporal control. Near-field optical methods provide particular flexibility and ease of on-chip integration with other microfluidic components. Here, we demonstrate the first all-optical, near-field Brownian ratchet. Our approach uses an asymmetrically patterned photonic crystal and yields an ultra-stable trap stiffness of 253.6 pN/nm-W, 100x greater than conventional optical tweezers. By modulating the laser power, optical ratcheting with transport speed of 1 micron/s can be achieved, allowing a variety of dynamical lab-on-a-chip applications. The resulting transport speed matches well with the theoretical prediction.

  10. IEMDC-IN-LINE ELECTRIC MOTOR DRIVEN COMPRESSOR

    Energy Technology Data Exchange (ETDEWEB)

    Michael J. Crowley; Prem N. Bansal; John E. Tessaro

    2003-06-01

    During this reporting period, significant progress has been made towards the development of the IEMDC System design. Considerable effort was put forth by Curtiss-Wright EMD in the resolution of the technical issue of aerodynamically induced radial forces. This has provided a design basis with which to establish the radial magnetic bearing load capacity and the rotordynamic design. Dresser-Rand has made considerable progress on the flowpath design for the compressor section particularly on the volute and inlet aerodynamic design. All efforts show progression towards the successful integration of a centrifugal compressor and variable speed electric motor ventilated by the process gas. These efforts continue to confirm the feasibility of the IEMDC system design.

  11. Fuzzy auto-tuning PID control of multiple joint robot driven by ultrasonic motors.

    Science.gov (United States)

    Sun, Zhijun; Xing, Rentao; Zhao, Chunsheng; Huang, Weiqing

    2007-11-01

    A three-joint robot is directly driven by ultrasonic motors with advantage of high torque at low speed. The speed of the ultrasonic motors is actually controlled by regulating their operating frequencies. The kinematic and kinetic analyses of the robot have been carried out using Adams. Due to the lack of accurate control model of ultrasonic motors and the time-varying motor parameters, a fuzzy auto-tuning proportional integral derivative (PID) controller for the robot is experimented, in which a simple method to tune parameters of the PID type fuzzy controller on-line is developed and a new position-speed feedback strategy is proposed and implemented. The effectiveness of the proposed control strategy and fuzzy logic controller is verified by experimental investigation.

  12. Integrated regulation of motor-driven organelle transport by scaffolding proteins.

    Science.gov (United States)

    Fu, Meng-meng; Holzbaur, Erika L F

    2014-10-01

    Intracellular trafficking pathways, including endocytosis, autophagy, and secretion, rely on directed organelle transport driven by the opposing microtubule motor proteins kinesin and dynein. Precise spatial and temporal targeting of vesicles and organelles requires the integrated regulation of these opposing motors, which are often bound simultaneously to the same cargo. Recent progress demonstrates that organelle-associated scaffolding proteins, including Milton/TRAKs (trafficking kinesin-binding protein), JIP1, JIP3 (JNK-interacting proteins), huntingtin, and Hook1, interact with molecular motors to coordinate activity and sustain unidirectional transport. Scaffolding proteins also bind to upstream regulatory proteins, including kinases and GTPases, to modulate transport in the cell. This integration of regulatory control with motor activity allows for cargo-specific changes in the transport or targeting of organelles in response to cues from the complex cellular environment.

  13. Stall force of a cargo driven by N interacting motor proteins

    Science.gov (United States)

    Bhat, Deepak; Gopalakrishnan, Manoj

    2017-01-01

    We study a generic one-dimensional model for an intracellular cargo driven by N motor proteins against an external applied force. The model includes motor-cargo and motor-motor interactions. The cargo motion is described by an over-damped Langevin equation, while motor dynamics is specified by hopping rates which follow a local detailed balance condition with respect to the change in energy per hopping event. Based on this model, we show that the stall force, the mean external force corresponding to zero mean cargo velocity, is completely independent of the details of the interactions and is, therefore, always equal to the sum of the stall forces of the individual motors. This exact result is arrived on the basis of a simple assumption: the (macroscopic) state of stall of the cargo is analogous to a state of thermodynamic equilibrium, and is characterized by vanishing net probability current between any two microstates, with the latter specified by motor positions relative to the cargo. The corresponding probability distribution of the microstates under stall is also determined. These predictions are in complete agreement with numerical simulations, carried out using specific forms of interaction potentials.

  14. Structural Design and Control of Variable Camber Wing Driven by Ultrasonic Motors

    Institute of Scientific and Technical Information of China (English)

    Liu Weidong; Zhu Hua; Zhou Shengqiang; Bai Yalei; Zhao Chunsheng

    2015-01-01

    A novel variable camber wing driven by ultrasonic motors is proposed .Key techniques of distributed lay-out of drive mechanisms ,coordination control of distributed ultrasonic motors as well as novel flexible skin under-going one-dimensional morphing are studied .The system integration of small variable camber wing is achieved . Distributed layout of parallelogram linkages driven by geared ultrasonic motors is adopted for morphing ,aimed at reducing the load for each motor and producing various aerodynamic configurations suitable for different flying states .Programmable system-on-chip (PSoC) is used to realize the coordination control of the distributed ultrason-ic motors .All the morphing driving systems are assembled in the interior of the wing .The wing surface is covered with a novel smooth flexible skin in order to maintain wing shape and decrease the aerodynamic drag during mor-phing .Wind tunnel test shows that the variable camber wing can realize morphing under low speed flight condi-tion .Lift and drag characteristics and aerodynamic efficiency of the wing are improved .Appropriate configurations can be selected to satisfy aerodynamic requirements of different flight conditions .The study provides a practical ap-plication of piezoelectric precision driving technology in flow control .

  15. Integrated control strategies for railway vehicles with independently-driven wheel motors

    Institute of Scientific and Technical Information of China (English)

    Jinzhi FENG; Jun LI; R. M. Goodall

    2008-01-01

    This paper studies the development of inte-grated control strategies for railway vehicles with inde-pendently-driven wheel motors. First, a non-linear vehicle dynamic model and motor drive strategy are pre-sented, which are followed by an investigation of the inte-grated control of stabilization, steering, and traction for the vehicle. Meanwhile a reformulated Kalman filter is developed and applied to estimate the required feedback by the control system. Finally, the effectiveness and prac-ticality of the proposed integrated controller are examined and assessed by real-time simulation based on host-target computer technology provided by Matlab/Simulink.

  16. Intelligent Control Algorithm of PTZ System Driven by Two-DOF Ultrasonic Motor

    Institute of Scientific and Technical Information of China (English)

    Wu Songsen; Leng Xuefei; Jin Jiamei; Wang Bihui; Mao Xingyun

    2015-01-01

    It is difficult for the traditional pan-tilt-zoom (PTZ) system driven by electromagnetic motor to meet the growing demand for video surveillance system .The key challenge is high positioning accuracy ,high dynamic per-formance and miniaturization of the PTZ system .Here a PTZ system driven by two degree-of-freedom obelisk-shaped ultrasonic motor with single stator is presented ,and its intelligent control algorithm is studied .The struc-ture and driving mechanism of the presented PTZ system are analyzed by both simulation and experiment .To solve the complex nonlinear factors ,e .g .time-variation ,dead zone ,the fuzzy PID control algorithm and the variable gain cross-coupled control strategy are combined to improve the control performance .The results show that the proposed algorithm has faster response ,higher precision than traditional control algorithm ,and it also has a good robustness to prevent the effect of interference .

  17. Torsional Vibration Analysis of Reciprocating Compressor Trains driven by Induction Motors

    Science.gov (United States)

    Brunelli, M.; Fusi, A.; Grasso, F.; Pasteur, F.; Ussi, A.

    2015-08-01

    The dynamic study of electric motor driven compressors, for Oil&Gas (O&G) applications, are traditionally performed in two steps separating the mechanical and the electrical systems. The packager conducts a Torsional Vibration Analysis (TVA) modeling the mechanical system with a lumped parameter scheme, without taking into account the electrical part. The electric motor supplier later performs a source current pulsation analysis on the electric motor system, based on the TVA results. The mechanical and the electrical systems are actually linked by the electromagnetic effect. The effect of the motor air-gap on TVA has only recently been taken into account by adding a spring and a damper between motor and ground in the model. This model is more accurate than the traditional one, but is applicable only to the steady-state condition and still fails to consider the reciprocal effects between the two parts of the system. In this paper the torsional natural frequencies calculated using both the traditional and the new model have been compared. Furthermore, simulation of the complete system has been achieved through the use of LMS AMESim, multi-physics, one-dimensional simulation software that simultaneously solves the shafts rotation and electric motor voltage equation. Finally, the transient phenomena that occur during start-up have been studied.

  18. Nongrounded Common-Mode Equivalent Circuit for Brushless DC Motor Driven by PWM Inverter

    Science.gov (United States)

    Maetani, Tatsuo; Isomura, Yoshinori; Watanabe, Akihiko; Iimori, Kenichi; Morimoto, Shigeo

    This paper describes nongrounded common-mode equivalent circuit for a motor driven by a voltage-source PWM inverter. When the capacitance of the rotor was small, the phenomenon that polarity of the common mode voltage and shaft voltage reversed was observed. In order to model this phenomenon, the bridge type equivalent circuit is proposed. It is verified with the calculation and experiment that shaft voltage values and polarity are accurately calculated with the proposed equivalent circuit.

  19. Workspace control of biarticular manipulator driven by direct drive spiral motors

    OpenAIRE

    Shukor, Ahmad Zaki bin Hj

    2013-01-01

    Robotics have shown tremendous developments, such as industrial robots that assist us in production lines in manufacturing such as KUKA, FANUC and mobile robots in our everyday lives/work that perform various tasks such as material handling or inspection in hazardous environments, space exploration as well as entertainment or services that involve interaction with humans or objects. Many of these robot designs are driven by servo motors that actuate the joints, i.e. classical two link planar ...

  20. Local synaptic signaling enhances the stochastic transport of motor-driven cargo in neurons

    KAUST Repository

    Newby, Jay

    2010-08-23

    The tug-of-war model of motor-driven cargo transport is formulated as an intermittent trapping process. An immobile trap, representing the cellular machinery that sequesters a motor-driven cargo for eventual use, is located somewhere within a microtubule track. A particle representing a motor-driven cargo that moves randomly with a forward bias is introduced at the beginning of the track. The particle switches randomly between a fast moving phase and a slow moving phase. When in the slow moving phase, the particle can be captured by the trap. To account for the possibility that the particle avoids the trap, an absorbing boundary is placed at the end of the track. Two local signaling mechanisms-intended to improve the chances of capturing the target-are considered by allowing the trap to affect the tug-of-war parameters within a small region around itself. The first is based on a localized adenosine triphosphate (ATP) concentration gradient surrounding a synapse, and the second is based on a concentration of tau-a microtubule-associated protein involved in Alzheimer\\'s disease-coating the microtubule near the synapse. It is shown that both mechanisms can lead to dramatic improvements in the capture probability, with a minimal increase in the mean capture time. The analysis also shows that tau can cause a cargo to undergo random oscillations, which could explain some experimental observations. © 2010 IOP Publishing Ltd.

  1. Properties of sodium-driven bacterial flagellar motor: A two-state model approach

    CERN Document Server

    Zhang, Yunxin

    2013-01-01

    Bacterial flagellar motor (BFM) is one of the ion-driven molecular machines, which drives the rotation of flagellar filaments and enable bacteria to swim in viscous solutions. Understanding its mechanism is one challenge in biophysics. Based on previous models and inspired by the idea used in description of motor proteins, in this study one two-state model is provided. Meanwhile, according to corresponding experimental data, mathematical relationship between BFM membrane voltage and pH value of the environment, and relationship between internal and external sodium concentrations are given. Therefore, with model parameter values obtained by fitting theoretical results of torque-speed relation to recent experimental data, many biophysical properties of bacterial flagellar motor can be obtained for any pH values and any external sodium concentrations. Including the rotation speed, stall torque (i.e. the torque generated by BFM), rotation dispersion, and rotation randomness. In this study, the single-stator BFM w...

  2. Methodologies of Measuring Mechanical Power Delivered at the Shaft of an Induction Motor Driven by VFD

    Directory of Open Access Journals (Sweden)

    Mariana MANEA

    2012-12-01

    Full Text Available Measuring precise power used by a load of an induction motor driven by a VFD implies a few facts that need to be considered. First, the real electric power. When dealing with waveforms of electric current that contain harmonics, traditional methods of power measuring could lead to inaccurate results. Therefore, further investigation needs to be performed in order to provide meaningful values. Then there is the efficiency. Motor losses are to be taken into account for finding out exactly how much power is being used for a specific application.This paper shows a method of measuring and calculating the electric real power of fundamental harmonic and of extracting an actual output value of mechanical power at the motor shaft. For this purpose we used a data acquisition system made of a basic power quality analyzer and data acquisition software. Harmonic analysis of the waveforms is considered, combined with the use of the true power factor.

  3. An investigation of the dynamic electromechanical coupling effects in machine drive systems driven by asynchronous motors

    Science.gov (United States)

    Szolc, Tomasz; Konowrocki, Robert; Michajłow, Maciej; Pręgowska, Agnieszka

    2014-12-01

    In the paper dynamic electromechanical interaction between the rotating machine drive system and the electric driving motor is considered. The investigations are performed by means of the circuit model of the asynchronous motor as well as using an advanced structural hybrid model of the drive system. Using the analytical solutions applied for the electrical and the mechanical systems the electromagnetic stiffness and coefficient of damping, both generated by the electric motor rotationally interacting with the mechanical system of the given dynamic properties, were determined. By means of experimentally validated computational responses obtained for torsional harmonic excitation induced by the driven machine working tool, a modification of dynamic properties of the mechanical system by the electromagnetic flux between the stator and the rotor has been studied.

  4. A Peristaltic Micro Pump Driven by a Rotating Motor with Magnetically Attracted Steel Balls

    Directory of Open Access Journals (Sweden)

    Zhaoying Zhou

    2009-04-01

    Full Text Available In this paper, we present a membrane peristaltic micro pump driven by a rotating motor with magnetically attracted steel balls for lab-on-a-chip applications. The fabrication process is based on standard soft lithography technology and bonding of a PDMS layer with a PMMA substrate. A linear flow rate range ~490 μL/min was obtained by simply varying the rotation speed of a DC motor, and a maximum back pressure of 592 Pa was achieved at a rotation speed of 43 rpm. The flow rate of the pump can also be adjusted by using steel balls with different diameters or changing the number of balls. Nevertheless, the micro pump can also work in high speed mode. A high back pressure up to 10 kPa was achieved at 500 rpm using a high speed DC motor, and an utmost flow rate up to 5 mL/min was reached.

  5. A peristaltic micro pump driven by a rotating motor with magnetically attracted steel balls.

    Science.gov (United States)

    Du, Min; Ye, Xiongying; Wu, Kang; Zhou, Zhaoying

    2009-01-01

    In this paper, we present a membrane peristaltic micro pump driven by a rotating motor with magnetically attracted steel balls for lab-on-a-chip applications. The fabrication process is based on standard soft lithography technology and bonding of a PDMS layer with a PMMA substrate. A linear flow rate range ∼490 μL/min was obtained by simply varying the rotation speed of a DC motor, and a maximum back pressure of 592 Pa was achieved at a rotation speed of 43 rpm. The flow rate of the pump can also be adjusted by using steel balls with different diameters or changing the number of balls. Nevertheless, the micro pump can also work in high speed mode. A high back pressure up to 10 kPa was achieved at 500 rpm using a high speed DC motor, and an utmost flow rate up to 5 mL/min was reached.

  6. Universal Linear Motor Driven Leg Press Dynamometer and Concept of Serial Stretch Loading

    Science.gov (United States)

    2015-01-01

    Paper deals with backgrounds and principles of universal linear motor driven leg press dynamometer and concept of serial stretch loading. The device is based on two computer controlled linear motors mounted to the horizontal rails. As the motors can keep either constant resistance force in selected position or velocity in both directions, the system allows simulation of any mode of muscle contraction. In addition, it also can generate defined serial stretch stimuli in a form of repeated force peaks. This is achieved by short segments of reversed velocity (in concentric phase) or acceleration (in eccentric phase). Such stimuli, generated at the rate of 10 Hz, have proven to be a more efficient means for the improvement of rate of the force development. This capability not only affects performance in many sports, but also plays a substantial role in prevention of falls and their consequences. Universal linear motor driven and computer controlled dynamometer with its unique feature to generate serial stretch stimuli seems to be an efficient and useful tool for enhancing strength training effects on neuromuscular function not only in athletes, but as well as in senior population and rehabilitation patients. PMID:26913159

  7. Universal linear motor driven Leg Press Dynamometer and concept of Serial Stretch Loading

    Directory of Open Access Journals (Sweden)

    Dušan Hamar

    2015-08-01

    Full Text Available Paper deals with backgrounds and principles of universal linear motor driven leg press dynamometer and concept of serial stretch loading. The device is based on two computer controlled linear motors mounted to the horizontal rails. As the motors can keep either constant resistance force in selected position or velocity in both directions, the system allows simulation of any mode of muscle contraction. In addition, it also can generate defined serial stretch stimuli in a form of repeated force peaks. This is achieved by short segments of reversed velocity (in concentric phase or acceleration (in eccentric phase. Such stimuli, generated at the rate of 10 Hz, have proven to be a more efficient means for the improvement of rate of the force development. This capability not only affects performance in many sports, but also plays a substantial role in prevention of falls and their consequences. Universal linear motor driven and computer controlled dynamometer with its unique feature to generate serial stretch stimuli seems to be an efficient and useful tool for enhancing strength training effects on neuromuscular function not only in athletes, but as well as in senior population and rehabilitation patients.

  8. Hydraulic conductance of Acacia phyllodes (foliage) is driven by primary nerve (vein) conductance and density.

    Science.gov (United States)

    Sommerville, Katy E; Sack, Lawren; Ball, Marilyn C

    2012-01-01

    We determined effects of venation traits on hydraulic conductance of phyllodes (foliage), using an array of Acacia s.str. species with diverse phyllode morphologies as the source of variation. Measurements were made on phyllodes from 44 species, grown in common gardens but originating from different positions along a precipitation gradient. K(phyllode) varied 18-fold and was positively correlated with primary nerve hydraulic conductance, and with primary nerve (vein) density but not with minor nerve density, in contrast with previous studies of true leaves in other dicotyledons. Phyllodes with higher primary nerve density also had greater mass per area (PMA) and larger bundle sheath extensions (BSEs) from their minor nerves. We suggest that higher primary nerve conductivity and density may decrease the distance travelled in the high-resistance extra-xylem pathways of the phyllode. Further, larger BSEs may increase the area available for dispersion of water from the xylem to the extra-xylem tissue. High PMA phyllodes were more common in acacias from areas receiving lower annual precipitation. Maximizing efficient water movement through phyllodes may be more important where rainfall is meagre and infrequent, explaining relationships between nerve patterns and the climates of origin in Australian phyllodinous Acacia.

  9. Project calculation of the steering mechanism hydraulic servo control in motor vehicles

    Directory of Open Access Journals (Sweden)

    Zoran Đukan Majkić

    2013-10-01

    Full Text Available Hydraulic servo controls are designed to facilitate rotation in place without providing increased ppower to steering wheels. In the initial design phase, the dimensions required for control systems are usually obtained through the calculation of their load when wheels rotate in place, where the torque is calculated empirically. The starting point in the project calculation is thus to determine the hydraulic power steering torque torsional resistance which is then used to determine the maximum value of force i.e. the torque on the stering wheel. The calculation of the control system servo control consists of determining the basic parameters, the required pump capacity, the main dimensions of the hub and the  pipeline and the conditions for the stability of the system control mechanism. Introduction The aim of the calculation of the steering control system is to determine the basic parameters of its components which ensure the fulfilment of requirements of the control system. Calculations are performed in several stages with a simultaneous  detailed constructive analysis of the control system leading to the best variant. At each stage, design and control calculations of the hydraulic servo of the steering mechanism are performed. The design allows the computation to complete the selection of basic dimensions of the amplifer elements, starting from the approved scheme and the basic building loads of approximate values. Calculations control is carried out to clarify the structural solution and to obtain the output characteristics of the control amplifier which are applied in the  estimation of  potential properties of the structure. Project calculation Baseline data must be sufficiently reliable, ie. must correspond to the construction characteristics of the vehicle design and the control system as well as to service conditions..A proper deterimination of the torque calculation of torsional resistance in wheels is of utmost importance. Moment of

  10. An enantioselective synthetic route toward second-generation light-driven rotary molecular motors.

    Science.gov (United States)

    Pijper, Thomas C; Pijper, Dirk; Pollard, Michael M; Dumur, Frédéric; Davey, Stephen G; Meetsma, Auke; Feringa, Ben L

    2010-02-05

    Controlling the unidirectional rotary process of second-generation molecular motors demands access to these motors in their enantiomerically pure form. In this paper, we describe an enantioselective route to three new second-generation light-driven molecular motors. Their synthesis starts with the preparation of an optically active alpha-methoxy-substituted upper-half ketone involving an enzymatic resolution. The subsequent conversion of this ketone to the corresponding hydrazone by treatment with hydrazine led to full racemization. However, conversion to a TBDMS-protected hydrazone by treatment with bis-TBDMS hydrazine, prepared according to a new procedure, proceeds with nearly full retention of the stereochemical integrity. Oxidation of the TBDMS-protected hydrazone and subsequent coupling to a lower-half thioketone followed by recrystallization provided the molecular motors with >99% ee. As these are the first molecular motors that have a methoxy substituent at the stereogenic center, the photochemical and thermal isomerization steps involved in the rotary cycle of one of these new molecules were studied in detail with various spectroscopic techniques.

  11. Diagnosis of airgap eccentricity fault in the inverter driven induction motor drives by transformative techniques

    Directory of Open Access Journals (Sweden)

    Khadim Moin Siddiqui

    2016-09-01

    Full Text Available In the present paper, the airgap eccentricity fault of the induction motor has been diagnosed by digital signal processing transformative techniques in the inverter driven induction motor drives. The airgap eccentricity fault has been diagnosed in the transient condition by time domain as well as time-frequency domain techniques with the help of a proposed dynamic simulation model. In the past, many signal processing techniques had been used for various induction motor fault detection purpose such as fast Fourier transform, Hilbert transform, short term Fourier transform, etc. But, all techniques faced some sort of disadvantages. Therefore, in this paper, all shortcomings of the previous used signal processing techniques have been solved by newly wavelet transform's approximation signal. The low frequency approximation signal has been used to diagnose the eccentricity fault in the transient condition. Therefore, early fault diagnosis of the motor is possible and averted the motor before reaching in the ruinous conditions. As a result, the industries may save large revenues and unexpected failure conditions. The obtained results clearly demonstrate that the developed diagnostic technique may reliably separate airgap eccentricity fault in many stages.

  12. Increased speed of rotation for the smallest light-driven molecular motor.

    Science.gov (United States)

    ter Wiel, Matthijs K J; van Delden, Richard A; Meetsma, Auke; Feringa, Ben L

    2003-12-10

    In this paper we present the smallest artificial light-driven molecular motor consisting of only 28 carbon and 24 hydrogen atoms. The concept of controlling directionality of rotary movement at the molecular level by introduction of a stereogenic center next to the central olefinic bond of a sterically overcrowded alkene does not only hold for molecular motors with six-membered rings, but is also applicable to achieve the unidirectional movement for molecular motors having five-membered rings. Although X-ray analyses show that the five-membered rings in the cis- and trans-isomer of the new molecular motor are nearly flat, the energy differences between the (pseudo-)diaxial and (pseudo-)diequatorial conformations of the methyl substituents in both isomers are still large enough to direct the rotation of one-half of the molecule with respect to the other half in a clockwise fashion. The full rotary cycle comprises four consecutive steps: two photochemical isomerizations each followed by a thermal helix inversion. Both photochemical cis-trans isomerizations proceed with a preference for the unstable diequatorial isomers over the stable diaxial isomers. The thermal barriers for helix inversion of this motor molecule have decreased dramatically compared to its six-membered ring analogue, the half-life of the fastest step being only 18 s at room temperature.

  13. Damping Force Modeling and Suppression of Self-Excited Vibration due to Magnetic Fluids Applied in the Torque Motor of a Hydraulic Servovalve

    Directory of Open Access Journals (Sweden)

    Wei Zhang

    2017-05-01

    Full Text Available As a key component of hydraulic control systems, hydraulic servovalves influence their performance significantly. Unpredictable self-excited noise inside hydraulic servovalves may cause instability and even failure. Being functional, with higher saturation magnetization and increased viscosity when exposed to a magnetic field, magnetic fluids (MFs have been widely used in dampers, sealing, and biomedical treatment. In this paper, magnetic fluids are applied in the torque motor of a hydraulic servovalve to exert damping and resistance for vibration and noise suppression. Construction of the torque motor armature with magnetic fluids is introduced and the forces due to magnetic fluids on the torque motor armature are studied. Based on a bi-viscosity-constituted relationship, a mathematical model of the damping force from magnetic fluids is built when magnetic fluids are filled in the working gaps of the torque motor. Measurements of the properties of an Fe3O4 composite magnetic fluid are carried out to calculate the parameters of this mathematical model and to investigate the influence of magnetic fluids on the vibration characteristics of the armature assembly. The simulated and tested harmonic responses of the armature with and without magnetic fluids show the good suppression effects of magnetic fluids on the self-excited noise inside the servovalve.

  14. Specialized motor-driven dusp1 expression in the song systems of multiple lineages of vocal learning birds.

    Directory of Open Access Journals (Sweden)

    Haruhito Horita

    Full Text Available Mechanisms for the evolution of convergent behavioral traits are largely unknown. Vocal learning is one such trait that evolved multiple times and is necessary in humans for the acquisition of spoken language. Among birds, vocal learning is evolved in songbirds, parrots, and hummingbirds. Each time similar forebrain song nuclei specialized for vocal learning and production have evolved. This finding led to the hypothesis that the behavioral and neuroanatomical convergences for vocal learning could be associated with molecular convergence. We previously found that the neural activity-induced gene dual specificity phosphatase 1 (dusp1 was up-regulated in non-vocal circuits, specifically in sensory-input neurons of the thalamus and telencephalon; however, dusp1 was not up-regulated in higher order sensory neurons or motor circuits. Here we show that song motor nuclei are an exception to this pattern. The song nuclei of species from all known vocal learning avian lineages showed motor-driven up-regulation of dusp1 expression induced by singing. There was no detectable motor-driven dusp1 expression throughout the rest of the forebrain after non-vocal motor performance. This pattern contrasts with expression of the commonly studied activity-induced gene egr1, which shows motor-driven expression in song nuclei induced by singing, but also motor-driven expression in adjacent brain regions after non-vocal motor behaviors. In the vocal non-learning avian species, we found no detectable vocalizing-driven dusp1 expression in the forebrain. These findings suggest that independent evolutions of neural systems for vocal learning were accompanied by selection for specialized motor-driven expression of the dusp1 gene in those circuits. This specialized expression of dusp1 could potentially lead to differential regulation of dusp1-modulated molecular cascades in vocal learning circuits.

  15. Design and experiments of a linear piezoelectric motor driven by a single mode

    Science.gov (United States)

    Liu, Zhen; Yao, Zhiyuan; Li, Xiang; Fu, Qianwei

    2016-11-01

    In this contribution, we propose a novel linear piezoelectric motor with a compact stator that is driven by a single mode. The linear piezoelectric motor can realize bidirectional motion by changing the vibration modes of the stator. Finite element analysis is performed to determine the required vibration mode of the stator and obtain the optimal stator structure and dimensions. Furthermore, the trajectories of the driving foot are analyzed with and without consideration of the mechanical contact with the slider. It is shown that the trajectory of the driving foot is an oblique line when disregarding the contact, and the trajectory becomes an oblique ellipse while taking into account the contact. Finally, a prototype of the motor is fabricated based on the results of finite element analysis. The optimization results show that the motor reaches its maximum thrust force of 4.0 kg, maximum thrust-weight ratio of 33.3, maximum unloaded velocity of 385 mm/s under the excitation of Mode-B, and maximum unloaded velocity of 315 mm/s under the excitation of Mode-L.

  16. F1 rotary motor of ATP synthase is driven by the torsionally-asymmetric drive shaft

    Science.gov (United States)

    Kulish, O.; Wright, A. D.; Terentjev, E. M.

    2016-06-01

    F1F0 ATP synthase (ATPase) either facilitates the synthesis of ATP in a process driven by the proton moving force (pmf), or uses the energy from ATP hydrolysis to pump protons against the concentration gradient across the membrane. ATPase is composed of two rotary motors, F0 and F1, which compete for control of their shared γ -shaft. We present a self-consistent physical model of F1 motor as a simplified two-state Brownian ratchet using the asymmetry of torsional elastic energy of the coiled-coil γ -shaft. This stochastic model unifies the physical concepts of linear and rotary motors, and explains the stepped unidirectional rotary motion. Substituting the model parameters, all independently known from recent experiments, our model quantitatively reproduces the ATPase operation, e.g. the ‘no-load’ angular velocity is ca. 400 rad/s anticlockwise at 4 mM ATP. Increasing the pmf torque exerted by F0 can slow, stop and overcome the torque generated by F1, switching from ATP hydrolysis to synthesis at a very low value of ‘stall torque’. We discuss the motor efficiency, which is very low if calculated from the useful mechanical work it produces - but is quite high when the ‘useful outcome’ is measured in the number of H+ pushed against the chemical gradient.

  17. Light-driven rotary molecular motors without point chirality: a minimal design.

    Science.gov (United States)

    Wang, Jun; Oruganti, Baswanth; Durbeej, Bo

    2017-03-08

    A fundamental requirement for achieving photoinduced unidirectional rotary motion about an olefinic bond in a molecular motor is that the potential energy surface of the excited state is asymmetric with respect to clockwise and counterclockwise rotations. In most available light-driven rotary molecular motors, such asymmetry is guaranteed by the presence of a stereocenter. Here, we present non-adiabatic molecular dynamics simulations based on multiconfigurational quantum chemistry to demonstrate that this chiral feature is not essential for inducing unidirectional rotary motion in molecules that incorporate a cyclohexenylidene moiety into a protonated Schiff-base framework. Rather, the simulations show that it is possible to exploit the intrinsic asymmetry of the puckered cyclohexenylidene to control the direction of photoinduced rotation.

  18. Energy-Efficiency Policy Opportunities for Electric Motor-Driven Systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This publication is the first global analysis of energy consumption and energy efficiency potential of EMDS (electric motor- driven system). The electric motors and systems they drive are the largest single electricity end use, accounting for more than 40% of global electricity consumption. Huge energy efficiency potential was found untapped in EMDS - around 25% of EMDS electricity use could be saved cost-effectively, reducing total global electricity demand by about 10%. However, the energy efficiency of EMDS has been relatively neglected in comparison with other sustainable energy opportunities. It is crucial to scale up the operations and resources committed to realizing the vast savings potential of optimized EMDS. This paper proposes a comprehensive package of policy recommendations to help governments realize the potential for energy savings in EMDS.

  19. Bidirectional transport of motor-driven cargoes in cell: A random walk with memory

    Science.gov (United States)

    Bhat, Deepak; Gopalakrishnan, Manoj

    2013-02-01

    Motor-driven bidirectional transport inside a cell is an intriguing phenomenon where multiple dyneins and kinesins drag cargoes and deliver them to specific locations. Quite often, both anterograde (plus) and retrograde (minus) directed motors reside simultaneously on the cargo and co-ordinate their activity such that the motion of the cargo looks like spells of plus directed and minus directed segments, with pauses in between. The stochastic tug-of-war model is widely used to analyze this motion, largely studied by computer simulations. Here, we present some analytical results for this model, such as the average durations of plus and minus-run segments and tug-of-war events as well as probabilities of persistence and reversal of directions following a tug-of-war. We show that cargo motion has memory in case of 2 dyneins and 1 kinesin driving together, while it is absent when only a dynein and a kinesin is involved.

  20. Dynamically balanced, hydraulically driven compressor/pump apparatus for resonant free piston Stirling engines

    Science.gov (United States)

    Corey, John A.

    1984-05-29

    A compressor, pump, or alternator apparatus is designed for use with a resonant free piston Stirling engine so as to isolate apparatus fluid from the periodically pressurized working fluid of the Stirling engine. The apparatus housing has a first side closed by a power coupling flexible diaphragm (the engine working member) and a second side closed by a flexible diaphragm gas spring. A reciprocally movable piston is disposed in a transverse cylinder in the housing and moves substantially at right angles relative to the flexible diaphragms. An incompressible fluid fills the housing which is divided into two separate chambers by suitable ports. One chamber provides fluid coupling between the power diaphragm of the RFPSE and the piston and the second chamber provides fluid coupling between the gas spring diaphragm and the opposite side of the piston. The working members of a gas compressor, pump, or alternator are driven by the piston. Sealing and wearing parts of the apparatus are mounted at the external ends of the transverse cylinder in a double acting arrangement for accessibility. An annular counterweight is mounted externally of the reciprocally movable piston and is driven by incompressible fluid coupling in a direction opposite to the piston so as to damp out transverse vibrations.

  1. Waterfall formation driven by interacting flow hydraulics, sediment cover, and erosion in an experimental bedrock canyon

    Science.gov (United States)

    Scheingross, Joel; Lamb, Michael; Fuller, Brian

    2016-04-01

    Waterfalls are ubiquitous in steep landscapes and have been documented to retreat upstream at rates far outpacing standard fluvial incision into bedrock. While the formation of waterfalls following changes in climate and base-level lowering have been well-documented, little work has explored the formation of waterfalls via the internal dynamics from interacting flow hydraulics, sediment flux, and evolving channel morphology. Distinguishing between waterfalls formed via external versus internal forcing is important, as waterfall formation and retreat rate is often applied in inverse to determine the timing of external forcing. Here, we present results from a laboratory experiment designed to explore channel incision and waterfall formation. We fed water and sediment at constant rates over an initially planar surface tilted to 19.5% slope. A channel rapidly incised into the artificial bedrock substrate, and small-wavelength variations in erosion rate created steps and pools which grew in amplitude. As pools deepened, sediment cover at the downstream portion of pools locally limited erosion, while erosion in the upstream portion of the pool created steep faces. At the topographic breaks between these steep segments and their upstream treads, water detached from the bed forming ventilated waterfall jets which impacted the plunge pools below. Individual waterfalls were short-lived as pool-deepening promoted alluviation which prevented further pool-incision, while amplified erosion at the waterfall lip incised a new pool into the bedrock previously composing the waterfall face. Repetition of this process in our experiment suggests that interactions between bedrock erosion and sediment cover can result in the formation of a series of plunge pools which retreat upstream.

  2. Brief introduction of servo-driven hydraulic press%伺服驱动液压机浅析

    Institute of Scientific and Technical Information of China (English)

    李贵闪

    2011-01-01

    文章介绍了伺服驱动液压机液压结构原理,与普通液压机比较,伺服控制液压机具有诸多优点,可以取代现有的大多数普通液压机,具有广泛的市场前景.%The principle of hydraulic structure for servo hydraulic press has been introduced in the text. Comparing with the common hydraulic press, the servo hydraulic press has lots of advantages, which makes it possible to take place of the many common hydraulic presses. It shows a broad marking prospect.

  3. Enhanced Component Performance Study: Motor-Driven Pumps 1998–2014

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-02-01

    This report presents an enhanced performance evaluation of motor-driven pumps at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience failure reports from fiscal year 1998 through 2014 for the component reliability as reported in the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The motor-driven pump failure modes considered for standby systems are failure to start, failure to run less than or equal to one hour, and failure to run more than one hour; for normally running systems, the failure modes considered are failure to start and failure to run. An eight hour unreliability estimate is also calculated and trended. The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. Statistically significant increasing trends were identified in pump run hours per reactor year. Statistically significant decreasing trends were identified for standby systems industry-wide frequency of start demands, and run hours per reactor year for runs of less than or equal to one hour.

  4. Enhanced Component Performance Study: Motor-Driven Pumps 1998–2013

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, John Alton [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-02-01

    This report presents an enhanced performance evaluation of motor-driven pumps at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience failure reports from fiscal year 1998 through 2013 for the component reliability as reported in the Institute of Nuclear Power Operations (INPO) Consolidated Events Database (ICES). The motor-driven pump failure modes considered for standby systems are failure to start, failure to run less than or equal to 1 hour, and failure to run more than 1 hour; for normally running systems, the failure modes considered are failure to start and failure to run. An 8 hr unreliability estimate is also calculated and trended. The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. One statistically significant increasing trend was identified in the standby pump run hours per reactor year. Statistically significant decreasing trends were identified for standby systems industry-wide frequency of start demands, run hours per reactor year for runs of less than or equal to 1 hour, and frequency of fail to start events per reactor year.

  5. Modeling and verification of the nonlinear system of oscillation platform of continuous casting mold driven by servo motor

    Directory of Open Access Journals (Sweden)

    Le Liu

    2016-06-01

    Full Text Available The driving mode by servo motor is a new driving mode and can realize oscillations of continuous casting mold as expected. The oscillation system of continuous casting mold driven by servo motor is a complicated nonlinear system. Therefore, it is necessary to establish an accurate model for the system before performing simulation experiments. Based on the oscillation platform system of continuous casting mold driven by servo motor in the laboratory, the nonlinear models of servo motor speed system and mechanical transmission parts were respectively established and the viscous friction coefficient, moment of inertia, and load torque were identified. Then, the nonlinear mathematical model of the whole oscillation platform of continuous casting mold driven by servo motor was obtained. The comparison results between the simulated output curves of established model and the measured output curves of actual system under the same input signals indicated that the simulated curves were almost in accord with the measured curves. Therefore, the proposed model can reflect the capabilities of practical system and lay a good foundation for subsequent research on simulation experiments and accurate control of continuous casting mold oscillation driven by servo motor.

  6. Thermal-hydraulic analysis of LBE spallation target for accelerator-driven systems

    Indian Academy of Sciences (India)

    Aniseh Ahmed Atef Abdalla; Jiyang Yu; Yongwel Yang

    2013-01-01

    In an accelerator-driven subcritical system (ADS), a high-performance spallation neutron source is used to feed the subcritical reactor. Neutron generation depends on the proton beam intensity. If the beam intensity is increased by a given factor, the number of generated neutrons will increase. The mechanism yielding a high rate of neutron production per energy is the spallation process, and this mechanism produces very high-energy deposition in the spallation target material. Producing a high rate of neutrons is accompanied by creation of problems of decay heat cooling and radiological protection. As a first step in designing a full-scale industrial ADS, a small-scale experimental ADS, which is similar to the European experimental ADS (XADS) is analysed. The analysis presented in this paper is based on lead–bismuth eutectic (LBE) cooled XADS-type experimental reactors, designed during the European experimental (PDS-XADS) project. Computational fluid dynamics analysis has been carried out for the spallation target. Steady-state behaviour and shear stress transport turbulence model with the automatic wall treatment were applied in the present analysis.

  7. Dynamic Analysis & Characterization of Conventional Hydraulic Power Supply Units

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Liedhegener, Michael; Bech, Michael Møller

    2016-01-01

    Hydraulic power units operated as constant supply pres-sure systems remain to be widely used in the industry, to supply valve controlled hydraulic drives etc., where the hydraulic power units are constituted by variable pumps with mechanical outlet pressure control, driven by induction motors...... and drives will reduce the flow-to-pressure gain of the supply system, and hence increase the time constant of the sup-ply pressure dynamics. A consequence of this may be large vari-ations in the supply pressure, hence large variations in the pump shaft torque, and thereby the induction motor load torque......, with possible excitation of the induction motor dynamics as a result. In such cases, the coupled dynamics of the pressure controlled pump and induction motor may influence the supply pressure sig-nificantly, possibly affecting the dynamics of the supplied drives, especially in cases where pilot operated valves...

  8. Macroscopic contraction of a gel induced by the integrated motion of light-driven molecular motors.

    Science.gov (United States)

    Li, Quan; Fuks, Gad; Moulin, Emilie; Maaloum, Mounir; Rawiso, Michel; Kulic, Igor; Foy, Justin T; Giuseppone, Nicolas

    2015-02-01

    Making molecular machines that can be useful in the macroscopic world is a challenging long-term goal of nanoscience. Inspired by the protein machinery found in biological systems, and based on the theoretical understanding of the physics of motion at the nanoscale, organic chemists have developed a number of molecules that can produce work by contraction or rotation when triggered by various external chemical or physical stimuli. In particular, basic molecular switches that commute between at least two thermodynamic minima and more advanced molecular motors that behave as dissipative units working far from equilibrium when fuelled with external energy have been reported. However, despite recent progress, the ultimate challenge of coordinating individual molecular motors in a continuous mechanical process that can have a measurable effect at the macroscale has remained elusive. Here, we show that by integrating light-driven unidirectional molecular rotors as reticulating units in a polymer gel, it is possible to amplify their individual motions to achieve macroscopic contraction of the material. Our system uses the incoming light to operate under far-from-equilibrium conditions, and the work produced by the motor in the photostationary state is used to twist the entangled polymer chains up to the collapse of the gel. Our design could be a starting point to integrate nanomotors in metastable materials to store energy and eventually to convert it.

  9. Macroscopic contraction of a gel induced by the integrated motion of light-driven molecular motors

    Science.gov (United States)

    Li, Quan; Fuks, Gad; Moulin, Emilie; Maaloum, Mounir; Rawiso, Michel; Kulic, Igor; Foy, Justin T.; Giuseppone, Nicolas

    2015-02-01

    Making molecular machines that can be useful in the macroscopic world is a challenging long-term goal of nanoscience. Inspired by the protein machinery found in biological systems, and based on the theoretical understanding of the physics of motion at the nanoscale, organic chemists have developed a number of molecules that can produce work by contraction or rotation when triggered by various external chemical or physical stimuli. In particular, basic molecular switches that commute between at least two thermodynamic minima and more advanced molecular motors that behave as dissipative units working far from equilibrium when fuelled with external energy have been reported. However, despite recent progress, the ultimate challenge of coordinating individual molecular motors in a continuous mechanical process that can have a measurable effect at the macroscale has remained elusive. Here, we show that by integrating light-driven unidirectional molecular rotors as reticulating units in a polymer gel, it is possible to amplify their individual motions to achieve macroscopic contraction of the material. Our system uses the incoming light to operate under far-from-equilibrium conditions, and the work produced by the motor in the photostationary state is used to twist the entangled polymer chains up to the collapse of the gel. Our design could be a starting point to integrate nanomotors in metastable materials to store energy and eventually to convert it.

  10. Mixed Lubrication Simulation of Hydrostatic Spherical Bearings for Hydraulic Piston Pumps and Motors

    Science.gov (United States)

    Kazama, Toshiharu

    Mixed and fluid film lubrication characteristics of hydrostatic spherical bearings for swash-plate-type axial piston pumps and motors are studied theoretically under non-steady-state conditions. The basic equations incorporating interference and contact of surface roughness are derived fundamentally through combination of the GW and PC models. Furthermore, a programming code that is applicable to the caulked-socket-type and open-socket-type bearings is developed. Effects of caulking, operating conditions, and the bearing dimension on the motion of the sphere and tribological performance of the bearings are examined. Salient conclusions are the following: The sphere's eccentricity increases in the low supply pressure period. The time-lag of the load change engenders greater motion of the sphere. Caulking of the bearing socket suppresses the sphere's motion. The bearing stiffness increases and power loss decreases for smaller recess angles. Minimum power loss is given under the condition that the bearing socket radius nearly equals the equivalent load radius.

  11. Ultrahigh resolution endoscopic spectral domain optical coherence tomography with a tiny rotary probe driven by a hollow ultrasonic motor

    Science.gov (United States)

    Zhang, Ning; Chen, Tianyuan; Huo, Tiancheng; Wang, Chengming; Zheng, Jing-gao; Zhou, Tieying; Xue, Ping

    2013-03-01

    This paper proposes a novel rotary endoscopic probe for spectral-domain optical coherence tomography (SD-OCT). The probe with a large N.A. objective lens is driven by an ultra-small hollow rectangular ultrasonic motor for circular scanning. Compared to the conventional driven techniques, the hollow ultrasonic motor enables the fiber to pass through its inside. Therefore the fiber, the objective lens and the motor are all at the same side. This enables 360 degree unobstructed imaging without any shadow resulted from power wire as in the conventional motor-driven endoscopic OCT. Moreover, it shortens the length of the rigid tip and enhances the flexibility of the probe. Meanwhile, the ultrasonic motor is robust, simple, quiet and of high torque, very suitable for OCT endoscopic probe. The side length of the motor is 0.7 mm with 5mm in length. The outer diameter of the probe is 1.5mm. A significant improvement in the lateral resolution is demonstrated due to the novel design of the objective lens. A right-angle lens is utilized instead of the traditional right-angle prism as the last optics close to the sample, leading to a reduction of the working distance and an enlargement of the N.A. of the objective lens. It is demonstrated that the endoscopic SD-OCT system achieves an axial resolution of ~7μm, a lateral resolution of ~6μm and a SNR of ~96dB.

  12. Dynamic modeling of a 6-degree-of-freedom Stewart platform driven by a permanent magnet synchronous motor

    Institute of Scientific and Technical Information of China (English)

    Qiang MENG; Tao ZHANG; Jing-feng HE; Jing-yan SONG; Jun-wei HAN

    2010-01-01

    For an electrical six-degree-of-freedom Stewart platform,it is difficult to compute the equivalent inertia of each motor in real time,as the inertia is time-varying.In this study,an analysis using Kane's equation is undertaken of the driven torque of the movements of motor systems(including motor friction,movements of motor systems along with the actuators,rotation around axis of rotors and snails),as well as driven torque of the platform and actuators.The electromagnetic torque was calculated according to vector-controlled permanent magnet synchronous motor(PMSM)dynamics.By equalizing the driven torque and electromagnetic torque,a model was established.This method,taking into consideration the influence of counter electromotive force(EMF)and motor friction,could be applied to the real-time dynamic control of the platform,through which the calculation of the time-varying equivalent inertia is avoided.Finally,simulations with typically desired trajectory inputs are presented and the performance of the Stewart platform is determined,With this approach,the multi-body dynamics of the electrical Stewart platform is better understood.

  13. Reduction of power consumption in motor-driven applications by using PM motors; PM = Permanent Magnet; Reduktion af elforbrug til motordrift ved anvendelse af PM motorer

    Energy Technology Data Exchange (ETDEWEB)

    Hvenegaard, C.M.; Hansen, Mads P.R.; Groenborg Nikolaisen, C. (Teknologisk Institut, Taastrup (Denmark)); Nielsen, Sandie B. (Teknologisk Institut, AArhus (Denmark)); Ritchie, E.; Leban, K. (Aalborg Univ., Aalborg (Denmark))

    2009-12-15

    The traditional asynchronous motor with aluminum rotor is today by far the most widespread and sold electric motor, but a new and more energy efficient type of engine - the permanent magnet motor (PM motor) - is expected in the coming years to win larger and larger market shares. Several engine manufacturers in Europe, USA and Asia are now beginning to market the PM motors, which can replace the traditional asynchronous motor. The project aims to uncover the pros and cons of replacing asynchronous motors including EFF1 engines with PM motors, including the price difference. Furthermore, it is identified how the efficiency of PM motors is affected by low load levels and at various forms of control. Finally, the energy savings potential is analysed, by replacing asynchronous motors with PM motors. The study includes laboratory tests of PM motors, made in a test stand at Danish Technological Institute. (ln)

  14. Simulating Plant Water Stress and Phenology in Seasonally Dry Tropical Forests: Plant Hydraulics and Trait-Driven Trade-Offs

    Science.gov (United States)

    Xu, X.; Medvigy, D.; Powers, J. S.; Becknell, J. M.

    2014-12-01

    Seasonally dry tropical forests account for over 40% of the forested area in tropical and subtropical regions. Previous studies suggest that seasonal water stress is one main driver of phenology and related vegetation dynamics in seasonally dry tropical forests. Species that coexist in seasonally dry tropical forests have different plant traits, experience different degrees of plant water stress and show distinctive phenological patterns. However, the observed diversity in plant phenology and related vegetation dynamics is poorly represented in current dynamic vegetation models. In this study, we employ a new modeling approach to enhance our model skills in seasonally dry tropical forests. First, we implement a new plant hydraulic module under the framework of a state-of-the-art dynamic vegetation model, Ecosystem Demography 2 (ED2). Second, we link plant water stress with several key coordinated plant traits. Unlike previous models, the updated ED2 does not prescribe leaf phenology (deciduous or evergreen) and plant water stress is not determined by empirical water stress factors or by soil moisture alone. Instead, the model tracks more mechanistic indicators of plant water stress like leaf water potential, accounts for different abilities to tolerate water stress among plant functional types and predicts dry season leaf deciduousness and related vegetation dynamics. The updated model is then tested with in-situ meteorological data and long-term ecological observations. We also perform numerical experiments to explore the possible biases of ignoring the observed diversity in seasonally dry tropical forests. We find that (i) variations of several key plant traits (specific leaf area, wood density, turgor loss point and rooting depth) can account for the observed distinctive phenological patterns as well as inter-annual variations in vegetation growth among species. (ii) Ignoring the trait-driven trade-offs and diversity in seasonality would introduce significant

  15. Integrated lens auto-focus system driven by a nut-type ultrosonic motor (USM)

    Institute of Scientific and Technical Information of China (English)

    ZHOU TieYing; CHEN Yu; LU CunYue; FU DeYong; HU XiaoPing; LI Yi; TIANBin

    2009-01-01

    This paper introduces an integrated optical auto-focus system driven by a nut-type ultrasonic motor (USM). The system comprises an optical lens as a rotor (M6 or M7), a polyhedral tube of copper as a stator; an image sensor, and a driver IC of the motor. The sizes of the AF (auto-focus) module are 8.5 mm×8.5 mm×5.9 mm. The piezoelectric elements are bonded on the external surface of the stator. The rotor has external screw thread that engages with the inner screw thread of the stator. When the pie-zoelectric elements are excited by the driver IC, a bend traveling wave in plane is generated on the stator along the circle direction, that drives the lens rotor to rotate and then to move axially. The driver IC is controlled by an image feedback of an image sensor centered on the axis of the casing, then the optical focusing is realized. The power consumption is zero at rest and is less than 0.25 W in motion; focusing precision 3 r/s(180 r/min); response <10 ms; high reliability: resistant to shock and fall off; directly driven by the driver IC without transmission mechanism; the friction force is namely the driving force and noiseless. The integrated optical auto-focus system is very useful, espe-cially for cellular phones. The image resolution of 3-5 MP has been obtained in the module prototypes of the cellular phone.

  16. Integrated lens auto-focus system driven by a nut-type ultrosonic motor (USM)

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    This paper introduces an integrated optical auto-focus system driven by a nut-type ultrasonic motor (USM). The system comprises an optical lens as a rotor (M6 or M7), a polyhedral tube of copper as a stator; an image sensor, and a driver IC of the motor. The sizes of the AF (auto-focus) module are 8.5 mm×8.5 mm×5.9 mm. The piezoelectric elements are bonded on the external surface of the stator. The rotor has external screw thread that engages with the inner screw thread of the stator. When the piezoelectric elements are excited by the driver IC, a bend traveling wave in plane is generated on the stator along the circle direction, that drives the lens rotor to rotate and then to move axially. The driver IC is controlled by an image feedback of an image sensor centered on the axis of the casing, then the optical focusing is realized. The power consumption is zero at rest and is less than 0.25 W in motion; focusing precision <10 μm; speed >3 r/s(180 r/min); response <10 ms; high reliability: resistant to shock and fall off; directly driven by the driver IC without transmission mechanism; the friction force is namely the driving force and noiseless. The integrated optical auto-focus system is very useful, especially for cellular phones. The image resolution of 3―5 MP has been obtained in the module prototypes of the cellular phone.

  17. Coupling dynamic equations of motor-driven elastic linkage mechanism with links fabricated from three-dimensional braided composite materials

    Institute of Scientific and Technical Information of China (English)

    CAI Gan-wei; WANG Xiang; WANG Ru-gui; LI Zhao-jun; ZHANG Xiao-bin; CANG Ping-ping

    2005-01-01

    A motor-driven linkage system with links fabricated from 3-dimensional braided composite materials was studied. A group of coupling dynamic equations of the system, including composite materials parameters, electromagnetism parameters of the motor and structural parameters of the link mechanism, were established by finite element method. Based on the air-gap field of non-uniform airspace of three-phase alternating current motor caused by the vibration eccentricity of rotor, the relation of electromechanical coupling at the actual running state was analyzed. And the motor element, which defines the transverse vibration and torsional vibration of the motor as its nodal displacement, was established. Then, based on the damping element model and the expression of energy dissipation of the 3-dimentional braided composite materials, the damping matrix of the system was established by calculating each order modal damping of the mechanism.

  18. Hydraulic redistribution in dwarf Rhizophora mangle trees driven by interstitial soil water salinity gradients: impacts on hydraulic architecture and gas exchange.

    Science.gov (United States)

    Hao, Guang-You; Jones, Tim J; Luton, Corene; Zhang, Yong-Jiang; Manzane, Eric; Scholz, Fabian G; Bucci, Sandra J; Cao, Kun-Fang; Goldstein, Guillermo

    2009-05-01

    Rhizophora mangle L. trees of Biscayne National Park (Florida, USA) have two distinct growth forms: tall trees (5-10 m) growing along the coast and dwarf trees (1 m or less) growing in the adjacent inland zone. Sharp decreases in salinity and thus increases in soil water potential from surface soil to about a depth of 1 m were found at the dwarf mangrove site but not at the tall mangrove site. Consistent with our prediction, hydraulic redistribution detected by reverse sap flow in shallow prop roots was observed during nighttime, early morning and late afternoon in dwarf trees, but not in tall trees. In addition, hydraulic redistribution was observed throughout the 24-h period during a low temperature spell. Dwarf trees had significantly lower sapwood-specific hydraulic conductivity, smaller stem vessel diameter, lower leaf area to sapwood area ratio (LA/SA), smaller leaf size and higher leaf mass per area. Leaves of dwarf trees had lower CO(2) assimilation rate and lower stomatal conductance compared to tall trees. Leaf water potentials at midday were more negative in tall trees that are consistent with their substantially higher stomatal conductance and LA/SA. The substantially lower water transport efficiency and the more conservative water use of dwarf trees may be due to a combination of factors such as high salinity in the surface soil, particularly during dry periods, and substantial reverse sap flow in shallow roots that make upper soil layers with high salinity a competing sink of water to the transpiring leaves. There may also be a benefit for the dwarf trees in having hydraulic redistribution because the reverse flow and the release of water to upper soil layers should lead to dilution of the high salinity in the rhizosphere and thus relieve its potential harm to dwarf R. mangle trees.

  19. Self-powered suspension criterion and energy regeneration implementation scheme of motor-driven active suspension

    Science.gov (United States)

    Yan, Shuai; Sun, Weichao

    2017-09-01

    Active suspension systems have advantages on mitigating the effects of vehicle vibration caused by road roughness, which are one of the most important component parts in influencing the performances of vehicles. However, high amount of energy consumption restricts the application of active suspension systems. From the point of energy saving, this paper presents a self-powered criterion of the active suspension system to judge whether a motor-driven suspension can be self-powered or not, and then a motor parameter condition is developed as a reference to design a self-powered suspension. An energy regeneration implementation scheme is subsequently proposed to make the active suspension which has the potential to be self-powered achieve energy-saving target in the real application. In this implementation scheme, operating electric circuits are designed based on different working status of the actuator and power source and it is realizable to accumulate energy from road vibration and supply energy to the actuator by switching corresponding electric circuits. To apply the self-powered suspension criterion and energy regeneration implementation scheme, an active suspension system is designed with a constrained H∞ controller and calculation results indicate that it has the capability to be self-powered. Simulation results show that the performances of the self-powered active suspension are nearly the same as those of the active suspension with an external energy source and can achieve energy regeneration at the same time.

  20. Optimal Velocity Control for a Battery Electric Vehicle Driven by Permanent Magnet Synchronous Motors

    Directory of Open Access Journals (Sweden)

    Dongbin Lu

    2014-01-01

    Full Text Available The permanent magnet synchronous motor (PMSM has high efficiency and high torque density. Field oriented control (FOC is usually used in the motor to achieve maximum efficiency control. In the electric vehicle (EV application, the PMSM efficiency model, combined with the EV and road load system model, is used to study the optimal energy-saving control strategy, which is significant for the economic operation of EVs. With the help of GPS, IMU, and other information technologies, the road conditions can be measured in advance. Based on this information, the optimal velocity of the EV driven by PMSM can be obtained through the analytical algorithm according to the efficiency model of PMSM and the vehicle dynamic model in simple road conditions. In complex road conditions, considering the dynamic characteristics, the economic operating velocity trajectory of the EV can be obtained through the dynamic programming (DP algorithm. Simulation and experimental results show that the minimum energy consumption and global energy optimization can be achieved when the EV operates in the economic operation area.

  1. Hydraulic-driven Based the Design of the Transmission Assemblies%基于液压驱动的传动组合装置的设计

    Institute of Scientific and Technical Information of China (English)

    黄象珊; 谢颂京

    2013-01-01

    To meet the needs of the basic course teaching of the task-driven automotive major, a kind of hydraulic-driven transmission assemblies is designed. The device mainly consists of hydraulic-driven systems, transmission systems and test systems. It is free to mix different driven programs and collect data. It is proved through practice that the device is flexible for package and with strong function. The device is easy for operation and for secondary development. The students' practical abilities can be improved greatly.%为满足当前基于任务驱动的汽车专业基础类课程教学需要,设计了一种基于液压驱动的传动组合装置.该装置主要由液压驱动系统、传动系统和测试系统组成,能自由组合实现不同的传动方案并进行数据采集,通过实践证明,该组合装置组装灵活、功能强,具有较好的可操作性和二次开发性,能够提高学生综合实践能力和创新能力.

  2. 3D printed self-driven thumb-sized motors for in-situ underwater pollutant remediation

    Science.gov (United States)

    Yu, Fen; Hu, Qipeng; Dong, Lina; Cui, Xiao; Chen, Tingtao; Xin, Hongbo; Liu, Miaoxing; Xue, Chaowen; Song, Xiangwei; Ai, Fanrong; Li, Ting; Wang, Xiaolei

    2017-02-01

    Green fuel-driven thumb sized motors (TSM) were designed and optimized by 3D printing to explore their in-situ remediation applications in rare studied underwater area. Combined with areogel processing and specialized bacteria domestication, each tiny TSM could realize large area pollutant treatment precisely in an impressive half-automatically manner.

  3. Force Spectroscopy of Individual Stimulus-Responsive Poly(ferrocenyldimethylsilane) Chains: Towards a Redox-Driven Macromolecular Motor

    NARCIS (Netherlands)

    Zou, Shan; Hempenius, Mark A.; Schönherr, Holger; Vancso, G. Julius

    2006-01-01

    Progress in the development of a redox-driven macromolecular motor and the characterization of its redox-mechanical cycle using electrochemical AFM-based single-molecule force spectroscopy (SMFS) is described. The elasticities of individual neutral and oxidized poly(ferrocenyldimethylsilane) (PFS) m

  4. On the effect of donor and acceptor substituents on the behaviour of light-driven rotary molecular motors

    NARCIS (Netherlands)

    Pollard, Michael M.; Wesenhagen, Philana V.; Pijper, Dirk; Feringa, Ben L.

    2008-01-01

    Light-driven rotary molecular motors based on overcrowded alkenes can be substituted with electron-donating and electron-withdrawing substituents ( R = OMe, Cl and CN) in direct conjugation with the central double bond ( the axis of rotation) without having a significant influence on the rate-limiti

  5. Constant-Pressure Hydraulic Pump

    Science.gov (United States)

    Galloway, C. W.

    1982-01-01

    Constant output pressure in gas-driven hydraulic pump would be assured in new design for gas-to-hydraulic power converter. With a force-multiplying ring attached to gas piston, expanding gas would apply constant force on hydraulic piston even though gas pressure drops. As a result, pressure of hydraulic fluid remains steady, and power output of the pump does not vary.

  6. Using the motor to monitor pump conditions

    Energy Technology Data Exchange (ETDEWEB)

    Casada, D. [Oak Ridge National Lab., TN (United States)

    1996-12-01

    When the load of a mechanical device being driven by a motor changes, whether in response to changes in the overall process or changes in the performance of the driven device, the motor inherently responds. For induction motors, the current amplitude and phase angle change as the shaft load changes. By examining the details of these changes in amplitude and phase, load fluctuations of the driven device can be observed. The usefulness of the motor as a transducer to improve the understanding of devices with high torque fluctuations, such as positive displacement compressors and motor-operated valves, has been recognized and demonstrated for a number of years. On such devices as these, the spectrum of the motor current amplitude, phase, or power normally has certain characteristic peaks associated with various load components, such as the piston stroke or gear tooth meshing frequencies. Comparison and trending of the amplitudes of these peaks has been shown to provide some indication of their mechanical condition. For most centrifugal pumps, the load fluctuations are normally low in torque amplitude, and as a result, the motor experiences a correspondingly lower level of load fluctuation. However, both laboratory and field test data have demonstrated that the motor does provide insight into some important pump performance conditions, such as hydraulic stability and pump-to-motor alignment. Comparisons of other dynamic signals, such as vibration and pressure pulsation, to motor data for centrifugal pumps are provided. The effects of inadequate suction head, misalignment, mechanical and hydraulic unbalance on these signals are presented.

  7. Modeling and Parameter Identification of the Vibration Characteristics of Armature Assembly in a Torque Motor of Hydraulic Servo Valves under Electromagnetic Excitations

    Directory of Open Access Journals (Sweden)

    Jinghui Peng

    2014-07-01

    Full Text Available The resonance of the armature assembly is the main problem leading to the fatigue of the spring pipe in a torque motor of hydraulic servo valves, which can cause the failure of servo valves. To predict the vibration characteristics of the armature assembly, this paper focuses on the mathematical modeling of the vibration characteristics of armature assembly in a hydraulic servo valve and the identification of parameters in the models. To build models more accurately, the effect of the magnetic spring is taken into account. Vibration modal analysis is performed to obtain the mode shapes and natural frequencies, which are necessary to implement the identification of damping ratios in the mathematical models. Based on the mathematical models for the vibration characteristics, the harmonic responses of the armature assembly are analyzed using the finite element method and measured under electromagnetic excitations. The simulation results agree well with the experimental studies.

  8. Reliable fuzzy H∞ control for active suspension of in-wheel motor driven electric vehicles with dynamic damping

    Science.gov (United States)

    Shao, Xinxin; Naghdy, Fazel; Du, Haiping

    2017-03-01

    A fault-tolerant fuzzy H∞ control design approach for active suspension of in-wheel motor driven electric vehicles in the presence of sprung mass variation, actuator faults and control input constraints is proposed. The controller is designed based on the quarter-car active suspension model with a dynamic-damping-in-wheel-motor-driven-system, in which the suspended motor is operated as a dynamic absorber. The Takagi-Sugeno (T-S) fuzzy model is used to model this suspension with possible sprung mass variation. The parallel-distributed compensation (PDC) scheme is deployed to derive a fault-tolerant fuzzy controller for the T-S fuzzy suspension model. In order to reduce the motor wear caused by the dynamic force transmitted to the in-wheel motor, the dynamic force is taken as an additional controlled output besides the traditional optimization objectives such as sprung mass acceleration, suspension deflection and actuator saturation. The H∞ performance of the proposed controller is derived as linear matrix inequalities (LMIs) comprising three equality constraints which are solved efficiently by means of MATLAB LMI Toolbox. The proposed controller is applied to an electric vehicle suspension and its effectiveness is demonstrated through computer simulation.

  9. Social facilitation of insect reproduction with motor-driven tactile stimuli.

    Science.gov (United States)

    Uzsák, Adrienn; Dieffenderfer, James; Bozkurt, Alper; Schal, Coby

    2014-05-22

    Tactile stimuli provide animals with important information about the environment, including physical features such as obstacles, and biologically relevant cues related to food, mates, hosts and predators. The antennae, the principal sensory organs of insects, house an array of sensory receptors for olfaction, gustation, audition, nociception, balance, stability, graviception, static electric fields, and thermo-, hygro- and mechanoreception. The antennae, being the anteriormost sensory appendages, play a prominent role in social interactions with conspecifics that involve primarily chemosensory and tactile stimuli. In the German cockroach (Blattella germanica) antennal contact during social interactions modulates brain-regulated juvenile hormone production, ultimately accelerating the reproductive rate in females. The primary sensory modality mediating this social facilitation of reproduction is antennal mechanoreception. We investigated the key elements, or stimulus features, of antennal contact that socially facilitate reproduction in B. germanica females. Using motor-driven antenna mimics, we assessed the physiological responses of females to artificial tactile stimulation. Our results indicate that tactile stimulation with artificial materials, some deviating significantly from the native antennal morphology, can facilitate female reproduction. However, none of the artificial stimuli matched the effects of social interactions with a conspecific female.

  10. A novel voice coil motor-driven compliant micropositioning stage based on flexure mechanism

    Science.gov (United States)

    Shang, Jiangkun; Tian, Yanling; Li, Zheng; Wang, Fujun; Cai, Kunhai

    2015-09-01

    This paper presents a 2-degrees of freedom flexure-based micropositioning stage with a flexible decoupling mechanism. The stage is composed of an upper planar stage and four vertical support links to improve the out-of-plane stiffness. The moving platform is driven by two voice coil motors, and thus it has the capability of large working stroke. The upper stage is connected with the base through six double parallel four-bar linkages mechanisms, which are orthogonally arranged to implement the motion decoupling in the x and y directions. The vertical support links with serially connected hook joints are utilized to guarantee good planar motion with heavy-loads. The static stiffness and the dynamic resonant frequencies are obtained based on the theoretical analyses. Finite element analysis is used to investigate the characteristics of the developed stage. Experiments are carried out to validate the established models and the performance of the developed stage. It is noted that the developed stage has the capability of translational motion stroke of 1.8 mm and 1.78 mm in working axes. The maximum coupling errors in the x and y directions are 0.65% and 0.82%, respectively, and the motion resolution is less than 200 nm. The experimental results show that the developed stage has good capability for trajectory tracking.

  11. Auto-Gopher: A Wireline Deep Sampler Driven by Piezoelectric Percussive Actuator and EM Rotary Motor

    Science.gov (United States)

    Badescu, Mircea; Ressa, Aaron; Jae Lee, Hyeong; Bar-Cohen, Yoseph; Sherrit, Stewart; Zacny, Kris; Paulsen, Gale L.; Beegle, Luther; Bao, Xiaoqi

    2013-01-01

    The ability to penetrate subsurfaces and perform sample acquisition at depth of meters may be critical for future NASA in-situ exploration missions to bodies in the solar system, including Mars and Europa. A corer/sampler was developed with the goal of enabling acquisition of samples from depths of several meters where if used on Mars would be beyond the oxidized and sterilized zone. For this purpose, we developed a rotary-hammering coring drill, called Auto-Gopher, which employs a piezoelectric actuated percussive mechanism for breaking formations and an electric motor that rotates the bit to remove the powdered cuttings. This sampler is a wireline mechanism that can be fed into and retrieved from the drilled hole using a winch and a cable. It includes an inchworm anchoring mechanism allowing the drill advancement and weight on bit control without twisting the reeling and power cables. The penetration rate is being optimized by simultaneously activating the percussive and rotary motions of the Auto-Gopher. The percussive mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that is driven by piezoelectric stack and that was demonstrated to require low axial preload. The design and fabrication of this device were presented in previous publications. This paper presents the results of laboratory and field tests and lessons learned from this development.

  12. Auto-Gopher: a wireline deep sampler driven by piezoelectric percussive actuator and EM rotary motor

    Science.gov (United States)

    Badescu, Mircea; Ressa, Aaron; Lee, Hyeong Jae; Bar-Cohen, Yoseph; Sherrit, Stewart; Zacny, Kris; Paulsen, Gale L.; Beegle, Luther; Bao, Xiaoqi

    2013-04-01

    The ability to penetrate subsurfaces and perform sample acquisition at depth of meters may be critical for future NASA in-situ exploration missions to bodies in the solar system, including Mars and Europa. A corer/sampler was developed with the goal of enabling acquisition of samples from depths of several meters where if used on Mars would be beyond the oxidized and sterilized zone. For this purpose, we developed a rotary-hammering coring drill, called Auto-Gopher, which employs a piezoelectric actuated percussive mechanism for breaking formations and an electric motor that rotates the bit to remove the powdered cuttings. This sampler is a wireline mechanism that can be fed into and retrieved from the drilled hole using a winch and a cable. It includes an inchworm anchoring mechanism allowing the drill advancement and weight on bit control without twisting the reeling and power cables. The penetration rate is being optimized by simultaneously activating the percussive and rotary motions of the Auto-Gopher. The percussive mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism that is driven by piezoelectric stack and that was demonstrated to require low axial preload. The design and fabrication of this device were presented in previous publications. This paper presents the results of laboratory and field tests and lessons learned from this development.

  13. Enhanced Component Performance Study: Motor-Driven Pumps 1998–2012

    Energy Technology Data Exchange (ETDEWEB)

    T. E. Wierman

    2013-10-01

    This report presents an enhanced performance evaluation of motor-driven valves (MDPs) at U.S. commercial nuclear power plants. The data used in this study are based on the operating experience failure reports from fiscal year 1998 through 2012 for the component reliability as reported in the Equipment Performance and Information Exchange (EPIX). The MDP failure modes considered for standby systems are failure to start, failure to run less than or equal to 1 hour, and failure to run more than 1 hour; for normally running systems, the failure modes considered are failure to start and failure to run. An 8 hr unreliability estimate is also calculated and trended. The component reliability estimates and the reliability data are trended for the most recent 10-year period while yearly estimates for reliability are provided for the entire active period. One statistically significant increasing trend was identified in the MDP results for standby MDP run hours per reactor critical year. Statistically significant decreasing trends were identified for unreliability (for standby and normally running systems) frequency of failure-to-start events for standby systems and failure probability for standby systems.

  14. 自动脱螺纹注塑模液压马达脱螺纹与推板推出动作关系的工程分析%Engineering Analysis for Relations between Actions of Hydraulic MotorUnscrewing and Ejector Plate Ejecting in Automatic Unscrewing Injection Mould

    Institute of Scientific and Technical Information of China (English)

    畅国帏; 张凤兰

    2015-01-01

    Aiming at the problems of that the hydraulic motor unscrewing speed may not match the ejecting speed of the spring-driven ejector plate in automatic unscrewing injection mould,thus the rules of the hydraulic motor unscrewing actions were discussed,and the rules of the spring-driven ejector plate ejecting actions were also analyzed through kinematics. Through the comparison of these two kinds of rules,it comes to the conclusion that under the conditions that the low speed hydraulic motor type is mainly selected in the practical engineering application,the axial unscrewing speed of the hydraulic motor always restricts the ejecting speed of the spring-driven ejector plate,so they realize restricting synchronization. According to the conclusion,in order to avoid damage to the plastic parts thread,under the mould structure allowing conditions,low stiffness coefficient springs should be chosen in the mould for the ejector plate.%针对自动脱螺纹注塑模具中液压马达脱螺纹速度与弹簧驱动的推板推出速度可能存在不同步的问题,对液压马达脱螺纹动作规律进行了论述,对弹簧驱动的推板推出动作规律进行了运动学分析,通过对这两种动作规律的比较得出了一个结论,即在实际工程应用中选用的液压马达多为低速马达的情况下,液压马达轴向脱螺纹速度总是制约弹簧驱动的推板推出速度,从而实现了一种制约同步.根据这个结论,为避免出现塑件螺纹损坏的情况,在模具结构允许的情况下,应尽量选择劲度系数较低的推板弹簧.

  15. Plant root-driven hydraulic redistribution, root nutrient uptake and carbon exudation interact with soil properties to generate rhizosphere resource hotspots that vary in space and time

    Science.gov (United States)

    Espeleta, J. F.; Neumann, R. B.; Cardon, Z. G.; Mayer, K. U.; Rastetter, E. B.

    2014-12-01

    Hydraulic redistribution (HR) of soil water by plants occurs in seasonally dry ecosystems worldwide. During drought, water flows from deep moist soil, through plant roots, into dry (often litter-rich) upper soil layers. Using modeling, we explored how physical transport processes driven by transpiration and hydraulic redistribution interact with root physiology (nutrient uptake and carbon exudation) and soil properties (soil texture and cation exchange) to influence nitrogen and carbon concentrations in the rhizosphere. At the single root scale, we modeled a 10-cm radial soil domain, and simulated solute transport, soil cation exchange, and root exudation and nutrient uptake under two water flow patterns: daytime transpiration without nighttime HR, and daytime transpiration with nighttime HR. During HR, water efflux flushed solutes away from the root, diluting the concentrations of key nutrients like nitrate. The transport of cations by transpiration in the day and their accumulation near the root led to competitive desorption of ammonium from soil further from the root and generation of hotspots of ammonium availability at night. HR influenced the spatial and temporal patterns of these hotspots and their intensity. They were also influenced by soil properties of texture and cation exchange capacity. This dynamic resource landscape caused by diel cycling between transpiration and hydraulic redistribution presents a stage for greater complexity of microbial interactions. We are currently embedding a microbial community and small food web into this rhizosphere model in order to explore how organisms responsible for nutrient and soil carbon cycling respond to these fluctuating resource regimes.

  16. Static and Dynamic Characteristic Simulation of Feed System Driven by Linear Motor in High Speed Computer Numerical Control Lathe

    Directory of Open Access Journals (Sweden)

    Yang Zeqing

    2013-07-01

    Full Text Available In order to design the feed system of high speed Computer Numerical Control (CNC lathe, the static and dynamic characteristics of feed system driven by linear motor in high speed CNC lathe were analyzed. The slide board was taking as the main moving part of the feed system, and the guide rail was the main support component of the linear motor feed system. The mechanical structure static stiffness of feed system is researched through the slide board statics analysis. The simulation results show that the maximum deformation of the slide board occurs in the middle of the slide board where the linear motor is placed. The linear motor feed system control model was established based on analysis of high-speed linear feed system control principle, and the linear motor feed system transfer function was established, and servo dynamic stiffness factors were analyzed. The control parameters of the servo system and actuating mechanism parameters of feed system on the effect of the linear motor servo dynamic stiffness were analyzed using MATLAB software. The simulation results show that the position loop proportional gain, speed loop proportional gain and speed loop integral response time are the biggest influence factors on servo dynamic stiffness. The displacement response is reduced under the cutting interference force step inputting, the servo dynamic stiffness is increased, the number of system oscillation is also reduced, and the system tends to be stable.  

  17. Cleaning capacity promoted by motor-driven or manual instrumentation using ProTaper Universal system: Histological analysis

    OpenAIRE

    Matheus Franco da Frota; Idomeo Bonetti Filho; Fábio Luiz Camargo Villela Berbert; Emilio Carlos Sponchiado; André Augusto Franco Marques; Lucas da Fonseca Roberti Garcia

    2013-01-01

    Aim: The aim of this study was to assess the cleaning capacity of the Protaper system using motor-driven or manual instrumentation. Materials and Methods: Ten mandibular molars were randomly separated into 2 groups (n = 5) according to the type of instrumentation performed, as follows: Group 1 - instrumentation with rotary nickel-titanium (Ni-Ti) files using ProTaper Universal System (Dentsply/Maillefer); and, Group 2 - instrumentation with Ni-Ti hand files using ProTaper Universal (Den...

  18. Walking the Torque: Proposed Work Plan for Energy-Efficiency Policy Opportunities for Electric Motor-Driven Systems

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Electric motor-driven system is the largest single energy end use accounting for more than 40% of global electricity consumption. This paper sets out an ambitious but achievable target with the global work plan to improve the energy efficiency of electric motor-driven system by 10% to 15% based on the finding of working paper ''Energy-Efficiency Policy Opportunities for Electric Motor-Driven Systems (Waide et al., 2011)''. If governments commit to the proposed work plan immediately and maintain resourcing levels, this could be achieved by 2030 and it would be equivalent to reducing total global electricity use by around 5%. The proposed work plan of this paper is to align regulatory settings within a globally applicable scheme. The IEA believes this target can only be achieved through global co-operation leading to aligned national policy settings that countries can unlock the economies of scale that will result from using more energy efficient EMDS.

  19. Vibration Analysis and Experimental Research of the Linear-Motor-Driven Water Piston Pump Used in the Naval Ship

    Directory of Open Access Journals (Sweden)

    Ye-qing Huang

    2016-01-01

    Full Text Available Aiming at the existing problems of traditional water piston pump used in the naval ship, such as low efficiency, high noise, large vibration, and nonintelligent control, a new type of linear-motor-driven water piston pump is developed and its vibration characteristics are analyzed in this research. Based on the 3D model of the structure, the simulation analyses including static stress analysis, modal analysis, and harmonic response analysis are conducted. The simulation results reveal that the mode shape under low frequency stage is mainly associated with the eccentricity swing of the piston rod. The vibration experiment results show that the resonance frequency of linear-motor-driven water piston pump is concentrated upon 500 Hz and 800 Hz in the low frequency range. The dampers can change the resonance frequency of the system to a certain extent. The vibration under triangular motion curve is much better than that of S curve, which is consistent with the simulation conclusion. This research provides an effective method to detect the vibration characteristics and a reference for design and optimization of the linear-motor-driven water piston pump.

  20. Control of rotor motion in a light-driven molecular motor : Towards a molecular gearbox

    NARCIS (Netherlands)

    Wiel, Matthijs K.J. ter; Delden, Richard A. van; Meetsma, Auke; Feringa, Bernard

    2005-01-01

    Controlled intramolecular movement and coupling of motor and rotor functions is exerted by this new molecular device. The rate of rotation of the rotor part of the molecule can be adjusted by alteration of the conformation of the motor part of the molecule. For all states of the motor part, differen

  1. Numerical design and optimization of hydraulic resistance and wall shear stress inside pressure-driven microfluidic networks.

    Science.gov (United States)

    Damiri, Hazem Salim; Bardaweel, Hamzeh Khalid

    2015-11-07

    Microfluidic networks represent the milestone of microfluidic devices. Recent advancements in microfluidic technologies mandate complex designs where both hydraulic resistance and pressure drop across the microfluidic network are minimized, while wall shear stress is precisely mapped throughout the network. In this work, a combination of theoretical and modeling techniques is used to construct a microfluidic network that operates under minimum hydraulic resistance and minimum pressure drop while constraining wall shear stress throughout the network. The results show that in order to minimize the hydraulic resistance and pressure drop throughout the network while maintaining constant wall shear stress throughout the network, geometric and shape conditions related to the compactness and aspect ratio of the parent and daughter branches must be followed. Also, results suggest that while a "local" minimum hydraulic resistance can be achieved for a geometry with an arbitrary aspect ratio, a "global" minimum hydraulic resistance occurs only when the aspect ratio of that geometry is set to unity. Thus, it is concluded that square and equilateral triangular cross-sectional area microfluidic networks have the least resistance compared to all rectangular and isosceles triangular cross-sectional microfluidic networks, respectively. Precise control over wall shear stress through the bifurcations of the microfluidic network is demonstrated in this work. Three multi-generation microfluidic network designs are considered. In these three designs, wall shear stress in the microfluidic network is successfully kept constant, increased in the daughter-branch direction, or decreased in the daughter-branch direction, respectively. For the multi-generation microfluidic network with constant wall shear stress, the design guidelines presented in this work result in identical profiles of wall shear stresses not only within a single generation but also through all the generations of the

  2. Study on the Rollover Characteristic of In-Wheel-Motor-Driven Electric Vehicles Considering Road and Electromagnetic Excitation

    Directory of Open Access Journals (Sweden)

    Di Tan

    2016-01-01

    Full Text Available For in-wheel-motor-driven electric vehicles, the motor is installed in the wheel directly. Tyre runout and uneven load can cause magnet gap deformation in the motor, which will produce electromagnetic forces that further influence the vehicle rollover characteristics. To study the rollover characteristics, a verified 16-degree-of-freedom rollover dynamic model is introduced. Next, the vehicle rollover characteristics both with and without electromagnetic force are analyzed under conditions of the Fixed Timing Fishhook steering and grade B road excitation. The results show that the electromagnetic force has a certain effect on the load transfer and can reduce the antirollover performance of the vehicle. Therefore, the effect of the electromagnetic force on the rollover characteristic should be considered in the vehicle design. To this end, extensive analysis was conducted on the effect of the road level, vehicle speed, and the road adhesion coefficient on the vehicle rollover stability. The results indicate that vehicle rollover stability worsens when the above-mentioned factors increase, the most influential factor being the road adhesion coefficient followed by vehicle speed and road level. This paper can offer certain theory basis for the design of the in-wheel-motor-driven electric vehicles.

  3. A Research Review on the Transmission System of AC Servo Motor Direct Drive Hydraulic Press%交流伺服电机直驱液压机传动系统研究综述

    Institute of Scientific and Technical Information of China (English)

    范淑琴; 赵升吨; 陈超; 杨建辉

    2015-01-01

    交流伺服电机直驱液压机相比传统液压机,具有低速锻冲、快速空程向下及快速回程的特点,其交流伺服电机直驱的传动方式可有效减少滑块上行和下行的时间,大大提高液压机工作速度。介绍了国内外交流伺服电机直驱液压机传动系统的研究现状,提出了一种无油泵交流伺服电机直驱新型液压机传动方式,介绍了该新型液压机传动系统的构成及工作原理,并提出了研制该无油泵交流伺服电机直驱新型液压机所需要解决的科学问题。%Compared to the traditional hydraulic press, Ac servo motor direct drive hydraulic press has the characteris-tics including rapid falling, slow forging and fast return. The transmission mode of AC servo motor direct drive can effec-tively reduce both the falling time and rising time of the slider, and greatly improve the working speed of hydraulic press. The research status of transmission system of Ac servo motor direct drive hydraulic press are introduced in this paper, and the transmission model of a new type AC servo motor direct drive hydraulic press without oil pump is proposed. Both the composition and working principle of the transmission system of the new type hydraulic presser are introduced, and the sci-entific problems about the new type AC servo motor direct drive hydraulic press without oil pump are put forward.

  4. Planar Task Space Control of a Biarticular Manipulator Driven by Spiral Motors

    Directory of Open Access Journals (Sweden)

    Ahmad Zaki bin Hj Shukor

    2012-10-01

    Full Text Available This paper elaborates upon a musculoskeletal‐inspired robot manipulator using a prototype of the spiral motor developed in our laboratory. The spiral motors represent the antagonistic muscles due to the high forward/backward drivability without any gears or mechanisms. Modelling of the biarticular structure with spiral motor dynamics was presented and simulations were carried out to compare two control methods, Inverse Kinematics (IK and direct‐Cartesian control, between monoarticular only structures and biarticular structures using the spiral motor. The results show the feasibility of the control, especially in maintaining air gaps within the spiral motor.

  5. Technologies and Innovations for Hydraulic Pumps

    OpenAIRE

    Ivantysynova, Monika

    2016-01-01

    Positive displacement machines working as hydraulic pumps or hydraulic motors have always been, are and will be an essential part of any hydraulic system. Current trends and future demands on energy efficient systems will not only drastically increase the number of positive displacement machines needed for modern efficient hydraulic circuits but will significantly change the performance requirements of pumps and motors. Throttleless system configurations will change the landscape of hydraulic...

  6. Robust H(∞) positional control of 2-DOF robotic arm driven by electro-hydraulic servo system.

    Science.gov (United States)

    Guo, Qing; Yu, Tian; Jiang, Dan

    2015-11-01

    In this paper an H∞ positional feedback controller is developed to improve the robust performance under structural and parametric uncertainty disturbance in electro-hydraulic servo system (EHSS). The robust control model is described as the linear state-space equation by upper linear fractional transformation. According to the solution of H∞ sub-optimal control problem, the robust controller is designed and simplified to lower order linear model which is easily realized in EHSS. The simulation and experimental results can validate the robustness of this proposed method. The comparison result with PI control shows that the robust controller is suitable for this EHSS under the critical condition where the desired system bandwidth is higher and the external load of the hydraulic actuator is closed to its limited capability. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  7. Efficient industrial motor-driven system: the view of the Brazil Energy - Energy Efficiency Plan; Sistemas motrizes industriais eficientes: a visao do Plano Energia Brasil- eficiencia energetica

    Energy Technology Data Exchange (ETDEWEB)

    Soares, George Alves; Barros, Maclaudio M. [Centro de Pesquisas de Energia Eletrica (CEPEL), Rio de Janeiro, RJ (Brazil)]. E-mails: soares@cepel.br; mac@cepel.br; Shindo, Reinaldo [Fundacao COPPETEC - Coordenacao de Projetos, Pesquisas e Estudos Tecnologicos, Rio de Janeiro, RJ (Brazil)]. shindo@cepel.br

    2002-07-01

    This work presents the motor-driven systems project developed under the Brazil Energy-Energy Efficiency, elaborated by the Technical Committee for the Energy Efficient Use of the Chamber for Energy Crisis Management. This project aims the rationalization of the motor-driven systems in the industrial sector, considering the importance of these systems for the industrial area, from the energy and cost viewpoint.

  8. Random intermittent search and the tug-of-war model of motor-driven transport

    KAUST Repository

    Newby, Jay

    2010-04-16

    We formulate the \\'tug-of-war\\' model of microtubule cargo transport by multiple molecular motors as an intermittent random search for a hidden target. A motor complex consisting of multiple molecular motors with opposing directional preference is modeled using a discrete Markov process. The motors randomly pull each other off of the microtubule so that the state of the motor complex is determined by the number of bound motors. The tug-of-war model prescribes the state transition rates and corresponding cargo velocities in terms of experimentally measured physical parameters. We add space to the resulting Chapman-Kolmogorov (CK) equation so that we can consider delivery of the cargo to a hidden target at an unknown location along the microtubule track. The target represents some subcellular compartment such as a synapse in a neuron\\'s dendrites, and target delivery is modeled as a simple absorption process. Using a quasi-steady-state (QSS) reduction technique we calculate analytical approximations of the mean first passage time (MFPT) to find the target. We show that there exists an optimal adenosine triphosphate (ATP) concentration that minimizes the MFPT for two different cases: (i) the motor complex is composed of equal numbers of kinesin motors bound to two different microtubules (symmetric tug-of-war model) and (ii) the motor complex is composed of different numbers of kinesin and dynein motors bound to a single microtubule (asymmetric tug-of-war model). © 2010 IOP Publishing Ltd.

  9. An Inverter-Driven Induction Motor System with a Deadlock Breaking Capability

    Science.gov (United States)

    Ichikawa, Takuto; Yoshida, Toshiya; Miyashita, Osamu

    Induction motors are very widely used in various industrial applications. In semiconductor manufacturing processes, deadlock failure of pumps may occur by the adhering of glass material contained in the gas to the rotor. This can lead to the shutdown of the manufacturing plant. Therefore, a countermeasure to prevent deadlocking of a motor is required. This paper proposes a method for generating an impulse torque in an induction motor fed by an inverter. The proposed inverter circuit is composed of a conventional inverter and a few additional relays. The on-and-off control of the relays supplies an appropriate magnetizing current and a large torque current from the dc-link capacitor. In experiment, a 1.5-kW cage-type induction motor generated a torque that was approximately seven times larger than the rated torque of the motor. This large impulse torque is useful for breaking the motor deadlock.

  10. Adhesion of Photon-Driven Molecular Motors to Surfaces via 1,3-Dipolar Cycloadditions : Effect of Interfacial Interactions on Molecular Motion

    NARCIS (Netherlands)

    Carroll, Gregory T.; London, Gabor; Fernández Landaluce, Tatiana; Rudolf, Petra; Feringa, Ben L.

    2011-01-01

    We report the attachment of altitudinal light-driven molecular motors to surfaces using 1,3-dipolar cycloaddition reactions. Molecular motors were designed containing azide or alkyne groups for attachment to alkyne- or azide-modified surfaces. Surface attachment was characterized by UV-vis, IR, XPS,

  11. Visible-Light-Driven Photoisomerization and Increased Rotation Speed of a Molecular Motor Acting as a Ligand in a Ruthenium(II) Complex

    NARCIS (Netherlands)

    Wezenberg, Sander J.; Chen, Kuang-Yen; Feringa, Ben L.

    2015-01-01

    Toward the development of visible-light-driven molecular rotary motors, an overcrowded alkene-based ligand and the corresponding ruthenium(II) complex is presented. In our design, a 4,5-diazafluorenyl coordination motif is directly integrated into the motor function. The photochemical and thermal

  12. Visible-Light-Driven Photoisomerization and Increased Rotation Speed of a Molecular Motor Acting as a Ligand in a Ruthenium(II) Complex

    NARCIS (Netherlands)

    Wezenberg, Sander J; Chen, Kuang-Yen; Feringa, Ben L

    2015-01-01

    Toward the development of visible-light-driven molecular rotary motors, an overcrowded alkene-based ligand and the corresponding ruthenium(II) complex is presented. In our design, a 4,5-diazafluorenyl coordination motif is directly integrated into the motor function. The photochemical and thermal is

  13. Active Vibration Suppression of a Motor-Driven Piezoelectric Smart Structure Using Adaptive Fuzzy Sliding Mode Control and Repetitive Control

    Directory of Open Access Journals (Sweden)

    Chi-Ying Lin

    2017-03-01

    Full Text Available In this paper, we report on the use of piezoelectric sensors and actuators for the active suppression of vibrations associated with the motor-driven rotation of thin flexible plate held vertically. Motor-driven flexible structures are multi-input multi-output systems. The design of active vibration-suppression controllers for these systems is far more challenging than for flexible structures with a fixed end, due to the effects of coupling and nonlinear vibration behavior generated in structures with poor damping. To simplify the design of the controller and achieve satisfactory vibration suppression, we treated the coupling of vibrations caused by the rotary motion of the thin flexible plate as external disturbances and system uncertainties. We employed an adaptive fuzzy sliding mode control algorithm in the design of a single-input–single-output controller for the suppression of vibrations using piezoelectric sensors and actuators. We also used a repetitive control system to reduce periodic vibrations associated with the repetitive motions induced by the motor. Experimental results demonstrate that the hybrid intelligent control approach proposed in this study can suppress complex vibrations caused by modal excitation, coupling effects, and periodic external disturbances.

  14. A High Revolution Speed Noncontact Ultrasonic Motor Driven by a Non-Symmetrical Electrode

    Institute of Scientific and Technical Information of China (English)

    YANG Bin; LIU Jing-Quan; CHEN Di; CAI Bing-Chu

    2005-01-01

    @@ A noncontact ultrasonic motor based on a non-symmetrical electrode is proposed. This motor has the advantages of using a simple driving electrode and having a high revolution speed. The revolution speed of its three-blade rotor can reach 5100rpm under a driving voltage of 20 V. A method operated easily is proposed to measure the output torque.

  15. Computational design of faster rotating second-generation light-driven molecular motors by control of steric effects.

    Science.gov (United States)

    Oruganti, Baswanth; Fang, Changfeng; Durbeej, Bo

    2015-09-07

    We report a systematic computational investigation of the possibility to accelerate the rate-limiting thermal isomerizations of the rotary cycles of synthetic light-driven overcrowded alkene-based molecular motors through modulation of steric interactions. Choosing as a reference system a second-generation motor known to accomplish rotary motion in the MHz regime and using density functional theory methods, we propose a three-step mechanism for the thermal isomerizations of this motor and show that variation of the steric bulkiness of the substituent at the stereocenter can reduce the (already small) free-energy barrier of the rate-determining step by a further 15-17 kJ mol(-1). This finding holds promise for future motors of this kind to reach beyond the MHz regime. Furthermore, we demonstrate and explain why one particular step is kinetically favored by decreasing and another step is kinetically favored by increasing the steric bulkiness of this substituent, and identify a possible back reaction capable of impeding the rotary rate.

  16. Mathematical modelling, numerical simulations and experimental verification of bifurcation dynamics of a pendulum driven by a dc motor

    Science.gov (United States)

    Kaźmierczak, Marek; Kudra, Grzegorz; Awrejcewicz, Jan; Wasilewski, Grzegorz

    2015-09-01

    A mathematical model of a system consisting of a dc motor, mechanism converting the rotational motion to the linear one and a single physical pendulum with the joint horizontally driven is developed. Constant angular velocity of the crank is assumed. The parameters of the model are estimated using the experimental data consisting of five solutions corresponding to the five different values of constant input voltage. Different versions of the mathematical model, with different details concerning friction and damping modelling, are tested. A good agreement between real and simulated behaviour of the system is obtained. Moreover the model is validated by testing its ability to predict critical values of the bifurcation parameter.

  17. Forced desorption of semiflexible polymers, adsorbed and driven by molecular motors

    CERN Document Server

    Chaudhuri, Abhishek

    2014-01-01

    We formulate and characterize a model to describe dynamics of semiflexible polymers in the presence of activity due to motor proteins attached irreversibly to a substrate, and a transverse pulling force acting on one end of the filament. The stochastic binding-unbinding of the motor proteins and their ability to move along the polymer, generates active forces. As the pulling force reaches a threshold value, the polymer eventually desorbs from the substrate. We present a mean field theory that predicts increase in desorption force with polymer bending rigidity, active velocity and processivity of the motor proteins. Performing molecular dynamics simulations of the polymer in presence of a Langevin heat bath, and stochastic motor activity we obtain desorption phase diagrams that show good agreement with theory. With increase in pulling force, the polymer undergoes a first order phase transition from mostly adsorbed to fully desorbed state via a regime of coexistence where the steady state dynamics of the polyme...

  18. Tensegrity and Motor-Driven Effective Interactions in a Model Cytoskeleton

    CERN Document Server

    Wang, Shenshen; 10.1063/1.3702583

    2012-01-01

    Actomyosin networks are major structural components of the cell. They provide mechanical integrity and allow dynamic remodeling of eukaryotic cells, self-organizing into the diverse patterns essential for development. We provide a theoretical framework to investigate the intricate interplay between local force generation, network connectivity and collective action of molecular motors. This framework is capable of accommodating both regular and heterogeneous pattern formation, arrested coarsening and macroscopic contraction in a unified manner. We model the actomyosin system as a motorized cat's cradle consisting of a crosslinked network of nonlinear elastic filaments subjected to spatially anti-correlated motor kicks acting on motorized (fibril) crosslinks. The phase diagram suggests there can be arrested phase separation which provides a natural explanation for the aggregation and coalescence of actomyosin condensates. Simulation studies confirm the theoretical picture that a nonequilibrium many-body system ...

  19. Thrust Reduction of Magnetic Levitation Vehicle Driven by Long Stator Linear Synchronous Motor

    Directory of Open Access Journals (Sweden)

    Wan-Tsun Tseng

    2013-01-01

    Full Text Available The propulsion technology of long stator linear synchronous motors is used to drive high-speed maglev trains. The linear synchronous motor stator is divided into sections placed on guideway. The electric power supplies to stator sections in which the train just passes in change-step mode for long-distance operation. However, a thrust drop will be caused by change-step machinery for driving magnetic vehicle. According to the train speed and vehicle data, the change-step mode has three types of operation, namely premature commutation, simultaneous commutation, and late commutation. Each type of operation has a different thrust drop which can be affected by several parameters such as jerk, running speed, motor section length, and vehicle data. This paper focuses on determining the thrust drop of the change-step mode. The study results of this paper can be used to improve the operation system of high-speed maglev trains.

  20. Detection of a static eccentricity fault in a closed loop driven induction motor by using the angular domain order tracking analysis method

    Science.gov (United States)

    Akar, Mehmet

    2013-01-01

    In this study, a new method was presented for the detection of a static eccentricity fault in a closed loop operating induction motor driven by inverter. Contrary to the motors supplied by the line, if the speed and load, and therefore the amplitude and frequency, of the current constantly change then this also causes a continuous change in the location of fault harmonics in the frequency spectrum. Angular Domain Order Tracking analysis (AD-OT) is one of the most frequently used fault diagnosis methods in the monitoring of rotating machines and the analysis of dynamic vibration signals. In the presented experimental study, motor phase current and rotor speed were monitored at various speeds and load levels with a healthy and static eccentricity fault in the closed loop driven induction motor with vector control. The AD-OT method was applied to the motor current and the results were compared with the traditional FFT and Fourier Transform based Order Tracking (FT-OT) methods. The experimental results demonstrate that AD-OT method is more efficient than the FFT and FT-OT methods for fault diagnosis, especially while the motor is operating run-up and run-down. Also the AD-OT does not incur any additional cost for the user because in inverter driven systems, current and speed sensor coexist in the system. The main innovative parts of this study are that AD-OT method was implemented on the motor current signal for the first time.

  1. Bio-inspired piezoelectric linear motor driven by a single-phase harmonic wave with an asymmetric stator

    Science.gov (United States)

    Pan, Qiaosheng; Miao, Enming; Wu, Bingxuan; Chen, Weikang; Lei, Xiujun; He, Liangguo

    2017-07-01

    A novel, bio-inspired, single-phase driven piezoelectric linear motor (PLM) using an asymmetric stator was designed, fabricated, and tested to avoid mode degeneracy and to simplify the drive mechanism of a piezoelectric motor. A piezoelectric transducer composed of two piezoelectric stacks and a displacement amplifier was used as the driving element of the PLM. Two simple and specially designed claws performed elliptical motion. A numerical simulation was performed to design the stator and determine the feasibility of the design mechanism of the PLM. Moreover, an experimental setup was built to validate the working principles, as well as to evaluate the performance, of the PLM. The prototype motor outputs a no-load speed of 233.7 mm/s at a voltage of 180 Vp-p and a maximum thrust force of 2.3 N under a preload of 10 N. This study verified the feasibility of the proposed design and provided a method to simplify the driving harmonic signal and structure of PLMs.

  2. Thrust Reduction of Magnetic Levitation Vehicle Driven by Long Stator Linear Synchronous Motor

    OpenAIRE

    Wan-Tsun Tseng

    2013-01-01

    The propulsion technology of long stator linear synchronous motors is used to drive high-speed maglev trains. The linear synchronous motor stator is divided into sections placed on guideway. The electric power supplies to stator sections in which the train just passes in change-step mode for long-distance operation. However, a thrust drop will be caused by change-step machinery for driving magnetic vehicle. According to the train speed and vehicle data, the change-step mode has three types of...

  3. Use of fuzzy logic for condition monitoring of motor driven machineries

    Science.gov (United States)

    Janier, Josefina Barnachea; Zaim Zaharia, M. Fazrin

    2012-06-01

    An intelligent system called Fuzzy Logic is one of the current technologies that allow a description of the desired system behavior using common language. It generalizes the yes-no Boolean logic into numerical value of 1 and 0 but also permits the in between values. This paper presents the use of Fuzzy Logic to determine the unusual increase of vibrations of an induction motor called vibration analysis. Sudden increase of vibrations could be a good indicator of faulty condition of the motor. Based on the vibration characteristics of the motor, a Fuzzy Inference System (FIS) was created. The system classified the motor of the gas distribution pump as `acceptable' of the vibration ranges from 1.8mm/s to 4.5mm/s or `monitor closely' of the vibration ranges from 4.5mm/s to 7.1mm/s respectively. The system enabled an early detection of faults which is very important in maintenance management.

  4. Allosteric Regulation of the Rotational Speed in a Light-Driven Molecular Motor

    NARCIS (Netherlands)

    Faulkner, Adele; van Leeuwen, Thomas; Feringa, Ben L; Wezenberg, Sander J

    2016-01-01

    The rotational speed of an overcrowded alkene-based molecular rotary motor, having an integrated 4,5-diazafluorenyl coordination motif, can be regulated allosterically via the binding of metal ions. DFT calculations have been used to predict the relative speed of rotation of three different (i.e. zi

  5. Fault Diagnosis and Treatment of Hydraulic Motor for Pretreatment Slag-raking Machine%预处理扒渣机液压马达故障诊断与处理

    Institute of Scientific and Technical Information of China (English)

    时慧斌

    2014-01-01

    To the problem of frequent failure of the hydraulic motor in a pretreatment slag-raking machine ,the hydraulic system was improved ,being equipped with controllable differential damping loop ,and the goal of decreasing fault was achieved .%预处理扒渣机液压马达故障频繁,通过对液压系统进行分析改造,加装可控微分阻尼回路,达到了降低故障的目的。

  6. Design and Analysis of Hydraulic Chassis with Obstacle Avoidance Function

    Science.gov (United States)

    Hong, Yingjie; Zhang, Xiang

    2017-07-01

    This article mainly expounds the design of hydraulic system for the hydraulic chassis with obstacle avoidance function. Including the selection of hydraulic motor wheels, hydraulic pump, digital hydraulic cylinder and the matching of engine power. And briefly introduces the principle of obstacle avoidance.

  7. On the control performance of motors driven by long cables for remote handling at ITER

    Energy Technology Data Exchange (ETDEWEB)

    Sol, Enrique del, E-mail: enrique.delsol@oxfordtechnologies.co.uk [Oxford Technologies Ltd., 7 Nuffield Way, Abingdon OX141RL (United Kingdom); Meek, Richard [Oxford Technologies Ltd., 7 Nuffield Way, Abingdon OX141RL (United Kingdom); Ruiz Morales, Emilio; Vitelli, Ricardo; Esqué, Salvador [Fusion for Energy, Josep Pla, 2, Barcelona 08019 (Spain)

    2016-06-15

    Highlights: • We show the dangerous effects of reflections on the actuator’s system. • We prove how to solve the reflections issue with a commercial LC filter. • We study the filter influence for short cables on two control modes. • We show the filter performance under a real remote handling operation. • We study the excellent performance of the filter for different cable lengths. - Abstract: Pulse Width Modulation (PWM) is nowadays the most used method for controlling a servo-motor. When combining PWM with motors and long cables, such as the ones that will be found at ITER, the standing waves originated are potentially very harmful for both actuator’s life span and control performance. Several methods have been investigated to cope with this issue, such as the use of chokes, filters, snubbers or active modification of the PWM signal. Of all possible locations where an electrical servo-motor could be used at ITER, the most critical scenario arises when mounting a low power motor, with a low gear ratio, in a dexterous manipulator for bilateral teleoperation. In those circumstances cable lengths of more than 150 m are expected between manipulator and control cubicle. In this paper, the effects of long cables in the system safety are analysed on a custom made test bench. The most common solutions to cope with this issue are analysed and a commercial LC filter is selected for further experimentation. An extensive set of experiments are carried out in order to validate the proposed solution for being used on remote handling equipment at ITER.

  8. Contouring Control for a CNC Milling Machine Driven by Direct thrust Controlled Linear Induction Motors

    Directory of Open Access Journals (Sweden)

    Khaled N. Faris

    2015-12-01

    Full Text Available According to various advantages of linear induction motor (LIM, such as high starting thrust force, high speed operation and reduction of mechanical losses, more applications have utilized this type of motors. Direct Thrust Control (DTC technique is considered as one of the most efficient techniques that can be used for LIM. DTC is preferable to give a fast and good dynamic thrust response. So, to improve the accuracy and robustness of contouring control for CNC machine tools, linear induction motors with a direct thrust control technique are introduced for driving these machines. An industry standard motion control system is applied for reducing the tracking error and improving the desired accuracy. Different loading conditions are simulated to validate the reliability and robustness of the introduced system to match the application field. The proposed system is simulated using the MATLAB/SIMULINK Package; simulation results validated both tracking accuracy and robustness of the proposed motion control system for contouring control for a CNC (Computer Numerical Control milling machine.

  9. Experimental investigation of the thermal hydraulics in lead bismuth eutectic-helium experimental loop of an accelerator-driven system

    Energy Technology Data Exchange (ETDEWEB)

    Xi, Wenxuan; Wang, Yong Wei; Li, Xun Feng; Huai, Xiulan; Cal, Jun [Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing (China)

    2016-10-15

    The heat transfer characteristics between liquid lead bismuth eutectic (LBE) and helium are of great significance for the two-loop cooling system based on an accelerator-driven system (ADS). This paper presents an experimental study on the resistance characteristics and heat transfer performance in a LBE-helium experimental loop of ADS. Pressure drops in the LBE loop, the main heat transfer, and the coupled heat transfer characteristics between LBE and helium are investigated experimentally. The temperature of LBE has a significant effect on the LBE thermo-physical properties, and is therefore considered in the prediction of pressure drops. The results show that the overall heat transfer coefficient increases with the increasing helium flow rate and the decreasing inlet temperature of helium. Increasing the LBE Reynolds number and LBE inlet temperature promotes the heat transfer performance of main heat transfer and thus the overall heat transfer coefficient. The experimental results give an insight into the flow and heat transfer properties in a LBE-helium heat exchanger and are helpful for the optimization of an ADS system design.

  10. Analysis on Photovoltaic Assisted Three Phase five level Unipolar PWM Inverter for Induction Motor Driven Water Pumping System

    Directory of Open Access Journals (Sweden)

    Ajay Kumar Maurya, Kishore Chahar, Y. K. Chauhan

    2013-03-01

    Full Text Available This paper presents the analysis of a photovoltaicbases three-phase five level voltage source inverter(VSI supplying induction motor driven waterpump. The VSI uses a unipolar PWM technique forproducing three phase 5 level voltage output andthis output is used to drive three-phase inductionmotor driving a pump load. Multilevel inverters areused for generating AC voltage from several levelsof DC voltages and enhance the performance of thesystem. The proposed system is used to reduce thefiltering requirements and reduce the amplitude ofall harmonics at the output of the inverter. ThePower quality improves by reducing the harmonicslevel. The complete simulation model is simulatedin MATLAB/SIMULINK and validates thetheoretical considerations

  11. Hydraulic System Design of Hydraulic Actuators for Large Butterfly Valves

    OpenAIRE

    HUANG, Ye; Liu, Changsheng; Shiongur Bamed

    2014-01-01

    Hydraulic control systems of butterfly valves are presently valve-controlled and pump-controlled. Valve-controlled hydraulic systems have serious power loss and generate much heat during throttling. Pump-controlled hydraulic systems have no overflow or throttling losses but are limited in the speed adjustment of the variable-displacement pump, generate much noise, pollute the environment, and have motor power that does not match load requirements, resulting in low efficiency under...

  12. 液压冲击下五星式径向柱塞马达配流轴疲劳分析%Fatigue analysis of pintle valve of motor with five-star radial piston under effect of hydraulic shock

    Institute of Scientific and Technical Information of China (English)

    王建利; 刘晋浩

    2014-01-01

    Hydraulic shock often happens when valves are opened or closed suddenly, and it may cause a series of trouble for the hydraulic system. If the motor in the hydraulic system has a huge initial load, hydraulic shocks might be larger when the valve is closed. When a hydraulic motor drives a plate whose rotary inertia is as large as 17 kg·m2 running at a highest rotating speed of 400 r/min, if the control valve is suddenly closed, the hydraulic shock is not ignorable. In order to determine the fatigue damage mechanism for a specific five-star radial piston motor under the hydraulic shock, the AMESim software was employed to study hydraulic shock waves and its highest pressure value. The simulation model was built under the guide of the hydraulic schematic of the hydraulic system. In the model, relief valve 1’s opening pressure was set to be 35 MPa, while relief valve 2 and relief valve 3 were both set to be 31 MPa, relief valve 4 was 21 MPa. An IR-C-IR submodel was employed in hose 7 and 8 to simulate hydraulic waves in hoses, while the other pipes were considered as rigid pipe. The control valve was open at the very beginning of the simulation, and closed 4 seconds later, until 16 seconds later the simulation terminated. Simulation results showed that a hydraulic shock whose pressure as high as 36 MPa occurred just after the control valve was shut down, and the amplitude of the wave decreased step by step. After that, the highest pressure value was considered as the pressure boundary on the simulation of ANSYS CFX to simulate impact pressure acting against on valve plate, and the results showed that the impact pressure could be up to 34.9 MPa. This high hydraulic pressure shock pushed the valve plate to knock the upper shell hardly, and the frictional moment between valve plate and upper shell could reach 60.02 Nm. This moment was taken as the load into pintle valve to calculate the fatigue life of the pintle valve, and the results showed that the fatigue life only

  13. Linking hydraulic traits to tropical forest function in a size-structured and trait-driven model (TFS v.1-Hydro)

    Science.gov (United States)

    Christoffersen, Bradley O.; Gloor, Manuel; Fauset, Sophie; Fyllas, Nikolaos M.; Galbraith, David R.; Baker, Timothy R.; Kruijt, Bart; Rowland, Lucy; Fisher, Rosie A.; Binks, Oliver J.; Sevanto, Sanna; Xu, Chonggang; Jansen, Steven; Choat, Brendan; Mencuccini, Maurizio; McDowell, Nate G.; Meir, Patrick

    2016-11-01

    Forest ecosystem models based on heuristic water stress functions poorly predict tropical forest response to drought partly because they do not capture the diversity of hydraulic traits (including variation in tree size) observed in tropical forests. We developed a continuous porous media approach to modeling plant hydraulics in which all parameters of the constitutive equations are biologically interpretable and measurable plant hydraulic traits (e.g., turgor loss point πtlp, bulk elastic modulus ɛ, hydraulic capacitance Cft, xylem hydraulic conductivity ks,max, water potential at 50 % loss of conductivity for both xylem (P50,x) and stomata (P50,gs), and the leaf : sapwood area ratio Al : As). We embedded this plant hydraulics model within a trait forest simulator (TFS) that models light environments of individual trees and their upper boundary conditions (transpiration), as well as providing a means for parameterizing variation in hydraulic traits among individuals. We synthesized literature and existing databases to parameterize all hydraulic traits as a function of stem and leaf traits, including wood density (WD), leaf mass per area (LMA), and photosynthetic capacity (Amax), and evaluated the coupled model (called TFS v.1-Hydro) predictions, against observed diurnal and seasonal variability in stem and leaf water potential as well as stand-scaled sap flux. Our hydraulic trait synthesis revealed coordination among leaf and xylem hydraulic traits and statistically significant relationships of most hydraulic traits with more easily measured plant traits. Using the most informative empirical trait-trait relationships derived from this synthesis, TFS v.1-Hydro successfully captured individual variation in leaf and stem water potential due to increasing tree size and light environment, with model representation of hydraulic architecture and plant traits exerting primary and secondary controls, respectively, on the fidelity of model predictions. The plant

  14. Hydraulic System Design of Hydraulic-Driven Load Exoskeleton Robot%液压驱动型负重外骨骼机器人液压系统设计

    Institute of Scientific and Technical Information of China (English)

    周加永; 张昂; 莫新民; 赵浩; 纪平鑫

    2016-01-01

    Started from human motion characteristics, the hydraulic drive overall load exoskeleton robot skeleton structure was an-alyzed. According to the characteristics of the load exoskeleton robot, a complete hydraulic drive system was designed, and the main el-ements of the selection calculation were carried out as hydraulic system, hydraulic pumps, servo valves and hydraulic cylinders, and etc. Simhydraulics software was used to establish the simulation schematics for hydraulic system of load exoskeleton robot, study and simulation analysis were carried out for the hydraulic system, and simulation results were proved of the rational design of the hydraulic system. In the last, technology challenges faced by the hydraulic drive load exoskeleton robot are analyzed, which provide reference for further design of the hydraulic system.%从人体运动特征出发,分析了液压驱动负重外骨骼机器人的整体骨架结构。根据负重外骨骼机器人的特点要求设计了一套完整的液压传动系统,对液压系统中液压泵、伺服阀和液压缸等主要元件进行了选型计算。利用Simhydraulics软件建立了负重外骨骼机器人液压系统仿真原理图,并对液压系统进行了仿真分析研究,由仿真结果证明了所设计液压系统的合理性。最后对液压驱动型负重外骨骼机器人技术面临的挑战进行了分析,为该液压系统的深化设计提供了参考。

  15. A numerical method to enhance the performance of a cam-type electric motor-driven left ventricular assist device.

    Science.gov (United States)

    Huang, Huan; Yang, Ming; Lu, Cunyue; Xu, Liang; Zhuang, Xiaoqi; Meng, Fan

    2013-10-01

    Pulsatile left ventricular assist devices (LVADs) driven by electric motors have been widely accepted as a treatment of heart failure. Performance enhancement with computer assistance for this kind of LVAD has seldom been reported. In this article, a numerical method is proposed to assist the design of a cam-type pump. The method requires an integrated model of an LVAD system, consisting of a motor, a transmission mechanism, and a cardiovascular circulation. Performance indices, that is, outlet pressure, outlet flow, and pump efficiency, were used to select the best cam profile from six candidates. A prototype pump connected to a mock circulatory loop (MCL) was used to calibrate the friction coefficient of the cam groove and preliminarily evaluate modeling accuracy. In vitro experiments show that the mean outlet pressure and flow can be predicted with high accuracy by the model, and gross geometries of the measurements can also be reproduced. Simulation results demonstrate that as the total peripheral resistance (TPR) is fixed at 1.1 mm Hg.s/mL, the two-cycle 2/3-rise profile is the best. Compared with other profiles, the maximum increases of pressure and flow indices are 75 and 76%, respectively, and the maximum efficiency increase is over 51%. For different TPRs (0.5∼1.5 mm Hg.s/mL) and operation intervals (0.1∼0.4 s) in counterpulsation, the conclusion is also acceptable.

  16. Hydraulic System Design of Hydraulic Actuators for Large Butterfly Valves

    Directory of Open Access Journals (Sweden)

    Ye HUANG

    2014-09-01

    Full Text Available Hydraulic control systems of butterfly valves are presently valve-controlled and pump-controlled. Valve-controlled hydraulic systems have serious power loss and generate much heat during throttling. Pump-controlled hydraulic systems have no overflow or throttling losses but are limited in the speed adjustment of the variable-displacement pump, generate much noise, pollute the environment, and have motor power that does not match load requirements, resulting in low efficiency under light loads and wearing of the variable-displacement pump. To overcome these shortcomings, this article designs a closed hydraulic control system in which an AC servo motor drives a quantitative pump that controls a spiral swinging hydraulic cylinder, and analyzes and calculates the structure and parameters of a spiral swinging hydraulic cylinder. The hydraulic system adjusts the servo motor’s speed according to the requirements of the control system, and the motor power matches the power provided to components, thus eliminating the throttling loss of hydraulic circuits. The system is compact, produces a large output force, provides stable transmission, has a quick response, and is suitable as a hydraulic control system of a large butterfly valve.

  17. Improvement of energy storage motor control circuit of hydraulic actuator in high-voltage circuit breakers%高压断路器液压操动机构储能电机控制回路改进

    Institute of Scientific and Technical Information of China (English)

    张全民; 赵玉柱

    2011-01-01

    高压断路器液压操动机构的常见故障是储能电机频繁启动。通过合理地设计储能电机的控制回路,减少了液压机构频繁启动的现象。%The fault of the mechanism of High voltage circuit-breaker is motor of storaging power high frequency starup.That rationally design control circuit of hydraulic mechanism reduce the fault that motor of storaging power high frequency starup.

  18. Robust control of wire-driven system using linear DC motor; Linear DC motor ni yoru wire kudokei no robust seigyo

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, M. [Asahi Chemical Industry Co. Ltd., Tokyo (Japan); Hashimoto, H. [The University of Tokyo, Tokyo (Japan). Institute of Industrial Science

    1994-10-20

    The driving system and its control method were studied to miniaturizing the robot and multiplying its degree of freedom. Through designing the composition of force-transferring device driven by wire and actuator done by thin linear motor, the space can be saved by separating the places needing the force-transferring device and those doing the actuator. However, the driving by wire has the unknown stiffness, backlash, friction and other hardly controllable elements. Three types of robust control, observer-based control, sliding-mode control and H{infinity} control were applied and mutually compared. The H{infinity} control was a H{infinity} norm which was adopted, with optimization, into the evaluation function to measure the objective transfer function. Enabling the comparatively easy designing of high-gain controller to comply with the objective, the H{infinity} control theory was known to be effectively applicable even to the objective having the backlash, friction and resonance point. The present control was robust also against the fluctuation in load. 10 refs., 15 figs., 2 tabs.

  19. 42 CFR 84.142 - Air supply source; hand-operated or motor driven air blowers; Type A supplied-air respirators...

    Science.gov (United States)

    2010-10-01

    ... air blowers; Type A supplied-air respirators; minimum requirements. 84.142 Section 84.142 Public....142 Air supply source; hand-operated or motor driven air blowers; Type A supplied-air respirators; minimum requirements. (a) Blowers shall be designed and constructed to deliver an adequate amount of...

  20. Analysis and measure of novel stereo-garage driven by linear induction motor

    Directory of Open Access Journals (Sweden)

    Lu Qinfen

    2015-12-01

    Full Text Available The car access time is a key parameter, especially in a huge stereo-garage, where this one should be decreased as much as possible. This paper proposes a novel stereo-garage. Adopting the linear induction motors (LIMs, the system has a simple structure and rapid response capability. In the stereo-garage, several LIMs are installed below the crossbeam on a lifting platform, and several LIMs are fixed on the top of a moving frame. During the operation of LIMs, the moving frame moves forward and backward to reach the required parking place, whereas the crossbeam moves horizontally in order to take or store the vehicle rapidly. All these LIMs are the same and should be designed at a low frequency. The influences of key structure parameters and dynamic performances are investigated, based on FEM. The predicted results are validated by a prototype. Finally, the designed LIMs are successfully applied in two 8-layer stereo-garages.

  1. Mutational analysis and overproduction effects of MotX, an essential component for motor function of Na+-driven polar flagella of Vibrio.

    Science.gov (United States)

    Takekawa, Norihiro; Kojima, Seiji; Homma, Michio

    2016-10-25

    The bacterial flagellar motor is a rotary motor complex composed of various proteins. The motor contains a central rod, multiple ring-like structures and stators. The Na(+)-driven polar flagellar motor of the marine bacterium Vibrio alginolyticus has a specific ring, called the 'T-ring', which consists of two periplasmic proteins, MotX and MotY. The T-ring is essential for assembly of the torque-generating unit, the PomA/PomB stator complex, into the motor. To investigate the role of the T-ring for motor function, we performed random mutagenesis of the motX gene on a plasmid. The isolated MotX mutants showed nonmotile, slow-motile, and up-motile phenotypes by the expression from the plasmid. Deletion analysis indicated that the C-terminal region and the signal peptide in MotX are not always essential for flagellar motor function. We also found that overproduction of MotX caused the delay of growth and aberrant cell shape. MotX might have unexpected roles not only in flagellar motor function but also in cell morphology control.

  2. Research on Sealing Structure of Electro-hydraulic Servo Swing Motor%电液伺服摆动马达密封结构研究∗

    Institute of Scientific and Technical Information of China (English)

    李阁强; 赵巧莉; 李跃松; 郭冰菁

    2015-01-01

    为研究电液伺服摆动马达密封结构的性能,建立其密封件的有限元仿真模型,在相同预压缩量、不同介质压力条件下,对矩形密封结构、梯形密封结构、星形密封结构进行仿真分析,根据仿真结果比较3种密封结构的密封效果。结果表明,星形密封结构因其截面有4个密封唇,在沟槽中不易产生扭曲,耐压力较强,其密封有效性优于矩形密封结构,更适合用于大功率液压密封系统;梯形密封结构在靠近流体端具有较陡的压力梯度,在一端具有较缓的压力梯度,可以减小油膜厚度,从而减少泄漏量,因而其密封效果优于星形和矩形密封。%The finite element simulation model of the sealing structure of electro⁃hydraulic servo swing motor was estab⁃lished to study the performance of sealing structure�Three kinds of sealing structures, the rectangular sealing structure, the trapezoidal sealing structure, the star sealing structure were investigated by simulation method under the conditions of the same pre⁃compression and different medium pressure, and the sealing effect of three kinds of sealing structures were com⁃pared according to the results of simulation analysis�The results show that the star seal structure has four sealing lips on the cross⁃section and can avoid the distortion of seal structure in the groove, its sealing effectiveness is better than the rec⁃tangular seal structure and it is more suitable for high⁃power hydraulic sealing system�For the trapezoidal seal structure has a steeper pressure gradient near the fluid end and a moderate pressure gradient at one end, the leakage is reduced, and good sealing effect is achieved compared with the star and rectangular seal structure�

  3. Thermally Actuated Hydraulic Pumps

    Science.gov (United States)

    Jones, Jack; Ross, Ronald; Chao, Yi

    2008-01-01

    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research

  4. Effects of hydraulic retention time and [Formula: see text] ratio on thiosulfate-driven autotrophic denitrification for nitrate removal from micro-polluted surface water.

    Science.gov (United States)

    Wang, Zheng; Fei, Xiang; He, Sheng-Bing; Huang, Jung-Chen; Zhou, Wei-Li

    2017-01-18

    This study was carried out to investigate the possibility of a thiosulfate-driven autotrophic denitrification for nitrate-N removal from micro-polluted surface water. The aim was to study the effects of [Formula: see text] ratio (S/N molar ratio) and hydraulic retention time (HRT) on the autotrophic denitrification performance. Besides, utilization efficiencies of [Formula: see text] along the biofilter and the restart-up of the bioreactor were also investigated. Autotrophic denitrification using thiosulfate as an electron donor for treating micro-polluted surface water without the addition of external alkalinity proved to be feasible and the biofilter could be readied in two weeks. Average nitrate-N removal efficiencies at HRTs of 0.5, 1 and 2 h were 78.7%, 87.8% and 97.4%, respectively, and corresponding removal rates were 186.24, 103.92 and 58.56 g [Formula: see text], respectively. When water temperature was in the range of 8-12°C and HRT was 1 h, average nitrate-N removal efficiencies of 41.9%, 97.1% and 97.0%, nitrite accumulation concentrations of 1.45, 0.46 and 0.22 mg/L and thiosulfate utilization efficiencies of 100%, 98.8% and 92.1% were obtained at S/N ratios of 1.0, 1.2 and 1.5, respectively. Besides, the autotrophic denitrification rate in the filtration media layer was the highest along the biofilter at an S/N ratio of 1.5. Finally, after a one-month period of starvation, the biofilter could be restarted successfully in three weeks without inoculation of seed sludge.

  5. Single DNA molecule jamming and history-dependent dynamics during motor-driven viral packaging

    Science.gov (United States)

    Keller, Nicholas; Grimes, Shelley; Jardine, Paul J.; Smith, Douglas E.

    2016-08-01

    In many viruses, molecular motors forcibly pack single DNA molecules to near-crystalline density into ~50-100 nm prohead shells. Unexpectedly, we found that packaging frequently stalls in conditions that induce net attractive DNA-DNA interactions. Here, we present findings suggesting that this stalling occurs because the DNA undergoes a nonequilibrium jamming transition analogous to that observed in many soft-matter systems, such as colloidal and granular systems. Experiments in which conditions are changed during packaging to switch DNA-DNA interactions between purely repulsive and net attractive reveal strongly history-dependent dynamics. An abrupt deceleration is usually observed before stalling, indicating that a transition in DNA conformation causes an abrupt increase in resistance. Our findings suggest that the concept of jamming can be extended to a single polymer molecule. However, compared with macroscopic samples of colloidal particles we find that single DNA molecules jam over a much larger range of densities. We attribute this difference to the nanoscale system size, consistent with theoretical predictions for jamming of attractive athermal particles.

  6. 船舶综合液压推进及其泵马达设计%Integrated Hydraulic Propulsion Ship and Its Pump and Motor Design

    Institute of Scientific and Technical Information of China (English)

    孙玉清; 纪玉龙; 陈海泉

    2007-01-01

    为解决船舶在向大型化、高速化方向发展时船舶主机设计困难,机舱布置不合理以及机动性能差等问题,提出了一种新型船舶推进方式,即船舶综合液压推进.给出了该推进方式的推进原理,通过工况配合特性曲线图,对其工况配合特性进行分析,对该推进方式的优缺点进行讨论并对其重要组件液压泵以及马达进行设计计算.结果表明船舶综合液压推进具有其独特的优点,是对现有船舶推进方式的有益补充.%Conventional ship propulsion methods meet some limitations in ship development towards high-speed,large-scale and high-power.A new ship propulsion method,integrated hydraulic propulsion (IHP),was put forward to solve the problem.Then further research work was done on the principle of IHP method.Working condition-matching characteristic was discussed through the working condition matching characteristic chart.After that,the advantages and disadvantages of IHP method were given.And the pump and motor,important parts of IHP,was designed through physical analytical method.IHP method can be used extensively in some special kinds of ship for its own characteristics.To a certain extent,the limitation problem of ship propulsion method can be solved.IHP method diversifies the existing ship propulsion methods.

  7. Adhesion of photon-driven molecular motors to surfaces via 1,3-dipolar cycloadditions: effect of interfacial interactions on molecular motion.

    Science.gov (United States)

    Carroll, Gregory T; London, Gábor; Landaluce, Tatiana Fernández; Rudolf, Petra; Feringa, Ben L

    2011-01-25

    We report the attachment of altitudinal light-driven molecular motors to surfaces using 1,3-dipolar cycloaddition reactions. Molecular motors were designed containing azide or alkyne groups for attachment to alkyne- or azide-modified surfaces. Surface attachment was characterized by UV-vis, IR, XPS, and ellipsometry measurements. Surface-bound motors were found to undergo photochemical and thermal isomerizations consistent with unidirectional rotation in solution. Confinement at a surface was found to reduce the rate of the thermal isomerization process. The rate of thermal isomerization was also dependent on the surface coverage of the motors. In solution, changes in the UV-vis signal that accompany thermal isomerization can be fit with a single monoexponential decay. In contrast, thermal isomerization of the surface-bound motors does not follow a single monoexponential decay and was found to fit a biexponential decay. Both one- and two-legged motors were attached to surfaces. The kinetics of thermal isomerization was not affected by the valency of attachment, indicating that the changes in kinetics from solution to surface systems are related to interactions between the surface-bound motors.

  8. Emission of 1,3-butadiene from petrol-driven motor vehicles

    Science.gov (United States)

    Ye, Y.; Galbally, I. E.; Weeks, I. A.

    This study reports the measurement of 1,3-butadiene emissions from 30 petrol-driven vehicles from the Australian car fleet using the Australian Design Rule 37/00 vehicle test procedure. Six of the cars tested were not equipped with catalytic converters and used leaded petrol as fuel. The remaining 24 cars were fitted with catalytic converters and used unleaded petrol. 1,3-Butadiene in exhaust samples was found to degrade rapidly in SUMMA treated stainless steel canisters and the degradation followed first-order kinetics. The rate coefficient of the decay can be represented by a linear dependence on the concentration of nitrogen oxides in the exhaust ( r2 = 0.79, n = 43), and the gas-phase reaction of NO 2 and 1,3-butadiene may have a major role in this loss. The 1,3-butadiene concentrations used to estimate vehicle emissions were corrected for this loss using the decay rate constant either observed from replicate analyses or from the NO x concentrations in the samples. The measurements showed that 1,3-butadiene was emitted at a rate of 20.7 ± 9.2 mg km -1 from 6 non-catalyst vehicles. There was considerable scatter in the observations from catalyst equipped vehicles and we infer that this was due to the malfunction of the emission control devices on some vehicles. The 19 vehicles that appeared to have functioning catalyst emission control devices had an average emission rate of 2.1 ± 1.5 mg km -1. These emission rates are consistent with atmospheric observations and are much higher than those reported previously. We calculate that more than 90% of the 1,3-butadiene in engine exhaust comes from the common alkane and aromatic constituents of the fuel. A comparison of emissions in the different phases of the drive cycle indicates that current emission controls remove more than 90% of the 1,3-butadiene from the initial exhaust mixture.

  9. Deep drilling and sampling via the wireline auto-gopher driven by piezoelectric percussive actuator and EM rotary motor

    Science.gov (United States)

    Bar-Cohen, Yoseph; Badescu, Mircea; Sherrit, Stewart; Zacny, Kris; Paulsen, Gale L.; Beegle, Luther; Bao, Xiaoqi

    2012-04-01

    The ability to penetrate subsurfaces and perform sample acquisition at depths of meters is critical for future NASA in-situ exploration missions to bodies in the solar system, including Mars, Europa, and Enceladus. A corer/sampler was developed with the goal of acquiring pristine samples by reaching depths on Mars beyond the oxidized and sterilized zone. The developed rotary-hammering coring drill, called Auto-Gopher, employs a piezoelectric actuated percussive mechanism for breaking formations and an electric motor rotates the bit to remove the powdered cuttings. This sampler is a wireline drill that is incorporated with an inchworm mechanism allowing thru cyclic coring and core removal to reach great depths. The penetration rate is optimized by simultaneously activating the percussive and rotary motions of the Auto-Gopher. The percussive mechanism is based on the Ultrasonic/Sonic Drill/Corer (USDC) mechanism, which is driven by a piezoelectric stack, demonstrated to require low axial preload. The Auto-Gopher has been produced taking into account the lessons learned from the development of the Ultrasonic/Sonic Gopher that was designed as a percussive ice drill and was demonstrated in Antarctica in 2005 to reach about 2 meters deep. A field demonstration of the Auto-Gopher is currently being planned with the objective of reaching as deep as 3 to 5 meters in tufa formation.

  10. 径向低速大扭矩水液压马达定子曲线分析%Analysis of stator curve of low speed high torque water hydraulic motor with radial piston

    Institute of Scientific and Technical Information of China (English)

    高殿荣; 王志强; 温茂森; 吴晓明

    2011-01-01

    提出了一种采用自然水(含海水和淡水)作为液压介质进行工作的径向低速大扭矩马达.与油压马达相比,摩擦、磨损、腐蚀等是水压马达面临的主要问题,而合适的定子曲线可以减少摩擦、磨损、水击等现象的发生.本文根据运动学理论对水液压马达的定子曲线进行了设计与分析.对幅角修正等加速运动规律和匀变加速修正等加速运动规律的加速度公式进行了修正.对9种不同类型运动规律的各区段幅角进行了设计,并结合曲线方程和水压马达的相关参数绘制出相应的定子曲线.综合分析了9种类型定子曲线下柱塞副(滚球与柱塞)的加速度、速度以及曲线压力角等特性,指出有过渡区的等加速运动规律曲线较适合于所研究的低速大扭矩水液压马达.%A novel low speed high torque hydraulic motor with radial piston, using seawater and fresh water as the hydraulic medium, is presented. Compared with hydraulic motor, friction, wear and corrosion are the main problems to be concerned. However, the friction, the wear and the water hammer could be reduced using the optimal stator curve. The stator curve of this motor is designed and analyzed based on the kinematics. The acceleration formulae of revised argument equal-acceleration motion and uniform variable accelerated modifier are revised. Every zone of argument of nine different motions is designed. On the basis of curve equations and hydraulic motor parameters, the stator curves are got. The acceleration, velocity of piston pairs (roller and piston) and pressure angle of nine stator curves are comprehensively analyzed. Results show that the transition region equal-acceleration motion curve is suitable for this motor.

  11. Analysis of torque-current characteristic of brushless DC motor driven by three-phase H-bridge

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Presents the simulation and analysis of the steady state characteristic of a brushless DC motor studies the torque-current characteristic of the motor as well and discusses the design of a current-measure circuit for torque controlling.

  12. 液压同步系统和液压制动系统在行走马达上的应用%Application of Hydraulic Synchronization System and Hydraulic Brake System on Walking Motor

    Institute of Scientific and Technical Information of China (English)

    张帅君; 赖雨薇; 刘会涛; 高伟航; 张庆勇; 苏伟民

    2015-01-01

    A new kind of loop was introduced in which hydraulic synchronization and hydraulic brake could be realized. How to realize synchronization and braking functions was illustrated through example. And the loop has simple structure, practicality and safety utmostly.%介绍一种可同时实现液压同步和液压制动的回路,通过具体实例说明如何实现同步和制动的功能,并且最大可能实现结构简单、经济实用和安全可靠。

  13. Development of hydraulic power unit and accumulator charging circuit for electricity generation, storage and distribution

    Institute of Scientific and Technical Information of China (English)

    C.N.Okoye; JIANG Ji-hai; LIU Hai-chang

    2008-01-01

    It is the purpose of the present paper to convert hydraulic energy to electric energy and saves both the pressure and electrical energy for re - use during the next system upstroke using two secondary units coupled to induction motor to drive cylinder loads. During upstroke operation, the variable pump/motor (P/M) driven by both electric motor and the second (P/M) works as hydraulic pump and output flow to the cylinders which drive the load. During load deceleration, the cylinders work as pump while the operation of the two secondary units are reversed, the variable (P/M) works as a motor generating a torque with the electric motor to drive the other(P/M) which transforms mechanical energy to hydraulic energy that is saved in the accumulator. When the en-ergy storage capacity of the accumulator is attained as the operation continues, energy storage to the accumulator is thermostatically stopped while the induction motor begins to work as a generator and generates electricity that is stored in the power distribution unit. Simulations were performed using a limited PT2 Block, I.e. 2nd-ordertransfer function with limitation of slope and signal output to determine suitable velocity of the cylinder which will match high performance and system stability. A mathematical model suited to the simulation of the hydrau-lic accumulator both in an open-or close-loop system is presented. The quest for improvement of lower energy capacity storage, saving and re-utilization of the conventional accumulator resulting in the short cycle time usage of hydraulic accumulators both in domestic and industrial purposes necessitates this research. The outcome of the research appears to be very efficient for generating fluctuation free electricity, power quality and reliability, energy saving/reutilization and system noise reduction.

  14. 46 CFR 112.50-3 - Hydraulic starting.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Hydraulic starting. 112.50-3 Section 112.50-3 Shipping... POWER SYSTEMS Emergency Diesel and Gas Turbine Engine Driven Generator Sets § 112.50-3 Hydraulic starting. A hydraulic starting system must meet the following: (a) The hydraulic starting system must be...

  15. Hydraulic structures

    CERN Document Server

    Chen, Sheng-Hong

    2015-01-01

    This book discusses in detail the planning, design, construction and management of hydraulic structures, covering dams, spillways, tunnels, cut slopes, sluices, water intake and measuring works, ship locks and lifts, as well as fish ways. Particular attention is paid to considerations concerning the environment, hydrology, geology and materials etc. in the planning and design of hydraulic projects. It also considers the type selection, profile configuration, stress/stability calibration and engineering countermeasures, flood releasing arrangements and scouring protection, operation and maintenance etc. for a variety of specific hydraulic structures. The book is primarily intended for engineers, undergraduate and graduate students in the field of civil and hydraulic engineering who are faced with the challenges of extending our understanding of hydraulic structures ranging from traditional to groundbreaking, as well as designing, constructing and managing safe, durable hydraulic structures that are economical ...

  16. HYDRAULIC SERVO

    Science.gov (United States)

    Wiegand, D.E.

    1962-05-01

    A hydraulic servo is designed in which a small pressure difference produced at two orifices by an electrically operated flapper arm in a constantly flowing hydraulic loop is hydraulically amplified by two constant flow pumps, two additional orifices, and three unconnected ball pistons. Two of the pistons are of one size and operate against the additional orifices, and the third piston is of a different size and operates between and against the first two pistons. (AEC)

  17. Hydraulic wind energy conversion system

    Energy Technology Data Exchange (ETDEWEB)

    1981-07-01

    The purpose of this research was to design, build and test a hydraulic wind energy system. This design used a three bladed turbine, which drove a hydraulic pump. The energy is transmitted from the pump through a long hose and into a hydraulic motor, where the energy is used. This wind system was built and tested during the winter of 1980-1981. The power train included a five meter, three bladed wind turbine, a 9.8:1 ratio gearbox, a 1.44 cubic inch displacement pump with a small supercharge gear pump attached. The hydraulic fluid was pumped through a 70', 3/4'' I-D-high pressure flexhose, then through a volume control valve and into a 1.44 cubic inch displacement motor. The fluid was returned through a 70', 1'' I-D-flexhose.

  18. Fundamental characteristics of oil hydraulic servo system; Yuatsu servo kei no kihonteki tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, K. [Musashi Instsitute of Technology, Tokyo (Japan)

    1999-05-15

    Since a hydraulic servo generates a great force very quickly upon receiving a small force or electric power, it is widely used in machine tools, construction machinery, and vehicles. The basics are that a high pressure fluid generated by a hydraulic pump is controlled by a valve and forwarded to a hydraulic cylinder or rotary hydraulic motor for the generation of a parallel motion or rotation. For the control of the valve, there are the mechanical-hydraulic servo mechanism in which the valve is operated by mechanical linkage and the electrical-hydraulic servo system in which the valve is driven by electric signals. It is difficult to perform sophisticated control such as optimum control by use of the mechanical method while the electrical method may be applied to such sophisticated control. In the former, a hydraulic servo system is constructed using mechanical feedback. It is simpler and more reliable than the other, and is used for the control of aircraft wings and for the steering of ships and vehicles. Using the latter, electric signals low in power are amplified in a servo amplifier before being sent to the servo valve. For the driving of the spool in a servo valve, the nozzle and flapper system is widely in use. (NEDO)

  19. 超磁致伸缩电液伺服阀驱动机构控制系统设计%Design of Control System of Giant Magnetostrictive Electro-hydraulic Servo Valve Driven Machine

    Institute of Scientific and Technical Information of China (English)

    杨朝舒; 何忠波; 李冬伟; 薛光明

    2014-01-01

    为了实现超磁致伸缩电液伺服阀的快速、准确控制,论述了基于PWM控制的超磁致伸缩电液伺服阀的基本结构和工作原理,设计了基于PicoScope2203数字示波器和STC89C51单片机的超磁致伸缩材料电液伺服阀驱动机构的控制系统。结果表明:该控制系统具有控制精度高、控制迅速、集成度高、操作便捷等特点。%In order to achieve the speedy and precision control of electro⁃hydraulic servo valve based on giant magnetostrictive material, the basic structure and working principle of a kind of Electro⁃hydraulic Servo Valve based on giant magnetostrictive material with PWM control was discussed. A control system for the giant magnetostrictive electro⁃hydraulic servo valve driven machine based on PicoScope2203 Digital Oscilloscope and STC89C51 series MCU was designed. The results show that the control system has properties of high speed and precision, highly integrated and convenient for operation, and etc.

  20. A Computational Model of Hydraulic Volume Displacement Drive

    Directory of Open Access Journals (Sweden)

    V. N. Pil'gunov

    2014-01-01

    Full Text Available The paper offers a computational model of industrial-purpose hydraulic drive with two hydraulic volume adjustable working chamber machines (pump and motor. Adjustable pump equipped with the pressure control unit can be run together with several adjustable hydraulic motors on the principle of three-phase hydraulic socket-outlet with high-pressure lines, drain, and drainage system. The paper considers the pressure-controlled hydrostatic transmission with hydraulic motor as an output link. It shows a possibility to create a saving hydraulic drive using a functional tie between the adjusting parameters of the pump and hydraulic motor through the pressure difference, torque, and angular rate of the hydraulic motor shaft rotation. The programmable logic controller can implement such tie. The Coulomb and viscous frictions are taken into consideration when developing a computational model of the hydraulic volume displacement drive. Discharge balance considers external and internal leakages in equivalent clearances of hydraulic machines, as well as compression loss volume caused by hydraulic fluid compressibility and deformation of pipe walls. To correct dynamic properties of hydraulic drive, the paper offers that in discharge balance are included the additional regulated external leakages in the open circuit of hydraulic drive and regulated internal leakages in the closed-loop circuit. Generalized differential equations having functional multipliers and multilinked nature have been obtained to describe the operation of hydraulic positioning and speed drive with two hydraulic volume adjustable working chamber machines. It is shown that a proposed computational model of hydraulic drive can be taken into consideration in development of LS («Load-Sensing» drives, in which the pumping pressure is tuned to the value required for the most loaded slave motor to overcome the load. Results attained can be used both in designing the industrial-purpose heavy

  1. 舵机弯矩电动加载测试系统的设计%Design of Motor-Driven Bending Moment Loading Test System

    Institute of Scientific and Technical Information of China (English)

    周军; 刘光辉; 周凤岐; 张佼龙

    2011-01-01

    针对舵机测试需求,设计了一种弯矩电动加载测试系统.系统以直流电机为执行元件能够实现几百到几万牛力加载,介绍了系统的工作原理和机械结构,分析计算了弯矩加载对其他力矩加载的干扰和系统影响,从测试技术要求上论证了方案的可行性.最后进行了理论分析和研究,建立了加载系统的数学模型,基于PID控制算法,进行了计算机仿真.仿真结果表明,能够满足系统预定的性能指标要求.%To meet the requirements to current rudder motor test, the bending moment loading test system is designed. The system can achieve a few hundred to tens of thousands of N force output with DC motor driven. Based on an introduction to the structure and principle of electrical loading system, and the calculation of disturbance on torque from bending moment, the test system design is feasible to meet rudder motor test requirements. A mathematical model of the system is established to analyze and to computer simulate with PID control arithmetic. Simulation results indicated that the performance of the motor-driven bending moment loading test system is competent for rudder motor test.

  2. Resolving discrepancies between hydraulic and chemical calibration data for seawater intrusion groundwater flow models by considering climate-driven sea level change.

    Energy Technology Data Exchange (ETDEWEB)

    J. Chapman; A. Hassan; K. Pohlmann

    2001-10-18

    Groundwater models of seawater intrusion environments can be calibrated using both hydraulic and chemical information. The possible impact of the long-term transient process of sea level change is difficult to identify, but important to accurate simulation of present conditions. The response times of the pressure and chemical fields to major fluctuations in sea level change are investigated

  3. OPTIMAL DESIGN FOR INVERTER-DRIVEN INDUCTION MOTORS%变频调速异步电机的优化设计

    Institute of Scientific and Technical Information of China (English)

    关慧; 赵争鸣; 孟朔; 邬向东

    2004-01-01

    With the development of adjustable speed withvariable frequency systems, the induction motor is applied more and more widely in the industrial drive. The conventional induction motor design is not suitable for the inverter-driven induction motor any longer. The key-points of the design for a conventional motor are its efficiency, power factor, maximum torque, starting torque, starting current, elevated temperature of the operating performance and the cost. But the emphases of the design for an inverter-driven induction motor are the efficiency,power factor, elevated temperature in the variable speed range,and dynamic response. Based on the characteristics of adjustable speed with variable frequency systems, the paper presents an design methods. On the whole, the optimal design brings higher efficiency to the inverter-driven induction motors.%随着变频调速技术的发展,异步电机在工业传动领域中的应用越来越广泛.传统的异步电机设计方法已经不适应变频调速异步电机的设计要求.传统电机的设计重点在于额定点效率、功率因数、最大转矩、起动转矩、起动电流、运行温升和价格等指标.而变频调速电机的设计重点是在调速范围内的效率、功率因数、温升,以及动态响应性能等.本文根据变频调速集成系统的特点,提出具有针对性的变频调速电机优化设计策略.该策略具有以下几个特点:①采用自适应设计模型;②针对变频器供电的谐波影响分析模型:③采用最优滑差控制和面向系统的优化设计方法.利用该优化设计方法,使得变频调速异步电机更加高效节能.

  4. Lua Application in DC-motor driven Load Simulator Control System%Lua在电动负载模拟器控制系统中的应用

    Institute of Scientific and Technical Information of China (English)

    汪玲; 闫杰

    2011-01-01

    将脚本语言Lua解释器与负载模拟器的实时控制软件,以及控制系统设计仿真软件MATLAB/SIMULINK相结合,构建了功能强大,操作方便的控制系统设计与实验环境.能够在实现各种典型控制算法与负载模拟算法的基础上为各种新算法提供丰富的接口.实际使用表明,脚本语言的引入,增强了原有实验系统的功能,为负载模拟器控制系统中各种算法的实现提供了包括设计、仿真与验证的完整实验环境.%According to the characteristics of DC-motor driven load simulator experiments, script language Lua, real time control software for DC-motor driven load simulator and control system design and simulation tools MATLAB/SIMULINK are integrated to build a powerful, easy to use DC-motor driven load simulator experiment environment. Interfaces for new control strategy experiments are presented as well as implementation of several typical control algorithms and load simulation algorithms. Application shows original experiment system is expanded through the introduction of script language. A comprehensive experiment environment consisting of design, simulation, verification is provided for controller algorithm design.

  5. Basic hydraulics

    CERN Document Server

    Smith, P D

    1982-01-01

    BASIC Hydraulics aims to help students both to become proficient in the BASIC programming language by actually using the language in an important field of engineering and to use computing as a means of mastering the subject of hydraulics. The book begins with a summary of the technique of computing in BASIC together with comments and listing of the main commands and statements. Subsequent chapters introduce the fundamental concepts and appropriate governing equations. Topics covered include principles of fluid mechanics; flow in pipes, pipe networks and open channels; hydraulic machinery;

  6. 新型涡轮驱动水力振荡器设计与实验研究%Design and experimental study on a new type of turbine driven hydraulic oscillator

    Institute of Scientific and Technical Information of China (English)

    王杰; 夏成宇; 冯定; 于长柏

    2016-01-01

    提出了一种新型的石油钻井用水力振荡器,可有效降低管柱摩阻,提高钻井效率.该水力振荡器采用涡轮驱动,并使用双偏心动定阀作为压力脉冲发生机构.通过建立双偏心动定阀的运动特性方程,结合实际工况得出阀盘的最优尺寸.通过选定阀型的水力振荡器性能测试实验,得出在模拟钻压为30 kN ,流量为28 L/s ,工作介质为清水时的振动冲击力约为15859 N ,振动位移约为4.1 mm ,振动频率约为11.4 Hz .该分析与实验结果对水力振荡器的设计与应用具有指导意义.%A new type of hydraulic oscillator for oil drilling is presented ,w hich can effectively re‐duce the frictional resistance and increase the drilling efficiency . The hydraulic oscillator was driven by a turbine ,and double eccentric valve was used as the pressure pulse generating mecha‐nism .By establishing the motion characteristic equation of the double eccentric valve ,the optimal size of the valve disc was obtained based on the actual working conditions .The performance test experiment of the hydraulic oscillator with selected valve was carried out ,the experimental re‐sults showed that the vibration impact force of the hydraulic oscillator was about 15 859 N ,the vibration displacement was about 4.1 mm ,and the vibration frequency was about 11.4 Hz when the drilling pressure was 30 kN ,the flow rate was 28 L/s ,and the working medium was water . The analysis and experimental results have guiding significance for the design and application of the hydraulic oscillator .

  7. Hydraulic Structures

    Data.gov (United States)

    Department of Homeland Security — This table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the FIRM, channels containing the...

  8. Training implications of maximal forces on a computer-controlled and motor-driven leg press by age group, sex, footplate direction, and speed

    Science.gov (United States)

    Schulz, Brian W.; Hart-Hughes, Stephanie; Gordon, Mark T.; Bulat, Tatjana

    2017-01-01

    Strength training that overloads lengthening muscle fibers may result in greater strength gains with less effort and perceived exertion than conventional training modalities. This study evaluates a device capable of this overloading (a motor-driven and computer-controlled leg press) to develop recommendations for future training interventions. Unimpaired younger and older men and women (7/group, total n=28) performed three maximal-effort trials for both directions of footplate motion (IN and OUT) at three speed profiles (knee rotation speeds of 15, 25, and 35°/s) on a motor-driven and computer-controlled leg press. Normalized forces were tested for effects of age group, sex, direction of footplate motion, and knee rotation speed. Peak forces were 57% greater for younger and 20% greater for IN. Trends of greater IN relative to OUT forces (IN overloading) were present in women, but this was due to an inverse correlation between strength and IN overloading that was independent of age group and sex. Leg press strength training on a device that is capable of overloading lengthening muscle fibers is a promising new training method that appears to have the greatest potential benefits for the weakest participants. Training target profiles on the device tested and others similar to it should be set based on participant-specific maximums across the ROM in both IN and OUT directions at a speed in the middle of the range to be trained. PMID:22289381

  9. 基于SVPWM的直线电机地铁的驱动控制%Driven control of linear motor in subway based on SVPWM

    Institute of Scientific and Technical Information of China (English)

    张进高; 卢琴芬; 王利; 叶云岳

    2011-01-01

    The subway train driven by linear induction motor (LIM)has the merits of small turning radius, good climbing ability, simple structure , small size, little maintenance, reliable operation etc.. It has been well used in urban rail transit. In order to further promote and apply linear motor subway, a self-designed subway test line driven by linear induction motor was introduced. Using wireless remote control, a control system based on space vector pulse width modulation (SVPWM) was designed, simulative test was taken in the laboratory. The experimental results show that this control system can meet the various working conditions when the locomotive is running in the test line and work reliably.%地铁列车用直线感应电动机(LIM)驱动,具有转弯半径小、爬坡能力强、结构简单、体积小、维护少、运行可靠等众多优点,已经在城市轨道交通中得到了很好的应用.为进一步推广、应用直线电机地铁,介绍了一条自主设计的直线感应电动机驱动的地铁试验线.采用无线遥控控制,设计了基于空间矢量脉宽调制(SVPWM)的控制系统,在实验室中进行了模拟试验.试验结果表明该套控制系统能满足机车在试验线上运行时的各种工况并可靠地工作.

  10. M1078 Hybrid Hydraulic Vehicle Fuel Economy Evaluation

    Science.gov (United States)

    2012-09-01

    PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. 1. REPORT DATE (DD-MM-YYYY) 28-09-2012 2. REPORT TYPE Interim Report 3. DATES COVERED (From...system shakedown and developmental testing. During developmental testing, a hydraulic motor failure occurred. Although not catastrophic, the motor...main hydraulic hybrid system control module to request the TCM to shift the transmission. Clutch Operation with engine- off (hydraulic-only power) or

  11. Approaches to Suppressing Shaft Voltage in Brushless DC Motor Driven by PWM Inverter Based on Ungrounded Common-Mode Equivalent Circuit

    Science.gov (United States)

    Maetani, Tatsuo; Isomura, Yoshinori; Watanabe, Akihiko; Iimori, Kenichi; Morimoto, Shigeo

    This paper describes an ungrounded common-mode equivalent circuit for a motor driven by a voltage-source PWM inverter. When the capacitance of the rotor was is small, the reversal of the polarities of the common-mode voltage and shaft voltage is observed. In order to model this reversal, a bridge-type equivalent circuit is proposed. On the basis of calculations and experiment, it is found the values and polarity of the shaft voltage can be are accurately determined with the proposed equivalent circuit. Furthermore, the capacitance value of the insulated rotor required to make the shaft voltage equal to or less than the dielectric breakdown voltage of the bearing grease is obtained.

  12. Withholding a Reward-driven Action: Studies of the Rise and Fall of Motor Activation and the Effect of Cognitive Depletion.

    Science.gov (United States)

    Freeman, Scott M; Aron, Adam R

    2016-02-01

    Controlling an inappropriate response tendency in the face of a reward-predicting stimulus likely depends on the strength of the reward-driven activation, the strength of a putative top-down control process, and their relative timing. We developed a rewarded go/no-go paradigm to investigate such dynamics. Participants made rapid responses (on go trials) to high versus low reward-predicting stimuli and sometimes had to withhold responding (on no-go trials) in the face of the same stimuli. Behaviorally, for high versus low reward stimuli, responses were faster on go trials, and there were more errors of commission on no-go trials. We used single-pulse TMS to map out the corticospinal excitability dynamics, especially on no-go trials where control is needed. For successful no-go trials, there was an early rise in motor activation that was then sharply reduced beneath baseline. This activation-reduction pattern was more pronounced for high- versus low-reward trials and in individuals with greater motivational drive for reward. A follow-on experiment showed that, when participants were fatigued by an effortful task, they made more errors on no-go trials for high versus low reward stimuli. Together, these studies show that, when a response is inappropriate, reward-predicting stimuli induce early motor activation, followed by a top-down effortful control process (which we interpret as response suppression) that depends on the strength of the preceding activation. Our findings provide novel information about the activation-suppression dynamics during control over reward-driven actions, and they illustrate how fatigue or depletion leads to control failures in the face of reward.

  13. Controls of Hydraulic Wind Turbine

    Directory of Open Access Journals (Sweden)

    Zhang Yin

    2016-01-01

    Full Text Available In this paper a hydraulic wind turbine generator system was proposed based on analysis the current wind turbines technologies. The construction and principles were introduced. The mathematical model was verified using MATLAB and AMsim. A displacement closed loop of swash plate of motor and a speed closed loop of generator were setup, a PID control is introduced to maintain a constant speed and fixed frequency at wind turbine generator. Simulation and experiment demonstrated that the system can connect grid to generate electric and enhance reliability. The control system demonstrates a high performance speed regulation and effectiveness. The results are great significant to design a new type hydraulic wind turbine system.

  14. District Heating using a gas-motor-driven heat pump - result checking; Erfolgskontrolle. Heizzentrale mit indirekter Gasmotor-Waermepumpe. Berufsschulen Bern-Lorraine

    Energy Technology Data Exchange (ETDEWEB)

    Eggen, B.; Lanz, S.

    2003-07-01

    This final report for the Swiss Federal Office of Energy presents the results of a project that evaluated the operation of a district heating scheme that supplies various school and college buildings, residential buildings and Berne's Botanical Gardens with heat. This pilot and demonstration system comprises an indirect gas motor heat pump with co-generation unit and an electrically-driven heat pump. In order to achieve a high performance ratio the co-generation unit was additionally equipped with a heat-recovery heat pump which condenses the waste gas and recovers radiation heat losses. The implementation of the district heating project was done in stages to meet annual heat demands of around 6'500 MWh. About 50% of these demands are met by the indirect gas motor heat pump. Figures are presented on the optimisation of heat utilisation from ground water which permitted an improvement in the total efficiency of the plant of around 30% compared with a conventional installation. The authors state that, with this installation, it could be demonstrated in an exemplary fashion that heat pumps can also be installed in existing, non-renovated buildings. In the planning of such heat pump systems they recommend that special attention be paid to the overall performance ratio, and that the rate of flow of the heat source and system temperatures be taken into account.

  15. Parallel Rolling Robot with Hydraulic Driven Expandable Chain%液压驱动缩放支链的并联式滚动机器人

    Institute of Scientific and Technical Information of China (English)

    沈海阔; 丁万; 仝龙飞; 黄齐来; 姚燕安

    2015-01-01

    A novel three degrees of freedom (DOF) parallel rolling robot is proposed. The main consideration for proposing the robot aims at acquiring large deformation capability, powerful strength output, rapid response and flexible locomotion. The robot adopts the parallel mechanism as its architecture to guarantee the stiffness of the robot. The large deformation capability is obtained by taking advantage of the planar expandable mechanism as the extension ratio enlarging mechanism. The usage of the hydraulic actuation as the telescopic input increases the locomotion flexibility and the strength output of the robot. The robot rolls by properly planning and controlling the relations between the center of mass (CM) of the robot and the supporting region. The mechanical construction and configuration of the robot is described, the rolling gaits are planned, and the optimal locomotion rule is given. Based on the rule, the kinematic model of the robot is built. The correctness of the kinematic model is verified by the given numerical example. The locomotion feasibility of the two locomotion periods is analysed. A set of experimental system including the hydraulic system and robotic system is built. Four rolling experiments are carried out accordingly. The experimental results demonstrate that the experimental system is reliable and possesses the rapid response capability, and verify that the validity and feasibility of the theoretical analysis and the rolling locomotion.%提出一种新型三自由度并联式滚动机器人。该机器人以大变形、强力输出、快速响应和运动灵活为目标,构型上采用提出的新型并联机构为本体以保证机构整体刚度,设计上应用平面缩放支链作为伸缩比放大机构以获得大变形能力,驱动上利用液压执行元件作为伸缩驱动输入以增强滚动机器人运动的灵活性与力量输出。其翻滚运动是通过合理规划与控制机器人质心与支撑区域之间关系而

  16. Discarded Motors Converted into Wind Driven Generator%废旧电机改装风力发电机

    Institute of Scientific and Technical Information of China (English)

    周郭牛; 蔡悦

    2012-01-01

    随着全球能源危机日益加剧,寻找一种新的能源迫在眉睫,风能以其取之方便、无污染等优点成为大家关注的焦点。根据电磁感应定律,利用风能推动桨叶带动电机旋转,从而输出电压,达到风能发电的目的。根据这个基本原理,可以利用电动车废旧电机制造成小型发电机,对解决一些偏远山区、海岛用电问题有一定的参考价值。%With the growing global energy crisis,looking for a new energy is extremely urgent.Wind energy becomes the focus of attention for its convenience and pollution-free.According to the law of electromagnetic induction,the use of wind energy to promote the blade drives motor rotation,and thus to output voltage to achieve the purpose of wind energy.According to this basic principle,the wasted motors of electric car can be used to produce small generators and solve certain problems in some remote mountainous areas and islands.

  17. Single-phase driven ultrasonic motor using two orthogonal bending modes of sandwiching piezo-ceramic plates

    Science.gov (United States)

    Ma, Yuting; Choi, Minkyu; Uchino, Kenji

    2016-11-01

    A compact ultrasonic motor using sandwiching piezo-ceramic plates was developed, having advantages of low manufacturing costs, simple driving circuit, and high scalability. The stator is composed of two piezoelectric plates attached to a T-shaped steel body. Two orthogonal bending modes can be excited by driving one piezoelectric plate and the reversed motion of the rotor can be obtained by driving the piezoelectric plate on the opposite side. The prototype stator with a size of 15 mm × 2.44 mm × 2 mm, operated at 44.8 kHz, was experimentally characterized, and a maximum torque of 2 mN m was obtained. Maximum power of 2.3 mW and efficiency of 9% were produced with a load of 0.8 mN m at a rotation speed of 27 rpm.

  18. Single-phase driven ultrasonic motor using two orthogonal bending modes of sandwiching piezo-ceramic plates.

    Science.gov (United States)

    Ma, Yuting; Choi, Minkyu; Uchino, Kenji

    2016-11-01

    A compact ultrasonic motor using sandwiching piezo-ceramic plates was developed, having advantages of low manufacturing costs, simple driving circuit, and high scalability. The stator is composed of two piezoelectric plates attached to a T-shaped steel body. Two orthogonal bending modes can be excited by driving one piezoelectric plate and the reversed motion of the rotor can be obtained by driving the piezoelectric plate on the opposite side. The prototype stator with a size of 15 mm × 2.44 mm × 2 mm, operated at 44.8 kHz, was experimentally characterized, and a maximum torque of 2 mN m was obtained. Maximum power of 2.3 mW and efficiency of 9% were produced with a load of 0.8 mN m at a rotation speed of 27 rpm.

  19. A novel energy recovery system for parallel hybrid hydraulic excavator.

    Science.gov (United States)

    Li, Wei; Cao, Baoyu; Zhu, Zhencai; Chen, Guoan

    2014-01-01

    Hydraulic excavator energy saving is important to relieve source shortage and protect environment. This paper mainly discusses the energy saving for the hybrid hydraulic excavator. By analyzing the excess energy of three hydraulic cylinders in the conventional hydraulic excavator, a new boom potential energy recovery system is proposed. The mathematical models of the main components including boom cylinder, hydraulic motor, and hydraulic accumulator are built. The natural frequency of the proposed energy recovery system is calculated based on the mathematical models. Meanwhile, the simulation models of the proposed system and a conventional energy recovery system are built by AMESim software. The results show that the proposed system is more effective than the conventional energy saving system. At last, the main components of the proposed energy recovery system including accumulator and hydraulic motor are analyzed for improving the energy recovery efficiency. The measures to improve the energy recovery efficiency of the proposed system are presented.

  20. An integrated control strategy for the composite braking system of an electric vehicle with independently driven axles

    Science.gov (United States)

    Sun, Fengchun; Liu, Wei; He, Hongwen; Guo, Hongqiang

    2016-08-01

    For an electric vehicle with independently driven axles, an integrated braking control strategy was proposed to coordinate the regenerative braking and the hydraulic braking. The integrated strategy includes three modes, namely the hybrid composite mode, the parallel composite mode and the pure hydraulic mode. For the hybrid composite mode and the parallel composite mode, the coefficients of distributing the braking force between the hydraulic braking and the two motors' regenerative braking were optimised offline, and the response surfaces related to the driving state parameters were established. Meanwhile, the six-sigma method was applied to deal with the uncertainty problems for reliability. Additionally, the pure hydraulic mode is activated to ensure the braking safety and stability when the predictive failure of the response surfaces occurs. Experimental results under given braking conditions showed that the braking requirements could be well met with high braking stability and energy regeneration rate, and the reliability of the braking strategy was guaranteed on general braking conditions.

  1. Two-axis hydraulic joint for high speed, heavy lift robotic operations

    Energy Technology Data Exchange (ETDEWEB)

    Vaughn, M.R.; Robinett, R.D.; Phelan, J.R.; VanZuiden, D.M.

    1994-04-01

    A hydraulically driven universal joint was developed for a heavy lift, high speed nuclear waste remediation application. Each axis is driven by a simple hydraulic cylinder controlled by a jet pipe servovalve. Servovalve behavior is controlled by a force feedback control system, which damps the hydraulic resonance. A prototype single joint robot was built and tested. A two joint robot is under construction.

  2. 阀控液压马达速度伺服系统仿真分析%Simulation of the Hydraulic Motor of Speed Servo System Controlled by Valve

    Institute of Scientific and Technical Information of China (English)

    贾文铜; 周瑞祥; 张忠

    2012-01-01

    针对干扰力矩对阀控液压马达速度伺服系统的影响,利用结构不变性原理给系统加入了补偿器来消除干扰力矩的影响,同时利用PID控制来提高系统的抗干扰性.仿真表明,在利用结构不变性原理后再通过PID控制可以有效提高系统抗干扰能力和控制精度.%Aiming at the interfere moment affecting the hydraulic motor of speed servo system controlled by valve,the structure unchangeable principle was applied to eliminate the effect of the interfere moment and PID control was also managed to enhance the anti-jamming of the system, The simulation indicates that the application of the PID controll after the application of structure unchangeable principle can effectively improve the anti-jamming ability and control precision.

  3. 航空用永磁无刷电机复合驱动中转速波动研究%Analysis of Speed Fluctuation of Brushless PM Motor in Aircraft by Compound Driven

    Institute of Scientific and Technical Information of China (English)

    吕永健; 李飞; 解亮

    2011-01-01

    This paper analysed the sine/square wave compound driven for brushless PM motors in aircraft EMA, deduced the dynamical equation of the speed during the switch process and researched the major factors which affect the speed fluctuation. The simulation model of compound driven for brushless PM motor and the platform of the motion control system for universal motors were established. The results of the analysis, simulations and experiments prove that the speed fluctuation can be controlled within acceptable limits and the compound driven for brushless PM motor is feasibility.%研究了航空EMA用永磁无刷电机正弦波/方波复合驱动策略,推导了永磁无刷电机在驱动方式切换时的转速动态方程,分析了影响切换过程中转速波动的主要因素.建立了永磁无刷电机复合驱动的仿真模型和实验平台,仿真和实验结果表明,正弦波/方波复合驱动时的转速波动可以控制在允许的范围内,验证了复合驱动控制策略的有效性.

  4. Intelligent Hydraulic Actuator and Exp-based Modelling of Losses in Pumps and .

    DEFF Research Database (Denmark)

    Zhang, Muzhi

    A intelligent fuzzy logic self-organising PD+I controller for a gearrotor hydraulic motor was developed and evaluated. Furthermore, a experimental-based modelling methods with a new software tool 'Dynamodata' for modelling of losses in hydraulic motors and pumps was developed.......A intelligent fuzzy logic self-organising PD+I controller for a gearrotor hydraulic motor was developed and evaluated. Furthermore, a experimental-based modelling methods with a new software tool 'Dynamodata' for modelling of losses in hydraulic motors and pumps was developed....

  5. FEEDBACK LINEARISATION APPLIED ON A HYDRAULIC

    DEFF Research Database (Denmark)

    Andersen, Torben Ole; Hansen, Michael Rygaard; Pedersen, Henrik C.;

    2005-01-01

    Generally most hydraulic systems are intrensically non-linear, why applying linear control techniques typically results in conservatively dimensioned controllers to obtain stable performance. Non-linear control techniques have the potential of overcoming these problems, and in this paper the focus...... is on developing and applying several different feedback linearisation (FL) controllers to the individual servo actuators in a hydraulically driven servo robot to evaluate and compare their possiblities and limitations. This is done based on both simulation and experimental results....

  6. DESIGN AND CONSTRUCTION OF A HYDRAULIC PISTON

    OpenAIRE

    Santos De La Cruz, Eulogio; Universidad Nacional Mayor de San Marcos; Rojas Lazo, Oswaldo; Universidad Nacional Mayor de San Marcos; Yenque Dedios, Julio; Universidad Nacional Mayor de San Marcos; Lavado Soto, Aurelio; Universidad Nacional Mayor de San Marcos

    2014-01-01

    A hydraulic system project includes the design, materials selection and construction of the hydraulic piston, hydraulic circuit and the joint with the pump and its accesories. This equiment will be driven by the force of moving fluid, whose application is in the devices of machines, tools, printing, perforation, packing and others. El proyecto de un sistema hidráulico, comprende el diseño, selección de materiales y construcción del pistón hidráulico, circuito hidráulico y el ensamble con l...

  7. 晶闸管直流电机系统的异常暂态研究%Study of abnormal transient of thyristor driven DC motor

    Institute of Scientific and Technical Information of China (English)

    李娜; 刘明光; 杨恒

    2009-01-01

    According to the pulsating current of thyristor driven DC motor,the transient process of abnormal system operation is modeled and analyzed and its mathematic expressions are deduced. With an actual system as an example ,the transient process of abnormal operation is described. According to the nonlinearity of the DC motor magnetic field, its dynamic simulation model is built and the over -current and over-voltage produced during abnormal operation is simulated. Experimental results show that,the current is doubled or tripled suddenly,and the higher the terminal voltage or speed is,the higher the instantaneous over-current will be. The sudden current increase will result in over-voltage at both sides of the transformer ,which may damage the rectifier,capacitor and insulation.%针对晶闸管直流电机系统电流脉动的特点,对系统异常运行时的暂态过程进行了建模与分析.推导出系统异常运行时暂态过程的数学表达式.以一个实际系统为例,对异常运行时系统的暂态过程进行计算.考虑直流电机磁路的非线性建立了系统的动态仿真模型,对异常运行时系统产生的过电流及过电压进行仿真,通过实验对理论及仿真结果进行验证.结果表明,系统异常运行会使回路电流瞬时突增2~3倍,且电机端电压越大、电机运行速度越高,瞬时产生的过电流也就越大.异常运行时变压器原、副边分别会产生高出额定值2~3倍左右的过电压,可能使整流器烧毁、保护电容损坏、绝缘击穿.

  8. Silanization of quartz, silicon and mica surfaces with light-driven molecular motors : construction of surface-bound photo-active nanolayers

    NARCIS (Netherlands)

    London, Gabor; Carroll, Gregory T.; Feringa, Ben L.

    2013-01-01

    The attachment of molecular rotary motors containing triethoxysilane functional groups to quartz, silicon and mica surfaces is described. Motors containing silane coupling agents in their structure form stable molecular layers on quartz and silicon surfaces. Motors attached to these surfaces were fo

  9. Hydraulic drive and control system of the cone collecting robot

    Institute of Scientific and Technical Information of China (English)

    Kong Qinghua; Liu Jinhao; Lu Huaimin

    1999-01-01

    This paper describes the basic structure and design and operation principle of the hydraulic drive and control system with two pumps and two circuits. The manipulator of the cone collecting robot designed is full driven by hydraulic, which has five freedoms. The computer and electrohydraulic proportion velocity regulating valve were installed to realize open loop serve control for reducing cost and easy application.

  10. Intelligent Hydraulic Actuator and Exp-based Modelling of Losses in Pumps and .

    DEFF Research Database (Denmark)

    Zhang, Muzhi

    A intelligent fuzzy logic self-organising PD+I controller for a gearrotor hydraulic motor was developed and evaluated. Furthermore, a experimental-based modelling methods with a new software tool 'Dynamodata' for modelling of losses in hydraulic motors and pumps was developed....

  11. Silanization of quartz, silicon and mica surfaces with light-driven molecular motors: construction of surface-bound photo-active nanolayers

    OpenAIRE

    London, Gábor; Carroll, Gregory T.; Feringa, Ben L.

    2013-01-01

    The attachment of molecular rotary motors containing triethoxysilane functional groups to quartz, silicon and mica surfaces is described. Motors containing silane coupling agents in their structure form stable molecular layers on quartz and silicon surfaces. Motors attached to these surfaces were found to undergo photochemical and thermal isomerization steps similar to those observed in solution. Additionally, successful formation of molecular "carpets" on atomically flat mica extending micro...

  12. Recovery of post stroke proximal arm function, driven by complex neuroplastic bilateral brain activation patterns and predicted by baseline motor dysfunction severity

    Directory of Open Access Journals (Sweden)

    Svetlana ePundik

    2015-07-01

    Full Text Available Objectives: Neuroplastic changes that drive recovery of shoulder/elbow function after stoke have been poorly understood. The purpose of this study was to determine the relationship between neuroplastic brain changes related to shoulder/elbow movement control in response to treatment and recovery of arm motor function in chronic stroke survivors. Methods: Twenty-three chronic stroke survivors were treated with 12 weeks of arm rehabilitation. Outcome measures included functional Magnetic Resonance Imaging (fMRI for the shoulder/elbow components of reach and a skilled motor function test (Arm Motor Abilities Test (AMAT, collected before and after treatment.Results: We observed two patterns of neuroplastic changes that were associated with gains in motor function: decreased or increased task-related brain activation. Those with significantly better motor function at baseline exhibited a decrease in brain activation in response to treatment, evident in the ipsilesional primary motor and contralesional supplementary motor regions; in contrast, those with greater baseline motor impairment, exhibited increased brain activation in response to treatment. There was an linear relationship between greater functional gain (AMAT and increased activation in bilateral primary motor, contralesional primary and secondary sensory regions, and contralesional lateral premotor area, after adjusting for baseline AMAT, age, and time since stroke. Conclusions: Recovery of functional reach involves recruitment of several contralesional and bilateral primary motor regions. In response to intensive therapy, the direction of functional brain change (i.e. increase or decrease in task-related brain recruitment for shoulder/elbow reach components depends on baseline level of motor function and may represent either different phases or different strategies of neuroplasticity that drive functional recovery.

  13. Recovery of post stroke proximal arm function, driven by complex neuroplastic bilateral brain activation patterns and predicted by baseline motor dysfunction severity

    Science.gov (United States)

    Pundik, Svetlana; McCabe, Jessica P.; Hrovat, Ken; Fredrickson, Alice Erica; Tatsuoka, Curtis; Feng, I Jung; Daly, Janis J.

    2015-01-01

    Objectives: Neuroplastic changes that drive recovery of shoulder/elbow function after stroke have been poorly understood. The purpose of this study was to determine the relationship between neuroplastic brain changes related to shoulder/elbow movement control in response to treatment and recovery of arm motor function in chronic stroke survivors.Methods: Twenty-three chronic stroke survivors were treated with 12 weeks of arm rehabilitation. Outcome measures included functional Magnetic Resonance Imaging (fMRI) for the shoulder/elbow components of reach and a skilled motor function test (Arm Motor Abilities Test, AMAT), collected before and after treatment.Results: We observed two patterns of neuroplastic changes that were associated with gains in motor function: decreased or increased task-related brain activation. Those with significantly better motor function at baseline exhibited a decrease in brain activation in response to treatment, evident in the ipsilesional primary motor and contralesional supplementary motor regions; in contrast, those with greater baseline motor impairment, exhibited increased brain activation in response to treatment. There was a linear relationship between greater functional gain (AMAT) and increased activation in bilateral primary motor, contralesional primary and secondary sensory regions, and contralesional lateral premotor area, after adjusting for baseline AMAT, age, and time since stroke.Conclusions: Recovery of functional reach involves recruitment of several contralesional and bilateral primary motor regions. In response to intensive therapy, the direction of functional brain change (i.e., increase or decrease in task-related brain recruitment) for shoulder/elbow reach components depends on baseline level of motor function and may represent either different phases of recovery or different patterns of neuroplasticity that drive functional recovery. PMID:26257623

  14. 机动泵早期失效研究及改进%Research and Improvement of Early Failure for Motored Pump

    Institute of Scientific and Technical Information of China (English)

    王爱军

    2015-01-01

    Motored pump is small super-high pressure hydraulic pump station consisted of hydraulic pump driven by the gasoline engine. It mainly applied in the railway, electric power, chemical, machinery and other industries to provide hydraulic power source. In practical appli-cations, because temperature rapidly rise and vibration is larger , which cause early failure of motored pump and seriously influence applica-tions in industries. This paper focuses on the research of early failure and low life for motored pump, put forward the corrective measures from the hydraulic principle, structure design to greatly improve the reliability of motored pump.%机动泵是由汽油机驱动液压泵组成的小型超高压液压泵站,主要应用于铁路、电力、化工、机械等行业,提供液压动力源。在实际应用中,由于机动泵温升快、振动大造成早期失效,严重影响在各行业中的应用。该文重点对机动泵的早期失效、寿命低进行研究,从液压原理、结构设计提出改进措施并实际应用,大大提高机动泵的可靠性。

  15. HYDRAULICS, LOUISA COUNTY, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydraulic analysis for estimating flood stages for a flood insurance study. It...

  16. Hydraulic Hybrid Vehicles

    Science.gov (United States)

    EPA and the United Parcel Service (UPS) have developed a hydraulic hybrid delivery vehicle to explore and demonstrate the environmental benefits of the hydraulic hybrid for urban pick-up and delivery fleets.

  17. 一种用于液体静压导轨的高精密液压站设计%Design of the Ultra-precision Hydraulic Station for Hydraulic Static Pressured Guide

    Institute of Scientific and Technical Information of China (English)

    赵午云; 郭勇

    2014-01-01

    Hydraulic static pressured guide is the important function unit of precision machine tool. Hydraulic station is indispen-sable and supplementary unit for hydraulic static pressured guide in normal operation,and must provide hydraulic static pressured guide with lubricating oil of invariable pressure. An ultra-precision hydraulic station for hydraulic static pressured guide was designed. In this hydraulic station,lubricating oil was provided by precision gear pump driven by variable frequency motor,and pressure export was ensured to be steady by full-closed loop feedback control. The export pressure precision of the hydraulic station can reach ± 0.05%. Good effect is gained in the application of the hydraulic station on the hydraulic static pressured guide of ultra-precision machine tool.%液体静压导轨是精密超精密加工机床的重要功能单元,液压站是液体静压导轨正常工作的必要辅助单元。液体静压导轨要保持高的精度,液压站必须能够为静压导轨提供压力非常稳定的润滑油输入。设计一种用于液体静压导轨的高精密液压站,该液压站利用变频电机驱动精密齿轮泵供给润滑油,利用全闭环反馈调节装置控制润滑油的稳压输出。实际测量证明:该液压站的输出压力稳定精度可达±0.05%,应用于超精密机床上的液体静压导轨取得了良好的效果。

  18. Application of Open-hydrostatic Slider Driven by Linear Motor in Grinding Machine%由直线电机驱动的静压导轨在磨床上的应用

    Institute of Scientific and Technical Information of China (English)

    潘慧; 范晓; 戴惠良

    2012-01-01

    介绍开式液体静压导轨的原理以及应用于磨床的设计过程,同时根据静压导轨的计算结果选择合适的直线电机,并总结了直线电机驱动的静压导轨的优点.%The principles of the open-hydrostatic slider and its application in the designing process of grinding machine were introduced. According to the calculating results of the open-hydrostatic slider, the right linear motor was chosen. The advantages of open-hydrostatic slider driven by linear motor were summarized.

  19. Method for assessing motor insulation on operating motors

    Science.gov (United States)

    Kueck, John D.; Otaduy, Pedro J.

    1997-01-01

    A method for monitoring the condition of electrical-motor-driven devices. The method is achieved by monitoring electrical variables associated with the functioning of an operating motor, applying these electrical variables to a three phase equivalent circuit and determining non-symmetrical faults in the operating motor based upon symmetrical components analysis techniques.

  20. Silanization of quartz, silicon and mica surfaces with light-driven molecular motors: construction of surface-bound photo-active nanolayers.

    Science.gov (United States)

    London, Gábor; Carroll, Gregory T; Feringa, Ben L

    2013-06-07

    The attachment of molecular rotary motors containing triethoxysilane functional groups to quartz, silicon and mica surfaces is described. Motors containing silane coupling agents in their structure form stable molecular layers on quartz and silicon surfaces. Motors attached to these surfaces were found to undergo photochemical and thermal isomerization steps similar to those observed in solution. Additionally, successful formation of molecular "carpets" on atomically flat mica extending micrometer-sized length scales is presented. These "carpets" were found to undergo morphological changes upon irradiation with UV-light.

  1. 利用回转工作台伺服电动机驱动托盘交换装置%The tray exchange device driven by servo motor of rotary table

    Institute of Scientific and Technical Information of China (English)

    李全普; 邵连英; 王坤

    2012-01-01

    介绍一种利用回转工作台伺服电动机驱动的托盘交换装置,结构简化、交换时间短、生产效率高、成本低、可靠性好、实用性强.%This text introduces a tray exchange device driven by servo motor of rotary table. The device has simple structure, short exchange time, high efficiency, low cost, and is reliable and practical.

  2. Innovative design and optimization of suspension of in-wheel-motor-driven electric vehicles%轮毂驱动电动汽车悬架创新设计与优化

    Institute of Scientific and Technical Information of China (English)

    聂高法; 时培成; 孙阳敏; 彭闪闪; 张军

    2016-01-01

    To improve vertical performance of suspension of in-wheel-motor-driven electric vehicle,a quarter-car dynamic model of a electric vehicle drived by in-wheel motor was established and simulated in Matlab/Simulink.First,compared with the original vehicle's suspension,the effect of torque ripple to performance of vertical vibration of in-wheel motor was studied.Second,with in-wheel motor connected, by wheel hub elastically (using spring-damper)and turned into similar sprung mass,the suspension pa-rameters were optimized.Finally,the quarter-car dynamic model before-and-after optimization was com-pared.The simulation results showed that the suspension after optimization was superior to the suspen-sion with rigid connection between the motor and wheel hub in performance of vertical vibration.The re-sults provided the basis for improving performance of vertical vibration of the in-wheel-motor-driven e-lectric vehicle.%为了改善轮毂驱动电动汽车悬架垂向振动特性,建立轮毂驱动电动汽车1/4车辆动力学模型,在 Mat-lab/Simulink中进行仿真分析。首先,对比原车悬架,研究轮毂电机转矩波动对车辆垂向振动特性的影响。其次,将轮毂电机利用弹簧阻尼器与轮毂弹性连接,使轮毂电机变成类簧载质量,并优化悬架参数。最后,对优化前后的1/4车辆动力学模型进行对比分析。仿真表明,优化后的悬架系统使得车身垂向振动特性优于电机与轮毂刚性连接的悬架,研究结果为改善轮毂电机电动汽车垂向振动特性提供了依据。

  3. Output speed and flow of double-acting double-stator multi-pumps and multi-motors

    Institute of Scientific and Technical Information of China (English)

    De-sheng WEN; Zhi-li WANG; Jun GAO; Yong ZHANG; Shi-jun LV; Tetsuhiro TSUKIJI

    2011-01-01

    The primary focus of this study was to investigate a series of novel motors and pumps, based on a new type of structure called double-stator. The double-stator structure can be used as pump or motor just based on the application requirements. A certain amount of pumps or motors can be formed in one shell, and these sub-pumps or sub-motors can work alone or be combined without influence on each other. So this kind of double-stator pump (motor) is called a multi-pump (multi-motor). Through the analysis of multifarious connection modes of the double-acting double-stator multi-pumps and multi-motors, the mathematical expressions of the output flow rate and the rotational speed are acquired. The results indicate that a quantity of different flow rates can be provided by one fixed-displacement multi-pump under the condition of unalterable driven speed by electromotor. Likewise,when supplied by settled input flow, without complex variable mechanism, the functions of double-speed, multiple-speed, and even differential connection can be obtained by employing the use of a double-stator multi-motor. The novel hydraulic transmission is made of such a double-stator multi-pump and multi-motor, and has broad application prospects.

  4. 超声电机驱动的旋转变倍机构%Rotary varifocal mechanism driven by ultrasonic motor

    Institute of Scientific and Technical Information of China (English)

    王守印; 冷雪飞; 何锋赟; 贾庆莲; 张春林; 姚志远

    2009-01-01

    A rotary varifocal mechanism driven by ultrasonic motor was designed to remedy the shortcomings of a traditional varifocal mechanism in moving along the axial or radial directions,such as large occupation space, complicated configuration, long time consumption, low control precision, and the lack of selflocking function.This new varifocal mechanism has the advantages of the small space, simple configuration, short time for zoom completed, high control precision of rotating angle, strong repeatability, and selflocking function. The results of 100 shutoff characteristics of repeatability experiments show that the longest and the shortest shutoffs are 0.756 ms and 0.748 ms,respectively, when the average rotation speed is 150 r/min. Therefore, the maximum error of the shutoff time is 0.008 ms, the largest rotating angle error of the rotary varifocal mechanism is 0.432′,and the largest angle error displacement in the imager is less than 0.015 mm.These data can meet the system requirement.%为了弥补传统的沿光轴切向移入移出变倍镜组方式与沿光轴同向移动变倍镜组方式的变倍机构存在占用空间大、机构复杂、变倍时间长、控制精度低以及断电不能自锁等缺点,设计了一种超声电机驱动的光轴旋转方式移入移出的变倍机构.新变倍机构具有占用空间小、机构简单、变倍完成时间短、转角控制精确、可重复性强以及断电自锁等优点.实验结果表明,该变倍机构在100次可重复性关断特性试验中,平均转速为150 r/min,试验得到最长的关断时间为0.756 ms,最短的关断时间为0.748 ms,关断时间最大误差为0.008 ms,旋转变倍机构的最大转角误差为0.432′.最大转角误差在成像面上的偏移量<0.015 mm,其误差在系统所要求的范围内.

  5. Neuroplasticity & Motor Learning

    DEFF Research Database (Denmark)

    Jensen, Jesper Lundbye

    Practice of a new motor task is usually associated with an improvement in performance. Indeed, if we stop practicing and return the next day to the same task, we find that our performance has been maintained and may even be better than it was at the start of the first day. This improvement...... is a measure of our ability to form and store a motor memory of the task. However, the initial memory of the task is labile and may be subject to interference. During and following motor learning plastic changes occur within the central nervous system. On one hand these changes are driven by motor practice......, on the other hand the changes underlie the formation of motor memory and the retention of improved motor performance. During motor learning changes may occur at many different levels within the central nervous system dependent on the type of task and training. Here, we demonstrate different studies from our...

  6. 分布式电驱动汽车 AFS 与电液复合制动集成控制%Integrated Control of Active Front Steering and Motor/Hydraulic Hybrid Braking in Distributed Electric Drive Vehicles

    Institute of Scientific and Technical Information of China (English)

    袁希文; 桂林; 周兵

    2016-01-01

    针对分布式电驱动汽车,以实现车辆主动安全性同时兼顾制动能量回收为目标,提出一种主动前轮转向(AFS)与电液复合制动集成的控制策略.AFS 控制器采用滑模变结构控制,滑移率控制器采用滑模极值搜索算法,基于分层结构(上层为期望制动力矩计算模块,中层为考虑执行器带宽的动态控制分配模块,下层为电机与液压复合执行器),并考虑位置与速率约束.转向制动时,考虑车辆纵向动力学对侧向动力学的影响,引入前轮转角对滑移率控制律进行了修正.在 MATLAB/Simulink 中建立七自由度整车模型,对控制算法进行了验证.结果表明:分离路面直线制动时,所提出的控制策略可以同时保证制动能量回收和制动方向稳定性;转弯制动时,可以更好地跟踪理想横摆角速度,提高了车辆的侧向稳定性.%A new control strategy was proposed by integrating active front steering and electro-hydrau-lic braking in distributed electric drive vehicles to ensure vehicle active safety by taking into account bra-king energy recuperation.The AFS controller was synthesized by means of sliding mode control.The wheel slip controller was designed with a hierarchical control structure.In the upper layer,sliding mode extremum-seeking algorithm was adopted to obtain the desired braking torque,and a dynamic control allo-cator considering different actuators bandwidths was employed to determine the optimal split between the electric and friction brake torque in the middle layer.In the lower layer,a hybrid actuator system consis-ting of the hydraulic brake and the electrical motor was designed on the basis of actuator position and rate constraints.The wheel slip control law was modified by introducing the road wheel angle factor consider-ing the strongly coupled dynamics of steering and braking systems when braking-in-turn.Simulation re-sults obtained with a 7-Do

  7. Dynamic Simulation of a Motor-driven Mini-UAV’s Hand-throwing Process%小型电动无人机手抛过程动力学仿真研究

    Institute of Scientific and Technical Information of China (English)

    张琳; 龚喜盈; 周明

    2015-01-01

    Boundary conditions limits in hand-throwing process of a motor-driven UAV are quite vital to the Mini-UAV’s launching. By constructing motor-driven Mini-UAV simulation platform, including a motor-driven Mini-UAV six degrees of freedom nonlinear dynamic model,flight control system model,engine model,gravity model ,standard atmosphere model,control command model,servo-motor model,hand-throwing initial state model ,cross wind model simulations are carried out in Matlab/simulink to obtain the Mini-UAV’s initial safely launching condition of hand-throwing process. Results demonstrate that boundary conditions provide important reference for safely hand-throwing process.%小型电动无人机手抛阶段,初始状态限制边界条件的确定对于实现无人机的安全发射至关重要。以某小型电动无人机为研究对象,在Matlab/simulink中建立电动无人机仿真平台,其中包含无人机六自由度非线性力学模型、飞行控制系统模型、发动机模型、重力模型、标准大气模型、操纵指令模型、舵机模型、手抛初始状态模型、侧风模型等。通过仿真各种手抛初始状态来分析研究电动无人机手抛阶段安全发射的初始条件。仿真结果表明:限制边界条件的确定为无人机手抛发射提供重要参考依据,在边界条件内即可实现无人机安全发射。

  8. Track guided self-driven container wagon

    NARCIS (Netherlands)

    Hansen, I.A.

    1999-01-01

    The linear motor consists of a series of stator coils (2) located along the Track guided self-driven container wagon Track guided self-driven container wagon track and a reaction rail (3) fitted under the wagon chassis (4).

  9. Road Test Analysis for Interior Noise of Wheel-hub Motor Driven Micro Electric Vehicle%轮毂电机驱动电动微型车车内噪声道路试验分析

    Institute of Scientific and Technical Information of China (English)

    于增亮; 张立军; 孙北

    2009-01-01

    Identification of vibration source,transfer way and main contribution panels are conducted consider-ing the interior noise of four--wheel-hub motor driven vehicle based on road test.Measurement of interior noise and vibration signal is conducted in accelera-ting,regenerative braking and constant speed driving conditions.Combining time domain,frequency do-main and order spectral analysis,and the result shows that the major source of interior noise is the sixth harmonic vibration of wheel-hub motor.The in-fluence of every body panel in different frequency range is also presented,which has reference value for the development of wheel-hub motor driven electric vehicle.%通过道路试验的方法针对四轮轮毂电机驱动电动微型车车内噪声问题进行振源、传递途径以及主要贡献板件识别.分析中分别加速工况、回馈制动工况和匀速行驶工况下车内噪声和结构振动信号进行测量,通过对试验数据时间域、频率域、阶次跟踪分析发现:轮毂电机引起的6阶振动是车身结构振动和车内噪声的振源;不同频率范围内车身各结构板件对车内噪声有不同的影响并进行了相关的分析.试验结果对轮毂电机驱动电动车的进一步开发具有参考价值.

  10. 30 CFR 18.34 - Motors.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Motors. 18.34 Section 18.34 Mineral Resources... PRODUCTS ELECTRIC MOTOR-DRIVEN MINE EQUIPMENT AND ACCESSORIES Construction and Design Requirements § 18.34 Motors. Explosion-proof electric motor assemblies intended for use in approved equipment in...

  11. Visually driven chaining of elementary swim patterns into a goal-directed motor sequence: a virtual reality study of zebrafish prey capture

    Directory of Open Access Journals (Sweden)

    Chintan A Trivedi

    2013-05-01

    Full Text Available Prey capture behavior critically depends on rapid processing of sensory input in order to track, approach and catch the target. When using vision, the nervous system faces the problem of extracting relevant information from a continuous stream of input in order to detect and categorize visible objects as potential prey and to select appropriate motor patterns for approach. For prey capture, many vertebrates exhibit intermittent locomotion, in which discrete motor patterns are chained into a sequence, interrupted by short periods of rest. Here, using high-speed recordings of full-length prey capture sequences performed by freely swimming zebrafish larvae in the presence of a single paramecium, we provide a detailed kinematic analysis of first and subsequent swim bouts during prey capture. Using Fourier analysis, we show that individual swim bouts represent an elementary motor pattern. Changes in orientation are directed towards the target on a graded scale and are implemented by an asymmetric tail bend component superimposed on this basic motor pattern. To further investigate the role of visual feedback on the efficiency and speed of this complex behavior, we developed a closed-loop virtual reality setup in which minimally restrained larvae recapitulated interconnected swim patterns closely resembling those observed during prey capture in freely moving fish. Systematic variation of stimulus properties showed that prey capture is initiated within a narrow range of stimulus size and velocity. Furthermore, variations in the delay and location of swim-triggered visual feedback showed that the reaction time of secondary and later swims is shorter for stimuli that appear within a narrow spatio-temporal window following a swim. This suggests that the larva may generate an expectation of stimulus position, which enables accelerated motor sequencing if the expectation is met by appropriate visual feedback.

  12. Visually driven chaining of elementary swim patterns into a goal-directed motor sequence: a virtual reality study of zebrafish prey capture.

    Science.gov (United States)

    Trivedi, Chintan A; Bollmann, Johann H

    2013-01-01

    Prey capture behavior critically depends on rapid processing of sensory input in order to track, approach, and catch the target. When using vision, the nervous system faces the problem of extracting relevant information from a continuous stream of input in order to detect and categorize visible objects as potential prey and to select appropriate motor patterns for approach. For prey capture, many vertebrates exhibit intermittent locomotion, in which discrete motor patterns are chained into a sequence, interrupted by short periods of rest. Here, using high-speed recordings of full-length prey capture sequences performed by freely swimming zebrafish larvae in the presence of a single paramecium, we provide a detailed kinematic analysis of first and subsequent swim bouts during prey capture. Using Fourier analysis, we show that individual swim bouts represent an elementary motor pattern. Changes in orientation are directed toward the target on a graded scale and are implemented by an asymmetric tail bend component superimposed on this basic motor pattern. To further investigate the role of visual feedback on the efficiency and speed of this complex behavior, we developed a closed-loop virtual reality setup in which minimally restrained larvae recapitulated interconnected swim patterns closely resembling those observed during prey capture in freely moving fish. Systematic variation of stimulus properties showed that prey capture is initiated within a narrow range of stimulus size and velocity. Furthermore, variations in the delay and location of swim triggered visual feedback showed that the reaction time of secondary and later swims is shorter for stimuli that appear within a narrow spatio-temporal window following a swim. This suggests that the larva may generate an expectation of stimulus position, which enables accelerated motor sequencing if the expectation is met by appropriate visual feedback.

  13. Hydraulic Redistribution: A Modeling Perspective

    Science.gov (United States)

    Daly, E.; Verma, P.; Loheide, S. P., III

    2014-12-01

    Roots play a key role in the soil water balance. They extract and transport water for transpiration, which usually represents the most important soil water loss in vegetated areas, and can redistribute soil water, thereby increasing transpiration rates and enhancing root nutrient uptake. We present here a two-dimensional model capable of describing two key aspects of root water uptake: root water compensation and hydraulic redistribution. Root water compensation is the ability of root systems to respond to the reduction of water uptake from areas of the soil with low soil water potential by increasing the water uptake from the roots in soil parts with higher water potential. Hydraulic redistribution is a passive transfer of water through the root system from areas of the soil with greater water potential to areas with lower water potential. Both mechanisms are driven by gradients of water potential in the soil and the roots. The inclusion of root water compensation and hydraulic redistribution in models can be achieved by describing root water uptake as a function of the difference in water potential between soil and root xylem. We use a model comprising the Richards equation for the water flow in variably saturated soils and the Darcy's equation for the water flow in the xylem. The two equations are coupled via a sink term, which is assumed to be proportional to the difference between soil and xylem water potentials. The model is applied in two case studies to describe vertical and horizontal hydraulic redistribution and the interaction between vegetation with different root depths. In the case of horizontal redistribution, the model is used to reproduce the fluxes of water across the root system of a tree subjected to uneven irrigation. This example can be extended to situations when only part of the root system has access to water, such as vegetation near creeks, trees at the edge of forests, and street trees in urban areas. The second case is inspired by recent

  14. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong

    2013-01-01

    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  15. Aircraft Hydraulic Systems Dynamic Analysis

    Science.gov (United States)

    1978-10-01

    4400 PSIG OUTLET PRESSURE ~’f UM5 S1 l .( FIF ~0RV lR 1 .I. AP (c R (V) IFWM) APPROX C ASE !VPý :iI S ReUN N•;MRF.. r p kN i t, isI A! f IN, I:E • ’l...and 1F.GI pump modelo were assumed from data supplied by CECO. 165 _ -- --- - SECTION V HYDRAULIC MOTOR MODEL DEVELOPMENT AND VERIFICATION A fixed...3 70 P.,0 601 ~4 M24.0 3 1p ’, 4 r I 1 1 ISIS 2411 APPENDIX E (CONT.) HSFR TECHNICAL MANUAL (AFAPL-TR-76-43, VOL. IV) 4.15 VANE PU`MP SUBROUTINE 4.15A

  16. Handbook of hydraulic fluid technology

    CERN Document Server

    Totten, George E

    2011-01-01

    ""The Handbook of Hydraulic Fluid Technology"" serves as the foremost resource for designing hydraulic systems and for selecting hydraulic fluids used in engineering applications. Featuring new illustrations, data tables, as well as practical examples, this second edition is updated with essential information on the latest hydraulic fluids and testing methods. The detailed text facilitates unparalleled understanding of the total hydraulic system, including important hardware, fluid properties, and hydraulic lubricants. Written by worldwide experts, the book also offers a rigorous overview of h

  17. Incoherence of the Thrust Force and the Attractive Force of a Single-sided Linear Induction Motor Driven by a Power Source with Multi-Frequency Components

    Science.gov (United States)

    Morizane, Toshimitsu; Iwaki, Kaoru; Kimura, Noriyuki; Taniguchi, Katsunori

    We propose a maglev transportation system that has only the Single-sided Linear Induction Motor (SLIM) without the levitation magnet and a novel control method of the attractive force and thrust force of the SLIM by the power source that has different frequency components. In the proposed system, the total force is the sum of the forces generated by the different frequency components. We verified the incoherent characteristics of the attractive force and thrust force by experiment.

  18. 变频调速异步电机的谐波分析%Analysis of the Harmonic of Inverter-driven Induction Motor

    Institute of Scientific and Technical Information of China (English)

    刘万太; 彭晓; 谢卫才; 李永坚

    2011-01-01

    分析了异步电机在变频电源驱动下的谐波产生基理及对电机运行性能的影响.建立了变频调速系统的仿真模型,并对变频器供电及标准正弦供电时电机的运行性能进行了仿真比较.结果显示,异步电机的电流及转矩在变频器驱动下都出现了明显的脉动.%A theory that the induction motor would produce harmonic under the variable-frequency power is studied in this paper. Furthermore, the influence of the harmonic on the motor operating performance is also analysed. Then the simulation model of the variable frequency speed control is established. The simulation result shows that there is evident pulsation in the current and the torque of the induction motor under the drive of the converter.

  19. Time-Dependent Measure of a Nano-Scale Force-Pulse Driven by the Axonemal Dynein Motors in Individual Live Sperm Cells

    Energy Technology Data Exchange (ETDEWEB)

    Allen, M J; Rudd, R E; McElfresh, M W; Balhorn, R

    2009-04-23

    Nano-scale mechanical forces generated by motor proteins are crucial to normal cellular and organismal functioning. The ability to measure and exploit such forces would be important to developing motile biomimetic nanodevices powered by biological motors for Nanomedicine. Axonemal dynein motors positioned inside the sperm flagellum drive microtubule sliding giving rise to rhythmic beating of the flagellum. This force-generating action makes it possible for the sperm cell to move through viscous media. Here we report new nano-scale information on how the propulsive force is generated by the sperm flagellum and how this force varies over time. Single cell recordings reveal discrete {approx}50 ms pulses oscillating with amplitude 9.8 {+-} 2.6 nN independent of pulse frequency (3.5-19.5 Hz). The average work carried out by each cell is 4.6 x 10{sup -16} J per pulse, equivalent to the hydrolysis of {approx}5,500 ATP molecules. The mechanochemical coupling at each active dynein head is {approx}2.2 pN/ATP, and {approx}3.9 pN per dynein arm, in agreement with previously published values obtained using different methods.

  20. 轮缘驱动式姿控飞轮电机设计%Design of rim-driven attitude control flywheel motor

    Institute of Scientific and Technical Information of China (English)

    王辉; 武俊峰; 吴一辉

    2012-01-01

    为了提高小卫星用姿控飞轮的转动惯量/质量比,实现飞轮调姿系统的轻量化,设计了一种飞轮用永磁无刷直流电机.根据电机磁路,推导了磁钢尺寸与最大磁能积的关系;采用有限元法分析了磁路参数对飞轮性能的影响;针对飞轮电机大气隙、大径长比的结构特点,给出了气隙磁通密度的计算方法;建立了绕组参数与电机额定数据间的关系;仿真分析了电机性能.通过对一台最高转速为6 000 r/min、角动量为5 Nms的飞轮电机样机进行实验验证,得出最大设计误差为6.5%,证明了设计方法的正确性.%To improve the inertia / mass ratio of attitude control flywheel used in small satellite and lighten the weight of flywheel attitude adjustment system,a brushless DC motor used in flywheel was designed. According to the motor magnetic circuit,the corresponding relationship between the size and maximum energy of magnet was derived. The influence of magnetic circuit parameters on the flywheel performance was analyzed by using the Finite Element Method (FEM). For the flywheel structure feature of large equivalent air-gap and large ratio of diameter to length, a method for calculating air-gap magnetic flux density was proposed. The relationship between winding parameters and the motor rated data was established. Simulation method was used to analyze the motor performances. Compared with a flywheel motor with the angular moment of 5 Nms at the highest speed of 6 000 r/min,the maximum error is 6. 5% .which proves the correctness of the design method.

  1. Hydraulics and pneumatics a technician's and engineer's guide

    CERN Document Server

    Parr, Andrew

    2011-01-01

    Nearly all industrial processes require objects to be moved, manipulated or subjected to some sort of force. Such movements and manipulations are frequently accomplished by means of devices driven by liquids (hydraulics) or air (pneumatics), the subject of this book. Hydraulics and Pneumatics is written by a practicing process control engineer as a guide to the successful operation of hydraulic and pneumatic systems for all engineers and technicians working with them. Keeping mathematics and theory to a minimum, this practical guide is thorough but accessible to technicians without a

  2. Research on the induction motor current signature for centrifugal pump at cavitation condition

    Directory of Open Access Journals (Sweden)

    Yin Luo

    2015-11-01

    Full Text Available Cavitation is a major undesirable phenomenon for centrifugal pump because it can cause hydraulic performance deterioration, pump damage by pitting and material erosion, and structural vibration and noise. Cavitation can appear within the entire range of the operating conditions; therefore, it must be prevented by all means. Sensorless monitoring technology based on motor current signature analysis is non-intrusive and economic for monitoring motor-driven equipment. Thus, this technology is suitable for centrifugal pump systems. The motor current signature for centrifugal pump load at the cavitation condition is the basis of this technology. However, systematic research is lacking on sensorless monitoring technology based on motor current signature. As a result, the tentative exploration for motor current signature at cavitation load was conducted in this study. The results show that the stator current is still a sinusoidal alternating current strictly to the law of sine. Moreover, the root mean square of the current fluctuates because of different flow regimes in the cavitation progress and decreases because vapor density is smaller than water density when cavitation is fully formed. For the stator current spectrum, the noise level, noise distribution, rotation speed, and vane pass frequency components show features in the cavitation process. These indicator indexes change according to the stage of cavitation development. Thus, the motor current signature analysis is found to be a feasible and cost-effective method for the stages of cavitation condition.

  3. Geometric Optimization of Hydraulic Rotation Device for Neutron Transmutation Doping

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yongsoo; Kang, Hanok; Park, Kijung; Kim, Seong Hoon; Park, Cheol [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The Korea Atomic Energy Research Institute (KAERI) is developing a Hydraulic Rotation Device (HRD) for NTD facilities (NTDHRD) as a part of the Kijang Research Reactor (KJRR) project. This concept has many advantages when compared to the motor driven method, which is currently used in the HANARO research reactor located at KAERI. The OPAL research reactor located at ANSTO has already applied this method. To achieve a constant rotation speed, which is substantial for uniform doping, with a minimal amount of fluid flow, certain geometric requirements should be satisfied. This paper describes the approach we used while determining the number of impulse jet nozzles used to rotate the NTDHRD at a set number of blades as well as the angle of the nozzles of the NTDHRD. The approach that our group has used to geometrically optimize the design of a NTDHRD was described. The adaptation of this approach allows one to predict the required amount of inlet fluid flow and to determine the number of nozzles based on the rule that it should avoid being a divisor of the number of blades, and provides a reference while determining the tile angle of the nozzles. A CFD analysis will be performed as a future study.

  4. Phase and speed synchronization control of four eccentric rotors driven by induction motors in a linear vibratory feeder with unknown time-varying load torques using adaptive sliding mode control algorithm

    Science.gov (United States)

    Kong, Xiangxi; Zhang, Xueliang; Chen, Xiaozhe; Wen, Bangchun; Wang, Bo

    2016-05-01

    In this paper, phase and speed synchronization control of four eccentric rotors (ERs) driven by induction motors in a linear vibratory feeder with unknown time-varying load torques is studied. Firstly, the electromechanical coupling model of the linear vibratory feeder is established by associating induction motor's model with the dynamic model of the system, which is a typical under actuated model. According to the characteristics of the linear vibratory feeder, the complex control problem of the under actuated electromechanical coupling model converts to phase and speed synchronization control of four ERs. In order to keep the four ERs operating synchronously with zero phase differences, phase and speed synchronization controllers are designed by employing adaptive sliding mode control (ASMC) algorithm via a modified master-slave structure. The stability of the controllers is proved by Lyapunov stability theorem. The proposed controllers are verified by simulation via Matlab/Simulink program and compared with the conventional sliding mode control (SMC) algorithm. The results show the proposed controllers can reject the time-varying load torques effectively and four ERs can operate synchronously with zero phase differences. Moreover, the control performance is better than the conventional SMC algorithm and the chattering phenomenon is attenuated. Furthermore, the effects of reference speed and parametric perturbations are discussed to show the strong robustness of the proposed controllers. Finally, experiments on a simple vibratory test bench are operated by using the proposed controllers and without control, respectively, to validate the effectiveness of the proposed controllers further.

  5. Position-and Velocity- Sensorless Control of Cylindrical Brushless DC Motors Driven by Sinusoidal Current at Low Speed Using Eddy Current

    Science.gov (United States)

    Takashima, Hiroshi; Tomita, Mutuwo; Chen, Zhiqian; Satoh, Mitsuhiko; Doki, Shinji; Okuma, Shigeru

    This paper proposes to paste non-magnetic materials on the rotor surface of a cylindrical brushless DC motor and to use the model including the extended e.m.f. for sensorless control. In the proposed method, the inductance changes depending on the rotor position because of eddy currents, which flow on the non-magnetic material at high frequency. The rotor position can be estimated at standstill and at low speeds. The simulation results show that the proposed method is very useful.

  6. Research on the Driven Head's Elliptic Motion of the V-Shape Linear Ultrasonic Motor%V形直线超声波电动机运动分析和实验

    Institute of Scientific and Technical Information of China (English)

    许海; 李志荣

    2012-01-01

    The V-shape linear ultrasonic motor was large thrust, high efficiency by making full use of the piezoelectric ceramic d33 effect. The author developed this type of prototype, analyzed the motor symmetric and anti-symmetry modal excitation process, and the elliptic movement of driven head in actual work process, and proved the ellipse was inclined. The angle of the inclined ellipse was not only depended on the longitudinal vibration of the Langevin vibrators, but also the installation angle θ. The installation angle d affected the maximum speed and the maximum output thrust of linear ultrasonic motor. This angle should be fully guarantee accuracy in design and installation.%试制了V型直线超声波电动机样机,分析了该电机实际工作状态下对称和反对称模态的激发过程;对实际工作过程中驱动足的椭圆运动进行了分析,得出电机实际工作时驱动足的椭圆运动轨迹为一斜椭圆.斜椭圆的轨迹不仅与两个兰杰文振子的纵向振幅有关还和安装角θ角有关.通过理论分析可知,安装角θ直接影响到电机的最大速度和电机最大输出推力.该角度在设计和安装时应该充分保证精度.

  7. 一种数字伺服驱动的多元电机控制系统设计%Deign of Multi-motor Control System Driven by Digital Servo

    Institute of Scientific and Technical Information of China (English)

    董宇; 王广龙; 陈建辉; 乔中涛

    2013-01-01

    At present, most of the servo control systems feature weak operation capability, and impossible to execute complicated algorithms. To solve these problems, the multi-motor control system driven by digital servo has been designed. The set up of the hardware platform of the system is introduced. With this platform as the foundation, the high-level control software based on Ubuntu Linux operating system is designed. The design concept of the software is presented, and the designs of the variable integral PID algorithm, motor speed control algorithm, motor angle control algorithm are discussed emphatically; and the flowchart of the systematic software is analysed. The experimental result shows that the system runs normally with high reliability and robustness.%针对目前大多数伺服控制系统运算能力较弱、无法执行复杂算法的问题,设计了一种数字伺服驱动的多元电机控制系统.介绍了系统硬件平台的搭建,并以该硬件平台为基础,基于Ubuntu Linux操作系统设计了上层控制软件.对软件设计思想进行了介绍,重点讨论了变速积分PID算法和电机速度控制、角度控制等算法的设计,并对系统的软件流程进行了分析.试验结果表明,系统运行正常,具有较高的可靠性和较好的鲁棒性.

  8. Tuning Multiple Motor Travel Via Single Motor Velocity

    Science.gov (United States)

    Xu, Jing; Shu, Zhanyong; King, Stephen J.; Gross, Steven P.

    2012-01-01

    Microtubule-based molecular motors often work in small groups to transport cargos in cells. A key question in understanding transport (and its regulation in vivo) is to identify the sensitivity of multiple-motor-based motion to various single molecule properties. Whereas both single-motor travel distance and microtubule binding rate have been demonstrated to contribute to cargo travel, the role of single-motor velocity is yet to be explored. Here, we recast a previous theoretical study, and make explicit a potential contribution of velocity to cargo travel. We test this possibility experimentally, and demonstrate a strong negative correlation between single-motor velocity and cargo travel for transport driven by two motors. Our study thus discovers a previously unappreciated role of single-motor velocity in regulating multiple-motor transport. PMID:22672518

  9. FEMA DFIRM Hydraulic Structures

    Data.gov (United States)

    Minnesota Department of Natural Resources — This layer and accompanying attribute table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the...

  10. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on......-going research projects on fluid power and mechatronics based on tap water hydraulic servovalves and linear servo actuators and rotary vane actuators for motion control and power transmission. Development and design a novel water hydraulic rotary vane actuator for robot manipulators. Proposed mathematical...... modelling, control and simulation of a water hydraulic rotary vane actuator applied to power and control a two-links manipulator and evaluate performance. The results include engineering design and test of the proposed simulation models compared with IHA Tampere University’s presentation of research...

  11. Advanced Ultra-High Speed Motor for Drilling

    Energy Technology Data Exchange (ETDEWEB)

    Impact Technologies LLC; University of Texas at Arlington

    2007-03-31

    Three (3) designs have been made for two sizes, 6.91 cm (2.72 inch) and 4.29 cm (1.69 inch) outer diameters, of a patented inverted configured Permanent Magnet Synchronous Machines (PMSM) electric motor specifically for drilling at ultra-high rotational speeds (10,000 rpm) and that can utilize advanced drilling methods. Benefits of these motors are stackable power sections, full control (speed and direction) of downhole motors, flow hydraulics independent of motor operation, application of advanced drilling methods (water jetting and abrasive slurry jetting), and the ability of signal/power electric wires through motor(s). Key features of the final designed motors are: fixed non-rotating shaft with stator coils attached; rotating housing with permanent magnet (PM) rotor attached; bit attached to rotating housing; internal channel(s) in a nonrotating shaft; electric components that are hydrostatically isolated from high internal pressure circulating fluids ('muds') by static metal to metal seals; liquid filled motor with smoothed features for minimized turbulence in the motor during operation; and new inverted coated metal-metal hydrodynamic bearings and seals. PMSM, Induction and Switched Reluctance Machines (SRM), all pulse modulated, were considered, but PMSM were determined to provide the highest power density for the shortest motors. Both radial and axial electric PMSM driven motors were designed with axial designs deemed more rugged for ultra-high speed, drilling applications. The 6.91 cm (2.72 inch) OD axial inverted motor can generate 4.18KW (5.61 Hp) power at 10,000 rpm with a 4 Nm (2.95 ft-lbs) of torque for every 30.48 cm (12 inches) of power section. The 6.91 cm (2.72 inch) OD radial inverted motor can generate 5.03 KW (6.74 Hp) with 4.8 Nm (3.54 ft-lb) torque at 10,000 rpm for every 30.48 cm (12 inches) of power section. The 4.29 cm (1.69 inch) OD radial inverted motor can generate 2.56 KW (3.43 Hp) power with 2.44 Nm (1.8 ft-lb) torque at

  12. Elevator and hydraulics; Elevator to yuatsu

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, I. [Hitachi, Ltd., Tokyo (Japan)

    1994-07-15

    A hydraulic type elevator is installed in relatively lower buildings as compared with a rope type elevator, but the ratio in the number of installation of the former elevator is increasing. This paper explains from its construction and features to especially various control systems for the riding comfort and safety. A direct push-up system with hydraulic jacks arranged beneath a car, and an indirect push-up system that has hydraulic jacks arranged on flank of a car and transmits the movement of a plunger via a rope are available. The latter system eliminates the need of large holes to embed hydraulic jacks. While the speed is controlled by controlling flow rates of high-pressure oil, the speed, position, acceleration and even time differential calculus of the acceleration must be controlled severely. The system uses two-step control for the through-speed and the landing speed. Different systems that have been realized may include compensation for temperatures in flow rate control valves, load pressures, and oil viscosity, from learning control to fuzzy control for psychological effects, or control of inverters in motors. 13 refs., 12 figs., 1 tab.

  13. Valve and Manifold considerations for Efficient Digital Hydraulic Machines

    DEFF Research Database (Denmark)

    Roemer, Daniel Beck; Nørgård, Christian; Bech, Michael Møller

    2016-01-01

    This paper seeks to shed light on the topic of design and sizing of switching valves and connecting manifolds found in large digital hydraulic motors, also known commercially as Digital Displacement Motors. These motors promise very high operation efficiencies with broad operation ranges, which set...... strict requirements to the switching valves and the overall manifold design. To investigate this topic, the largest known digital motor (3.5 megawatt) is studied using models and optimization. Based on the limited information available about this motor, a detailed reconstruction of the motor architecture...... valves when considering also the manifold flow losses. A global optimization is conducted by use of the generalized differential evolution 3 algorithm, where the valve diameters, valve stroke lengths, actuator force capabilities and actuator timing signals are used as design variables. The results...

  14. ENERGY EFFICIENCY OF DIESEL LOCOMOTIVE HYDRAULIC TRANSMISSION TESTS AT LOCOMOTIVE REPAIR PLANT

    Directory of Open Access Journals (Sweden)

    B. E. Bodnar

    2015-10-01

    Full Text Available Purpose. In difficult economic conditions, cost reduction of electricity consumption for the needs of production is an urgent task for the country’s industrial enterprises. Technical specifications of enterprises, which repair diesel locomotive hydraulic transmission, recommend conducting a certain amount of evaluation and regulatory tests to monitor their condition after repair. Experience shows that a significant portion of hydraulic transmission defects is revealed by bench tests. The advantages of bench tests include the ability to detect defects after repair, ease of maintenance of the hydraulic transmission and relatively low labour intensity for eliminating defects. The quality of these tests results in the transmission resource and its efficiency. Improvement of the technology of plant post-repairs hydraulic tests in order to reduce electricity consumption while testing. Methodology. The possible options for hydraulic transmission test bench improvement were analysed. There was proposed an energy efficiency method for diesel locomotive hydraulic transmission testing in locomotive repair plant environment. This is achieved by installing additional drive motor which receives power from the load generator. Findings. Based on the conducted analysis the necessity of improving the plant stand testing of hydraulic transmission was proved. The variants of the stand modernization were examined. The test stand modernization analysis was conducted. Originality. The possibility of using electric power load generator to power the stand electric drive motor or the additional drive motor was theoretically substantiated. Practical value. A variant of hydraulic transmission test stand based on the mutual load method was proposed. Using this method increases the hydraulic transmission load range and power consumption by stand remains unchanged. The additional drive motor will increase the speed of the input shaft that in its turn wil allow testing in

  15. Trend of hydraulic units

    Energy Technology Data Exchange (ETDEWEB)

    Deshimaru, Jun' ichi

    1988-11-01

    The gear, vane and piston pumps occupy a more then 90% share in the hydraulic pumps. Comparatively large pumps are mainly variable delivery piston pumps. The piston pumps are comparatively high in output density (output per unit weight), indicating the hydraulic pump in performance, and tend to become higher and higher in it. Though they are mainly 210 to 350kgf/cm/sup 2/ in rated pressure, some of them come to surpass 400kgf/cm/sup 3/ in it. While the progress in computation also requires the high speed operation, high accuracy and other severe conditions for the hydraulic units, which accordingly and increasingly intensify the requirement for hydraulic oil in abrasion resistibility, oxidation stability and response characteristics. While cavitation comes to easily occur, which considerably and disadvantageously influences hydraulic oil in life through degradation, noise level and respondingness. From now on, the development of high performance oil and study of mechanical structure are important. 19 references, 9 figures, 2 tables.

  16. Chloride-driven electromechanical phase lags at acoustic frequencies are generated by SLC26a5, the outer hair cell motor protein.

    Science.gov (United States)

    Santos-Sacchi, Joseph; Song, Lei

    2014-07-01

    Outer hair cells (OHC) possess voltage-dependent membrane bound molecular motors, identified as the solute carrier protein SLC26a5, that drive somatic motility at acoustic frequencies. The electromotility (eM) of OHCs provides for cochlear amplification, a process that enhances auditory sensitivity by up to three orders of magnitude. In this study, using whole cell voltage clamp and mechanical measurement techniques, we identify disparities between voltage sensing and eM that result from stretched exponential electromechanical behavior of SLC26a5, also known as prestin, for its fast responsiveness. This stretched exponential behavior, which we accurately recapitulate with a new kinetic model, the meno presto model of prestin, influences the protein's responsiveness to chloride binding and provides for delays in eM relative to membrane voltage driving force. The model predicts that in the frequency domain, these delays would result in eM phase lags that we confirm by measuring OHC eM at acoustic frequencies. These lags may contribute to canceling viscous drag, a requirement for many models of cochlear amplification. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  17. Valve and Manifold considerations for Efficient Digital Hydraulic Machines

    DEFF Research Database (Denmark)

    Roemer, Daniel Beck; Nørgård, Christian; Bech, Michael Møller;

    2016-01-01

    This paper seeks to shed light on the topic of design and sizing of switching valves and connecting manifolds found in large digital hydraulic motors, also known commercially as Digital Displacement Motors. These motors promise very high operation efficiencies with broad operation ranges, which set...... valves when considering also the manifold flow losses. A global optimization is conducted by use of the generalized differential evolution 3 algorithm, where the valve diameters, valve stroke lengths, actuator force capabilities and actuator timing signals are used as design variables. The results...

  18. A 6-DOF vibration isolation system for hydraulic hybrid vehicles

    Science.gov (United States)

    Nguyen, The; Elahinia, Mohammad; Olson, Walter W.; Fontaine, Paul

    2006-03-01

    This paper presents the results of vibration isolation analysis for the pump/motor component of hydraulic hybrid vehicles (HHVs). The HHVs are designed to combine gasoline/diesel engine and hydraulic power in order to improve the fuel efficiency and reduce the pollution. Electric hybrid technology is being applied to passenger cars with small and medium engines to improve the fuel economy. However, for heavy duty vehicles such as large SUVs, trucks, and buses, which require more power, the hydraulic hybridization is a more efficient choice. In function, the hydraulic hybrid subsystem improves the fuel efficiency of the vehicle by recovering some of the energy that is otherwise wasted in friction brakes. Since the operation of the main component of HHVs involves with rotating parts and moving fluid, noise and vibration are an issue that affects both passengers (ride comfort) as well as surrounding people (drive-by noise). This study looks into the possibility of reducing the transmitted noise and vibration from the hydraulic subsystem to the vehicle's chassis by using magnetorheological (MR) fluid mounts. To this end, the hydraulic subsystem is modeled as a six degree of freedom (6-DOF) rigid body. A 6-DOF isolation system, consisting of five mounts connected to the pump/motor at five different locations, is modeled and simulated. The mounts are designed by combining regular elastomer components with MR fluids. In the simulation, the real loading and working conditions of the hydraulic subsystem are considered and the effects of both shock and vibration are analyzed. The transmissibility of the isolation system is monitored in a wide range of frequencies. The geometry of the isolation system is considered in order to sustain the weight of the hydraulic system without affecting the design of the chassis and the effectiveness of the vibration isolating ability. The simulation results shows reduction in the transmitted vibration force for different working cycles of

  19. Cavitation in Hydraulic Machinery

    Energy Technology Data Exchange (ETDEWEB)

    Kjeldsen, M.

    1996-11-01

    The main purpose of this doctoral thesis on cavitation in hydraulic machinery is to change focus towards the coupling of non-stationary flow phenomena and cavitation. It is argued that, in addition to turbulence, superimposed sound pressure fluctuations can have a major impact on cavitation and lead to particularly severe erosion. For the design of hydraulic devices this finding may indicate how to further limit the cavitation problems. Chapter 1 reviews cavitation in general in the context of hydraulic machinery, emphasizing the initial cavitation event and the role of the water quality. Chapter 2 discusses the existence of pressure fluctuations for situations common in such machinery. Chapter 3 on cavitation dynamics presents an algorithm for calculating the nucleation of a cavity cluster. Chapter 4 describes the equipment used in this work. 53 refs., 55 figs.,10 tabs.

  20. Hydraulic Robotic Surgical Tool Changing Manipulator.

    Science.gov (United States)

    Pourghodrat, Abolfazl; Nelson, Carl A; Oleynikov, Dmitry

    2017-03-01

    Natural orifice transluminal endoscopic surgery (NOTES) is a surgical technique to perform "scarless" abdominal operations. Robotic technology has been exploited to improve NOTES and circumvent its limitations. Lack of a multitasking platform is a major limitation. Manual tool exchange can be time consuming and may lead to complications such as bleeding. Previous multifunctional manipulator designs use electric motors. These designs are bulky, slow, and expensive. This paper presents design, prototyping, and testing of a hydraulic robotic tool changing manipulator. The manipulator is small, fast, low-cost, and capable of carrying four different types of laparoscopic instruments.

  1. Popeye Project: Hydraulic umbilical

    Energy Technology Data Exchange (ETDEWEB)

    Jordan, K.G.; Williams, V.T.

    1996-12-31

    For the Popeye Project, the longest super-duplex hydraulic umbilical in the world was installed in the Gulf of Mexico. This paper reports on its selection and project implementation. Material selection addresses corrosion in seawater, water-based hydraulic fluid, and methanol. Five alternatives were considered: (1) carbon-steel with traditional coating and anodes, (2) carbon-steel coated with thermally sprayed aluminum, (3) carbon-steel sheathed in aluminum, (4) super-duplex, and (5) titanium. The merits and risks associated with each alternative are discussed. The manufacture and installation of the selected umbilical are also reported.

  2. Three-dimensional Space Mechanics Analysis of Hexapod Robot with Electro-hydraulic Driven%电液驱动六足机器人三维空间力学分析

    Institute of Scientific and Technical Information of China (English)

    程乾; 蒋刚

    2015-01-01

    A 3D model of hexapod robot leg mechanism is built,and the optimization problems of hydraulic design are discussed.Then its mechanics model is established.The output torque characteristics of robot each joint at steady state are obtained through the statics analysis,and the output torque characteristics of robot each joint in the process of movement are obtained by Lagrange method as an approach for the dynamics analysis.Finally,based on the dynamics analysis results,the foot trajectory and leg posture simulations of single leg mechanism are carried out by using ADAMS,and through the results,the smooth movement of the leg mechanism is verified and the theoretical support for the follow-up research is provided.%建立了六足机器人的腿部机构三维空间模型,对其关节液压缸设计优化问题进行了讨论.接着进一步建立了腿部机构力学模型,通过对静力学分析得到了机器人稳定状态时各关节的输出力矩特性,同时采用拉格朗日方法对机器人单腿机构进行了动力学分析,得到了单腿结构在运动过程中各关节的输出力矩特性.最后根据动力学分析结果用ADAMS软件对单腿机构进行了足端轨迹和腿部位姿仿真,仿真结果验证了腿部结构的运动平稳性,为后续研究工作提供了理论支撑.

  3. Internal hydraulics of an agricultural drainage denitrification bioreactor

    Science.gov (United States)

    Denitrification bioreactors to reduce the amount of nitrate-nitrogen in agricultural drainage are now being deployed across the U.S. Midwest. However, there are still many unknowns regarding internal hydraulic-driven processes in these "black box" engineered treatment systems. To improve this unders...

  4. Hydraulic Arm Modeling via Matlab SimHydraulics

    OpenAIRE

    Věchet, Stanislav; Krejsa, Jiří

    2009-01-01

    System modeling is a vital tool for cost reduction and design process speed up in most engineering fields. The paper is focused on modeling of hydraulic arm as a part of intelligent prosthesis project, in the form of 2DOF open kinematic chain. The arm model combines mechanical, hydraulic and electric subsystems and uses Matlab as modeling tool. SimMechanics Matlab extension is used for mechanical part modeling, SimHydraulics toolbox is used for modeling of hydraulic circuit used for actuating...

  5. 49 CFR 571.105 - Standard No. 105; Hydraulic and electric brake systems.

    Science.gov (United States)

    2010-10-01

    ... signal or signals. Electric vehicle or EV means a motor vehicle that is powered by an electric motor... or control signals in an antilock brake system, or a total functional electrical failure in a... 49 Transportation 6 2010-10-01 2010-10-01 false Standard No. 105; Hydraulic and electric...

  6. HYDRAULICS, TUSCARAWAS COUNTY, OHIO, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydraulic procedures for estimating flood discharges for a flood insurance...

  7. Magnetostrictive direct drive motor

    Science.gov (United States)

    Naik, Dipak; Dehoff, P. H.

    1991-01-01

    Highly magnetostrictive materials such as Tb.3Dy.7Fe2, commercially known as TERFENOL-D, have been used to date in a variety of devices such as high power actuators and linear motors. The larger magnetostriction available in twinned single crystal TERFENOL-D, approx. 2000 ppm at moderate magnetic field strengths, makes possible a new generation of magnetomechanical devices. NASA researchers are studying the potential of this material as the basis for a direct microstepping rotary motor with torque densities on the order of industrial hydraulics and five times greater than that of the most efficient, high power electric motors. Such a motor would be a micro-radian stepper, capable of precision movements and self-braking in the power-off state. Innovative mechanical engineering techniques are juxtaposed on proper magnetic circuit design to reduce losses in structural flexures, inertias, thermal expansions, eddy currents, and magneto-mechanical coupling, thus optimizing motor performance and efficiency. Mathematical models are presented, including magnetic, structural, and both linear and nonlinear dynamic calculations and simulations. In addition, test results on prototypes are presented.

  8. Analysis on Discharge Characteristics of the Variable Frequency Electric Motor Pump in Aircraft Hydraulic System%飞机液压系统变频电动泵输出特性分析

    Institute of Scientific and Technical Information of China (English)

    高锋; 夏鹤鸣

    2015-01-01

    Focusing on the discharge pressure and flow control problem of hydraulic pump powered by variable frequency electric power system in aircraft, the pressure control structure with the unload function was modeled and analyzed. Discharge characteristics of the pump under variable frequency were obtained and the feasibility of the variable frequency electric pump was validated.%针对某型飞机采用变频供电系统后液压系统电动泵在大频率范围内工作造成的压力流量控制问题,提出了包含卸荷功能的电动泵压力控制结构,建模并分析了该电动泵输出特性,得到典型供电频率下该电动泵的工作特性,验证了这种变频电动泵调压结构的可行性。

  9. Hydraulic hoist-press

    Energy Technology Data Exchange (ETDEWEB)

    Babayev, Z.B.; Abashev, Z.V.

    1982-01-01

    The efficiency expert of the Angrenskiy production-technological administration of the production association Sredazugol A. V. Bubnov has suggested a hydraulic hoist-press for repairing road equipment which is a device consisting of lifting mechanism, press and test stand for verifying the high pressure hoses and pumps.

  10. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...

  11. Water Treatment Technology - Hydraulics.

    Science.gov (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on hydraulics provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: head loss in pipes in series, function loss in…

  12. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn

    2005-01-01

    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on-going...

  13. Modeling and control for hydraulic transmission of unmanned ground vehicle

    Institute of Scientific and Technical Information of China (English)

    王岩; 张泽; 秦绪情

    2014-01-01

    Variable pump driving variable motor (VPDVM) is the future development trend of the hydraulic transmission of an unmanned ground vehicle (UGV). VPDVM is a dual-input single-output nonlinear system with coupling, which is difficult to control. High pressure automatic variables bang-bang (HABB) was proposed to achieve the desired motor speed. First, the VPDVM nonlinear mathematic model was introduced, then linearized by feedback linearization theory, and the zero-dynamic stability was proved. The HABB control algorithm was proposed for VPDVM, in which the variable motor was controlled by high pressure automatic variables (HA) and the variable pump was controlled by bang-bang. Finally, simulation of VPDVM controlled by HABB was developed. Simulation results demonstrate the HABB can implement the desired motor speed rapidly and has strong robustness against the variations of desired motor speed, load and pump speed.

  14. Optimal Position Control for Motor-driven Shifting Actuator in Electrical AMT%电动AMT选换挡电机执行机构位置最优控制

    Institute of Scientific and Technical Information of China (English)

    高智; 钟再敏; 孙泽昌

    2011-01-01

    Based on the theories of linear quadratic regulator (LQR) control and sliding mode control, a scheme of optimal position control for motor-driven shifting actuator is proposed and is applied to the shifting control of electrical AMT vehicle. The results of simulation and real vehicle tests show that the scheme proposed can effectively reduce the shifting time and power interruption of electrical AMT, enhance its stability, robustness and shifting quality, and finally improve the power performance and ride comfort of vehicle.%基于线性二次型最优控制和滑模控制的理论,提出了一种选换挡电机的位置最优控制方法,并将它应用于电动AMT汽车选换挡电机执行机构的控制上.仿真与实车试验结果都表明,该方法能有效减少电动AMT的换挡时间和动力中断,增强稳定性和鲁棒性,提高换挡品质,最终改善汽车的动力性和舒适性.

  15. 核电厂电动主给水泵调速系统研究及改进%Research and Improvement of the Speed Regulation System of Motor Driven Main Feed Water Pump in Nuclear Power Plant

    Institute of Scientific and Technical Information of China (English)

    张冲; 王旭峰

    2015-01-01

    对核电厂电动主给水泵( APA)的调速系统进行了研究,并针对手动调速模式下给水泵转速调节幅度过大的工程问题进行了研究及验证. 研究及验证采用理论研究结合现场试验的方式. 理论研究主要集中在手动调速和自动调速两个可编程逻辑控制器( PLC)程序,再经过现场的实际操作进行结果验证,最终及时解决了以上问题.%The research on speed regulation system of motor driven main feed water pump in nuclear power plant is conducted, and the engineering problem of excessive adjusting amplitude for the speed in manual operating mode is researched and validated. The way of research and validation is theoretical research combining with field tests;theoretic research is mainly focused on controlling the PLC programs for manual regulation and automatic regulation of the speed, and then the results are validated through practical operation on site, finally above problem is resolved promptly.

  16. A Built-in Electric Cable Winch Driven by DC Motor%一种直流电机驱动的内装式电动电缆绞盘

    Institute of Scientific and Technical Information of China (English)

    杨少琴; 庄衍平

    2014-01-01

    介绍一种新型的直流电动机驱动的内装式电动电缆绞盘,这种电缆绞盘由直流电动机驱动,减速器为活齿减速器结构,把驱动装置和减速机构装在电缆绞盘滚筒里面。整体结构简单、紧凑,传动效率高,广泛应用于移动电源的电缆收放作业。%This paper introduces a new type built-in electric cable winch driven by DC motor .Decelerator structure is oscillating tooth decelerator , make the driving device and reducing mechanism installed in the roller of cable winch .The whole structure is simple and compact .Its transmission efficiency is high and widely used in twis-ted and released of the cable operation of mobile power supply .

  17. Nonlinear, Adaptive and Fault-tolerant Control for Electro-hydraulic Servo Systems

    DEFF Research Database (Denmark)

    Choux, Martin

    Fluid power systems have been in use since 1795 with the rst hydraulic press patented by Joseph Bramah and today form the basis of many industries. Electro hydraulic servo systems are uid power systems controlled in closed-loop. They transform reference input signals into a set of movements...... in hydraulic actuators (cylinders or motors) by the means of hydraulic uid under pressure. With the development of computing power and control techniques during the last few decades, they are used increasingly in many industrial elds which require high actuation forces within limited space. However, despite...... numerous attractive properties, hydraulic systems are always subject to potential leakages in their components, friction variation in their hydraulic actuators and deciency in their sensors. These violations of normal behaviour reduce the system performances and can lead to system failure...

  18. Hydraulic manipulator research at ORNL

    Energy Technology Data Exchange (ETDEWEB)

    Kress, R.L.; Jansen, J.F. [Oak Ridge National Lab., TN (United States); Love, L.J. [Oak Ridge Inst. for Science and Education, TN (United States)

    1997-03-01

    Recently, task requirements have dictated that manipulator payload capacity increase to accommodate greater payloads, greater manipulator length, and larger environmental interaction forces. General tasks such as waste storage tank cleanup and facility dismantlement and decommissioning require manipulator life capacities in the range of hundreds of pounds rather than tens of pounds. To meet the increased payload capacities demanded by present-day tasks, manipulator designers have turned once again to hydraulics as a means of actuation. In order to successfully design, build, and deploy a new hydraulic manipulator (or subsystem), sophisticated modeling, analysis, and control experiments are usually needed. Oak Ridge National Laboratory (ORNL) has a history of projects that incorporate hydraulics technology, including mobile robots, teleoperated manipulators, and full-scale construction equipment. In addition, to support the development and deployment of new hydraulic manipulators, ORNL has outfitted a significant experimental laboratory and has developed the software capability for research into hydraulic manipulators, hydraulic actuators, hydraulic systems, modeling of hydraulic systems, and hydraulic controls. The purpose of this article is to describe the past hydraulic manipulator developments and current hydraulic manipulator research capabilities at ORNL. Included are example experimental results from ORNL`s flexible/prismatic test stand.

  19. Coupling with concentric contact around motor shaft for line start synchronous motor

    Energy Technology Data Exchange (ETDEWEB)

    Melfi, Michael J.; Burdeshaw, Galen E.

    2017-10-03

    A method comprises providing a line-start synchronous motor. The motor has a stator, a rotor core disposed within the stator, and a motor shaft. In accordance with a step of the method, a coupling for coupling a load to the motor is provided. The coupling has a motor shaft attachment portion configured to provide substantially concentric contact around the shaft at the end of the motor shaft. The coupling has a load attachment portion configured to operatively connect to a load. In accordance with a step of the method, a load is coupled to the motor with the coupling, and driven from start to at least near synchronous speed during steady state operation of the motor with a load coupled thereto. The motor shaft attachment portion may comprise a bushing assembly with matching and opposed tapered surfaces that cooperate to secure the motor shaft attachment portion around the motor shaft.

  20. Wind tunnel experiments to prove a hydraulic passive rotor speed control concept for variable speed wind turbines (poster)

    NARCIS (Netherlands)

    Diepeveen, N.F.B.; Jarquin Laguna, A.

    2012-01-01

    As alternative to geared and direct drive solutions, fluid power drive trains are being developed by several institutions around the world. The common configuration is where the wind turbine rotor is coupled to a hydraulic pump. The pump is connected through a high pressure line to a hydraulic motor

  1. Remotely Adjustable Hydraulic Pump

    Science.gov (United States)

    Kouns, H. H.; Gardner, L. D.

    1987-01-01

    Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

  2. 望远镜双电机驱动消齿隙的动力学设计%Anti-backlash Research of Telescopes Driven by Dual-bias Motors Using Dynamic Method

    Institute of Scientific and Technical Information of China (English)

    冯锦平; 马文礼; 黄金龙

    2009-01-01

    The backlash of gear influences the pointing accuracy and tracking accuracy. Backlash could be eliminated by applying bias torque in multi-motor driving system. Dual bias driving system was taken as research objective. The mathematics model of dynamics was established, and many nonlinear factors which might affect the dynamic behavior were considered including gear backlash, stiffness of the gear train, random wind disturbing and cogging torque of motors. Minimum of bias torque was taken as the objective function. The driving gear and driven gear didn't separate during work, which was taken as the bound for objective function. Moreover, the optimum bias torque under every driving torque at full range of speed was calculated. The changing rules of the optimum bias torque charged by each gear train parameter including inertia, stiffness and damping were analyzed and achieved.%齿侧间隙会影响齿轮传动式望远镜的指向和跟踪精度.采用多电机驱动,通过施加偏置力矩能消除齿隙影响.以双电机驱动为例,建立动力学的数学模型,考虑齿隙非线性,齿轮传动链刚度的周期时变性,随机风扰力矩以及电机齿槽力矩的作用,以最小化偏置力矩为目标函数,齿轮不脱离啮合为约束条件,进行优化设计,获得了各驱动力矩下,全速度范围内的最优偏置力矩,并分析了传动系统的转动惯量,刚度及阻尼等参数,对偏置力矩设计的影响,得到了偏置力矩的变化规律.

  3. Undular Hydraulic Jump

    Directory of Open Access Journals (Sweden)

    Oscar Castro-Orgaz

    2015-04-01

    Full Text Available The transition from subcritical to supercritical flow when the inflow Froude number Fo is close to unity appears in the form of steady state waves called undular hydraulic jump. The characterization of the undular hydraulic jump is complex due to the existence of a non-hydrostatic pressure distribution that invalidates the gradually-varied flow theory, and supercritical shock waves. The objective of this work is to present a mathematical model for the undular hydraulic jump obtained from an approximate integration of the Reynolds equations for turbulent flow assuming that the Reynolds number R is high. Simple analytical solutions are presented to reveal the physics of the theory, and a numerical model is used to integrate the complete equations. The limit of application of the theory is discussed using a wave breaking condition for the inception of a surface roller. The validity of the mathematical predictions is critically assessed using physical data, thereby revealing aspects on which more research is needed

  4. Advanced motor-controller development

    Science.gov (United States)

    Lesster, L. E.; Zeitlin, D. B.; Hall, W. B.

    1983-06-01

    The purpose of this development program was to investigate a promising alternative technique for control of a squirrel cage induction motor for subsea propulsion or hydraulic power applications. The technique uses microprocessor based generation of the pulse width modulation waveforms, which in turn permits use of a true integral volt-second pulse width control for the generation of low harmonic content sine waves from a 3 phase Graetz transistor power bridge.

  5. Experimental evaluation of control strategies for hydraulic servo robot

    DEFF Research Database (Denmark)

    Bech, Michael Møller; Andersen, Torben Ole; Pedersen, Henrik C.

    2013-01-01

    In this paper different linear and non-linear controllers applied to a hydraulically driven servo robot are evaluated and validated. The task is to make the actuators of the manipulator track a position reference with minimum error. Hydraulic systems are intrinsically non-linear and using linear...... control techniques typically results in conservatively dimensioned controllers to obtain stable performance. Non-linear control techniques have the potential of overcoming these problems and in this paper the focus is on applying simple nonlinear robust and adaptive controllers feasible for implementation...... in industrial servo drives. The different controllers are compared and evaluated from simulation and experimental results....

  6. PWM Control of Directly-driven Permanent Magnet Synchronous Wind Turbines in Motor Side%直驱式永磁同步风电机组机侧PWM控制

    Institute of Scientific and Technical Information of China (English)

    孙延昭; 黄守道; 黄科元; 佘峰

    2009-01-01

    在介绍永磁同步发电机(PMSG)d,q轴数学模型和矢量控制理论基础上,提出在直驱式永磁同步风电系统机侧采用PWM控制方式,通过转子磁场定向控制策略.实现有功无功功率解耦控制,减小了损耗,并且较好地控制了转速.利用Matlab/Simulink进行仿真,并给出了仿真结果.同时搭建了基于TMS320F2808控制器的试验平台,对该控制策略进行了实验,实验结果验证了该控制系统的正确性与可行性.%The PWM control strategy of directly-driven permanent magnet synchronous wind turbine sys-tem in motor-side was presented,which based on the dq-axis mathematical model of PMSG and the vector con-trol theory, by using the strategy of rotor field oriented, the active power and reactive power can be deeoupled, while the loss can be decreased, and the rotor speed is controlled very well. Matlab/Simulink was carried out to prove the validity of the system, and the simulating results was given. An experimental system based on TMS320F2808 was set up to verify the validity and the feasibility.

  7. Design of Motor-Driven Load Simulator Based on Improved Compensation Control Strategy%基于改进补偿控制策略的电动负载模拟器设计

    Institute of Scientific and Technical Information of China (English)

    李瑞; 王明艳; 张奥扬

    2013-01-01

      负载模拟器可以模拟飞行器飞行过程中受到的空气力矩,是重要的半实物仿真设备之一。针对电动负载模拟器存在的多余力矩,且严重影响了加载精度和系统的稳定性,通过在加载系统的基本结构和原理上,对加载系统进行建模,分析常规补偿法的局限性,提出改进的补偿方法,并用复合控制策略来设计控制系统。仿真结果表明,此方法能够大幅度消除多余力矩,且在工程中有一定的可行性。%Load simulator is an important equipment in hardware-in-the-loop simulation, which can simulate the air torque during aircraft flight. The extra torque existing in the motor-driven load simulator influenced the load precision and system stability. The model of load system is built based on the basic structure and principle of load system, the limitations of the conventional compensation method are analyzed, and the improved compensation method is proposed. The control system is designed by compound control strategy. The simulation results show that the method can greatly reduce the extra torque and can be used in the engineering.

  8. Design Analysis and Experiment of High Speed CNC Machine Tool Feed System Driven by Liner Motor%直驱型高速数控机床进给系统设计分析及实验∗

    Institute of Scientific and Technical Information of China (English)

    万莉平; 张军; 郑天池; 鞠家全; 郭永海; 邱自学

    2015-01-01

    In order to overcome the problems of traditional feed drive way composed by spin motor com-bined with ball screw in machine tool, such as high elastic deformation, slow response speed and easy to wear , a high speed CNC machine tool feed system driven by liner motor was designed using permanent mag-net linear synchronous motor ( PMSM) . The influence of mechanical structure on the dynamic characteris-tics was analyzed theoretically. On the basis of this, the stiffness, strength and modal analysis of the main structure of the system were made under the working condition of the maximum cutting force. Finally, the position precision and dynamic balance precision of the feed system were tested. The results show that the deformation of the system structure is less than 0. 01 mm and the maximum stress is 5. 7MPa. And in low frequency range, a high anti vibration characteristics of the feed system can be obtained by avoiding 1, 2, 5, 6 order processing excitation frequency. At the same time, the system position precision and balance pre-cision both meet the design index, and dynamic precision and stability of main structure of the feed system are guaranteed effectively.%为克服传统机床“旋转电机+滚珠丝杠”进给传动方式存在的弹性变形大、响应速度慢、易磨损等问题,利用永磁直线同步电机( PMLSM)设计了一种直线电机驱动高速数控机床进给系统。从理论上分析了系统机械结构对动态特性的影响,在此基础上,对最大切削力工况下的进给系统主体结构进行了刚度、强度以及模态分析,最后,实验测试了进给系统的位置精度及动平衡精度。结果表明,该进给系统结构变形量小于0.01mm,最大应力为5.7MPa,且在低阶频率范围内,主动避开1、2、5、6阶加工激振频率可使进给系统具有较高的抗振特性,同时该系统的位置精度、平衡精度均在设计指标内,有效的保证了进给系统主体结构的动态精度及稳定性。

  9. Bio-inspired novel design principles for artificial molecular motors.

    Science.gov (United States)

    Hugel, Thorsten; Lumme, Christina

    2010-10-01

    Since we have learned that biological organisms like ourselves are driven by tiny biological molecular motors we try to design and produce artificial molecular motors. However, despite the huge efforts since decades, man-made artificial molecular motors are still far from biological molecular motors or macroscopic motors with regard to performance, especially with respect to energy efficiency. This review highlights recent progress towards artificial molecular motors and discusses how their design and development can be guided by the design concepts of biological molecular motors or macroscopic motors.

  10. Hydraulic refinement of an intraarterial microaxial blood pump.

    Science.gov (United States)

    Siess, T; Reul, H; Rau, G

    1995-05-01

    Intravascularly operating microaxial pumps have been introduced clinically proving to be useful tools for cardiac assist. However, a number of complications have been reported in literature associated with the extra-corporeal motor and the flexible drive shaft cable. In this paper, a new pump concept is presented which has been mechanically and hydraulically refined during the developing process. The drive shaft cable has been replaced by a proximally integrated micro electric motor and an extra-corporeal power supply. The conduit between pump and power supply consists of only an electrical power cable within the catheter resulting in a device which is indifferent to kinking and small curvature radii. Anticipated insertion difficulties, as a result of a large outer pump diameter, led to a two-step approach with an initial 6,4mm pump version and a secondary 5,4mm version. Both pumps meet the hydraulic requirement of at least 2.5l/min at a differential pressure of 80-100 mmHg. The hydraulic refinements necessary to achieve the anticipated goal are based on ongoing hydrodynamic studies of the flow inside the pumps. Flow visualization on a 10:1 scale model as well as on 1:1 scale pumps have yielded significant improvements in the overall hydraulic performance of the pumps. One example of this iterative developing process by means of geometrical changes on the basis of flow visualization is illustrated for the 6.4mm pump.

  11. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik

    1997-01-01

    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...... of the laws of physics on the system. The unknown (or uncertain) parameters are estimated with Maximum Likelihood (ML) parameter estimation. The identified model has been evaluated by comparing the measurements with simulation of the model. The identified model was much more capable of describing the dynamics...... of the system than the deterministic model....

  12. Hydraulic mining method

    Science.gov (United States)

    Huffman, Lester H.; Knoke, Gerald S.

    1985-08-20

    A method of hydraulically mining an underground pitched mineral vein comprising drilling a vertical borehole through the earth's lithosphere into the vein and drilling a slant borehole along the footwall of the vein to intersect the vertical borehole. Material is removed from the mineral vein by directing a high pressure water jet thereagainst. The resulting slurry of mineral fragments and water flows along the slant borehole into the lower end of the vertical borehole from where it is pumped upwardly through the vertical borehole to the surface.

  13. Spinning hydraulic jump

    Science.gov (United States)

    Abderrahmane, Hamid; Kasimov, Aslan

    2013-11-01

    We report an experimental observation of a new symmetry breaking of circular hydraulic jump into a self-organized structure that consists of a spinning polygonal jump and logarithmic-spiral waves of fluid elevation downstream. The waves are strikingly similar to spiral density waves in galaxies. The fluid flow exhibits counterparts of salient morphological features of galactic flows, in particular the outflow from the center, jets, circum-nuclear rings, gas inflows toward the galactic center, and vortices. The hydrodynamic instability revealed here may have a counterpart that plays a role in the formation and sustainability of spiral arms in galaxies.

  14. 46 CFR 28.880 - Hydraulic equipment.

    Science.gov (United States)

    2010-10-01

    ... hydraulic equipment and the adjacent work area. Protection shall be afforded to the operator of hydraulic... 46 Shipping 1 2010-10-01 2010-10-01 false Hydraulic equipment. 28.880 Section 28.880 Shipping... INDUSTRY VESSELS Aleutian Trade Act Vessels § 28.880 Hydraulic equipment. (a) Each hydraulic system must...

  15. Applied hydraulic transients

    CERN Document Server

    Chaudhry, M Hanif

    2014-01-01

    This book covers hydraulic transients in a comprehensive and systematic manner from introduction to advanced level and presents various methods of analysis for computer solution. The field of application of the book is very broad and diverse and covers areas such as hydroelectric projects, pumped storage schemes, water-supply systems, cooling-water systems, oil pipelines and industrial piping systems. Strong emphasis is given to practical applications, including several case studies, problems of applied nature, and design criteria. This will help design engineers and introduce students to real-life projects. This book also: ·         Presents modern methods of analysis suitable for computer analysis, such as the method of characteristics, explicit and implicit finite-difference methods and matrix methods ·         Includes case studies of actual projects ·         Provides extensive and complete treatment of governed hydraulic turbines ·         Presents design charts, desi...

  16. Motor Neurons

    DEFF Research Database (Denmark)

    Hounsgaard, Jorn

    2017-01-01

    Motor neurons translate synaptic input from widely distributed premotor networks into patterns of action potentials that orchestrate motor unit force and motor behavior. Intercalated between the CNS and muscles, motor neurons add to and adjust the final motor command. The identity and functional...... properties of this facility in the path from synaptic sites to the motor axon is reviewed with emphasis on voltage sensitive ion channels and regulatory metabotropic transmitter pathways. The catalog of the intrinsic response properties, their underlying mechanisms, and regulation obtained from motoneurons...... in in vitro preparations is far from complete. Nevertheless, a foundation has been provided for pursuing functional significance of intrinsic response properties in motoneurons in vivo during motor behavior at levels from molecules to systems....

  17. Distributed Stepping Motor Control System

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The beam diagnostic devices used at RIBLL are driven by stepper motors, which are controlled by I/O modules based on ISA-bus in an industrial computer. The disadvantages of such mode are that a large number of long cables are used and one computer to control is unsafe. We have developed a distributed stepping motor control system for the remote, local and centralized control of the stepping motors. RS-485 bus is used for the connection between the remote control unit and the local control units. The con...

  18. Molecular motor transport through hollow nanowires

    DEFF Research Database (Denmark)

    Lard, Mercy; Ten Siethoff, Lasse; Generosi, Johanna;

    2014-01-01

    Biomolecular motors offer self-propelled, directed transport in designed microscale networks and can potentially replace pump-driven nanofluidics. However, in existing systems, transportation is limited to the two-dimensional plane. Here we demonstrate fully one-dimensional (1D) myosin-driven mot......Biomolecular motors offer self-propelled, directed transport in designed microscale networks and can potentially replace pump-driven nanofluidics. However, in existing systems, transportation is limited to the two-dimensional plane. Here we demonstrate fully one-dimensional (1D) myosin......-driven motion of fluorescent probes (actin filaments) through 80 nm wide, Al2O 3 hollow nanowires of micrometer length. The motor-driven transport is orders of magnitude faster than would be possible by passive diffusion. The system represents a necessary element for advanced devices based on gliding assays...

  19. 远洋船用伸缩折叠起重机液压系统设计%Marine telescopic folding crane hydraulic system design

    Institute of Scientific and Technical Information of China (English)

    卢志珍; 倪学虎; 舒希勇; 王成龙

    2012-01-01

    在分析伸缩折叠起重机对液压系统要求的基础上,针对起重机技术参数及客户要求提出了液压系统设计的思路.对关键液压元件——液压泵、液压马达、液压缸进行了计算选型,设计了液压原理图,并阐述了起重机液压回路的工作原理.%Based on the analysis of telescopic folding crane hydraulic system requirements,put forward the hydraulic system design thinking according to crane technical parameters and requirements of customers. Calculation and type selection of the key hydraulic components------hydraulic pump and hydraulic motor, hydraulic cylinder, design hydraulic principle diagram and expoundscrane hydraulic loop principle of work.

  20. Construction of a Measurement and Control System for a Sawyer Motor-driven Planar Motion Stage%一种Sawyer马达驱动二维运动平台测量和控制系统设计

    Institute of Scientific and Technical Information of China (English)

    TANO M; 高伟; DIAN S Y; KIYONO S; TOMITA Y; MAKINO K; MOTITA H

    2006-01-01

    This paper describes a precision positioning system combined with a Sawyer motor-driven stage and a surface encoder. The stage consists of a platen and forcers ( linear pulse motors). The platen is a passive steel plate with teeth over the surface. Each of the forcers, which is levitated on the platen as stage moving element by air-bearing, is composed of a permanent magnet and two driving coils to generate X-directional and Y-directional thrust forces against the platen for driving the stage. A surface encoder is constructed for measurement and control of the stage movement. A sine-grid is mounted on the platen and a sensor-unit is mounted on the stage moving element. There are three optical sensors in the sensor unit for measurement of the X-and Y-positions at three separate points. The θz displacement of the stage can be calculated from the sensor outputs. A feedback control system is developed for controlling the movement of the stage. Measurement and feedback control experiments are carried out to verify the feasibility of the precision positioning system.%介绍一种使用Sawyer马达驱动的平台和表面编码器组成的精密定位系统.该平台包括一个台板和若干线性脉冲马达推动器.台板由防腐钢板制成,在其表面加工了齿牙.线性脉冲马达推动器靠空气支承悬浮在台板上,用以驱动平台.每一驱动器均由一个永久磁铁和两个驱动线圈组成,用以产生X向和Y向的平台驱动力.设计了一种表面编码器用以测量和控制平台的运动.一个正弦格栅装在台板上,一个传感组件装在平台驱动器上.在该传感组件中有三个光学传感器,用以测量三个分离点上的X和Y方向的位置,平台的θz向位置可以从传感器输出求得.开发了一种反馈控制系统用以控制平台运动.测量和反馈控制实验证明了该精密系统的可行性.

  1. Powered orthosis and attachable power-assist device with Hydraulic Bilateral Servo System.

    Science.gov (United States)

    Ohnishi, Kengo; Saito, Yukio; Oshima, Toru; Higashihara, Takanori

    2013-01-01

    This paper discusses the developments and control strategies of exoskeleton-type robot systems for the application of an upper limb powered orthosis and an attachable power-assist device for care-givers. Hydraulic Bilateral Servo System, which consist of a computer controlled motor, parallel connected hydraulic actuators, position sensors, and pressure sensors, are installed in the system to derive the joint motion of the exoskeleton arm. The types of hydraulic component structure and the control strategy are discussed in relation to the design philosophy and target joints motions.

  2. Hydraulic rams; a comparative investigation

    NARCIS (Netherlands)

    Tacke, J.H.P.M.

    1988-01-01

    A mathematical model describing the essential features of hydraulic ram operation is developed in order to clarify the possibilities and limitations of the ram relative to its site and its adjustments. The model distinguishes three different periods in the pumping cycle of the hydraulic ram: acceler

  3. Hydraulics. FOS: Fundamentals of Service.

    Science.gov (United States)

    John Deere Co., Moline, IL.

    This manual on hydraulics is one of a series of power mechanics texts and visual aids for training in the servicing of agricultural and industrial machinery. Focus is on oil hydraulics. Materials provide basic information and illustrations for use by vocational students and teachers as well as shop servicemen and laymen. The twelve chapters focus…

  4. RECONSTRUCTION OF EXISTING LIVESTOCK FEED PRODUCTION PLANTS BY ADDING A HYDRAULIC ADDER

    Directory of Open Access Journals (Sweden)

    D. Kiš

    2007-06-01

    Full Text Available Recipes determine the quality of livestock feed and the hydraulic adders are one of the elements determining if the given recipe will be carried out. Generally, construction of existing adders does not allow accomplishment of that aim i.e. they do not meet recipe requirements. Consequently, researches which determined deviations in ingredient adding present with existing adders and with the experimental hydraulic adder were conducted. The research was conducted for two years (2005 and 2006 in two livestock feed factories in the Republic of Croatia on samples of feed mixtures for pigs weighing up to 15 and 25 kilos. Relative error was the means for comparison of weighing deviations between the hydraulic adder and the adders powered by means of an electric motor. Research results indicate that none of the two observed livestock feed production plants in 30 repetitions for two kinds of feed mixture showed a feed mixture weighing that would correspond to the specifications in the recipe. Additionally, hydraulic adders showed a greater precision in adding fish meal, extruded soybean and soybean meal when compared with the adders powered by means of an electric motor. However, the adders powered by means of an electric motor showed greater precision in adding corn. Based on the research results it can be concluded that using hydraulic adders instead of the adders powered by means of an electric motor will result in more accuracy in dosing ingredients with fine and middle granularity, whereas this can not be applied to dosing coarse grained ingredients.

  5. Hydraulic Stability of Accropode Armour

    DEFF Research Database (Denmark)

    Jensen, T.; Burcharth, H. F.; Frigaard, Peter

    , and to assess the influence of core permeability on the hydraulic stability of Accropodes. Two structures were examined, one with a relatively permeable core and one with a relatively impermeable core. In November/December 1995, Ph.D.-student Marten Christensen carried out the model tests on the structure...... with permeable core (crushed granite with a gradation of 5-8 mm). The outcome of this study is described in "Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers" by Christensen & Burcharth (1995). In January/February 1996, Research Assistant Thomas Jensen carried out a similar study......The present report describes the hydraulic model tests of Accropode armour layers carried out at the Hydraulics Laboratory at Aalborg University from November 1995 through March 1996. The objective of the model tests was to investigate the hydraulic stability of Accropode armour layers...

  6. Hydraulic Stability of Accropode Armour

    DEFF Research Database (Denmark)

    Jensen, T.; Burcharth, H. F.; Frigaard, Peter

    , and to assess the influence of core permeability on the hydraulic stability of Accropodes. Two structures were examined, one with a relatively permeable core and one with a relatively impermeable core. In November/December 1995, Ph.D.-student Marten Christensen carried out the model tests on the structure...... with permeable core (crushed granite with a gradation of 5-8 mm). The outcome of this study is described in "Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers" by Christensen & Burcharth (1995). In January/February 1996, Research Assistant Thomas Jensen carried out a similar study......The present report describes the hydraulic model tests of Accropode armour layers carried out at the Hydraulics Laboratory at Aalborg University from November 1995 through March 1996. The objective of the model tests was to investigate the hydraulic stability of Accropode armour layers...

  7. Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Mørkholt, M.

    As wind turbines increase in size, combined with increased lifetime demands, new methods for load reduction needs to be examined. One method is to make the yaw system of the turbine soft/flexible and hereby dampen the loads to the system, which is the focus of the current paper. By utilizing...... the HAWC2 aeroelastic code and an extended model of the NREL 5MW turbine combined with a simplified linear model of the turbine, the parameters of the soft yaw system are optimized to reduce loading in critical components. Results shows that a significant reduction in fatigue and extreme loads to the yaw...... system and rotor shaft when utilizing the soft yaw drive concept compared to the original stiff yaw system. The physical demands of the hydraulic yaw system are furthermore examined for a life time of 20 years. Based on the extrapolated loads, the duty cycles show that it is possible to construct...

  8. Electro Hydraulic Hitch Control

    DEFF Research Database (Denmark)

    Hansen, M. R.; Andersen, T. O.; Nielsen, B.

    2003-01-01

    system for agricultural applications and driving for transportation. During tranport phases, the lack of suspension causes the vehicle to bounce and pitch, and makes it difficalt to control. Many systems have been proposed to cope with the oscillatory behavior, and different solutions exist. Common......This paper present and discusses R&D results on electro hydraulic hitch control for off-road vehicle, in particular active damping of oscillation occuring on tractors. The research deals with analysis and control of the oscillations occuring on tractors which are design without any susspection...... for most of the systems are that they operate on the hydrailc actuators generally providing the motive forces for moving the implement and/or attachment, typically a plough. The basic idea and physical working principle are to use the implement, moveable relative to the vehicle, as a damper mass. The paper...

  9. Linear Perturbation Adaptive Control of Hydraulically Driven Manipulators

    DEFF Research Database (Denmark)

    Andersen, T.O.; Hansen, M.R.; Conrad, Finn

    2004-01-01

    control.Using the Lyapunov approach, under slowly time-varying assumptions, it is shown that the tracking error and the parameter error remain bounded. This bound is a function of the ideal parameters and a bounded disturbance. The control algorithm decouples and linearizes the manipulator so that each...

  10. Motor syndromes.

    Science.gov (United States)

    Corea, Francesco; Micheli, Sara

    2012-01-01

    Motor disturbances alone or associated with other focal deficits are the most common symptoms suggesting a neurovascular event. An appropriate clinical assessment of these signs and symptoms may help physicians to better diagnose and to both better treat and predict outcome. In this paper the main clinical features of motor deficit are described together with other motor-related events such as ataxia and movement disturbances.

  11. Hydraulic conductivity of compacted zeolites.

    Science.gov (United States)

    Oren, A Hakan; Ozdamar, Tuğçe

    2013-06-01

    Hydraulic conductivities of compacted zeolites were investigated as a function of compaction water content and zeolite particle size. Initially, the compaction characteristics of zeolites were determined. The compaction test results showed that maximum dry unit weight (γ(dmax)) of fine zeolite was greater than that of granular zeolites. The γ(dmax) of compacted zeolites was between 1.01 and 1.17 Mg m(-3) and optimum water content (w(opt)) was between 38% and 53%. Regardless of zeolite particle size, compacted zeolites had low γ(dmax) and high w(opt) when compared with compacted natural soils. Then, hydraulic conductivity tests were run on compacted zeolites. The hydraulic conductivity values were within the range of 2.0 × 10(-3) cm s(-1) to 1.1 × 10(-7) cm s(-1). Hydraulic conductivity of all compacted zeolites decreased almost 50 times as the water content increased. It is noteworthy that hydraulic conductivity of compacted zeolite was strongly dependent on the zeolite particle size. The hydraulic conductivity decreased almost three orders of magnitude up to 39% fine content; then, it remained almost unchanged beyond 39%. Only one report was found in the literature on the hydraulic conductivity of compacted zeolite, which is in agreement with the findings of this study.

  12. Hydraulic Actuators with Autonomous Hydraulic Supply for the Mainline Aircrafts

    Directory of Open Access Journals (Sweden)

    I. S. Shumilov

    2014-01-01

    Full Text Available Applied in the aircraft control systems, hydraulic servo actuators with autonomous hydraulic supply, so-called, hydraulic actuators of integrated configuration, i.e. combination of a source of hydraulic power and its load in the single unit, are aimed at increasing control system reliability both owing to elimination of the pipelines connecting the actuator to the hydraulic supply source, and owing to avoidance of influence of other loads failure on the actuator operability. Their purpose is also to raise control system survivability by eliminating the long pipeline communications and their replacing for the electro-conductive power supply system, thus reducing the vulnerability of systems. The main reason for a delayed application of the hydraulic actuators in the cutting-edge aircrafts was that such aircrafts require hydraulic actuators of considerably higher power with considerable heat releases, which caused an unacceptable overheat of the hydraulic actuators. Positive and negative sides of the hydraulic actuators, their alternative options of increased reliability and survivability, local hydraulic systems as an advanced alternative to independent hydraulic actuators are considered.Now to use hydraulic actuators in mainline aircrafts is inexpedient since there are the unfairly large number of the problems reducing, first and last, safety of flights, with no essential weight and operational advantages. Still works to create competitive hydraulic actuators ought to be continued.Application of local hydraulic systems (LHS will allow us to reduce length of pressure head and drain pipelines and mass of pipelines, as well as to raise their general fail-safety and survivability. Application of the LHS principle will allow us to use a majority of steering drive advantages. It is necessary to allocate especially the following:- ease of meeting requirements for the non-local spread of the engine weight;- essentially reducing length and weight of

  13. Hydraulic conductivity of organomodified soil

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, R.B.; Grant, J.M.; Voice, T.C.; Rakhshandehroo, G.; Xu, S.; Boyd, S.A. [Michigan State Univ., East Lansing, MI (United States)

    1995-11-01

    The effects of organomodification on soil hydraulic conductivity were investigated. Hydraulic conductivity and porosity of treated and untreated samples of a sandy loam were measured as a function of effective stress. Batch treatment with hexadecyltrimethyl ammonium (HDTMA) and dry packing produced organomodified samples that were 79% less conducive than untreated samples prior to loading. Treated samples lost less hydraulic conductivity as a result of loading than untreated samples so that treated samples had higher conductivity at high loads. Observed differences in conductivity are explained in terms of the role of the treated and untreated clay in controlling initial effective pore size and its change during consolidation.

  14. Influence of direct motor-motor interaction in models for cargo transport by a single team of motors

    CERN Document Server

    Bouzat, Sebastian; 10.1088/1478-3975/7/4/046009

    2010-01-01

    We analyze theoretically the effects of excluded-volume interactions between motors on the dynamics of a cargo driven by multiple motors. The model considered shares many commons with other recently proposed in the literature, with the addition of direct interaction between motors and motor back steps. The cargo is assumed to follow a continuum Langevin dynamics, while individual motors evolve following a Monte Carlo algorithm based on experimentally accessible probabilities for discrete forward and backward jumps, and attachment and detachment rates. The links between cargo and motors are considered as non linear springs. By means of numerical simulations we compute the relevant quantities characterizing the dynamical properties of the system, and we compare the results to those for non interacting motors. We find that interactions lead to quite relevant changes in the force-velocity relation for cargo, with a considerable reduction of the stall force, and cause also a notable decrease of the run length. The...

  15. Investigation of hydraulic transmission noise sources

    Science.gov (United States)

    Klop, Richard J.

    Advanced hydrostatic transmissions and hydraulic hybrids show potential in new market segments such as commercial vehicles and passenger cars. Such new applications regard low noise generation as a high priority, thus, demanding new quiet hydrostatic transmission designs. In this thesis, the aim is to investigate noise sources of hydrostatic transmissions to discover strategies for designing compact and quiet solutions. A model has been developed to capture the interaction of a pump and motor working in a hydrostatic transmission and to predict overall noise sources. This model allows a designer to compare noise sources for various configurations and to design compact and inherently quiet solutions. The model describes dynamics of the system by coupling lumped parameter pump and motor models with a one-dimensional unsteady compressible transmission line model. The model has been verified with dynamic pressure measurements in the line over a wide operating range for several system structures. Simulation studies were performed illustrating sensitivities of several design variables and the potential of the model to design transmissions with minimal noise sources. A semi-anechoic chamber has been designed and constructed suitable for sound intensity measurements that can be used to derive sound power. Measurements proved the potential to reduce audible noise by predicting and reducing both noise sources. Sound power measurements were conducted on a series hybrid transmission test bench to validate the model and compare predicted noise sources with sound power.

  16. Important Parameters Design of Inverter-driven Cryogenic Induction Motor for Submerged Liquid Natural Gas Pump%潜液式液化天然气泵用变频低温异步电机的关键参数设计

    Institute of Scientific and Technical Information of China (English)

    艾程柳; 黄元峰; 王海峰; 顾国彪

    2015-01-01

    Cryogenic electrical motors are the key component of submerged liquid natural gas (LNG) pumps. In this paper, some design aspects of an inverter-driven cryogenic electrical motor for a submerged LNG pump were presented. First of all, the characteristics of conductive material and magnetic material in the motor were discussed to determine the electric and magnetic loadings of the cryogenic induction motor by combining with the thermal analysis. Secondly, this paper proposed to design the motor starting with its rotor. And its slots, especially the rotor slots should be designed as short and fat shape to decrease leakage inductances and friction losses. Finally, the designed 11kW prototype was simulated to analyze its performance in?161℃ LNG and?196℃ liquid nitrogen. And we tested the prototype in liquid nitrogen. The experimental results matched the simulation data so that the theoretical analysis was validated. Therefore, the proposed design aspects can serve as a designing reference for ainverter-driven cryogenic induction motor.%低温电机是潜液式液化天然气(liquefied natural gas, LNG)泵的核心部件.该文主要讨论了潜液式LNG泵用变频低温异步电机的设计方案.首先研究了电机电磁材料的低温特性,结合低温异步电机温升情况确定了电机的电磁负荷.建议从转子开始设计变频低温异步电机,并认为变频低温异步电机的槽形特别是转子槽,应设计为"矮胖"形以减少该类电机的漏抗和转子摩擦损耗.仿真分析了 11 kW 设计样机在LNG(?161℃)及液氮(?196℃)的运行性能,并进行了液氮低温试验,试验数据与仿真分析相吻合,验证了理论分析的正确性,该文的研究成果可为变频低温异步电机的设计提供参考.

  17. HYDRAULICS, ATHENS COUNTY, OHIO, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  18. HYDRAULICS, JACKSON COUNTY, KENTUCKY, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  19. HYDRAULICS, MADISON COUNTY, ALABAMA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — This Hydraulic data was reviewed and approved by FEMA during the initial MT-2 processing. Recent developments in digital terrain and geospatial database management...

  20. HYDRAULICS, HAMPDEN COUNTY, MA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data in this submittal include spatial datasets and model outputs necessary for computation of the 1-percent flooding extent. The minimum requirement for...

  1. 14 CFR 29.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 29.1435 Section 29.1435... STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Equipment Miscellaneous Equipment § 29.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows: (1) Each element of the hydraulic system...

  2. 14 CFR 23.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 23.1435 Section 23.1435... § 23.1435 Hydraulic systems. (a) Design. Each hydraulic system must be designed as follows: (1) Each hydraulic system and its elements must withstand, without yielding, the structural loads expected...

  3. 46 CFR 28.405 - Hydraulic equipment.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Hydraulic equipment. 28.405 Section 28.405 Shipping... Operate With More Than 16 Individuals on Board § 28.405 Hydraulic equipment. (a) Each hydraulic system... than four times the system maximum operating pressure. (c) Each hydraulic system must be equipped...

  4. Advanced Performance Hydraulic Wind Energy

    Science.gov (United States)

    Jones, Jack A.; Bruce, Allan; Lam, Adrienne S.

    2013-01-01

    The Jet Propulsion Laboratory, California Institute of Technology, has developed a novel advanced hydraulic wind energy design, which has up to 23% performance improvement over conventional wind turbine and conventional hydraulic wind energy systems with 5 m/sec winds. It also has significant cost advantages with levelized costs equal to coal (after carbon tax rebate). The design is equally applicable to tidal energy systems and has passed preliminary laboratory proof-of-performance tests, as funded by the Department of Energy.

  5. Climbing robot actuated by meso-hydraulic artificial muscles

    Science.gov (United States)

    Bryant, Matthew; Fitzgerald, Jason; Miller, Samuel; Saltzman, Jonah; Kim, Sangkyu; Lin, Yong; Garcia, Ephrahim

    2014-03-01

    This paper presents the design, construction, experimental characterization, and system testing of a legged, wall-climbing robot actuated by meso-scale hydraulic artificial muscles. While small wall-climbing robots have seen increased research attention in recent years, most authors have primarily focused on designs for the gripping and adhesion of the robot to the wall, while using only standard DC servo-motors for actuation. This project seeks to explore and demonstrate a different actuation mechanism that utilizes hydraulic artificial muscles. A four-limb climbing robot platform that includes a full closed-loop hydraulic power and control system, custom hydraulic artificial muscles for actuation, an on-board microcontroller and RF receiver for control, and compliant claws with integrated sensing for gripping a variety of wall surfaces has been constructed and is currently being tested to investigate this actuation method. On-board power consumption data-logging during climbing operation, analysis of the robot kinematics and climbing behavior, and artificial muscle force-displacement characterization are presented to investigate and this actuation method.

  6. Motor homopolar

    OpenAIRE

    Agustín Martín Muñoz

    2007-01-01

    Mostramos la construcción de un modelo de motor homopolar, uno de los más antiguos tipos de motores eléctricos. Se caracterizan porque el campo magnético del imán mantiene siempre la misma polaridad (de ahí su nombre, del griego homos, igual), de modo que, cuando una corriente eléctrica atraviesa el campo magnético, aparece una fuerza que hace girar los elementos no fijados mecánicamente. En el sencillísimo motor homopolar colgado (Schlichting y Ucke 2004), el imán puede girar ...

  7. Lipid - Motor Interactions: Soap Opera or Symphony?

    Science.gov (United States)

    Pathak, Divya; Mallik, Roop

    2017-02-01

    Intracellular transport of organelles can be driven by multiple motor proteins that bind to the lipid membrane of the organelle and work as a team. We review present knowledge on how lipids orchestrate the recruitment of motors to a membrane. Looking beyond recruitment, we also discuss how heterogeneity and local mechanical properties of the membrane may influence function of motor-teams. These issues gain importance because phagocytosed pathogens use lipid-centric strategies to manipulate motors and survive in host cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Ultrasonic Motors

    Science.gov (United States)

    2003-06-01

    and T. Higuchi, "Cylindrical Micro Ultrasonic Motor Utilizing Bulk Lead Zirconate Titanate (PZT)," Japanese Journal of Applied Physics Part 1-Regular Papers Short Notes & Review Papers, vol. 38, pp. 3347-3350, 1999.

  9. Development of Force Reflecting Joystick for Hydraulic Excavator

    Science.gov (United States)

    Ahn, Kyoungkwan

    In teleoperation field robotic system such as hydraulically actuated robotic excavator, the maneuverability and convenience is the most important in the operation of robotic excavator. Particularly the force information is important in dealing with digging and leveling operation in the teleoperated excavator. This paper presents a new force reflecting joystick in a velocity-force type bilateral teleoperation system. The master system is electrical joystick and the slave system is hydraulic cylinder. Particularly pneumatic motor is used newly in the master joystick for force reflection and the information of the pressure of slave cylinder is measured and utilized as force feedback signal. This paper also proposes a novel force-reflection gain selecting algorithm based on artificial neural network. Finally a series of experiments are conducted under various load conditions using a laboratory-made one axis slave cylinder and load simulator.

  10. Primary control of a Mach scale swashplateless rotor using brushless DC motor actuated trailing edge flaps

    Science.gov (United States)

    Saxena, Anand

    driven trailing edge flap concept. In conclusion, the concept of using brushless DC motors as on-blade actuators, actuating trailing edge flaps has the potential to replace the current mechanically complex swashplate with a hydraulic-free swashplateless system and thereby reduce overall weight and hub drag.

  11. Powertrains 2011. Electronics, mechanics and hydraulics in application; Antriebssysteme 2011. Elektrik, Mechanik und Hydraulik in der Anwendung

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    Within the VDI/VDE conference at 13th-14th September, 2011 in Stuttgart (Federal Republic of Germany) the following lectures and posters were presented: (1) Sieve printed windings of rotating small drives and their evaluation (P. Braeuer); (2) Variable impedance induction motor - Measurement results of a variable impedance induction motor prototype (H. Gholizad); (3) Utilization of a multiphase winding in a star-polygon hybrid circuit for squirrel asynchronous motors for increasing the energy efficiency - generation of flooding waves of a 6-phase machine with a 3-phase connection (T. Knopik); (4) Virtual development of electric moors - Design of an asynchronous motor for propel drives by means of a numeric optimization and software automation (V. Reinhardt); (5) A hybrid microproduction system driven by piezoactuators and linear motors (C. Hast); (6) MRF actors with minimized standby losses (D. Gueth); (7) Experimental determination of rotor losses in a homopolar magnetic bearing (E. Fleischer); (8) Vibrational condition monitoring of coiler heads of electric large machines (C. Kreischer); (9) Recovery potentials in the electric propulsion technology - ''What is left usable from the energy'' (M. Schumacher); (10) Overall energy balance in the powertrain - The application decides - Energetic analysis of a powertrain (A. Thomas); (11) Optimal dimensioning of an actuator in the mechatronic overall system electric motor - gear - load (M. Lindner); (12) Electric and hydraulic hybrid actuator: Competing and complementary systems (K. Dehnert); (13) Intelligent pump drives - Simulation, condition monitoring, fault diagnosis and energy efficiency (S. Kleinmann); (14) Parametric models of the permanent magnet-synchronous machine (PMSM) under consideration of the impacts of magnetic saturation (F. Mink); (15) Electromagnetic, structure dynamic acoustic FEM simulation of an asynchronous motor for the evaluation of noise emission (J. Wibbeler); (16

  12. Complex Fluids and Hydraulic Fracturing.

    Science.gov (United States)

    Barbati, Alexander C; Desroches, Jean; Robisson, Agathe; McKinley, Gareth H

    2016-06-07

    Nearly 70 years old, hydraulic fracturing is a core technique for stimulating hydrocarbon production in a majority of oil and gas reservoirs. Complex fluids are implemented in nearly every step of the fracturing process, most significantly to generate and sustain fractures and transport and distribute proppant particles during and following fluid injection. An extremely wide range of complex fluids are used: naturally occurring polysaccharide and synthetic polymer solutions, aqueous physical and chemical gels, organic gels, micellar surfactant solutions, emulsions, and foams. These fluids are loaded over a wide range of concentrations with particles of varying sizes and aspect ratios and are subjected to extreme mechanical and environmental conditions. We describe the settings of hydraulic fracturing (framed by geology), fracturing mechanics and physics, and the critical role that non-Newtonian fluid dynamics and complex fluids play in the hydraulic fracturing process.

  13. Hydraulic properties of ladle slags

    Directory of Open Access Journals (Sweden)

    J. Vlček

    2016-07-01

    Full Text Available The article presents results of examining of hydraulic properties of ladle slags formed during production of steel. The studied ladle slags were subjected to different cooling mode from the molten state. Based on the ability of the slag react with the water was assessed their hydraulic activity. The hydraulic properties are caused by the presence of minerals dicalcium silicate, tricalcium aluminate, mayenite, brownmillerite and dicalcium ferite. The emergence of required hydrating phases in the ladle slags is conditioned by a sufficient CaO content and their cooling rate. The contact the slag with water during processing and their ageing has a negative effect. The experiment has shown that the phase transformation of the mineral dicalcium silicate which occurs during cooling of the ladle slags cause their volume instability.

  14. A Hydraulic Blowdown Servo System For Launch Vehicle

    Science.gov (United States)

    Chen, Anping; Deng, Tao

    2016-07-01

    This paper introduced a hydraulic blowdown servo system developed for a solid launch vehicle of the family of Chinese Long March Vehicles. It's the thrust vector control (TVC) system for the first stage. This system is a cold gas blowdown hydraulic servo system and consist of gas vessel, hydraulic reservoir, servo actuator, digital control unit (DCU), electric explosion valve, and pressure regulator etc. A brief description of the main assemblies and characteristics follows. a) Gas vessel is a resin/carbon fiber composite over wrapped pressure vessel with a titanium liner, The volume of the vessel is about 30 liters. b) Hydraulic reservoir is a titanium alloy piston type reservoir with a magnetostrictive sensor as the fluid level indicator. The volume of the reservoir is about 30 liters. c) Servo actuator is a equal area linear piston actuator with a 2-stage low null leakage servo valve and a linear variable differential transducer (LVDT) feedback the piston position, Its stall force is about 120kN. d) Digital control unit (DCU) is a compact digital controller based on digital signal processor (DSP), and deployed dual redundant 1553B digital busses to communicate with the on board computer. e) Electric explosion valve is a normally closed valve to confine the high pressure helium gas. f) Pressure regulator is a spring-loaded poppet pressure valve, and regulates the gas pressure from about 60MPa to about 24MPa. g) The whole system is mounted in the aft skirt of the vehicle. h) This system delivers approximately 40kW hydraulic power, by contrast, the total mass is less than 190kg. the power mass ratio is about 0.21. Have finished the development and the system test. Bench and motor static firing tests verified that all of the performances have met the design requirements. This servo system is complaint to use of the solid launch vehicle.

  15. Motor Planning.

    Science.gov (United States)

    Wong, Aaron L; Haith, Adrian M; Krakauer, John W

    2015-08-01

    Motor planning colloquially refers to any process related to the preparation of a movement that occurs during the reaction time prior to movement onset. However, this broad definition encompasses processes that are not strictly motor-related, such as decision-making about the identity of task-relevant stimuli in the environment. Furthermore, the assumption that all motor-planning processes require processing time, and can therefore be studied behaviorally by measuring changes in the reaction time, needs to be reexamined. In this review, we take a critical look at the processes leading from perception to action and suggest a definition of motor planning that encompasses only those processes necessary for a movement to be executed-that is, processes that are strictly movement related. These processes resolve the ambiguity inherent in an abstract goal by defining a specific movement to achieve it. We propose that the majority of processes that meet this definition can be completed nearly instantaneously, which means that motor planning itself in fact consumes only a small fraction of the reaction time. © The Author(s) 2014.

  16. Hydraulic resistance of biofilms

    KAUST Repository

    Dreszer, C.

    2013-02-01

    Biofilms may interfere with membrane performance in at least three ways: (i) increase of the transmembrane pressure drop, (ii) increase of feed channel (feed-concentrate) pressure drop, and (iii) increase of transmembrane passage. Given the relevance of biofouling, it is surprising how few data exist about the hydraulic resistance of biofilms that may affect the transmembrane pressure drop and membrane passage. In this study, biofilms were generated in a lab scale cross flow microfiltration system at two fluxes (20 and 100Lm-2h-1) and constant cross flow (0.1ms-1). As a nutrient source, acetate was added (1.0mgL-1 acetate C) besides a control without nutrient supply. A microfiltration (MF) membrane was chosen because the MF membrane resistance is very low compared to the expected biofilm resistance and, thus, biofilm resistance can be determined accurately. Transmembrane pressure drop was monitored. As biofilm parameters, thickness, total cell number, TOC, and extracellular polymeric substances (EPS) were determined, it was demonstrated that no internal membrane fouling occurred and that the fouling layer actually consisted of a grown biofilm and was not a filter cake of accumulated bacterial cells. At 20Lm-2h-1 flux with a nutrient dosage of 1mgL-1 acetate C, the resistance after 4 days reached a value of 6×1012m-1. At 100Lm-2h-1 flux under the same conditions, the resistance was 5×1013m-1. No correlation of biofilm resistance to biofilm thickness was found; Biofilms with similar thickness could have different resistance depending on the applied flux. The cell number in biofilms was between 4×107 and 5×108 cellscm-2. At this number, bacterial cells make up less than a half percent of the overall biofilm volume and therefore did not hamper the water flow through the biofilm significantly. A flux of 100Lm-2h-1 with nutrient supply caused higher cell numbers, more biomass, and higher biofilm resistance than a flux of 20Lm-2h-1. However, the biofilm thickness

  17. Parameter Design for the Energy-Regeneration System of Series Hydraulic-Hybrid Bus

    Directory of Open Access Journals (Sweden)

    SONG Yunpu

    2012-10-01

    Full Text Available This paper simplifies the energy recovery process in the series hydraulic hybrid bus’ energy regeneration system into a process in which the main axle’s moment of inertia drives the secondary element variable delivery pump/motor and brings hydraulic oil from the oil tank to the accumulator. This process enables braking of the vehicle and also allows recovery of energy to the accumulator. Based on the flow equation for the secondary element variable delivery pump/motor and the torque equilibrium equation for its axle, the force equilibrium equation for vehicle braking and the pressure variation and flow continuity equations for the accumulator, simulation studies are conducted to analyze the effects of various system parameters, such as accumulator capacity, displacement of the secondary element variable delivery pump/motor, initial operating pressure of the system, etc. on system performance during regenerative braking.  

  18. Integrating hydraulic equivalent sections into a hydraulic geometry study

    Science.gov (United States)

    Jia, Yanhong; Yi, Yujun; Li, Zhiwei; Wang, Zhaoyin; Zheng, Xiangmin

    2017-09-01

    Hydraulic geometry (HG) is an important geomorphic concept that has played an indispensable role in hydrological analyses, physical studies of streams, ecosystem and aquatic habitat studies, and sedimentology research. More than 60 years after Leopold and Maddock (1953) first introduced the concept of HG, researchers have still not uncovered the physical principles underlying HG behavior. One impediment is the complexity of the natural river cross section. The current study presents a new way to simplify the cross section, namely, the hydraulic equivalent section, which is generalized from the cross section in the ;gradually varied flow of an alluvial river; (GVFAR) and features hydrodynamic properties and bed-building laws similar to those of the GVFAR. Energy balance was used to derive the stage Z-discharge Q relationship in the GVFAR. The GVFAR in the Songhua River and the Yangtze River were selected as examples. The data, including measured discharge, river width, water stage, water depth, wet area, and cross section, were collected from the hydrological yearbooks of typical hydrological stations on the Songhua River and the Yangtze River from 1955 to 1987. The relationships between stage Z-discharge Q and cross-sectional area A-stage Z at various stations were analyzed, and ;at-a-station hydraulic geometry; (AHG) relationships were obtained in power-law forms. Based on derived results and observational data analysis, the Z-Q and Z-A relationships of AHG were similar to rectangular weir flows, thus the cross section of the GVFAR was generalized as a compound rectangular, hydraulic equivalent cross section. As to bed-building characteristics, the bankfull discharge method and the stage-discharge-relation method were used to calculate the dominant variables of the alluvial river. This hydraulic equivalent section has the same Z-Q relation, Z-A relation, dominant discharge, dominant river width, and dominant water depth as the cross section in the GVFAR. With the

  19. Robust Force Control of a 6-Link Electro-Hydraulic Manipulator

    Science.gov (United States)

    Ahn, Kyoungkwan; Yokota, Shinichi

    Uninterrupted power supply has become indispensable during the maintenance task of active electric power lines as a result of today's highly information-oriented society and increasing demand of electric utilities. This maintenance task has the risk of electric shock and the danger of falling from high place. Therefore it is necessary to realize an autonomous robot system using electro-hydraulic manipulator because hydraulic manipulators have the advantage of electric insulation and power/mass density. Meanwhile an electro-hydraulic manipulator using hydraulic actuators has many nonlinear elements, and its parameter fluctuations are greater than those of an electrically driven manipulator. So it is relatively difficult to realize not only stable contact work but also accurate force control for the autonomous assembly tasks using hydraulic manipulators. In this paper, the robust force control of a 6-link electro-hydraulic manipulator system used in the real maintenance task of active electic line is examined in detail. A nominal model for the system is obtained from experimental frequency responses of the system, and the deviation of the manipulator system from the nominal model is derived by a multiplicative uncertainty. Robust disturbance observers for force control are designed using this information in an H∞ framework, and implemented on the two different setups. Experimental results show that highly robust force tracking by a 6-link electro-hydraulic manipulator could be achieved even if the stiffness of environment and the shape of wall change.

  20. 我国机动车辆保险市场发展的需求拉动因素研究%Research on Demands-driven Factors for the Development of the Motor Insurance Market in China

    Institute of Scientific and Technical Information of China (English)

    刘璐; 张博江

    2012-01-01

    近些年来,我国机动车辆保险市场呈现出迅速扩张的势头,车险成为提升最快的险种之一。目前作为财产保险的第一大险种——机动车辆保险,在促进财产保险业发展的同时也成为整个保险业的重大影响因素之一。本文在对我国机动车辆保险市场发展现状进行阐述的基础上,分析各个因素对于机动车辆保险市场的影响。根据影响需求的因素分析并结合计量经济学回归模型,提出相关的政策与建议从而发掘机动车辆保险市场需求潜力,并根据模型得出的结论对未来几年我国机动车辆保险的保费收入做出相应的预测。%The motor vehicle insurance market in China has been expanding rapidly in recent years and has become one of the lines of business with the fastest growth rate. As the biggest insurance business of property insur- ance, motor vehicle insurance has greatly enhanced the development of the property insurance and is also one of the major drivers for the development of the whole insurance industry. This paper analyzed various factors affecting the motor vehicle insurance market following an elaboration on the current situation of motor vehicle insurance market in China. Based on the factors influencing motor vehicle insurance demands and in combination with the measurement economics model, the paper tried to come up with some advice and policy suggestions to further exploit the market potential and make a reasonable prediction for the premium income of motor vehicle insurance in China in the coming years according to the results of the analysis.

  1. 任务驱动教学模式在高职理论教学中的实践研究--以水利工程类专业“水利工程CAD与识读”课程为例%Study on the Practice of Task-driven Teaching Mode In Higher Vocational Teaching of Theory---Taking Water Conservancy Class Professional"Hydraulic CAD and Literacy"Courses as an example

    Institute of Scientific and Technical Information of China (English)

    黄梦琪

    2014-01-01

    水利工程类专业“水利工程CAD与识读”课程课堂理论教学中采用任务驱动教学模式,强调学生在完成任务或解决问题的过程中,通过自主协作、讨论、会话等方式,在轻松愉快的氛围中开展并完成学习活动,不仅能培养学生主观能动性、创新精神,完成课堂角色转换,对提高教师教学水平也很有帮助。%In the teaching of classroom theory, Water Conservancy Class Professional "Hydraulic CAD and Literacy" Courses adopt the task-driven teaching mode and emphasize the importance of the ways of autonomous collaboration, discussion and conversation, etc,to develop and finish the study activities in the telexing and pleasant atmosphere during the process of finishing the tasks or solving problems. In this way, it can not only develop students' subjective initiative and cultivation, and complete the role reversal in the classroom, but also be helpful to improve teachers' teaching levels.

  2. A New Type of Hydraulic Actuator Using Electrorheological Fluids

    Science.gov (United States)

    Wendt, Eckhard; Büsing, Klaus W.

    Electrorheological Fluids (ERF) are usually used in semi active damping elements, e.g. shock absorbers or engine mounts because of their continuously controllable shear stress. A totally new field of application may be achieved, if an ERF is used as a hydraulic fluid and not only as a control medium. In this case a fundamental need is the capability to produce a volume flow by using normal hydraulic pumps, e.g. gear pumps. The ERF and the hydraulic components both must have a long lifetime without unusual wear. Bayer AG has developed an ERF based on soft crosslinked PU-particles dispersed in silicone oil. These ERF are characterised by a low basic viscosity, a high ER-effect and a moderate conductivity. Compared with previous ERF where hard inorganic particles were used, the new fluid is not abrasive. It is foremostly this characteristic which gives the possibility of using the ERF in hydraulic systems with high shear rates and high shear stresses. The usage of ERF as hydraulic fluid allows the construction of proportional valves without mechanically driven parts. The control of the pressure drop over the valves is realised directly by an electrical signal. It is possible to realise actuators with very fast response times since the reaction time of ERF is within milliseconds. For demonstration purpose Bayer AG has built an actuator which is controlled by an electrorheological valve-block. The calculation of the dimension of this actuator and the valves will be shown and the realised response time will be demonstrated.

  3. CRITICALITY CURVES FOR PLUTONIUM HYDRAULIC FLUID MIXTURES

    Energy Technology Data Exchange (ETDEWEB)

    WITTEKIND WD

    2007-10-03

    This Calculation Note performs and documents MCNP criticality calculations for plutonium (100% {sup 239}Pu) hydraulic fluid mixtures. Spherical geometry was used for these generalized criticality safety calculations and three geometries of neutron reflection are: {sm_bullet}bare, {sm_bullet}1 inch of hydraulic fluid, or {sm_bullet}12 inches of hydraulic fluid. This document shows the critical volume and critical mass for various concentrations of plutonium in hydraulic fluid. Between 1 and 2 gallons of hydraulic fluid were discovered in the bottom of HA-23S. This HA-23S hydraulic fluid was reported by engineering to be Fyrquel 220. The hydraulic fluid in GLovebox HA-23S is Fyrquel 220 which contains phosphorus. Critical spherical geometry in air is calculated with 0 in., 1 in., or 12 inches hydraulic fluid reflection.

  4. DCS Hydraulics Submittal, Butler County, Alabama, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data includes spatial datasets and data tables necessary for documenting the hydraulic procedures for computing flood elevations for a flood insurance...

  5. DCS Hydraulics Submittal, Bullock County, Alabama, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data includes spatial datasets and data tables necessary for documenting the hydraulic procedures for computing flood elevations for a flood insurance...

  6. DCS Hydraulics Submittal, Covington County, Alabama, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data includes spatial datasets and data tables necessary for documenting the hydraulic procedures for computing flood elevations for a flood insurance...

  7. High Pressure Hydraulic Distribution System

    Science.gov (United States)

    1991-05-20

    to 500 0 F. 5 cycles. 5000 F room temperature to 50001F; 45 ______________ Icycles The tesis planned for the distribution system demonstrator were...American Society for Testing and Materials ASTM D412 - Tension Testing of Vulcanized Rubber ASTM D571 - Testing Automotive Hydraulic Brake Hose Society of

  8. Hydraulic fracturing system and method

    Energy Technology Data Exchange (ETDEWEB)

    Ciezobka, Jordan; Salehi, Iraj

    2017-02-28

    A hydraulic fracturing system and method for enhancing effective permeability of earth formations to increase hydrocarbon production, enhance operation efficiency by reducing fluid entry friction due to tortuosity and perforation, and to open perforations that are either unopened or not effective using traditional techniques, by varying a pump rate and/or a flow rate to a wellbore.

  9. Hydraulic jumps in a channel

    DEFF Research Database (Denmark)

    Bonn, D.; Andersen, Anders Peter; Bohr, Tomas

    2009-01-01

    We present a study of hydraulic jumps with flow predominantly in one direction, created either by confining the flow to a narrow channel with parallel walls or by providing an inflow in the form of a narrow sheet. In the channel flow, we find a linear height profile upstream of the jump as expected...

  10. Hydraulic Fracture Containment in Sand

    NARCIS (Netherlands)

    Dong, Y.

    2010-01-01

    The mechanism of hydraulic fracturing in soft, high permeability material is considered fundamentally different from that in hard, low permeability rock, where a tensile fracture is created and conventional linear elastic fracture mechanics (LEFM) applies. The fracturing and associated modeling work

  11. Design of hydraulic recuperation unit

    Directory of Open Access Journals (Sweden)

    Jandourek Pavel

    2016-01-01

    Full Text Available This article deals with design and measurement of hydraulic recuperation unit. Recuperation unit consist of radial turbine and axial pump, which are coupled on the same shaft. Speed of shaft with impellers are 6000 1/min. For economic reasons, is design of recuperation unit performed using commercially manufactured propellers.

  12. Tree Hydraulics: How Sap Rises

    Science.gov (United States)

    Denny, Mark

    2012-01-01

    Trees transport water from roots to crown--a height that can exceed 100 m. The physics of tree hydraulics can be conveyed with simple fluid dynamics based upon the Hagen-Poiseuille equation and Murray's law. Here the conduit structure is modelled as conical pipes and as branching pipes. The force required to lift sap is generated mostly by…

  13. Tree Hydraulics: How Sap Rises

    Science.gov (United States)

    Denny, Mark

    2012-01-01

    Trees transport water from roots to crown--a height that can exceed 100 m. The physics of tree hydraulics can be conveyed with simple fluid dynamics based upon the Hagen-Poiseuille equation and Murray's law. Here the conduit structure is modelled as conical pipes and as branching pipes. The force required to lift sap is generated mostly by…

  14. Hydraulic characterization of " Furcraea andina

    Science.gov (United States)

    Rivera-Velasquez, M. F.; Fallico, C.; Molinari, A.; Santillan, P.; Salazar, M.

    2012-04-01

    The present level of pollution, increasingly involving groundwaters, constitutes a serious risk for environment and human health. Therefore the remediation of saturated and unsaturated soils, removing pollutant materials through innovative and economic bio-remediation techniques is more frequently required. Recent studies on natural fiber development have shown the effectiveness of these fibers for removal of some heavy metals, due to the lignin content in the natural fibers which plays an important role in the adsorption of metal cations (Lee et al., 2004; Troisi et al., 2008; C. Fallico, 2010). In the context of remediation techniques for unsaturated and/or saturated zone, an experimental approach for the hydraulic characterization of the "Furcraea andina" (i.e., Cabuya Blanca) fiber was carried out. This fiber is native to Andean regions and grows easily in wild or cultivated form in the valleys and hillsides of Colombia, Ecuador, and Peru. Fibers of "Furcraea andina" were characterized by experimental tests to determine their hydraulic conductivity or permeability and porosity in order to use this medium for bioremediation of contaminated aquifer exploiting the physical, chemical and microbial capacity of natural fiber in heavy metal adsorption. To evaluate empirically the hydraulic conductivity, laboratory tests were carried out at constant head specifically on the fibers manually extracted. For these tests we used a flow cell (used as permeameter), containing the "Furcraea andina" fibers to be characterized, suitably connected by a tygon pipe to a Marriott's bottle, which had a plastic tube that allow the adjustment of the hydraulic head for different tests to a constant value. By this experiment it was also possible to identify relationships that enable the estimation of permeability as a function of density, i.e. of the compaction degree of the fibers. Our study was carried out for three values of hydraulic head (H), namely 10, 18, and 25 cm and for each

  15. THE MOTOR

    DEFF Research Database (Denmark)

    Gammelgaard Nielsen, Anders

    2011-01-01

    MOTOR is the first assignment that students at Unit 1a of the School of Architecture are introduced to. The purpose of the assignment is to shake up the students and their preconceptions of what architec- ture is. This is done by introducing them to a working method that al- lows them to develop...

  16. THE MOTOR

    DEFF Research Database (Denmark)

    Gammelgaard Nielsen, Anders

    2011-01-01

    MOTOR is the first assignment that students at Unit 1a of the School of Architecture are introduced to. The purpose of the assignment is to shake up the students and their preconceptions of what architec- ture is. This is done by introducing them to a working method that al- lows them to develop...

  17. 14 CFR 25.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 25.1435 Section 25.1435... STANDARDS: TRANSPORT CATEGORY AIRPLANES Equipment Miscellaneous Equipment § 25.1435 Hydraulic systems. (a) Element design. Each element of the hydraulic system must be designed to: (1) Withstand the proof...

  18. 14 CFR 27.1435 - Hydraulic systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Hydraulic systems. 27.1435 Section 27.1435... STANDARDS: NORMAL CATEGORY ROTORCRAFT Equipment Safety Equipment § 27.1435 Hydraulic systems. (a) Design. Each hydraulic system and its elements must withstand, without yielding, any structural loads...

  19. Linear hydraulic drive system for a Stirling engine

    Science.gov (United States)

    Walsh, Michael M.

    1984-02-21

    A hydraulic drive system operating from the periodic pressure wave produced by a Stirling engine along a first axis thereof and effecting transfer of power from the Stirling engine to a load apparatus therefor and wherein the movable, or working member of the load apparatus is reciprocatingly driven along an axis substantially at right angles to the first axis to achieve an arrangement of a Stirling engine and load apparatus assembly which is much shorter and the components of the load apparatus more readily accessible.

  20. Improved optically driven microrotors

    Science.gov (United States)

    Asavei, Theodor; Loke, Vincent L. Y.; Nieminen, Timo A.; Heckenberg, Norman R.; Rubinsztein-Dunlop, Halina

    2008-08-01

    Two-photon polymerization of optically curing resins is a powerful method to fabricate micron sized objects which can be used as tools to measure properties at small scales. These microdevices can be driven by means of externally applied focused laser beams (optical tweezers) through angular momentum exchange, giving rise to a net torque. The advantage of the optical drive is that no contact is required, therefore making the microdevices suited to non-invasive biological applications. The fabrication method is versatile and allows building objects of any 3D shape. We discuss the design and modelling of various optically driven rotors. In particular, we consider fabrication of microspheres with an internal shape birefringence in order to obtain rotation in an optical trap. The reason for fabricating this type of object is that they are well-suited for studies of mechanical properties of single biomolecules such as the torsional stiffness of DNA or torque generated by molecular motors. The microspheres fabricated are able to transduce torques of 2000 pNnm with optical powers of 500 mW and could be rotated with frequencies up to 40 Hz in circularly polarized light.

  1. Position Sensorless Drive o SRM Mounted on Hydraulic Pump Unit

    Science.gov (United States)

    Kosaka, Takashi; Nabeya, Yoshinari; Ohyama, Kazunobu; Matsui, Nobuyuki

    Recently, Switched Reluctance Motors (SRM)have been applied to several industrial products such as fans, blowers, pumps and so forth because of their simple construction and relatively high e ciency.As one of the examples, Daikin Industries Ltd.has been successful in manufacturing hydraulic pump unit using 2.2kW three-phase SRM with shaft mounted position sensor for its control. This paper presents the position sensorless drive o the SRM for the purposes of reducing cost and down sizing of the hydraulic pump unit system.The controller, intentionally designed for this special application, realizes the following characteristics;the maximum and minimum speeds are 5000 and 300rpm, the speed response between the maximum and minimum speeds is within 100msec and the starting torque is less than 20% of the rated torque.The experimental studies using the hydraulic pump unit show that the proposed sensorless control scheme satis es the requirements for this application.

  2. 一种引入位置比例控制提高电动负载模拟器性能的控制系统设计方法%An Effective Method for Designing Control System of Motor-Driven Torque Control Simulator by Introducing Position Proportional Control

    Institute of Scientific and Technical Information of China (English)

    郭行; 陈康; 孙力; 闫杰

    2014-01-01

    We establish the mathematical model of a motor-driven torque control simulator. Under the circumstance of passive load, we suppress the surplus torque by using the position-proportional control and angular-speed feed forward compensation. We design the control system that includes three loops:position-proportional control, angular speed feed forward compensation and closed-loop PID torque control. We then analyze the time domain and frequen-cy domain characteristics of the control system. The results and their analysis show preliminarily that the control sys-tem thus designed can significantly enhance the control precision of the motor-driven torque control simulator and expand the frequency band of its torque load to at least 25Hz.%仔细分析了电动负载模拟器的工作原理及多余力矩的产生机理,建立了电动负载模拟器的数学模型,在被动加载的情况下,提出了采用位置比例控制与角速度前馈补偿两种方法共同抑制多余力矩,设计了包含位置比例控制+角速度前馈补偿+力矩闭环控制的三回路控制系统,进一步提高了电动负载模拟器的控制精度并展宽了力矩加载频带,使得电动负载模拟器的加载频带提高到了25 Hz以上。

  3. Experimental Validation of Mathematical Framework for Fast Switching Valves used in Digital Hydraulic Machines

    DEFF Research Database (Denmark)

    Nørgård, Christian; Roemer, Daniel Beck; Bech, Michael Møller;

    2015-01-01

    A prototype of a fast switching valve designed for a digital hydraulic transmission has been manufactured and experimentally tested. The valve is an annular seat valve composed of a plunger connected with a direct electromagnetic moving coil actuator as the force producing element. Based...... on an elaborate optimization method the valve is designed to maximize the efficiency of a digital hydraulic motor targeted to a wind turbine transmission system. The optimisation method comprises a mathematical framework which predicts a valve switching time of approximately 1 ms with a peak actuator input power...

  4. Modeling and control of a hydraulically actuated flexible-prismatic link robot

    Energy Technology Data Exchange (ETDEWEB)

    Love, L.; Kress, R.; Jansen, J.

    1996-12-01

    Most of the research related to flexible link manipulators to date has focused on single link, fixed length, single plane of vibration test beds. In addition, actuation has been predominantly based upon electromagnetic motors. Ironically, these elements are rarely found in the existing industrial long reach systems. This manuscript describes a new hydraulically actuated, long reach manipulator with a flexible prismatic link at Oak Ridge National Laboratory (ORNL). Focus is directed towards both modeling and control of hydraulic actuators as well as flexible links that have variable natural frequencies.

  5. Dynamic simulation and optimal control strategy for a parallel hybrid hydraulic excavator

    Institute of Scientific and Technical Information of China (English)

    Xiao LIN; Shuang-xia PAN; Dong-yun WANG

    2008-01-01

    The primary focus of this study is to investigate the control strategies of a hybrid system used in hydraulic excavators. First, the structure and evaluation target of hybrid hydraulic excavators are analyzed. Then the dynamic system model including batteries, motor and engine is built as the simulation environment to obtain control results. A so-called multi-work-point dynamic control strategy, which has both closed-loop speed PI (proportion integral) control and direct torque control, is proposed and studied in the simulation model. Simulation results indicate that the hybrid system with this strategy can meet the power demand and achieve better system stability and higher fuel efficiency.

  6. Nanocoatings for High-Efficiency Industrial Hydraulic and Tooling Systems

    Energy Technology Data Exchange (ETDEWEB)

    Clifton B. Higdon III

    2011-01-07

    Industrial manufacturing in the U.S. accounts for roughly one third of the 98 quadrillion Btu total energy consumption. Motor system losses amount to 1.3 quadrillion Btu, which represents the largest proportional loss of any end-use category, while pumps alone represent over 574 trillion BTU (TBTU) of energy loss each year. The efficiency of machines with moving components is a function of the amount of energy lost to heat because of friction between contacting surfaces. The friction between these interfaces also contributes to downtime and the loss of productivity through component wear and subsequent repair. The production of new replacement parts requires additional energy. Among efforts to reduce energy losses, wear-resistant, low-friction coatings on rotating and sliding components offer a promising approach that is fully compatible with existing equipment and processes. In addition to lubrication, one of the most desirable solutions is to apply a protective coating or surface treatment to rotating or sliding components to reduce their friction coefficients, thereby leading to reduced wear. Historically, a number of materials such as diamond-like carbon (DLC), titanium nitride (TiN), titanium aluminum nitride (TiAlN), and tungsten carbide (WC) have been examined as tribological coatings. The primary objective of this project was the development of a variety of thin film nanocoatings, derived from the AlMgB14 system, with a focus on reducing wear and friction in both industrial hydraulics and cutting tool applications. Proof-of-concept studies leading up to this project had shown that the constituent phases, AlMgB14 and TiB2, were capable of producing low-friction coatings by pulsed laser deposition. These coatings combine high hardness with a low friction coefficient, and were shown to substantially reduce wear in laboratory tribology tests. Selection of the two applications was based largely on the concept of improved mechanical interface efficiencies for

  7. Thermal Hydraulic Performance of Tight Lattice Bundle

    Science.gov (United States)

    Yamamoto, Yasushi; Akiba, Miyuki; Morooka, Shinichi; Shirakawa, Kenetsu; Abe, Nobuaki

    Recently, the reduced moderation spectrum BWR has been studied. The fast neutron spectrum is obtained through triangular tight lattice fuel. However, there are few thermal hydraulic test data and thermal hydraulic correlation applicable to critical power prediction in such a tight lattice bundle. This study aims to enhance the database of the thermal hydraulic performance of the tight lattice bundle whose rod gap is about 1mm. Therefore, thermal hydraulic performance measurement tests of tight lattice bundles for the critical power, the pressure drop and the counter current flow limiting were performed. Moreover, the correlations to evaluate the thermal-hydraulic performance of the tight lattice bundle were developed.

  8. Design of hydraulic output Stirling engine

    Science.gov (United States)

    Toscano, W. M.; Harvey, A. C.; Lee, K.

    1983-01-01

    A hydraulic output system for the RE-1000 free piston stirling engine (FPSE) was designed. The hydraulic output system can be readily integrated with the existing hot section of RE-1000 FPSE. The system has two simply supported diaphragms which separate the engine gas from the hydraulic fluid, a dynamic balance mechanism, and a novel, null center band hydraulic pump. The diaphragms are designed to endure more than 10 billion cycles, and to withstand the differential pressure load as high as 14 MPa. The projected thermodynamic performance of the hydraulic output version of RE-1000 FPSE is 1.87 kW at 29/7 percent brake efficiency.

  9. Same phase drive-type ultrasonic motors using two degenerate bending vibration modes of a disk.

    Science.gov (United States)

    Takano, T; Tomikawa, Y; Kusakabe, C

    1992-01-01

    Same-phase drive-type ultrasonic motors, using two degenerate bending vibration modes of a disk, are presented. The distinctive feature of the motor is in using the standing wave modes. The motor is not driven by two input signals with different phases, but by input signals with the same phase. Therefore, only one amplifier is sufficient to drive the motor. The experimental results have proved that the motor can yield stable operational characteristics at low speed and high torque.

  10. Length regulation of active biopolymers by molecular motors.

    Science.gov (United States)

    Johann, Denis; Erlenkämper, Christoph; Kruse, Karsten

    2012-06-22

    For biopolymers like cytoskeletal actin filaments and microtubules, assembly and disassembly are inherently dissipative processes. Molecular motors can affect the rates of subunit removal at filament ends. We introduce a driven lattice-gas model to study the effects of motor-induced depolymerization on the length of active biopolymers and find that increasing motor activity sharpens unimodal steady-state length distributions. Furthermore, for sufficiently fast moving motors, the relative width of the length distribution is determined only by the attachment rate of motors. Our results show how established molecular processes can be used to robustly regulate the size of cytoskeletal structures like mitotic spindles.

  11. Hydraulic fracture during epithelial stretching

    Science.gov (United States)

    Casares, Laura; Vincent, Romaric; Zalvidea, Dobryna; Campillo, Noelia; Navajas, Daniel; Arroyo, Marino; Trepat, Xavier

    2015-03-01

    The origin of fracture in epithelial cell sheets subject to stretch is commonly attributed to excess tension in the cells’ cytoskeleton, in the plasma membrane, or in cell-cell contacts. Here, we demonstrate that for a variety of synthetic and physiological hydrogel substrates the formation of epithelial cracks is caused by tissue stretching independently of epithelial tension. We show that the origin of the cracks is hydraulic; they result from a transient pressure build-up in the substrate during stretch and compression manoeuvres. After pressure equilibration, cracks heal readily through actomyosin-dependent mechanisms. The observed phenomenology is captured by the theory of poroelasticity, which predicts the size and healing dynamics of epithelial cracks as a function of the stiffness, geometry and composition of the hydrogel substrate. Our findings demonstrate that epithelial integrity is determined in a tension-independent manner by the coupling between tissue stretching and matrix hydraulics.

  12. Modeling of Propagation of Interacting Cracks Under Hydraulic Pressure Gradient

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hai [Idaho National Laboratory; Mattson, Earl Douglas [Idaho National Laboratory; Podgorney, Robert Karl [Idaho National Laboratory

    2015-04-01

    A robust and reliable numerical model for fracture initiation and propagation, which includes the interactions among propagating fractures and the coupling between deformation, fracturing and fluid flow in fracture apertures and in the permeable rock matrix, would be an important tool for developing a better understanding of fracturing behaviors of crystalline brittle rocks driven by thermal and (or) hydraulic pressure gradients. In this paper, we present a physics-based hydraulic fracturing simulator based on coupling a quasi-static discrete element model (DEM) for deformation and fracturing with conjugate lattice network flow model for fluid flow in both fractures and porous matrix. Fracturing is represented explicitly by removing broken bonds from the network to represent microcracks. Initiation of new microfractures and growth and coalescence of the microcracks leads to the formation of macroscopic fractures when external and/or internal loads are applied. The coupled DEM-network flow model reproduces realistic growth pattern of hydraulic fractures. In particular, simulation results of perforated horizontal wellbore clearly demonstrate that elastic interactions among multiple propagating fractures, fluid viscosity, strong coupling between fluid pressure fluctuations within fractures and fracturing, and lower length scale heterogeneities, collectively lead to complicated fracturing patterns.

  13. Bi-modes alternation stepping ultrasonic motors

    Institute of Scientific and Technical Information of China (English)

    Jiamei JIN; Chunsheng ZHAO

    2008-01-01

    Based on the principle of alternative operation of two bending vibration modes in an annular stator, this paper presents a standing-wave stepping ultrasonic motor characterized by no accumulative errors driven by an open-loop control circuitry. The driving forces are generated from the motions of projections on the stator in two modes. The positioning of the motor is achieved by the cooperation between the stator projections and rotor teeth, and the number of the rotors determines the stepping angle of the motor. Two-phase sinusoidal signals corresponding to the two modal frequencies drive the motor bi-direction stepping rotation via a switch unit. The prototype runs steadily without miss-step on trial. The single-step angle displacement of the motor is 2.5°.

  14. Bio-based Hydraulic Fluids

    Science.gov (United States)

    2008-04-17

    currently formulated with vegetable oils (i.e., rapeseed , sun flower, corn, soybean, canola, coconut, etc.) and synthetic ester, such as polyol ester...2008 Vegetable Oil • Excellent lubrication • Nontoxic • Biodegradable • Derived from renewable resources such as rapeseed , sunflower, corn...Mineral Oil 100 SAE 15W-40 G Rapeseed 32 Commercial HF H Polyol ester 22 MIL-PRF-32073 Grade 2 I Canola - Cooking Oil *Hydraulic fluid 3717 April

  15. Fire Resistant Aircraft Hydraulic System.

    Science.gov (United States)

    1982-07-01

    and compounds based on new experimental elastomers as well as most commercially available elastomers were screened in seeking seals that were both...for hydraulic component testing. All of the available E6.5 stock was purchased for the screening tests. However, DuPont stated that other homologs of...with the lubricity and anti-wear additive olyvan A (molybdenum oxysulphide dithiocarbamate ) added in the quantity of less than one percent by weight

  16. Elasticity-Driven Backflow of Fluid-Driven Cracks

    Science.gov (United States)

    Lai, Ching-Yao; Zheng, Zhong; Dressaire, Emilie; Ramon, Guy; Huppert, Herbert E.; Stone, Howard A.

    2016-11-01

    Fluid-driven cracks are generated by the injection of pressurized fluid into an elastic medium. Once the injection pressure is released, the crack closes up due to elasticity and the fluid in the crack drains out of the crack through an outlet, which we refer to as backflow. We experimentally study the effects of crack size, elasticity of the matrix, and fluid viscosity on the backflow dynamics. During backflow, the volume of liquid remaining in the crack as a function of time exhibits a transition from a fast decay at early times to a power law behavior at late times. Our results at late times can be explained by scaling arguments balancing elastic and viscous stresses in the crack. This work may relate to the environmental issue of flowback in hydraulic fracturing. This work is supported by National Science Foundation via Grant CBET-1509347 and partially supported by Andlinger Center for Energy and the Environment at Princeton University.

  17. Severe environment turbine powered steerable motors

    Energy Technology Data Exchange (ETDEWEB)

    Gaynor, T.M. [Neyrfor-Weir Ltd., Aberdeen (United Kingdom). Dept. of Operations

    1995-12-31

    Turbine powered downhole motors have advantages for high temperature, high pressure, sour gas or hard formation drilling which stem from turbodrill construction rather than metallurgy, and from their power characteristics. The first part of the paper will discuss this, and compare turbine and Moineau powered motors in this context. The introduction in the last three years of new bearing materials, hydraulic thrust balancing devices and high performance flexible couplings have extended turbodrill performance and reliability margins in severe environment drilling. It is perfecting feasible to build steerable motors capable of drilling for 250 hours in 6-in. hole at 200 degrees Celsius (392 degrees Fahrenheit) in a deviated high pressure well since the individual problems in this ``Well from Hell`` have successfully been overcome. The second part of the paper will illustrate this through field examples.

  18. Ultrafast ignition of a uni-directional molecular motor

    Directory of Open Access Journals (Sweden)

    Feringa Ben L.

    2013-03-01

    Full Text Available Light-driven molecular motors convert light into mechanical energy via excited state reactions. In this work we follow sub-picosecond primary events in the cycle of a two-stroke unidirectional motor by fluorescence up-conversion and transient absorption.

  19. Hydraulic jumps within pyroclastic density currents and their sedimentary record

    Science.gov (United States)

    Douillet, G.; Mueller, S.; Kueppers, U.; Dingwell, D. B.

    2013-12-01

    This contribution presents a complete and comprehensive formulation of the hydraulic jump phenomenon and reviews sedimentary structures that may be associated with them. Beginning from the general fluid phenomenon, we then focus on examples from pyroclastic density currents in order to infer dynamic parameters on the parent flows. A hydraulic jump is a fluid dynamics phenomenon that corresponds to the sudden increase of the thickness of a flow accompanied by a decrease of its velocity and/or density. A hydraulic jump is the expression of the transition of the flow from two different flow regimes: supercritical to subcritical. This entrains a change in the energy balance between kinetic energy and gravity potential energy. Recently, the terms of 'pneumatic jumps' have been used for similar phenomenon driven within a gas phase, and granular jumps for dense granular flows. It is thought that such strong changes in the flow conditions may leave characteristic structures in the sedimentary record. Indeed, the main variables influencing the sedimentation rate are the flow velocity, particle concentration and turbulence level, all of them strongly affected by a hydraulic jump. Structures deposited by hydraulic/pneumatic jumps have been called cyclic steps and chute and pool structures. Chute and pools represent the record of a single supercritical to subcritical transition, whereas cyclic steps are produced by stable trains of hydraulic jumps and subsequent re-accelerations. Pyroclastic density currents (PDCs) are gas and pyroclasts flows. As such, they can be subjected to granular and pneumatic jumps and their deposit have often been interpreted as containing records of jumps. Steep sided truncations covered by lensoidal layers have been interpreted as the record of internal jumps within density stratified flows. Fines-depleted breccias at breaks in slope are thought to result from the enhanced turbulence at a jump of the entire flow. Sudden increases in thickness of

  20. Final design of a free-piston hydraulic advanced Stirling conversion system

    Science.gov (United States)

    Wallace, D. A.; Noble, J. E.; Emigh, S. G.; Ross, B. A.; Lehmann, G. A.

    1991-01-01

    Under the US Department of Energy's (DOEs) Solar Thermal Technology Program, Sandia National Laboratories is evaluating heat engines for solar distributed receiver systems. The final design is described of an engineering prototype advanced Stirling conversion system (ASCS) with a free-piston hydraulic engine output capable of delivering about 25 kW of electric power to a utility grid. The free-piston Stirling engine has the potential for a highly reliable engine with long life because it has only a few moving parts, has noncontacting bearings, and can be hermetically sealed. The ASCS is designed to deliver maximum power per year over a range of solar input with a design life of 30 years (60,000 h). The system includes a liquid Nak pool boiler heat transport system and a free-piston Stirling engine with high-pressure hydraulic output, coupled with a bent axis variable displacement hydraulic motor and a rotary induction generator.

  1. Subcritical growth of natural hydraulic fractures

    Science.gov (United States)

    Garagash, D.

    2014-12-01

    Joints are the most common example of brittle tensile failure in the crust. Their genesis at depth is linked to the natural hydraulic fracturing, which requires pore fluid pressure in excess of the minimum in situ stress [Pollard and Aidyn, JSG1988]. Depending on the geological setting, high pore pressure can result form burial compaction of interbedded strata, diagenesis, or tectonics. Common to these loading scenarios is slow build-up of pore pressure over a geological timescale, until conditions for initiation of crack growth are met on favorably oriented/sized flaws. The flaws can vary in size from grain-size cracks in igneous rocks to a fossil-size flaws in clastic rock, and once activated, are inferred to propagate mostly subcritically [Segall JGR 1984; Olson JGR 1993]. Despite many observational studies of natural hydraulic fractures, the modeling attempts appear to be few [Renshaw and Harvey JGR 1994]. Here, we use boundary integral formulation for the pore fluid inflow from the permeable rock into a propagating joint [Berchenko et al. IJRMMS 1997] coupled with the criteria for subcritical propagation assisted by the environmental effects of pore fluid at the crack tip to solve for the evolution of a penny-shape joint, which, in interbedded rock, may eventually evolve to short-blade geometry (propagation confined to a bed). Initial growth is exceedingly slow, paced by the stress corrosion reaction kinetics at the crack tip. During this stage the crack is fully-drained (i.e. the fluid pressure in the crack is equilibrated with the ambient pore pressure). This "slow" stage is followed by a rapid acceleration, driven by the increase of the mechanical stress intensity factor with the crack length, towards the terminal joint velocity. We provide an analytical expression for the latter as a function of the rock diffusivity, net pressure loading at the initiation (or flaw lengthscale), and parameters describing resistance to fracture growth. Due to a much slower

  2. A Hybrid Model of a Brushless DC Motor

    DEFF Research Database (Denmark)

    Bendtsen, Jan Dimon; Hansen, Hans Brink; Kallesøe, Carsten Skovmose

    2007-01-01

    This paper presents a novel approach to modeling of a Brush-Less Direct Current Motor (BLDCM) driven by an inverter using hybrid systems theory. Hybrid systems combine continuous and discrete (event-based) dynamics, which is exactly the case in an inverter-driven BLDCM. The model presented in thi...

  3. Friction characteristics of a new type of continuous rotary electro-hydraulic servomotor applied to simulator

    Institute of Scientific and Technical Information of China (English)

    CAO Jian; XU Hong-guang

    2008-01-01

    The principle of a new type of no-pulsation continuous rotary electro-hydraulic servomotor applied to simulators is introduced. LuGre friction model was analyzed. The identification method of LuGre parameters was proposed, and the measures to compensate the effect of friction forces were given. A friction torque model for the new rotary motor was proposed. The low-speed response and step response of the motor were studied experi-mentally. Experimental results proved that using friction compensation could eliminate stick-slip motion at the low speed, which makes the servomotor applicable to simulators.

  4. Vibrations of hydraulic pump and their solution

    OpenAIRE

    Dobšáková Lenka; Nováková Naděžda; Habán Vladimír; Hudec Martin; Jandourek Pavel

    2017-01-01

    The vibrations of hydraulic pump and connected pipeline system are very problematic and often hardly soluble. The high pressure pulsations of hydraulic pump with the double suction inlet are investigated. For that reason the static pressure and accelerations are measured. The numerical simulations are carried out in order to correlate computed data with experimental ones and assess the main source of vibrations. Consequently the design optimization of the inner hydraulic part of pump is done ...

  5. Conceptual design and cost analysis of hydraulic output unit for 15 kW free-piston Stirling engine

    Science.gov (United States)

    White, M. A.

    1982-01-01

    A long-life hydraulic converter with unique features was conceptually designed to interface with a specified 15 kW(e) free-piston Stirling engine in a solar thermal dish application. Hydraulic fluid at 34.5 MPa (5000 psi) is produced to drive a conventional hydraulic motor and rotary alternator. Efficiency of the low-maintenance converter design was calculated at 93.5% for a counterbalanced version and 97.0% without the counterbalance feature. If the converter were coupled to a Stirling engine with design parameters more typcial of high-technology Stirling engines, counterbalanced converter efficiency could be increased to 99.6%. Dynamic computer simulation studies were conducted to evaluate performance and system sensitivities. Production costs of the complete Stirling hydraulic/electric power system were evaluated at $6506 which compared with $8746 for an alternative Stirling engine/linear alternator system.

  6. Fault Analysis and Processing of INBA Closed Loop Hydraulic System%INBA闭环液压系统故障分析与处理

    Institute of Scientific and Technical Information of China (English)

    沈文卫; 黄敬; 李丹; 余其军

    2013-01-01

    INBA法是一种新型高炉炉渣处理技术.INBA的驱动方式为闭式液压系统驱动低速大扭矩液压马达,并经过链条来带动转鼓旋转.该文对闭式液压系统进行了说明.同时对INBA液压系统的常见故障进行了分析,并给了处理方法.%INBA method is a new type of blast furnace slag processing technology.INBA's driving way is closed hydraulic system which drives hydraulic motor which have low-speed big torque.Motor through the chain to drive the drum rotating.This article mainly introduces the closed hydraulic system.At the same time,The INBA's common failures of hydraulic system is analysed and the processing method is given.

  7. Development of a hydraulic borehole seismic source

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, R.P.

    1998-04-01

    This report describes a 5 year, $10 million Sandia/Industry project to develop an advanced borehole seismic source for use in oil and gas exploration and production. The development Team included Sandia, Chevron, Amoco, Conoco, Exxon, Raytheon, Pelton, and GRI. The seismic source that was developed is a vertically oriented, axial point force, swept frequency, clamped, reaction-mass vibrator design. It was based on an early Chevron prototype, but the new tool incorporates a number of improvements which make it far superior to the original prototype. The system consists of surface control electronics, a special heavy duty fiber optic wireline and draw works, a cablehead, hydraulic motor/pump module, electronics module, clamp, and axial vibrator module. The tool has a peak output of 7,000 lbs force and a useful frequency range of 5 to 800 Hz. It can operate in fluid filled wells with 5.5-inch or larger casing to depths of 20,000 ft and operating temperatures of 170 C. The tool includes fiber optic telemetry, force and phase control, provisions to add seismic receiver arrays below the source for single well imaging, and provisions for adding other vibrator modules to the tool in the future. The project yielded four important deliverables: a complete advanced borehole seismic source system with all associated field equipment; field demonstration surveys funded by industry showing the utility of the system; industrial sources for all of the hardware; and a new service company set up by their industrial partner to provide commercial surveys.

  8. Synergetic driving concepts for bundled miniature ultrasonic linear motors.

    Science.gov (United States)

    Mracek, Maik; Hemsel, Tobias

    2006-12-22

    Rotary ultrasonic motors have found broad industrial application in camera lens drives and other systems. Linear ultrasonic motors in contrast have only found limited applications. The main reason for the limited range of application of these very attractive devices seems to be their small force and power range. Attempts to build linear ultrasonic motors for high forces and high power applications have not been truly successful yet. To achieve larger force and higher power, multiple miniaturized motors can be combined. This approach, however, is not as simple as it appears at first glance. The electromechanical behaviour of the individual motors differs slightly due to manufacturing and assembly tolerances. The individual motor characteristics are strongly dependent on the driving parameters (frequency, voltage, temperature, pre-stress, etc.) and the driven load and the collective behaviour of the swarm of motors is not just the linear superposition of the individual drive's forces. Thus, the bundle of motors has to be synchronized and controlled appropriately in order to obtain an optimized drive that is not oversized and costly. We have investigated driving and control strategies of a set of linear ultrasonic motors. Our contribution will be divided into three main parts. In part I ultrasonic linear motors will be introduced. In part II driving strategies for a single motor as well as for a bundle of motors will be presented. These concepts will be verified by simulation results and experimental data. In part III a simplified model for the motor's electromechanical behaviour will be given.

  9. An electrostatic lower stator axial-gap polysilicon wobble motor part I: design and modeling

    NARCIS (Netherlands)

    Legtenberg, Rob; Berenschot, Erwin; Baar, van John; Elwenspoek, Miko

    1998-01-01

    This paper presents design issues and a theoretical model of electrostatically driven axial-gap polysilicon wobble motors. The motor design benefits from large axial rotor-to-stator overlap and large gear ratios, and motor designs with rotor radii of 50 and 100 ¿m are capable of generating torques i

  10. Diversity in plant hydraulic traits explains seasonal and inter-annual variations of vegetation dynamics in seasonally dry tropical forests.

    Science.gov (United States)

    Xu, Xiangtao; Medvigy, David; Powers, Jennifer S; Becknell, Justin M; Guan, Kaiyu

    2016-10-01

    We assessed whether diversity in plant hydraulic traits can explain the observed diversity in plant responses to water stress in seasonally dry tropical forests (SDTFs). The Ecosystem Demography model 2 (ED2) was updated with a trait-driven mechanistic plant hydraulic module, as well as novel drought-phenology and plant water stress schemes. Four plant functional types were parameterized on the basis of meta-analysis of plant hydraulic traits. Simulations from both the original and the updated ED2 were evaluated against 5 yr of field data from a Costa Rican SDTF site and remote-sensing data over Central America. The updated model generated realistic plant hydraulic dynamics, such as leaf water potential and stem sap flow. Compared with the original ED2, predictions from our novel trait-driven model matched better with observed growth, phenology and their variations among functional groups. Most notably, the original ED2 produced unrealistically small leaf area index (LAI) and underestimated cumulative leaf litter. Both of these biases were corrected by the updated model. The updated model was also better able to simulate spatial patterns of LAI dynamics in Central America. Plant hydraulic traits are intercorrelated in SDTFs. Mechanistic incorporation of plant hydraulic traits is necessary for the simulation of spatiotemporal patterns of vegetation dynamics in SDTFs in vegetation models.

  11. Position Control of an Over‐Actuated Direct Hydraulic Cylinder Drive

    DEFF Research Database (Denmark)

    Schmidt, Lasse; Grønkjær, Morten; Pedersen, Henrik Clemmensen

    2017-01-01

    This paper considers the analysis and control strategy for a novel direct hydraulic cylinder drive, that is overactuated in the sense that it has more inputs than sensible outputs. Efforts to overcome the inherent loss of energy due to th+rottling in valve driven hydraulic drives are many......, and various approaches have been proposed by research communities as well as the industry. Recently, a so-called Speed-variable Switched Differential Pump was proposed for direct drive of hydraulic differential cylinders. The main idea with this drive is to utilize an electric rotary drive with the shaft...... the ability to bleed off flow from the transmission lines to achieve reasonable pressure levels. This design renders the drive over-actuated as the line pressures and the cylinder piston motion cannot be controlled independently, due to the pressure difference being motion generating. In order to achieve...

  12. Hydraulic vs. Electric: A Review of Actuation Systems in Offshore Drilling Equipment

    Directory of Open Access Journals (Sweden)

    Witold Pawlus

    2016-01-01

    Full Text Available This article presents a survey on actuation systems encountered in offshore drilling applications. Specifically, it focuses on giving a comparison of hydraulic and electric drivetrains along with detailed explanations of their advantages and drawbacks. A significant number of industrial case studies is examined in addition to the collection of academic publications, in order to accurately describe the current market situation. Some key directions of research and development required to satisfy increasing demands on powertrains operating offshore are identified. The impact of the literature and application surveys is further strengthened by benchmarking two designs of a full-scale pipe handling machine. Apart from other benefits, the electrically actuated machine reduces the total power consumption by 70% compared to its hydraulically driven counterpart. It is concluded that electric actuation systems, among other advantages, in general offer higher efficiency and flexibility, however, in some specific applications (such as energy accumulation or translational motion control hydraulic powertrains are favorable.

  13. 基于螺杆钻具的旋冲钻井装置设计及试验研究%Designed and Testing of the Positive Displacement Motor Driven Rotary Percussion Drilling Device

    Institute of Scientific and Technical Information of China (English)

    马广军; 张海平; 王甲昌

    2016-01-01

    The stability and service life of common rotary percussion drilling downhole tool is influenced by poor working conditions and is far from the field requirement. In view of this, a PDM driven drill string reciprocating percussion concept has been proposed, and a downhole rotary percussion drilling device has been developed. The de-vice is driven by PDM, enabling high-speed cutting and high frequency percussion at the same time. Prototype test results indicate that the tool can convert the PDM rotational power to reciprocating impact of the percussion mecha-nism. Comparing to using the single PDM, 1.5 MPa additional pump pressure is required while the rotary percus-sion drilling device is used with the additional WOB of 20 kN, and torque and RPM are basically the same. The device has a little friction torque and a slight wear between upper and lower cam, indicating the structure and func-tion meet the design requirements. The designed rotary percussion drilling device has a simple structure, reliable performance and great drilling speed promotion potential, presenting a good application prospect.%常见的旋转冲击钻井工具受到井下恶劣工作环境影响,其稳定性和寿命与现场要求还有较大差距.鉴于此,提出了一种利用螺杆钻具旋转运动激发钻柱往复冲击振动的新理念,研发了一种井下旋转冲击钻井装置.该装置由螺杆钻具驱动,能够同时实现高速切削和高频冲击.样机试验测试结果表明,该工具能够将螺杆的旋转动力转化为冲击发生机构的往复冲击,附加20 kN钻压情况下,泵压比单用螺杆高出1.5 MPa,扭矩、 转数与单用螺杆基本一致,摩擦消耗扭矩较小,上、 下凸轮存在轻微磨损,其他保持完好,装置结构和功能达到了设计要求.设计的旋冲钻井装置结构简单,性能可靠,提速潜力大,具有良好应用前景.

  14. Gross motor control

    Science.gov (United States)

    Gross motor control is the ability to make large, general movements (such as waving an arm or lifting a leg). ... Gross motor control is a milestone in the development of an infant. Infants develop gross motor control before they develop ...

  15. Helical coil thermal hydraulic model

    Science.gov (United States)

    Caramello, M.; Bertani, C.; De Salve, M.; Panella, B.

    2014-11-01

    A model has been developed in Matlab environment for the thermal hydraulic analysis of helical coil and shell steam generators. The model considers the internal flow inside one helix and its associated control volume of water on the external side, both characterized by their inlet thermodynamic conditions and the characteristic geometry data. The model evaluates the behaviour of the thermal-hydraulic parameters of the two fluids, such as temperature, pressure, heat transfer coefficients, flow quality, void fraction and heat flux. The evaluation of the heat transfer coefficients as well as the pressure drops has been performed by means of the most validated literature correlations. The model has been applied to one of the steam generators of the IRIS modular reactor and a comparison has been performed with the RELAP5/Mod.3.3 code applied to an inclined straight pipe that has the same length and the same elevation change between inlet and outlet of the real helix. The predictions of the developed model and RELAP5/Mod.3.3 code are in fairly good agreement before the dryout region, while the dryout front inside the helical pipes is predicted at a lower distance from inlet by the model.

  16. The 25 kWe solar thermal Stirling hydraulic engine system: Conceptual design

    Science.gov (United States)

    White, Maurice; Emigh, Grant; Noble, Jack; Riggle, Peter; Sorenson, Torvald

    1988-01-01

    The conceptual design and analysis of a solar thermal free-piston Stirling hydraulic engine system designed to deliver 25 kWe when coupled to a 11 meter test bed concentrator is documented. A manufacturing cost assessment for 10,000 units per year was made. The design meets all program objectives including a 60,000 hr design life, dynamic balancing, fully automated control, more than 33.3 percent overall system efficiency, properly conditioned power, maximum utilization of annualized insolation, and projected production costs. The system incorporates a simple, rugged, reliable pool boiler reflux heat pipe to transfer heat from the solar receiver to the Stirling engine. The free-piston engine produces high pressure hydraulic flow which powers a commercial hydraulic motor that, in turn, drives a commercial rotary induction generator. The Stirling hydraulic engine uses hermetic bellows seals to separate helium working gas from hydraulic fluid which provides hydrodynamic lubrication to all moving parts. Maximum utilization of highly refined, field proven commercial components for electric power generation minimizes development cost and risk.

  17. WATER ENERGY IN HYDROAMELIORATIVE SYSTEMS USING THE HYDRAULIC TRANSFORMER TYPE A. BARGLAZAN AND THE HYDRAULIC HAMMER (HYDRAULIC PUMP

    Directory of Open Access Journals (Sweden)

    Teodor Eugen Man

    2010-01-01

    Full Text Available This paper presents two examples of exploitation of water energy that can be used in the irrigation field. First of theseexamples is the hydraulic transformer type A. Barglazan used for irrigation, pumped water is taken directly from theriver’s well, using a hydraulic pump which simultaneously carried out a double transformation in this way: hydraulicenergy into mechanic energy and mechanical energy into hydraulic energy. Technology preparation and devices designwas done in record time, seeing that this constructive solution is more robust, reliable and with improved energyperformance versus the laboratory prototype. The experimental research which was made at 1:1 scale proved theirgood function over time. Another example is the hydraulic hammer (hydraulic pump that uses low-head energy topump water, with a global efficiency of about 10 - 50%. Currently, the new situation of private ownership of landprovides conditions for new pumping microstations to be made where irrigation is necessary and optimal hydrauliclocations exist.

  18. A Study on the Performance Simulation and Control Scheme for In-wheel Motor Driven Vehicles%轮边电机驱动汽车性能仿真与控制方法的研究

    Institute of Scientific and Technical Information of China (English)

    智晋宁; 项昌乐; 朱丽君; 马越; 徐彬; 李明喜

    2012-01-01

    An in-wheel motor drive system is designed for the land driving of multi-domain vehicle. A vehicle model is set up based on the in-wheel drive system and the drive control method is studied. On the basis of the theoretical analysis on steering dynamics, a multi-body dynamic model for vehicle is established with ADAMS. The driving and steering control strategies are proposed and the control model is developed with Matlab/Simulink. By u-sing co-simulation scheme the driving performances of vehicle in typical working conditions including accelerating, steering and braking are validated. The results show that the basic performances of vehicle meet the expected objectives and the driving control strategy is effective.%为多域车辆的陆地行驶,设计了轮边电机驱动系统,构建了基于轮边驱动系统的车辆模型,并对驱动控制方法进行了研究.在转向动力学理论分析基础上,在ADAMS中建立了多体动力学模型;提出了车辆驱动与转向的控制策略,在Matlab/Simulink环境建立了控制模型,运用联合仿真方法对车辆在直线加速、转向和制动等典型工况下的行驶性能进行仿真验证.结果表明车辆的主要性能符合预期目标,驱动控制策略有效.

  19. A mini slug test method for determination of a local hydraulic conductivity of an unconfined sandy aquifer

    DEFF Research Database (Denmark)

    Hinsby, Klaus; Bjerg, Poul Løgstrup; Andersen, Lars J.;

    1992-01-01

    from level to level and thereby establish vertical profiles of the hydraulic conductivity. The head data from the test well are recorded with a 10 mm pressure transducer, and the initial head difference required is established by a small vacuum pump. The method described has provided 274 spatially......A new and efficient mini slug test method for the determination of local hydraulic conductivities in unconfined sandy aquifers is developed. The slug test is performed in a small-diameter (1 inch) driven well with a 0.25 m screen just above the drive point. The screened drive point can be driven...... distributed measurements of a local hydraulic conductivity at a tracer test site at Vejen, Denmark. The mini slug test results calculated by a modified Dax slug test analysing method, applying the elastic storativity in the Dax equations instead of the specific yield, are in good accordance with the results...

  20. HYDRAULIC CHARACTERISTICS OF VERTICAL VORTEX AT HYDRAULIC INTAKES

    Institute of Scientific and Technical Information of China (English)

    CHEN Yun-liang; WU Chao; YE Mao; JU Xiao-ming

    2007-01-01

    The trace of vertical vortex flow at hydraulic intakes is of the shape of spiral lines, which was observed in the presented experiments with the tracer technique. It represents the fluid particles flow spirally from the water surface to the underwater and rotate around the vortex-axis multi-cycle. This process is similar to the movement of screw. To describe the multi-circle spiral characteristics under the axisymmetric condition, the vertical vortex would change not only in the radial direction but also in the axial direction. The improved formulae for three velocity components for the vertical vortex flow were deduced by using the method of separation of variables in this article. In the improved formulae, the velocity components are the functions of the radial and axial coordinates, so the multi-circle spiral flow of vertical vortex could be simulated. The calculated and measured results for the vertical vortex flow were compared and the causes of errors were analyzed.

  1. Motor control for a brushless DC motor

    Science.gov (United States)

    Peterson, William J. (Inventor); Faulkner, Dennis T. (Inventor)

    1985-01-01

    This invention relates to a motor control system for a brushless DC motor having an inverter responsively coupled to the motor control system and in power transmitting relationship to the motor. The motor control system includes a motor rotor speed detecting unit that provides a pulsed waveform signal proportional to rotor speed. This pulsed waveform signal is delivered to the inverter to thereby cause an inverter fundamental current waveform output to the motor to be switched at a rate proportional to said rotor speed. In addition, the fundamental current waveform is also pulse width modulated at a rate proportional to the rotor speed. A fundamental current waveform phase advance circuit is controllingly coupled to the inverter. The phase advance circuit is coupled to receive the pulsed waveform signal from the motor rotor speed detecting unit and phase advance the pulsed waveform signal as a predetermined function of motor speed to thereby cause the fundamental current waveform to be advanced and thereby compensate for fundamental current waveform lag due to motor winding reactance which allows the motor to operate at higher speeds than the motor is rated while providing optimal torque and therefore increased efficiency.

  2. Hydraulic Transport Across Hydrophilic and Hydrophobic Nanopores: Flow Experiments with Water and n-Hexane

    CERN Document Server

    Gruener, Simon; Greulich, Stefanie; Busch, Mark; Huber, Patrick

    2015-01-01

    We experimentally explore pressure-driven flow of water and n-hexane across nanoporous silica (Vycor glass monoliths with 7 or 10 nm pore diameters, respectively) as a function of temperature and surface functionalization (native and silanized glass surfaces). Hydraulic flow rates are measured by applying hydrostatic pressures via inert gases (argon and helium, pressurized up to 70 bar) on the upstream side in a capacitor-based membrane permeability setup. For the native, hydrophilic silica walls, the measured hydraulic permeabilities can be quantitatively accounted for by bulk fluidity provided we assume a sticking boundary layer, i.e. a negative velocity slip length of molecular dimensions. The thickness of this boundary layer is discussed with regard to previous capillarity-driven flow experiments (spontaneous imbibition) and with regard to velocity slippage at the pore walls resulting from dissolved gas. Water flow across the silanized, hydrophobic nanopores is blocked up to a hydrostatic pressure of at l...

  3. Unidirectional rotary motion in achiral molecular motors.

    Science.gov (United States)

    Kistemaker, Jos C M; Štacko, Peter; Visser, Johan; Feringa, Ben L

    2015-11-01

    Control of the direction of motion is an essential feature of biological rotary motors and results from the intrinsic chirality of the amino acids from which the motors are made. In synthetic autonomous light-driven rotary motors, point chirality is transferred to helical chirality, and this governs their unidirectional rotation. However, achieving directional rotary motion in an achiral molecular system in an autonomous fashion remains a fundamental challenge. Here, we report an achiral molecular motor in which the presence of a pseudo-asymmetric carbon atom proved to be sufficient for exclusive autonomous disrotary motion of two appended rotor moieties. Isomerization around the two double bonds enables both rotors to move in the same direction with respect to their surroundings--like wheels on an axle--demonstrating that autonomous unidirectional rotary motion can be achieved in a symmetric system.

  4. Product Sound: Acoustically pleasant motor drives

    DEFF Research Database (Denmark)

    Mathe, Laszlo

    The work in this thesis is focused on the acoustic noise generated by electrical motors driven by a pulse width modulated (PWM) power electronic inverter. In a usual inverter based electrical drive, the modulation uses fixed switching frequency; that introduces a set of harmonics in the acoustic...... is to ameliorate this whistling acoustic noise, while maintaining the efficiency of the drive. The first chapter of the report is an introductory chapter where the motivation, objectives, limitations and an overview on electrical motor acoustics are presented. A list of main contributions of this PhD project...... the acoustic measurements of the ventilation system using various modulation techniques. A new trend in HVAC is to use permanent magnet synchronous motor (PMSM) instead of the asynchronous motor, in order to increase the efficiency of the electrical drive. In this chapter, the acoustic performance of the two...

  5. Design of Pumps for Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Klit, Peder; Olsen, Stefan; Bech, Thomas Nørgaard

    1999-01-01

    This paper considers the development of two pumps for water hydraulic applications. The pumps are based on two different working principles: The Vane-type pump and the Gear-type pump. Emphasis is put on the considerations that should be made to account for water as the hydraulic fluid.......KEYWORDS: water, pump, design, vane, gear....

  6. Hydraulic fracturing with distinct element method

    NARCIS (Netherlands)

    Pruiksma, J.P.; Bezuijen, A.

    2002-01-01

    In this report, hydraulic fracturing is investigated using the distinct element code PFC2D from Itasca. Special routines were written to be able to model hydraulic fracturing. These include adding fluid flow to PFC2D and updating the fluid flow domains when fractures appear. A brief description of t

  7. Hydraulic Actuator for Ganged Control Rods

    Science.gov (United States)

    Thompson, D. C.; Robey, R. M.

    1986-01-01

    Hydraulic actuator moves several nuclear-reactor control rods in unison. Electromagnetic pump pushes liquid lithium against ends of control rods, forcing them out of or into nuclear reactor. Color arrows show lithium flow for reactor startup and operation. Flow reversed for shutdown. Conceived for use aboard spacecraft, actuator principle applied to terrestrial hydraulic machinery involving motion of ganged rods.

  8. Reactor coolant pump testing using motor current signatures analysis

    Energy Technology Data Exchange (ETDEWEB)

    Burstein, N.; Bellamy, J.

    1996-12-01

    This paper describes reactor coolant pump motor testing carried out at Florida Power Corporation`s Crystal River plant using Framatome Technologies` new EMPATH (Electric Motor Performance Analysis and Trending Hardware) system. EMPATH{trademark} uses an improved form of Motor Current Signature Analysis (MCSA), technology, originally developed at Oak Ridge National Laboratories, for detecting deterioration in the rotors of AC induction motors. Motor Current Signature Analysis (MCSA) is a monitoring tool for motor driven equipment that provides a non-intrusive means for detecting the presence of mechanical and electrical abnormalities in the motor and the driven equipment. The base technology was developed at the Oak Ridge National Laboratory as a means for determining the affects of aging and service wear specifically on motor-operated valves used in nuclear power plant safety systems, but it is applicable to a broad range of electric machinery. MCSA is based on the recognition that an electric motor (ac or dc) driving a mechanical load acts as an efficient and permanently available transducer by sensing mechanical load variations, large and small, long-term and rapid, and converting them into variations in the induced current generated in the motor windings. The motor current variations, resulting from changes in load caused by gears, pulleys, friction, bearings, and other conditions that may change over the life of the motor, are carried by the electrical cables powering the motor and are extracted at any convenient location along the motor lead. These variations modulate the 60 Hz carrier frequency and appear as sidebands in the spectral plot.

  9. Control arrangement for the actuation of hydraulic consumers

    Energy Technology Data Exchange (ETDEWEB)

    Kussel, W.; Dettmers, M.; Weirich, W.

    1988-11-09

    An arrangement for controlling the actuation of hydraulic consumers, by selectively connecting the consumers to hydraulic pressure and return lines; the control arrangement comprising a respective hydraulically operated directional control valve associated with each of the hydraulic consumers, a respective electro-magnetically operated pre-control valve associated with each of the hydraulic directional control valves, and further electro-magnetically operated directional control valve means associated with the pre-control valves, each of the hydraulic consumers being connectible to the hydraulic pressure or return lines via the associated hydraulically operated directional control valve which is actuatable by a hydraulic control line leading from the output of the associated pre-control valve, wherein the inputs of the pre-control valves are connected directly to the hydraulic return line and indirectly, via the further control valve means, to the hydraulic return line or to a hydraulic control pressure line.

  10. Scaling hydraulic properties of a macroporous soil

    Science.gov (United States)

    Mohanty, Binayak P.

    1999-06-01

    Macroporous soils exhibit significant differences in their hydraulic properties for different pore domains. Multimodal hydraulic functions may be used to describe the characteristics of multiporosity media. I investigated the usefulness of scaling to describe the spatial variability of hydraulic conductivity (K(-h)) functions of a macroporous soil in Las Nutrias, New Mexico. Piecewise-continuous hydraulic conductivity functions suitable for macroporous soils in conjunction with a hybrid similar media-functional normalization scaling approach were used. Results showed that gravity-dominated flow and the related hydraulic conductivity (K(minus;h) functions of the macropore region are more readily scalable than capillary-dominated flow properties of the mesopore and micropore regions. A possible reason for this behavior is that gravity-dominated flow in the larger pores is mostly influenced by the pore diameter which remains more uniform as compared to tortuous mesopores and micropores with variable neck and body sizes along the pore length.

  11. Hydraulic conductivity of GCLs in MSW landfills

    Institute of Scientific and Technical Information of China (English)

    LI Guo-cheng; YANG Wu-chao; DAN Tang-hui

    2008-01-01

    The state of the art of the study on the hydraulic conductivity of GCLs is presented in terms of the in-fluence of the effective stress, chemical interactions, freeze - thaw cycles and temperature gradients. The chan-ges of void ratio caused by changes of effective stress have a direct linear effect on the hydraulic conductivity, regardless of the cation concentration or the thickness of the adsorbed layer. The hydraulic conductivity is relat-ed to the relative abundance of monovalent and divalent cation(RMD), and RMD has a great effect on the hy-draulic conductivity in weak solution. The long-term susceptibility of GCLs to increased hydraulic conductivity as a response to repeated freeze-thaw cycling is minimal, which has been proved after 150 freeze-thaw cycles. The potential of desiccation cracking increases with the increasing temperature gradient and is related to the ini-tial subsoil water content, the applied overburden stress, etc.

  12. Modeling and Simulation of Hydraulic Engine Mounts

    Institute of Scientific and Technical Information of China (English)

    DUAN Shanzhong; Marshall McNea

    2012-01-01

    Hydraulic engine mounts are widely used in automotive powertrains for vibration isolation.A lumped mechanical parameter model is a traditional approach to model and simulate such mounts.This paper presents a dynamical model of a passive hydraulic engine mount with a double-chamber,an inertia track,a decoupler,and a plunger.The model is developed based on analogy between electrical systems and mechanical-hydraulic systems.The model is established to capture both low and high frequency dynatmic behaviors of the hydraulic mount.The model will be further used to find the approximate pulse responses of the mounts in terms of the force transmission and top chamber pressure.The close form solution from the simplifiod linear model may provide some insight into the highly nonlinear behavior of the mounts.Based on the model,computer simulation has been carried out to study dynamic performance of the hydraulic mount.

  13. Hydraulic design of a low-specific speed Francis runner for a hydraulic cooling tower

    Science.gov (United States)

    Ruan, H.; Luo, X. Q.; Liao, W. L.; Zhao, Y. P.

    2012-11-01

    The air blower in a cooling tower is normally driven by an electromotor, and the electric energy consumed by the electromotor is tremendous. The remaining energy at the outlet of the cooling cycle is considerable. This energy can be utilized to drive a hydraulic turbine and consequently to rotate the air blower. The purpose of this project is to recycle energy, lower energy consumption and reduce pollutant discharge. Firstly, a two-order polynomial is proposed to describe the blade setting angle distribution law along the meridional streamline in the streamline equation. The runner is designed by the point-to-point integration method with a specific blade setting angle distribution. Three different ultra-low-specificspeed Francis runners with different wrap angles are obtained in this method. Secondly, based on CFD numerical simulations, the effects of blade setting angle distribution on pressure coefficient distribution and relative efficiency have been analyzed. Finally, blade angles of inlet and outlet and control coefficients of blade setting angle distribution law are optimal variables, efficiency and minimum pressure are objective functions, adopting NSGA-II algorithm, a multi-objective optimization for ultra-low-specific speed Francis runner is carried out. The obtained results show that the optimal runner has higher efficiency and better cavitation performance.

  14. The Analysis Regarding the Building of a Hydraulic Power Plant on the Black Sea Shore

    Directory of Open Access Journals (Sweden)

    Gheorghe Samoilescu

    2013-09-01

    Full Text Available The present paper represents the result of a research project regarding the construction of a wave driven hydraulic plant that is going to be installed on the Black Sea shore in the area of the city of Constanta. Several phases were analyzed: numerical simulations for the micro plant – wave energy theory; finite element simulation – results and conclusions; generating the blueprint for the construction of the plant.

  15. Study on Introduction of Frequency Conversion Control Mode for Motor-driven Feed Pump for 330 MW Coal-fired Boiler%330 MW级燃煤机组锅炉电动给水泵变频改造控制方式变更应用研究

    Institute of Scientific and Technical Information of China (English)

    黄文婧

    2014-01-01

    Energy saving is the most important topic in power generation works of coal-fired power plants now, how-ever, the production of subcritical coal-fired units in China still accounts for a large proportion in total power genera-tion at present. As the dominated subcritical coal-fired units in China, the 330MW units usually adopts 3 sets of mo-tor-driven constant speed feed pumps with single capacity of 70%. The boiler feedwater flows under various condi-tions are regulated through changing electric pump output by fluid coupling control, which unavoidably produces power loss and fluid coupling mechanical loss in electric pump in case of medium load or low load. With the develop-ment of frequency conversion technology, the introduction of the technology in boiler motor-driven feed pump can ef-fectively reduce the feed pump station-service power consumption rate and the unit coal consumption, and produce enormous economic benefits. The paper makes a study on the frequency conversion control mode for boiler mo-tor-driven feed pump based on the practical application.%∶节能降耗工作是目前燃煤发电站各项工作的重中之重,而目前国内亚临界燃煤机组在总发电量上仍占很大比重。330 MW级别机组作为目前国内主流的亚临界燃煤机组,大多采用3台70%容量定速锅炉电动给水泵,通过采取液偶控制方式改变电泵出力来调节各种工况下的锅炉给水流量。从而不可避免地存在中低负荷时电泵的电量损失以及液偶机械损失。随着变频技术的发展,将其运用至锅炉电动给水泵之中能有效地降低电动给水泵厂用电率以及机组供电煤耗,产生巨大的经济效益。文章将从实际应用出发对锅炉电动给水泵变频改造控制方式方面进行探讨研究。

  16. The Hydraulic Mission and the Mexican Hydrocracy: Regulating and Reforming the Flows of Water and Power

    Directory of Open Access Journals (Sweden)

    Philippus Wester

    2009-10-01

    Full Text Available In Mexico, the hydraulic mission, the centralisation of water control, and the growth of the federal hydraulic bureaucracy (hydrocracy recursively shaped and reinforced each other during the 20th century. The hydraulic mission entails that the state, embodied in an autonomous hydrocracy, takes the lead in water resources development to capture as much water as possible for human uses. The hydraulic mission was central to the formation of Mexico’s hydrocracy, which highly prized its autonomy. Bureaucratic rivals, political transitions, and economic developments recurrently challenged the hydrocracy’s degree of autonomy. However, driven by the argument that a single water authority should regulate and control the nation’s waters, the hydrocracy consistently managed to renew its, always precarious, autonomy at different political moments in the country’s history. The legacy of the hydraulic mission continues to inform water reforms in Mexico, and largely explains the strong resilience of the Mexican hydrocracy to 'deep' institutional change and political transitions. While the emphasis on infrastructure has lessened, the hydrocracy has actively renewed its control over water decisions and budgets and has played a remarkably constant, hegemonic role in defining and shaping Mexico’s water laws, policies and institutions.

  17. Hydraulic test for evaluation of hydrophone VSP

    Energy Technology Data Exchange (ETDEWEB)

    Yabuuchi, Satoshi; Koide, Kaoru [Power Reactor and Nuclear Fuel Development Corp., Toki, Gifu (Japan). Tono Geoscience Center

    1997-12-01

    This hydraulic test was carried out at the test site of Tono Geoscience Center, Mizunami-shi, Gifu Pref. in order to evaluate the reliability of the hydraulic conductivity estimated from hydrophone VSP experiment. From March to April 1997, we carried out measurements of pore-water pressure at five depths and permeability tests at seven depths down to G.L.-300m, within a borehole drilled in granitic rock. We compared the results of hydraulic test with hydrophone VSP experiment on condition that a single open fracture existed, and we obtained two notable results. First, for the granitic rock at which a single open fracture was found by BTV and also detected by hydrophone VSP experiment, the hydraulic conductivity was 1.54 x 10{sup -7} cm/sec, while for the same granitic rock at which another single open fracture was found by BTV but not detected by hydrophone VSP experiment, the hydraulic conductivity was less than 6 x 10{sup -10} cm/sec. Second, we converted the hydraulic conductivity of 1.54 x 10{sup -7} cm/sec which was obtained in a hydraulic test section of length 2.5 m into an equivalent value for a single open fracture of width 1 mm. The converted value (3.8 x 10{sup -4} cm/sec) was similar to the hydraulic conductivity estimated from hydrophone VSP experiment. In conclusion, the hydraulic test result shows that hydrophone VSP is useful to estimate an approximate hydraulic conductivity of a single open fracture. (author)

  18. Hydraulic assessment of the Buda Thermal Karst area and its vulnerability (Budapest, Hungary)

    Science.gov (United States)

    Czauner, Brigitta; Erőss, Anita; Erhardt, Ildikó; Ötvös, Viktória; Simon, Szilvia; Mádl-Szőnyi, Judit

    2017-04-01

    Thermal and medicinal water resources of Budapest (Hungary), the "City of Spas", are provided by the Buda Thermal Karst area. Assessment of its vulnerability requires the understanding of the discharge phenomena and thus the groundwater flow conditions in the area. Accordingly, BTK has already been the objective of several hydrogeological investigations, including numerical simulations as well, which led to conceptual models. The aim of the present study was the hydraulic evaluation of the flow systems based on the complex analysis of real, i.e. measured, archival hydraulic data of wells in order to i) get acquainted with the real flow systems, and ii) hydraulically confirm or disprove the previous conceptual models, in particular the applicability of gravity-driven regional groundwater flow concept and hydraulic continuity, separation of the natural discharge zones, and hypogenic karstification. Considering the data distribution, pressure vs. elevation profiles, tomographic fluid-potential maps, and hydraulic cross-sections were constructed for the first time in this area. As a result, gravitational flow systems and the modifying effects of aquitard units and faults were identified. Consequently, the differences in temperature, hydrochemistry, discharge distribution (one and two-components), and related cave forming processes between the Central (Rózsadomb) and Southern (Gellért Hill) natural discharge areas could be explained, as well as the hydraulic behaviour of the Northeastern Margin-fault of the Buda Hills could be determined. Regarding the on-going hypogenic karstification processes, regional upward flow conditions were confirmed along the main discharge zone of the Danube. Identification of gravity as the main fluid flow driving force, as well as the hydraulic effects of heterogeneities can significantly contribute to the recognition of the risk factors regarding the vulnerability of the Buda Thermal Karst area. The research was supported by the

  19. The composition and compression of biofilms developed on ultrafiltration membranes determine hydraulic biofilm resistance.

    Science.gov (United States)

    Derlon, Nicolas; Grütter, Alexander; Brandenberger, Fabienne; Sutter, Anja; Kuhlicke, Ute; Neu, Thomas R; Morgenroth, Eberhard

    2016-10-01

    This study aimed at identifying how to improve the level of permeate flux stabilisation during gravity-driven membrane filtration without control of biofilm formation. The focus was therefore on understanding (i) how the different fractions of the biofilms (inorganics particles, bacterial cells, EPS matrix) influence its hydraulic resistance and (ii) how the compression of biofilms impacts its hydraulic resistance, i.e., can water head be increased to increase the level of permeate flux stabilisation. Biofilms were developed on ultrafiltration membranes at 88 and 284 cm water heads with dead-end filtration for around 50 days. A larger water head resulted in a smaller biofilm permeability (150 and 50 L m(-2) h(-1) bar(-1) for biofilms grown at 88 cm and 284 cm water head, respectively). Biofilms were mainly composed of EPS (>90% in volume). The comparison of the hydraulic resistances of biofilms to model fouling layers indicated that most of the hydraulic resistance is due to the EPS matrix. The compressibility of the biofilm was also evaluated by subjecting the biofilms to short-term (few minutes) and long-term variations of transmembrane pressures (TMP). A sudden change of TMP resulted in an instantaneous and reversible change of biofilm hydraulic resistance. A long-term change of TMP induced a slow change in the biofilm hydraulic resistance. Our results demonstrate that the response of biofilms to a TMP change has two components: an immediate variation of resistance (due to compression/relaxation) and a long-term response (linked to biofilm adaptation/growth). Our results provide relevant information about the relationship between the operating conditions in terms of TMP, the biofilm structure and composition and the resulting biofilm hydraulic resistance. These findings have practical implications for a broad range of membrane systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Research on Trajectory Planning and Autodig of Hydraulic Excavator

    Directory of Open Access Journals (Sweden)

    Bin Zhang

    2017-01-01

    Full Text Available As the advances in computer control technology keep emerging, robotic hydraulic excavator becomes imperative. It can improve excavation accuracy and greatly reduce the operator’s labor intensity. The 12-ton backhoe bucket excavator has been utilized in this research work where this type of excavator is commonly used in engineering work. The kinematics model of operation device (boom, arm, bucket, and swing in excavator is established in both Denavit-Hartenberg coordinates for easy programming and geometric space for avoiding blind spot. The control approach is based on trajectory tracing method with displacements and velocities feedbacks. The trajectory planning and autodig program is written by Visual C++. By setting the bucket teeth’s trajectory, the program can automatically plan the velocity and acceleration of each hydraulic cylinder and motor. The results are displayed through a 3D entity simulation environment which can present real-time movements of excavator kinematics. Object-Oriented Graphics Rendering Engine and skeletal animation are used to give accurate parametric control and feedback. The simulation result shows that a stable linear autodig can be achieved. The errors between trajectory planning command and simulation model are analyzed.

  1. DLC coatings for hydraulic applications

    Institute of Scientific and Technical Information of China (English)

    Luca NOBILI; Luca MAGAGNIN

    2009-01-01

    Replacement of lubricating oils with water or low-viscosity fluids is highly desirable in many industrial fields, on account of the environmental and economical advantages. Low lubricity of water might be insufficient for proper operation of hydraulic components, and diamond-like carbon(DLC) coatings are very attractive as solid lubricant films. A remote-plasma PACVD process was utilized to deposit hydrogenated DLC coatings (a-C:H) on different substrates. Microindentation measurements show that the coating hardness is around 35 GPa. Tribological behavior was evaluated by block-on-ring tests performed in water and water with alumina. The wear rate was calculated after measuring the wear volume by a laser profilemeter. Morphological and compositional analysis of the wear tracks reveal that coating failure may occur by abrasive wear or delamination, depending on the substrate properties. Hard and smooth substrates give the best results and dispersed alumina particles increase the wear rate.

  2. High efficiency motors; Motores de alta eficiencia

    Energy Technology Data Exchange (ETDEWEB)

    Uranga Favela, Ivan Jaime [Energia Controlada de Mexico, S. A. de C. V., Mexico, D. F. (Mexico)

    1992-12-31

    This paper is a technical-financial study of the high efficiency and super-premium motors. As it is widely known, more than 60% of the electrical energy generated in the country is used for the operation of motors, in industry as well as in commerce. Therefore the importance that the motors have in the efficient energy use. [Espanol] El presente trabajo es un estudio tecnico-financiero de los motores de alta eficiencia y los motores super premium. Como es ampliamente conocido, mas del 60% de la energia electrica generada en el pais, es utilizada para accionar motores, dentro de la industria y el comercio. De alli la importancia que los motores tienen en el uso eficiente de la energia.

  3. Research of Control Method for Improving Mechanical Performance of Winding Motor

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhao-zhang; YANG Zheng-lin

    2002-01-01

    A reformed PHD (Proportional-Integral- Differential)motor controller is developed for the ideal winding performance. It is verified that the PHD motor controller can largely improve the mechanical performance and raise the production efficiency by means of the test of a winding production system driven by a motor with high internal resistance rotator. It indicates that improving the control method is one of the most effective ways to improve the winding performance of the motor in winding production.

  4. Permeability, storage and hydraulic diffusivity controlled by earthquakes

    Science.gov (United States)

    Brodsky, E. E.; Fulton, P. M.; Xue, L.

    2016-12-01

    Earthquakes can increase permeability in fractured rocks. In the farfield, such permeability increases are attributed to seismic waves and can last for months after the initial earthquake. Laboratory studies suggest that unclogging of fractures by the transient flow driven by seismic waves is a viable mechanism. These dynamic permeability increases may contribute to permeability enhancement in the seismic clouds accompanying hydraulic fracking. Permeability enhancement by seismic waves could potentially be engineered and the experiments suggest the process will be most effective at a preferred frequency. We have recently observed similar processes inside active fault zones after major earthquakes. A borehole observatory in the fault that generated the M9.0 2011 Tohoku earthquake reveals a sequence of temperature pulses during the secondary aftershock sequence of an M7.3 aftershock. The pulses are attributed to fluid advection by a flow through a zone of transiently increased permeability. Directly after the M7.3 earthquake, the newly damaged fault zone is highly susceptible to further permeability enhancement, but ultimately heals within a month and becomes no longer as sensitive. The observation suggests that the newly damaged fault zone is more prone to fluid pulsing than would be expected based on the long-term permeability structure. Even longer term healing is seen inside the fault zone of the 2008 M7.9 Wenchuan earthquake. The competition between damage and healing (or clogging and unclogging) results in dynamically controlled permeability, storage and hydraulic diffusivity. Recent measurements of in situ fault zone architecture at the 1-10 meter scale suggest that active fault zones often have hydraulic diffusivities near 10-2 m2/s. This uniformity is true even within the damage zone of the San Andreas fault where permeability and storage increases balance each other to achieve this value of diffusivity over a 400 m wide region. We speculate that fault zones

  5. Power conversion unit for linear motor drive for electric railcar; Linear motor kudo denshayo shuhenkan sochi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Power conversion units have been delivered, designed for use aboard linear motor-driven electric railcars to connect JFK Airport, New York City, and its outskirts. Using this system, 750VDC power is collected from a third rail, and AC power is supplied from two power conversion units installed on each railcar to linear motors mounted on two sets of bogies, one for each bogie set. The railcar may be operated singly, and its maximum speed is 110km/h. This is the first linear motor-driven railcar ever to run by vector control. It is found that the railcar is highly responsive to control across the whole speed range including sudden changes in load. The railcars will come into service operation upon completion of the railroads now being constructed. (translated by NEDO)

  6. Motor Priming in Neurorehabilitation

    OpenAIRE

    Stoykov, Mary Ellen; Madhavan, Sangeetha

    2015-01-01

    Priming is a type of implicit learning wherein a stimulus prompts a change in behavior. Priming has been long studied in the field of psychology. More recently, rehabilitation researchers have studied motor priming as a possible way to facilitate motor learning. For example, priming of the motor cortex is associated with changes in neuroplasticity that are associated with improvements in motor performance. Of the numerous motor priming paradigms under investigation, only a few ...

  7. Motor Priming in Neurorehabilitation

    OpenAIRE

    Stoykov, Mary Ellen; Madhavan, Sangeetha

    2015-01-01

    Priming is a type of implicit learning wherein a stimulus prompts a change in behavior. Priming has been long studied in the field of psychology. More recently, rehabilitation researchers have studied motor priming as a possible way to facilitate motor learning. For example, priming of the motor cortex is associated with changes in neuroplasticity that are associated with improvements in motor performance. Of the numerous motor priming paradigms under investigation, only a few ...

  8. Motor neuropathies and lower motor neuron syndromes.

    Science.gov (United States)

    Verschueren, A

    2017-05-01

    Motor or motor-predominant neuropathies may arise from disease processes affecting the motor axon and/or its surrounding myelin. Lower motor neuron syndrome (LMNS) arises from a disease process affecting the spinal motor neuron itself. The term LMNS is more generally used, rather than motor neuronopathy, although both entities are clinically similar. Common features are muscle weakness (distal or proximal) with atrophy and hyporeflexia, but no sensory involvement. They can be acquired or hereditary. Immune-mediated neuropathies (multifocal motor neuropathy, motor-predominant chronic inflammatory demyelinating polyneuropathy) are important to identify, as effective treatments are available. Other acquired neuropathies, such as infectious, paraneoplastic and radiation-induced neuropathies are also well known. Focal LMNS is an amyotrophic lateral sclerosis (ALS)-mimicking syndrome especially affecting young adults. The main hereditary LMNSs in adulthood are Kennedy's disease, late-onset spinal muscular atrophy and distal hereditary motor neuropathies. Motor neuropathies and LMNS are all clinical entities that should be better known, despite being rare diseases. They can sometimes be difficult to differentially diagnose from other diseases, particularly from the more frequent ALS in its pure LMN form. Nevertheless, correct identification of these syndromes is important because their treatment and prognoses are definitely different. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  9. Mobile platform for hydraulic turbine blade repair robot

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The wall-climbing mobile platform (MP) of a robot for repairing a hydraulic turbine blade onsite is developed.The MP is equipped with ferromagnetic adhesive devices and can work on a spatial curved surface.The contradiction between mobility and load-bearing ability is analyzed,and the problem of self-adaptation to the curved face is solved using differential-driven wheeled locomotion with ferromagnetic adhesive devices.The platform adheres to the blade surface through the force provided by the ferromagnetic devices,and a certain gap exists between the magnetic devices and the blade's surface.A mechanism of three revolution degrees of freedom,which connects the magnetic devices with the platform's chassis,is developed to make the platform self-adapt to the complex curved surface of the turbine blade.A proofof-principle prototype has been manufactured,and experiments prove the success of the MP.The payload of the zero-turn-radius MP with excellent maneuverability exceeds 80 kg.The platform can automatically adapt to complex spatial surfaces,which satisfy the requirements of a hydraulic turbine blade in-situ repair robot.

  10. In-Plant Testing of High-Efficiency Hydraulic Separators

    Energy Technology Data Exchange (ETDEWEB)

    G. H. Luttrell; R. Q. Honaker; R. C. Bratton; T. C. Westerfield; J. N. Kohmuench

    2006-06-30

    Hydraulic separators are commonly used for particle size classification and gravity concentration of minerals and coal. Unfortunately, the efficiency of these processes can be quite low due to poor equipment design and variations in feed consistency. To help alleviate these problems, an industry-driven R&D program has been undertaken to develop a new generation of hydraulic separators that are more efficient and less costly to operate and maintain. These units, which are commercially called the CrossFlow separator and HydroFloat separator, have the potential to improve performance (separation efficiency and throughput) and reduce operating costs (power consumption, water and reagent usage). In Phase I of this project, laboratory and pilot-scale test units were evaluated at various industrial sites in both the coal and mineral industries. Based on promising results obtained from Phase I, full-scale prototypes were purchased and installed by a major U.S. phosphate producer and a large eastern U.S. coal company. The test data obtained from these sites demonstrate that significant performance improvements can be realized through the application of these high-efficiency separators.

  11. IN-PLANT TESTING OF HIGH-EFFICIENCY HYDRAULIC SEPARATORS

    Energy Technology Data Exchange (ETDEWEB)

    G.H. Luttrell; R.Q. Honaker; R.C. Bratton; T.C. Westerfield; J.N. Kohmuench

    2006-05-22

    Hydraulic separators are commonly used for particle size classification and gravity concentration of minerals and coal. Unfortunately, the efficiency of these processes can be quite low due to poor equipment design and variations in feed consistency. To help alleviate these problems, an industry-driven R&D program has been undertaken to develop a new generation of hydraulic separators that are more efficient and less costly to operate and maintain. These units, which are commercially called the CrossFlow separator and HydroFloat separator, have the potential to improve performance (separation efficiency and throughput) and reduce operating costs (power consumption, water and reagent usage). In Phase I of this project, laboratory and pilot-scale test units were evaluated at various industrial sites in both the coal and mineral industries. Based on promising results obtained from Phase I, full-scale prototypes were purchased and installed by a major U.S. phosphate producer and a large eastern U.S. coal company. The test data obtained from these sites demonstrate that significant performance improvements can be realized through the application of these high-efficiency separators.

  12. Thermal-hydraulic modeling needs for passive reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, J.M. [Nuclear Regulatory Commission, Washington, DC (United States)

    1997-07-01

    The U.S. Nuclear Regulatory Commission has received an application for design certification from the Westinghouse Electric Corporation for an Advanced Light Water Reactor design known as the AP600. As part of the design certification process, the USNRC uses its thermal-hydraulic system analysis codes to independently audit the vendor calculations. The focus of this effort has been the small break LOCA transients that rely upon the passive safety features of the design to depressurize the primary system sufficiently so that gravity driven injection can provide a stable source for long term cooling. Of course, large break LOCAs have also been considered, but as the involved phenomena do not appear to be appreciably different from those of current plants, they were not discussed in this paper. Although the SBLOCA scenario does not appear to threaten core coolability - indeed, heatup is not even expected to occur - there have been concerns as to the performance of the passive safety systems. For example, the passive systems drive flows with small heads, consequently requiring more precision in the analysis compared to active systems methods for passive plants as compared to current plants with active systems. For the analysis of SBLOCAs and operating transients, the USNRC uses the RELAP5 thermal-hydraulic system analysis code. To assure the applicability of RELAP5 to the analysis of these transients for the AP600 design, a four year long program of code development and assessment has been undertaken.

  13. Bubble visualization in a simulated hydraulic jump

    CERN Document Server

    Witt, Adam; Shen, Lian

    2013-01-01

    This is a fluid dynamics video of two- and three-dimensional computational fluid dynamics simulations carried out at St. Anthony Falls Laboratory. A transient hydraulic jump is simulated using OpenFOAM, an open source numerical solver. A Volume of Fluid numerical method is employed with a realizable k-epsilon turbulence model. The goal of this research is to model the void fraction and bubble size in a transient hydraulic jump. This fluid dynamics video depicts the air entrainment characteristics and bubble behavior within a hydraulic jump of Froude number 4.82.

  14. Design of Hydraulic System for Embedded Double Pipes Amphibious Crane%内嵌双输油管两用起重机液压系统设计

    Institute of Scientific and Technical Information of China (English)

    卢志珍; 倪学虎; 舒希勇; 王成龙

    2012-01-01

    Based on analyzing requirements of embedded double pipes amphibious crane to hydraulic system, the hydraulic system design thinking was put forward according to crane technical parameters and customers requirements. Calculations and type selections of the key hydraulic components; hydraulic pump and hydraulic motor, hydraulic cylinder, were completed. The hydraulic principle diagram was designed and the work principle of the hydraulic loop was expounded.%在分析内嵌双输油管两用起重机对液压系统要求的基础上,针对起重机技术参数及客户要求提出了液压系统设计的思路,对关键液压元件——液压泵、液压马达、液压缸进行了计算选型,给出了液压原理图,并阐述了起重机液压回路的工作原理.

  15. Application of PLC in hydraulic transmission combination machine control system%PLC在液压传动组合机床控制中的应用

    Institute of Scientific and Technical Information of China (English)

    关红

    2012-01-01

      液压传动控制系统主要用来控制液压动力元件(液压缸、液压马达)按照规定的要求进行动作。文章给出了采用PLC来代替传统继电器来控制液压控制元件,从而实现对液压动力元件的控制,提高液压控制的自动化程度和可靠性的PLC液压动力滑台的应用和实现方法,并通过实践证明了该方法的可靠性和易行性。%  The hydraulic transmission control system is mainly used to control the hydraulic components (including hydraulic cylinders and hydraulic motor) and make them operate according to the requirements. The paper presents how the PLC replaces traditional relay to control the hydraulic control components in order to achieve control of hydraulics components, and gives application and implementation method of PLC hydraulic power slide to increase the automation level and reliability of the hydraulic control. And the practice verifies the reliability and feasibility of the method.

  16. Hydraulic Fracturing and the Environment

    Science.gov (United States)

    Ayatollahy Tafti, T.; Aminzadeh, F.; Jafarpour, B.; de Barros, F.

    2013-12-01

    In this presentation, we highlight two key environmental concerns of hydraulic fracturing (HF), namely induced seismicity and groundwater contamination (GC). We examine the induced seismicity (IS) associated with different subsurface fluid injection and production (SFIP) operations and the key operational parameters of SFIP impacting it. In addition we review the key potential sources for possible water contamination. Both in the case of IS and GC we propose modeling and data analysis methods to quantify the risk factors to be used for monitoring and risk reduction. SFIP include presents a risk in hydraulic fracturing, waste water injection, enhanced oil recovery as well as geothermal energy operations. Although a recent report (NRC 2012) documents that HF is not responsible for most of the induced seismicities, we primarily focus on HF here. We look into vaious operational parameters such as volume and rate of water injection, the direction of the well versus the natural fracture network, the depth of the target and the local stress field and fault system, as well as other geological features. The latter would determine the potential for triggering tectonic related events by small induced seismicity events. We provide the building blocks for IS risk assessment and monitoring. The system we propose will involve adequate layers of complexity based on mapped seismic attributes as well as results from ANN and probabilistic predictive modeling workflows. This leads to a set of guidelines which further defines 'safe operating conditions' and 'safe operating zones' which will be a valuable reference for future SFIP operations. We also illustrate how HF can lead to groundwater aquifer contamination. The source of aquifer contamination can be the hydrocarbon gas or the chemicals used in the injected liquid in the formation. We explore possible pathways of contamination within and discuss the likelihood of contamination from each source. Many of the chemical compounds used

  17. Study on Characteristics of Hydraulic Servo System for Force Control of Hydraulic Robots

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo-gon; Han, Changsoo [Hanyang University, Seoul (Korea, Republic of); Lee, Jong-won [Korea University of Science and Technology, Seoul (Korea, Republic of); Park, Sangdeok [Korea Institute of Industrial Technology, Seoul (Korea, Republic of)

    2015-02-15

    Because a hydraulic actuator has high power and force densities, this allows the weight of the robot's limbs to be reduced. This allows for good dynamic characteristics and high energy efficiency. Thus, hydraulic actuators are used in some exoskeleton robots and quadrupedal robots that require high torque. Force control is useful for robot compliance with a user or environment. However, force control of a hydraulic robot is difficult because a hydraulic servo system is highly nonlinear from a control perspective. In this study, a nonlinear model was used to develop a simulation program for a hydraulic servo system consisting of a servo valve, transmission lines, and a cylinder. The problems and considerations with regard to the force control performance for a hydraulic servo system were investigated. A force control method using the nonlinear model was proposed, and its effect was evaluated with the simulation program.

  18. System Driven by Correlated Gaussian Noises Related with Disorder

    Institute of Scientific and Technical Information of China (English)

    LI Jing-Hui

    2007-01-01

    A system driven by correlated Gaussian noises related with disorder is investigated. The Fokker-Planck equation (FPE) for the system is derived. Using the FPE derived, some systems driven by correlated Gaussian noises related with disorder can be investigated for Brownian motors, nonequilibrium transition, resonant activation,stochastic resonance, and so on. We only give one example: i.e., using the FPE derived, we study the resonant activation for a single motor protein model with correlated noises related to disorder. Since the correlated noise related to disorder usually exists with the friction, for the temperature, and so on, our results have generic physical meanings for physics, chemistry, biology and other sciences.

  19. Sensorless operation of surface mount permanent magnet AC (PMAC) motors

    Energy Technology Data Exchange (ETDEWEB)

    Toliyat, H.A.; Rahman, K.M.; Shet, D.S.

    1999-12-01

    A sensorless field oriented control scheme for surface mount permanent magnet ac (PMAC) motor with split phase stator windings is presented. This motor is obtained by splitting the phase windings of a conventional three phase motor. The six-phase motor, however is run as a three-phase motor by connecting the split phase stator windings in series, while the taps are made available for voltage measurements. By measuring the terminal voltages and the line currents, absolute position of the permanent magnet ac motor driven by a current regulated PWM inverter with a hysteresis controller is estimated. The estimated position information is independent of the stator resistance, thus this scheme is even applicable at low speeds. Results are presented to show the effectiveness of the new controller, and it is also shown that the position error is negligible.

  20. Motor assessment in pediatric neuropsychology: relationships to executive function.

    Science.gov (United States)

    Shaheen, Sandra

    2013-01-01

    Executive function often refers to control behaviors such as "initiating," "sustaining," "inhibiting," and "switching." These mechanisms contribute to regulation of thinking and emotion but can be observed most clearly in the motor system. Neuropsychology has been influenced by "top-down" models of cognitive control that emerged from information-processing theories of cognition. In fact, neural models provide evidence that control processes are highly interactive within the cortico-striatal-cerebellar circuits. Cognition unfolds in response to motor-driven adaptation, and evidence exists for similar firing of brain cells and circuits during "imagined action" as in actual motor behavior. The motor system develops early and yet is not routinely assessed in neuropsychological evaluation of children with neurodevelopmental disorders. This article reviews some of the approaches to motor assessment that have sensitivity to neurodevelopmental disorders, and advocates for inclusion of motor assessment, particularly in evaluating control processes independent of culture, language, and other confounders.

  1. A model for hydraulic redistribution incorporating coupled soil-root moisture transport

    Directory of Open Access Journals (Sweden)

    G. G. Amenu

    2007-10-01

    Full Text Available One of the adaptive strategies of vegetation, particularly in water limited ecosystems, is the development of deep roots and the use of hydraulic redistribution which enables them to make optimal use of resources available throughout the soil column. Hydraulic redistribution refers to roots acting as a preferential pathway for the movement of water from wet to dry soil layers driven by the moisture gradient – be it from the shallow to deep layers or vice versa. This occurs during the nighttime while during the daytime moisture movement is driven to fulfill the transpiration demand at the canopy. In this study, we develop a model to investigate the effect of hydraulic redistribution by deep roots on the terrestrial climatology. Sierra Nevada eco-region is chosen as the study site which has wet winters and dry summers. Hydraulic redistribution enables the movement of moisture from the upper soil layers to deeper zones during the wet months and this moisture is then available to meet the transpiration demand during the late dry season. It results in significant alteration of the profiles of soil moisture and water uptake as well as increase in the canopy transpiration, carbon assimilation, and the associated water-use-efficiency during the dry summer season. This also makes the presence of roots in deeper soil layers much more important than their proportional abundance would otherwise dictate. Comparison with observations of latent heat from a flux tower demonstrates improved predictability and provides validation of the model results. Hydraulic redistribution serves as a mechanism for the interaction between the variability of deep layer soil-moisture and the land-surface climatology and could have significant implications for seasonal and sub-seasonal climate prediction.

  2. A model for hydraulic redistribution incorporating coupled soil-root moisture transport

    Directory of Open Access Journals (Sweden)

    G. G. Amenu

    2008-01-01

    Full Text Available One of the adaptive strategies of vegetation, particularly in water limited ecosystems, is the development of deep roots and the use of hydraulic redistribution which enables them to make optimal use of resources available throughout the soil column. Hydraulic redistribution refers to roots acting as a preferential pathway for the movement of water from wet to dry soil layers driven by the moisture gradient – be it from the shallow to deep layers or vice versa. This occurs during the nighttime while during the daytime moisture movement is driven to fulfill the transpiration demand at the canopy. In this study, we develop a model to investigate the effect of hydraulic redistribution by deep roots on the terrestrial climatology. Sierra Nevada eco-region is chosen as the study site which has wet winters and dry summers. Hydraulic redistribution enables the movement of moisture from the upper soil layers to deeper zones during the wet months and this moisture is then available to meet the transpiration demand during the late dry season. It results in significant alteration of the profiles of soil moisture and water uptake as well as increase in the canopy transpiration, carbon assimilation, and the associated water-use-efficiency during the dry summer season. This also makes the presence of roots in deeper soil layers much more important than their proportional abundance would otherwise dictate. Comparison with observations of latent heat from a flux tower demonstrates improved predictability and provides validation of the model results. Hydraulic redistribution serves as a mechanism for the interaction between the variability of deep layer soil-moisture and the land-surface climatology and could have significant implications for seasonal and sub-seasonal climate prediction.

  3. Parker Hybrid Hydraulic Drivetrain Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Collett, Raymond [Parker-Hannifin Corporation, Cleveland, OH (United States); Howland, James [Parker-Hannifin Corporation, Cleveland, OH (United States); Venkiteswaran, Prasad [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2014-03-31

    This report examines the benefits of Parker Hannifin hydraulic hybrid brake energy recovery systems used in commercial applications for vocational purposes. A detailed background on the problem statement being addressed as well as the solution set specific for parcel delivery will be provided. Objectives of the demonstration performed in high start & stop applications included opportunities in fuel usage reduction, emissions reduction, vehicle productivity, and vehicle maintenance. Completed findings during the demonstration period and parallel investigations with NREL, CALSTART, along with a literature review will be provided herein on this research area. Lastly, results identified in the study by third parties validated the savings potential in fuel reduction of on average of 19% to 52% over the baseline in terms of mpg (Lammert, 2014, p11), Parker data for parcel delivery vehicles in the field parallels this at a range of 35% - 50%, emissions reduction of 17.4% lower CO2 per mile and 30.4% lower NOx per mile (Gallo, 2014, p15), with maintenance improvement in the areas of brake and starter replacement, while leaving room for further study in the area of productivity in terms of specific metrics that can be applied and studied.

  4. Thermal hydraulics development for CASL

    Energy Technology Data Exchange (ETDEWEB)

    Lowrie, Robert B [Los Alamos National Laboratory

    2010-12-07

    This talk will describe the technical direction of the Thermal-Hydraulics (T-H) Project within the Consortium for Advanced Simulation of Light Water Reactors (CASL) Department of Energy Innovation Hub. CASL is focused on developing a 'virtual reactor', that will simulate the physical processes that occur within a light-water reactor. These simulations will address several challenge problems, defined by laboratory, university, and industrial partners that make up CASL. CASL's T-H efforts are encompassed in two sub-projects: (1) Computational Fluid Dynamics (CFD), (2) Interface Treatment Methods (ITM). The CFD subproject will develop non-proprietary, scalable, verified and validated macroscale CFD simulation tools. These tools typically require closures for their turbulence and boiling models, which will be provided by the ITM sub-project, via experiments and microscale (such as DNS) simulation results. The near-term milestones and longer term plans of these two sub-projects will be discussed.

  5. 基于直线电动机驱动的2X-Y联动进给轴圆轮廓误差测试研究%Circle contour error measurement for 2X-Y coupling axis driven by linear motors

    Institute of Scientific and Technical Information of China (English)

    林献坤; 袁博; 韩世卓

    2011-01-01

    The advantages of linear motors drive system in high speed feed machine are analyzed, a contour testing platform with a 2X-Y coupling axis driven by linear motors is constructed. An evaluation way of circle contour error in the XOY plane is proposed, and two expression forming roundness error are presented: roundness deviation error and root mean square error. Then the method of testing the circle contour error on the testing machine by using laser interferometer is studied and the roundness deviation error and root mean square error is tested. The results indicate that both the roundness deviation error and the root mean square error become larger as the feed speed increase, and in reverse as the acceleration increase, the acceleration which smaller than 1 m/s2 should be avoided.%分析高速机床上直线电动机驱动进给轴的优越性,构建了基于直线电动机驱动的2X-Y联动进给轴实验平台,给出了联动进给轴在XOY平面内的圆轮廓误差的评定方法和误差值的两个表现形式:圆度的偏差和均方根差.探讨了应用双频激光干涉仪测量实验平台圆轮廓误差的测试原理和方法,并对2X-Y联动进给轴圆度的偏差和均方根偏差进行测试实验研究,测试结果表明圆度的偏差和均方根偏差都随进给速度增大而增大,随进给加速度增大而减小,圆轮廓插补过程应当避免1 m/s2以下的过小进给加速度.

  6. Transputer Control of Hydraulic Actuators and Robots

    DEFF Research Database (Denmark)

    Conrad, Finn

    1996-01-01

    Results from a Danish mechatronics research program entitled IMCIA - Intelligent Control and Intelligent Actuators. The objective is development of intelligent actuators for intelligent motion control. A mechatronics test facility with a transputer controlled hydraulic robot suiteable for real...

  7. Concept Evaluation for Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Andersen, Torben Ole

    2013-01-01

    a suspension system on a car, leading the loads away from the turbine structure. However, to realize a soft hydraulic yaw system a new design concept must be found. As a part of the development of the new concept a preliminary concept evaluation has been conducted, evaluating seven different hydraulic yaw...... concepts, ranging from a one-to-one copy of the electrical drive (electrical drives replaced by hydraulic dittos), to floating suspension systems mounted on hydraulic cylinders. Rough calculations of size and consequences of the different systems are presented ending up with the final concept for further...... investigation. Loads and yaw demands are based on the IEC 61400-1 standard for wind turbine design, and the loads for this examination are extrapolated from the HAWC2 aeroelastic design code. The concepts are based on a 5 MW off-shore turbine....

  8. HYDRAULICS, Des Moines COUNTY, IOWA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  9. ON THE THEORIES OF HYDRAULIC GEOMETRY

    Institute of Scientific and Technical Information of China (English)

    Vijay P. SINGH

    2003-01-01

    Hydraulic geometry is of fundamental importance in planning, design, and management of river engineering and training works. Although some concepts of hydraulic geometry were proposed toward the end of the nineteenth century, the real impetus toward formulating a theory of hydraulic geometry was provided by the work of Leopold and Maddock (1953). A number of theories have since been proposed.Some of the theories are interrelated but others are based on quite different principles. All theories,however, assume that the river flow is steady and uniform and the river tends to attain a state of equilibrium or quasi-equilibrium. The differences are due to the differences in hydraulic mechanisms that the theories employ to explain the attainment of equilibrium by the river.

  10. Stream restoration hydraulic design course: lecture notes

    National Research Council Canada - National Science Library

    Newbury, R

    2002-01-01

    Steam restoration encompasses a broad range of activities and disciplines. This lecture series is designed for practitioners who must fit habitat improvement works in the hydraulics of degraded channels...

  11. Drawing a pictogram operator - hydraulic stowing assembly

    Energy Technology Data Exchange (ETDEWEB)

    Bukhgol' ts, V.P.; Dinershtein, V.A.

    1984-11-01

    Hydraulic stowing is widely used during the extraction of coal from seams prone to spontaneous ignition or from seams situated under preserved structures. Experience has shown that the presence of a considerable number of controlling and measuring devices on hydraulic stowing assemblies results in erratic operations. The authors, after examining the controls of the hydraulic stowing complexes, recommend that all functions which the operator might perform badly or not at all should be controlled automatically. The operator must, however, have access to manual controls which should be included in the system in order to achieve an effective and trouble free operation. The authors propose a pictogram to explain the relationship between the human operator and the hydraulic complex, based on structural diagrams. The system developed, which was tried out at the Koksovaya mine, increased the efficiency of the complex and reduced the work load of the operator. 3 references.

  12. HYDRAULICS, Des Moines COUNTY, IOWA, USA

    Data.gov (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  13. Hydraulic fracturing chemicals and fluids technology

    CERN Document Server

    Fink, Johannes

    2013-01-01

    When classifying fracturing fluids and their additives, it is important that production, operation, and completion engineers understand which chemical should be utilized in different well environments. A user's guide to the many chemicals and chemical additives used in hydraulic fracturing operations, Hydraulic Fracturing Chemicals and Fluids Technology provides an easy-to-use manual to create fluid formulations that will meet project-specific needs while protecting the environment and the life of the well. Fink creates a concise and comprehensive reference that enables the engineer to logically select and use the appropriate chemicals on any hydraulic fracturing job. The first book devoted entirely to hydraulic fracturing chemicals, Fink eliminates the guesswork so the engineer can select the best chemicals needed on the job while providing the best protection for the well, workers and environment. Pinpoints the specific compounds used in any given fracturing operation Provides a systematic approach to class...

  14. Transputer Control of Hydraulic Actuators and Robots

    DEFF Research Database (Denmark)

    Conrad, Finn

    1996-01-01

    Results from a Danish mechatronics research program entitled IMCIA - Intelligent Control and Intelligent Actuators. The objective is development of intelligent actuators for intelligent motion control. A mechatronics test facility with a transputer controlled hydraulic robot suiteable for real...

  15. 21 CFR 870.2780 - Hydraulic, pneumatic, or photoelectric plethysmographs.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Hydraulic, pneumatic, or photoelectric... § 870.2780 Hydraulic, pneumatic, or photoelectric plethysmographs. (a) Identification. A hydraulic... using hydraulic, pneumatic, or photoelectric measurement techniques. (b) Classification. Class...

  16. RESEARCH OF THE DYNAMIC CHARACTERISTICS ON A NEW HYDRAULIC SYSTEM OF ELECTRO-HYDRAULIC HAMMER

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A new typed hydraulic system of electro-hydraulic hammer is researched and developed.By means of power bond graphs the modeling and simulation to the dynamic characteristics of the new hydraulic system are performed. The experimental research which is emphasized on the blowing stroke is also performed. It is proved from the result of simulation and experiment that this new hydraulic system possesses such advantages as simplification of structure,flexibleness of operation and reliability of working. Especially it possesses better dynamic characteristics.

  17. Design of a laboratory hydraulic device for testing of hydraulic pumps

    Directory of Open Access Journals (Sweden)

    Pavel Máchal

    2013-01-01

    Full Text Available The present contribution deals with solves problem of research of testing device to monitor of hydrostatic pumps durability about dynamic loading under laboratory conditions. When carrying out the design of testing device are based on load characteristics of tractor hydraulic circuit, the individual characteristics of hydraulic components and performed calculations. Load characteristics on the tractors CASE IH Magnum 310, JOHN DEERE 8100, ZETOR FORTERRA 114 41 and Fendt 926 Vario were measured. Design of a hydraulic laboratory device is based on the need for testing new types of hydraulic pumps or various types of hydraulic fluids. When creating of hydraulic device we focused on testing hydraulic pumps used in agricultural and forestry tractors. Proportional pressure control valve is an active member of the hydraulic device, which provides change of a continuous control signal into relative pressure of operating fluid. The advantage of a designed hydraulic system is possibility of simulation of dynamic operating loading, which is obtained by measurement under real conditions, and thereby creates laboratory conditions as close to real conditions as possible. The laboratory device is constructed at the Department of Transport and Handling, Faculty of Engineering, Slovak University of Agriculture in Nitra.

  18. Characterization of a hydraulically induced bedrock fracture

    OpenAIRE

    2014-01-01

    Hydraulic fracturing is a controversial practice because of concerns about environmental impacts due to its widespread use in recovering unconventional petroleum and natural gas deposits. However, water-only hydraulic fracturing has been used safely and successfully for many years to increase the permeability of aquifers used for drinking and irrigation water supply. This process extends and widens existing bedrock fractures, allowing groundwater storage to increase. Researchers have studied ...

  19. Data Analytics of Hydraulic Fracturing Data

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jovan Yang [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Viswanathan, Hari [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hyman, Jeffery [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Middleton, Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-08-11

    These are a set of slides on the data analytics of hydraulic fracturing data. The conclusions from this research are the following: they proposed a permeability evolution as a new mechanism to explain hydraulic fracturing trends; they created a model to include this mechanism and it showed promising results; the paper from this research is ready for submission; they devised a way to identify and sort refractures in order to study their effects, and this paper is currently being written.

  20. Dimensionamento de motores para o bombeamento de água Sizing motors for water pumping

    Directory of Open Access Journals (Sweden)

    Delly Oliveira Filho

    2010-12-01

    Full Text Available O dimensionamento de motores com potência acima da necessária acarreta maior custo inicial, menor rendimento e menor fator de potência. Desde 1996, que se fabricam no Brasil motores elétricos com fator de serviço maior do que a unidade, obedecendo a valores prescritos em norma. O fator de serviço informa a potência disponível do motor em regime contínuo para as condições de carga nominal. A literatura técnica de dimensionamento de motores para acionamento de bombas hidráulicas indica a necessidade da adoção de acréscimos na potência dos motores. Tanto o fator de serviço, quanto o acréscimo na potência constituem fatores de segurança para o dimensionamento. Estes fatores de segurança têm a função de suprir maior demanda de potência devido a variações nas condições de trabalho, como curvas características da bomba ou do motor, e a qualidade de energia, como oscilação e desequilíbrio do sinal de tensão. Conclui-se que não seja utilizado acréscimo na potência no dimensionamento de motores com fator de serviço maior do que a unidade para acionamento de bomba hidráulica, tendo em vista que o superdimensionamento pode acarretar redução de rendimento do sistema e maior custo inicial. O dimensionamento que considera, simultaneamente, os dois fatores de segurança, implica superdimensionamento de 15% a 88%.Sizing motors with power above the required implies in higher initial cost, lower performance and lower power factor. Since 1996, that electrical motor is built in Brazil with service factors greater than the unity, obeying the standard values. The service factor informs the motor's available power in continuous regime under nominal condition. The technical literature for sizing motors to operate hydraulic pumps indicates the need of adoption of sizing factors in the motor's power. Both the service factor and the sizing factor are security factors to size motors. These safety factors have the function to supply