共查询到20条相似文献,搜索用时 203 毫秒
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零开口流量阀在电液负载仿真台中的应用 总被引:1,自引:0,他引:1
零开口流量阀在电液负载仿真台中的应用哈尔滨工业大学裴忠才苏东海吴盛林刘庆和哈尔滨万昌本州制鞋有限公司单伟1引言电液负载模拟器是模拟飞行器在飞行过程中舵面所受空气力矩的加载装置,是典型的被动式电液力伺服系统,根据该系统的特点,其伺服阀应选择大预开口的压... 相似文献
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针对电液负载模拟器中的多余力矩问题,以阀控摆动马达电液负载模拟器为对象,在分析研究多余力矩产生机理及影响因素的基础上,提出一种同步结构解耦新方法,具体实现是将加载执行元件设计成复式双层结构,外层同步马达用于跟踪承载对象进行位置同步控制,内层马达用于加载,通过复式结构加载执行元件实现变被动加载为主动加载,从根本上解决了多余力矩问题。给出了复式摆动马达的参数匹配原则、密封及结构设计方案,仿真分析了内外层马达油道配流方式的合理性。最后,通过小梯度加载下电液负载模拟器性能的仿真分析验证了同步结构解耦新方法的正确性及有效性。 相似文献
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针对活塞式膨胀机的工作过程,利用能量方程、气体状态方程、拉格朗日方程等建立了非线性瞬时的热力学和动力学模型,实现对系统的精确建模和性能研究。利用MATLAB/Simulink得到的仿真转速/功率与实验平台测得的转速/功率进行比较,验证了数学模型的正确性。通过仿真模型研究了进气压力、负载扭矩对活塞式膨胀机系统性能的影响,并分析了进气温度对系统性能的影响。研究表明:在一定压力条件范围内,随着负载扭矩的增加,活塞式膨胀机的输出功率和效率分别增大到一定峰值后减小,最大峰值功率为3.97 kW,最大峰值效率为38.8%;负载扭矩40 N·m,进气压力2 MPa时,排气阶段的压力为 0.55 MPa,占进气压力的27.8%;提高进气温度会提高系统的输出功率和效率。 相似文献
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G. W. Melenka D. S. Nobes P. W. Major J. P. Carey 《Sensing and Imaging: An International Journal》2013,14(3-4):57-80
The design and testing of an orthodontic torque simulator that reproduces the effect of archwire rotation on orthodontic brackets is described. This unique device is capable of simultaneously measuring the deformation and loads applied to an orthodontic bracket due to archwire rotation. Archwire rotation is used by orthodontists to correct the inclination of teeth within the mouth. This orthodontic torque simulator will provide knowledge of the deformation and loads applied to orthodontic bracket that will aide clinicians by describing the effect of archwire rotation on brackets. This will also impact that design on new archwire\bracket systems by providing an assessment of performance. Deformation of the orthodontic bracket tie wings is measured using a digital image correlation process to measure elastic and plastic deformation. The magnitude of force and moments applied to the bracket though the archwire is also measured using a six-axis load cell. Initial tests have been performed on two orthodontic brackets of varying geometry to demonstrate the measurement capability of the orthodontic torque simulator. The demonstration experiment shows that a Damon Q bracket had a final plastic deformation after a single loading of 0.022 mm while the Speed bracket deformed 0.071 mm. This indicates that the Speed bracket plastically deforms 3.2 times more than the Damon Q bracket for similar magnitude of applied moment. The demonstration experiment demonstrates that bracket geometry affect the deformation of orthodontic brackets and this difference can be detected using the orthodontic torque simulator. 相似文献
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普通异步电动机的输出转矩基本恒定不变,而抽油机曲柄轴净转矩确是交变载荷,两者的载荷特性无法达到"和谐"的匹配,直接导致抽油机运行效率低下、能耗增高。利用游梁结构和导杆机构设计的曲柄导杆式六杆机构抽油机,实现了曲柄轴净转矩曲线呈小波动形态变化,大大提高了电动机的负荷率和电动机功率利用率,实现了抽油机节能降耗。根据设计方案,建立了导杆式六杆机构抽油机在复合平衡方式下的运动和动力学模型,并以Matlab优化工具箱为平台,对设计方案进行全参数优化设计,以实际载荷工况对导杆式六杆机构抽油机节能效果进行了对比分析。 相似文献
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设计了一种电驱高压气动减压阀,采用直流电机驱动活塞直动式减压阀,通过调节直流电机的转动角度来控制减压阀的出口压力。减压阀的调压性能受到直流电机控制电压、调压弹簧刚度以及活塞作用面积的影响。为此,建立电驱高压气动减压阀的数学模型,基于MATLAB/Simulink搭建电驱高压气动减压阀的仿真模型,分析直流电机控制电压、调压弹簧刚度以及活塞作用面积对其出口压力的影响,得出电驱高压气动减压阀合理的设计参数,最后对其进行阶跃响应与正弦响应仿真分析。结果表明,电驱高压气动减压阀具有良好的调压精度和动态特性,对同类型气动减压阀的结构设计和优化以及控制特性的改善具有一定的指导意义。 相似文献
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In this article, numerical analyses of hydrodynamic lubrication and dynamics of the crank, rolling piston, and vane were carried out to study the tribological performance of a rotary compressor. Dimensionless Reynolds equations of journal and thrust bearings in dynamic load condition were derived and solved numerically. To deal with the lubrication of the rolling piston, the effect of the nonuniformity of tangential velocity over the bearing surface on the Reynolds equation was taken into account. In addition, combined with the analyses of dynamics and kinematics of the crank, piston, and vane, the angular velocities of the crank and piston as well as the motion mode between the piston and vane were studied. Analysis results illustrate characteristic oil film pressure distributions of the crank and piston bearings, which are different from that of common journal bearings. Under the influences of dynamic load and eccentricity of the cam, the wedge effect as well as the stretch and squeeze effect contribute greatly to hydrodynamic pressure. The relative motion mode between the piston and vane tip is not always pure sliding but accompanies rolling in some cases, which depends on the magnitude of the friction coefficient between the piston and vane tip. The analysis results are helpful for the improvement of rotary compressor design. 相似文献
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In this study, a numerical analysis for the piston secondary dynamics of small refrigeration reciprocating compressors is performed. In general, the length of cylinder in this class of compressors is shortened to diminish the frictional losses of the piston-cylinder system. So, the contacting length between piston and cylinder wall is in variable with the rotating crank angle around the BDC of the reciprocating piston. In the problem formulation of the piston dynamics, the variation in bearing length of the piston and all corresponding forces and moments are considered in order to determine the piston trajectory, velocity and acceleration at each step. A Newton-Raphson procedure was employed in solving the secondary dynamic equations of the piston. The developed computer program can be used to calculate the entire piston trajectory and the lubrication characteristics as functions of crank angle under compressor running conditions. The results explored the effects of some design parameters and operating conditions on the stability of the piston, the oil leakage, and friction losses. 相似文献
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A five-station hip joint simulator for wear rate studies. 总被引:2,自引:0,他引:2
V Saikko P Paavolainen M Kleimola P St?tis 《Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine》1992,206(4):195-200
The aim of the work has been the development of a hip joint simulator for comparative wear rate studies of long duration. A five-station apparatus has been designed, constructed and tested. Five total hip joints can be tested at the same time in identical conditions. The flexion-extension motion and the superior-inferior component of the joint contact force are incorporated. The motion is electromechanical and the loading pneumatic. The angle and load waveforms are fixed and simulate level walking. For accurate wear measurements each station employs a control prosthesis. The conditions of the control prosthesis in regard to loading, exposure to lubricant and environment temperature (37 +/- 1 degree C) are identical to those of the test prosthesis. The acetabular cups can be readily removed for periodic wear measurements and reassembled in exactly the original position. Extensive tests have shown that the simulator is a practical and reliable instrument in the wear rate studies of various designs of total hip joint. 相似文献