摘要
为了分析间隙对平面机构的动力学效应,利用MATLAB软件中的动态仿真工具SIMULINK建立了含间隙机构动力学仿真模型,并以含间隙曲柄滑块机构为例,介绍了运用此方法的过程。通过仿真数据,得到以下结果:与理想无间隙机构相比,含间隙机构稳定性较差。在含间隙机构中,当曲柄以100 rad/s转动时,运动副间隙始终大于半径间隙,轴销与轴套始终保持连续接触;当曲柄以低速20 rad/s转动时,系统处于极不稳定的震荡状态,在转至300°左右时,运动副间隙小于半径间隙,脱离接触,发生明显的分离碰撞现象。在含间隙机构中,曲柄以低速20 rad/s转动,当取法向阻尼系数为175 N.s/m时,副元素发生明显的分离碰撞现象;当取法向阻尼系数为220 N.s/m时控制了副元素的分离,副元素一直处于连续接触状态。由仿真结果可知,运动副间隙的存在降低了机构的稳定性,而提高机构的速度或增大法向阻尼系数可降低运动副间隙对机构稳定性的影响。
Based on SIMULINK, a new method is proposed for simulating linkage mechanisms with clearances in order to analyze the dynamic effects of clearances. And as an example, dynamic simulation of a slider crank with clearances is given. Based on the simulation data, the effects of clearances, damping coefficient and the rotation speed on the dynamic behaviors are studied： compared with ideal mechanisms, mechanisms with clearances are less stable; as for mechanisms with clearances, when the crank rotates at the speed of 100 rad/s, the actual clearances are always above the radium of clearances, axle pin and axle cover keep contact throught the rotation; when the crank rotates at the speed of 20 rad/s, mechanisms are in an unstable state, at an angle of about 300°, the actual clearances are below the radium of clearances, pairs lose contact, which results in collision between them; with the speed of 20 rad/s,when damping coefficient is assumed 175 N ·s/m, distinct separation and collision happen between pairs~ when damping coefficient is assumed 220 N · s/m, separation and collision are controlled. Thus conclusions are drawn as follows： the existence of clearances reduces the stability of linkage mechanisms, while the increase of rotation speed or damping coefficient can reduce the side effect of clearances and improve the performance of mechanisms.
出处
《青岛大学学报（工程技术版）》
CAS
2005年第3期16-21,26,共7页
Journal of Qingdao University(Engineering & Technology Edition)
基金
国家自然科学基金资助项目(50075041)
山东省自然科学基金资助项目(Q99F10)
关键词
机构
间隙
动力学
仿真
mechanisms
clearances
dynamic
simulation
