超声电机减摩现象的仿真研究

Simulation Research on Antifriction Phenomenon of Ultrasonic Motors

基于商用有限元软件自动增量式非线性动力学分析(automatic dynamic incremental nonlinear analysis,简称ADINA),对超声电机的减摩现象进行仿真研究,提出等效摩擦因数的概念。分别在驻波激励和行波激励下研究了超声电机启动响应过程的瞬时等效摩擦因数。通过仿真计算,得到了不同预压力、激励频率和电压情况下的稳态等效摩擦因数。当预压力较小时,驻波激励下的减摩效应强于行波激励;当预压力较大时,超声振动受到抑制,此时2种激励方式的减摩效应近乎一致。研究发现:激励频率越接近谐振频率,预压力越小、驱动电压越大,减摩效果就越显著;其中,激励频率和预压力的影响要大一些。本研究为超声电机减摩现象的研究与应用提供有益的帮助。

Ultrasonic motor(USM) utilizes a frictional force generated by ultrasonic vibration to realize rotary or linear driving. However, the ultrasonic vibration can not only produce a frictional force but also lead to the occurrence of the antifriction phenom-enon. In this study, a detailed automatic dynamic incremental nonlinear analysis(ADINA) simulation research on USM’s antifriction phenomenon is proposed, as well as the equivalent friction coefficients. To measure the antifriction effect, the transient-state equivalent friction coefficients of USMs are studied respectively under the standing wave and traveling wave excitation. Meanwhile, during the simulation research, the steady-state equivalent friction coefficients under different preloads, excitation frequencies and voltages are obtained. When the preload is small, the antifriction effect under the standing wave excitation is stronger than that under the traveling wave excitation. However, when the preload is large, the ultrasonic vibration is suppressed, the antifriction effects of the two excitation modes are therefore almost the same. In general, as the excitation frequency is close to the resonant frequency, the preload becomes smaller. Meanwhile, the larger the driving voltage is, the more significant the antifriction effect is. Among them, the influence of excitation frequency and preload is greater. This paper provides a useful method for the research and application of USM’s ultrasonic antifriction.