超声电机接触界面的两种简化有限元模型

Two Simplified Finite Element Models for Contact Analysis of Ultrasonic Motor

采用ANSYS的三维点点接触单元,在刚性转子假设条件下,对旋转型行波超声电机接触界面的三维接触状态进行有限元分析。根据行波的特点,给出了时间域、空间域两种简化有限元模型。从有限元分析结果中得到了接触界面的动力输出特性,结果表明两种方法是一致的。空间域模型可以将预压力作为给定条件直接施加,这便于分析预压力对接触界面输出性能的影响;时间域模型则可用于分析接触界面的粘滑现象。空间域模型求解耗费的机时较少,更可以将此模型融入超声电机整机的优化设计。

For the traveling wave type rotary ultrasonic motor (TRUM),the contact interface of stator and rotor was modeled by a three dimensional point-to-point element using ANSYS. According to the characteristics of the traveling wave,two simplified models established in the space and time domain were presented. The output characteristics and losses at the contact interface were calculated from the models. The results show that the two methods are in good agreement. The preload force can be directly used as a given condition in the space domain,which is convenient to analyze the influence of preload force on TRUM. However,the stick-slip phenomenon can be analyzed in the time domain. The space domain model costs less time to be solved,which benefits integrating the model into the design of a complete TRUM.