摘要：针对小型超声电机两自由度驱动功能的需求，分析了两种对称性结构的振动特性，及其在超声电机中的典型应用方式和电机工作原理；并基于两种对称性，设计了一种通过低刚度梁串联组合换能器结构，通过对电机振动特性进行有限元仿真，阐明了工作原理，进而设计、组装了一种新型超声电机并进行了性能测试及分析。新型电机采用了多种模态复合激励的方式，实现了平面两自由度的驱动功能。
关键词：超声电机；压电换能器； 结构对称性

Abstract: To the demand of two DOF driving function of smallscale ultrasonic motor, the vibration characteristics of two symmetric structures were analyzed. The application method of structural symmetries in ultrasonic motor and the working principle were analyzed. Based on the two structural symmetries, a new structure of combined transducers in series connecting with low stiffness beams was designed. The vibration characteristics were simulated by FEM analysis to illustrate the working principle of motor. Then, a new ultrasonic motor was designed, fabricated and tested. The new motor utilizes the multimode excitation method, and realizes two degree of freedom (DOF) driving functions.
Key words: ultrasonic motor； piezoelectric transducer； symmetric structure