Optimum structural design of the miniature u-shape linear ultrasonic motor

USM (Ultrasonic Motor) is widely used in the aerospace, medical, micro-electromechanical systems (MEMS) for its distinguished feature including low speed, high torque, electromagnetic compatibility, and self-locking function etc. In this paper, we propose a small U-type linear motor stator structure, with the use of finite element analysis to select the structural parameters of the stator. Determine the final structural parameters of the stator to make the two operating mode frequencies which are identified by the modal assurance criteria as close as possible. The purpose of optimizing the stator structure is achieved. According to the experiment results, the motor has the virtues of high power efficiency and operation stability.