行波型超声波电动机PZT极化分区优化设计方法

摘要

In order to improve the mechanical output performances of the traveling-wave type ultrasonic motor ( USM), an optimal design method based on the energy indexes for the USM was proposed according to the force transform model of the ultrasonic motor contact surface between the stator and the rotor.The finite element model of the USM stator was established and the energy indexes under several different operating modals of the USM were computed. Based on the energy indexes, the effects on the vibration modals and the polarization pattern of the piezoelectric ceramic (PZT) of the USM were studied, and a modified B04 polarization pattern of the PZT was proposed to improve the mechanical output performances of the USM. Research results indicate that the output speed and the output torque of the modified USM are 960r/min and 9mN · m, respectively which are both larger than the output speed and the output torque of the USM without modifying the PZT. The proposed optimization method for PZT polarization pattern contributes to improving the structure design and the output performances of USMs.%为提高行波型超声波电动机的机械输出性能,根据超声波电动机定转子接触面力传递模型提出了基于能量指标的超声波电动机优化设计方法,以能量指标参数作为电动机优化设计的评价依据.建立超声波电动机定子有限元模型,计算得到电动机不同工作模态下的能量指标,在此基础上重点探讨了能量指标对压电陶瓷的极化分区模式优化设计的影响,提出改进的B04超声波电动机极化分区模式;研究结果表明PZT极化分区改进后的超声波电动机的速度和力矩分别为960r/min和9mN·m,电动机的性能指标(速度和力矩)较未改进前的提高了一倍.提出的PZT极化分区优化设计方法可以为超声波电动机的优化设计和输出性能的提高提供理论参考.