新型行波直线超声电机的结构与有限元分析

Structure and Finite Element Analysis of a Novel Traveling Wave Linear Ultrasonic Motor

提出了一种新型行波直线超声电机结构,该电机利用2个固有频率接近的面内弯曲模态叠加形成沿周向传播的行波,从而驱动动子做直线运动。首先,基于有限元法建立了考虑定、动子三维接触的整机动力学模型,对定子结构尺寸进行设计;其次,通过该模型分析了定、动子之间的接触力传递过程、电机的驱动机理、电机稳定运行时驱动足的椭圆运行轨迹、电机的启停特性以及不同输入参数下电机的输出性能等动力学特性;最后,试制原理样机,搭建实验平台对电机性能进行测试。研究结果表明:该电机工作原理可行,机械输出性能良好;所建立的有限元模型合理,使用该模型能预测电机的性能,并进一步指导电机的设计及优化。

In this paper,a novel traveling wave linear ultrasonic motor is proposed,which uses the combination of two in-plane bending modes with same natural frequencies to form a traveling wave propagating in the circum-ferential direction,thereby driving the mover to move. A dynamic model considering the three-dimensional contact between the stator and the slider is established based on the finite element method. Through the model,the contact force transmission process between the stator and the slider,the driving mechanism of the motor,the elliptical motion trajectory of the driving foot at the steady state and the output performance of the motor under different input parameters are analyzed. Finally,the experiment of principle prototype is carried out. Research results show that the mechanical output performance of the motor is good,and the finite element model is reasonable. It can not only predict the performance of the motor,but also provide corresponding theoretical guidance for the optimization of the motor.