基于板簧支撑结构的3自由度超声波电机静力学分析

Statics analysis of 3 DOF spherical traveling wave ultrasonic motor based on a spiral form of spring

提出一种采用板簧支撑结构的3自由度球形行波型超声波电机.概述该电机基本结构和驱动原理,使用板簧结构较好地解决了球转子与行波定子之间的对心问题,定转子之间的预紧力更加均匀一致.通过坐标变换关系和定转子的位置关系,分析球转子的受力情况,给出定转子接触圆周的接触力关系式;根据球转子和各个行波定子的力平衡方程,得到球转子球心的微位移和定子的轴向压紧量与定子预紧力的关系并做了仿真,进而分析受力情况与电机结构参数对电机定转子接触的影响,形成了板簧结构的3自由度超声波电机的理论基础.研制样机的球转子直径40 mm,定子直径30 mm,实现的保持力矩0.09 N·m,空转转速90 r·min-1.

Abstract： Three degree - of - freedom spherical traveling wave ultrasonic motor is a kind of multi de-gree - of -freedom motor. A novel type of traveling wave three degree - of - freedom spherical ultrasonic motor based on a spiral form of the spring was developed in this paper. In order to get its motion rule, statics analysis of the motor was to be discussed. The key issue of the self- regulation between the sta- to~ and the spherical rotor are solved by making use of the special - made spring. The preload between the stators and the spherical rotor is more smooth . The driving principle and basic structure of this kind of ultrasonic motor were introduced and the coordinate transformation model and position relation of rotor and stators of spherical ultrasonic motor were also set up. Then stress of rotor and contact force of rotor and stators on the contact circle were also analyzed. Through the force balance equation of its stator and rotor, relation of micro displacement of the center of rotor and axial compaction and preload force of sta-tots were presented in this paper. Also the basic relation of this kind of spherical motor were given out. Through simulation, the mechanical characteristics of this type of motor is got. This article lays a theo- retical foundation for control strategy of the motor. The diameter of prototype motor is 40 mm in rotor and 30 mm in stator and maximum holding torque is 0.09 N · m, maximum speed is 90 r · min^-1. From the above discussion and practical experiments availability of devices is to be verified.