面内弯纵型直线超声电机的驱动与摩擦分析

Analysis on Friction Driving of Linear Ultrasonic Motor with In-Plane Bending and Longitudinal Mode

分析了直线超声电机定子的质点切向运动和法向运动,认为等速点(定子质点的横向分速度与动子运动速度相等的点)将椭圆运动接触弧对动子的作用分成了驱动部分和阻碍部分。通过对定子的纵向伸缩振动分析,得知定子质心随着定子的振动而发生颤动,质心的颤动使定子两端的受力不是一个定值,并使定子的驱动足对动子进行跳跃性地驱动,电机定子对电机动子进行跳跃式驱动和粘滑摩擦受到材料刚度、预压力、定子振幅等多种因素的影响。文中的摩擦机理分析也可为其他类型的超声电机的驱动与摩擦分析提供参考。

The friction driving principle of ultrasonic motors is a complex issue.In this paper,tangential motion and normal motion of the particle in the drive-foot of the stator are analyzed.Equal speed points(ESPs)are defined as where the transverse velocity of the particle is equal to the velocity of the slider.The elliptical arc contacted with the slider is divided by ESPs into the driving-arc and hindering-arc.When the motor works,the center of the stator mass vibrates as the longitudinal vibration of the stator.Force applied to the end of the stator is not a constant value because of this vibration,and the slider is driven intermittently by the stator.Friction between the slider and stator is influenced by factors such as preloading, stiffness of materials,or stator vibration.The analysis on driving and the motor′s friction can also provide a reference for ultrasonic motors.