Mechanical Characteristics on Asynchronous Parallel Connection of Linear Ultrasonic Motors

Abstract

In order to meet the demand for high power linear ultrasonic motors (LUSMs) for many applications, the concept, asynchronous parallel connection (APC) of LUSMs, has been proposed. The basic principle is that multiple stators (vibrators) alternately drive a slider (rotor) in a vibration cycle, the actual driving frequency then increases by the order of the quantity of stators, and better output performance can be obtained. Analysis shows, in the APC, increasing the contact frequency between stator and slider can enhance the output force, speed of LUSM, while at the same time, the mutual interference of different stators in synchronous parallel connection (SPC) can be avoided. Experimental results of double-driving-tips LUSMs demonstrate that, in APC, over 30% more loading force is obtained than in SPC, and over 25% more is obtained than the sum of loading forces from single LUSM driven respectively. In APC, the no-load linear velocity of LUSM is increased more than 10% from that of individual LUSM driving.