Effect of shearing deformation on the transient response of a traveling wave ultrasonic motor

Some works take into account the shearing deformation of frictional material, but its effect on the transient response has not yet been considered. In this paper, optimal deformation angle and resonance frequency of frictional material are investigated. Force expressions in the stator/rotor interface are developed. Mechanical characteristics taking into account the effect of shearing deformation are deduced and presented. It is shown that the shearing deformation affects the initial state as well as on the steady state. Also, the fast time response of the motor is deduced. Results of the simulation are validated using the measurements made by other researchers on traveling wave piezoelectric motor AWM90-X, Daimler-Benz type, and a prototype USM(AWM-90).