A new disc-type ultrasonic motor

A new approach to establish a design rule for a new disc-type ultrasonic motor (LEMUM) is proposed. In this design rule, an elastic model of lateral elliptical motion induced by exciting piezoelectric ceramics embedded on an elastic metal disc is setup to estimate the frictional driving force between the rotor and stator of the ultrasonic motor. Furthermore, we evaluate the coupled interaction between mechanical vibration and electrical excitation by electrical equivalent circuit analysis. For the confirmation of the proposed design rule, we measure the characteristics of the new disc-type ultrasonic motor. As a consequence, the proposed design rule is very adaptive for disc-type ultrasonic motor. (C) 2001 Elsevier Science B.V. All rights reserved.