Development of piezoelectric motor using momentum generated by bimorph

Abstract

Piezoelectric motors have been used in many applications where excellent controllability and fine position resolution are required or magnetic field noise should be eliminated. However, the piezoelectric motor has two major drawbacks. One is difficulty in maintaining constant vibration amplitude with temperature rise and wear, and the other is heat generation induced by dielectric and mechanical losses. A piezoelectric motor that can overcome these problems is proposed. It is operated using momentum exchange between a bimorph and a rotor. To maximize the motor's steady state velocity and static torque, a guideline is established using two bimorph models. The guideline is then partially validated by comparison between simulation and experiment results. There was no heat generation in several hours of testing.