Development of the piezoelectric motor using momentum generated by bimorphs

Piezoelectric motors have been used in many applications where excellent controllability and fine position resolution are required and/or magnetic-field noise should be eliminated. However, the piezoelectric motor has two major drawbacks, difficulty in maintaining vibration amplitude constantly with temperature rise and wear and heat generation induced by dielectric and mechanical losses. In this article, a new piezoelectric motor that can overcome these problems is proposed. The proposed piezoelectric motor is operated using momentum exchange between four bimorphs and a rotor. In order to maximize the steady-state velocity and static torque of the proposed motor, a guideline is established using two bimorph models. The guideline is partially verified by comparison between simulations and experiments. There was no heat generation in a few hours of operation in experiments.