A multi-modes cylindrical piezoelectric rotary motor with a single-vibrator

This paper proposes a cylindrical piezoelectric motor, which used only a single vibrator to generate bidirectional rotations through changing the driving signal frequencies. The stator of the motor consists of a brass tube and a piezo-plate. The finite element analysis and theoretical analysis indicated that the motor could generate a clockwise rotation at a driving frequency around the second bending mode, and an anticlockwise rotation around the third bending mode. The prototype motor, whose stator was 6 mm in diameter and 26 mm in length, can rotate clockwise around a driving frequency of ~22.208kHz and anticlockwise around a driving frequency of ~51.605kHz. The motor achieved a maximum speed of 840 rpm. This research has provided a way of designing piezoelectric motors with simple structure and easy control, which has the potential for miniaturization.