Mechanistic Study of a Low Frequency Piezoelectric Motor With Natural Frequency Adjustment Method

Abstract

A variable frequency piezoelectric motor is studied, which can generate rotational motion under the excitation of variable-mode vibration response units. Two variable-mode vibration response units fixed in the inclined plane are excited by the square wave and drive the friction disk to achieve the rotation and translation. Thus, the friction torque on the rotor changes periodically, and the rotor is driven to produce positive displacement output. By adjusting the mass distribution of the variable-mode piezoelectric wafer vibration response unit, the natural frequency of the low-frequency motor is adjustable. In order to achieve the maximum displacement output of the low-frequency motor, the simulation analysis is initially performed on the stiffness, mode, and vibration shape in line with the motion principle. Then the experiments of the variable-natural-frequency motion characteristics of the low frequency motor are carried out, and the maximum rotation speed of the designed piezoelectric motor is improved by the variablenatural-frequency motion characteristics and reaches 520 mrad/s.INDEX TERMS Piezoelectric motor, variable-natural-frequency, mass distribution.