A Novel Low-Frequency Piezoelectric Motor Modulated by an Electromagnetic Field

Abstract

For expanding the driving mode of the piezoelectric motor, a novel piezoelectric motor modulated by a magnetic field is proposed. This driving system combines piezoelectric driving and magnetic modulation together and can transform the reciprocating swing of the stator into step running of the rotor via the intermittent magnetic clamping between the rotor and stator. For investigating the inherent character of dynamics, the dynamic equations of key parts of the driving system are established. The natural frequencies and mode functions of the driving system are solved. A prototype was fabricated to prove the dynamic analysis and measure the output characteristic. The results show that the nature of the frequency measured from the test is coincident with theoretical analysis. In addition, by applying the driving frequency of 3 Hz, the voltage of the modulating signal of 4.5 V, the phase difference α between driving signal and modulating signal of 30°, the ideal outputs are 0.1046 rad/min for velocity and 0.405 Nmm for torque.

Keywords

• electromagnetic modulation
• piezoelectric motor
• modal function
• output characteristic