Meshing Drive Mechanism of Double Traveling Waves for Rotary Piezoelectric Motors

Dawei An,Jinrui Xiao,Zhongwei Liang,Xiaochu Liu,Weiquan Liu,Weiqing Huang

doi:10.3390/math9040445

Abstract

Rotary piezoelectric motors based on converse piezoelectric effect are very competitive in the fields of precision driving and positioning. Miniaturization and larger output capability are the crucial design objectives, and the efforts on structural modification, new materials application and optimization of control systems are persistent but the effectiveness is limited. In this paper, the resonance rotor excited by stator is investigated and the meshing drive mechanism of double traveling waves is proposed. Based on the theoretical analysis of bending vibration, the finite element method (FEM) is used to compare the modal shape and modal response in the peripheric, axial, and radial directions for the stator and three rotors. By analyzing the phase offset and vibrational orientation of contact particles at the interface, the principle of meshing traveling waves is discussed graphically and the concise formula obtaining the output performance is summarized, which is analogous with the principles of gear connection. Verified by the prototype experimental results, the speed of the proposed motor is the sum of the velocity of the stator’s contact particle and the resonance rotor’s contact particle, while the torque is less than twice the motor using the reference rotor.

Highlights

Piezoelectric actuation is a key technology to achieve the function of precision drive and microfabrication
From the mode shape analysis, we find that the ninth eigenfrequency of the resonance rotor is very close to the stator, while the value of reference rotor is far away from the stator with the difference of 1116 Hz, especially the ninth mode shape does not exist for the flexible rotor within the sweeping range
As the modal frequency of the reference rotor and flexible rotor is far away from the stator, the ninth mode shape could be faintly energized by the vibration of the stator, of which the response amplitudes are much smaller than the stator and resonance rotor

Summary

Introduction

Piezoelectric actuation is a key technology to achieve the function of precision drive and microfabrication. The piezoelectric actuators using novel materials and complex modes are nowadays investigated to further enhance the torque-weight ratio and working stability. Wu et al designed the lightweight rotary piezoelectric motors using the polymer-based vibrator and studied the high-order vibration mode yielding a relatively high electromechanical coupling factor [18,19]. Cao et al researched the dynamics of a polymer-based bimodal piezoelectric motor by using the Kelvin–Voigt viscoelastic model [20].

Methods

Results

Discussion

Conclusion