Research On The Separation Type Bending-bending Hybrid Vibration Piezoelectric Motor Driven By Sinusoidal/Resonant Synthetic Square Wave

In this paper,the characteristics of resonant piezoelectric motor and non resonant piezoelectric motor are compared.Based on the principle of the PZT motor which actuated by the combination vibration between the longitudinal bending vibrations,a separation type bending-bending hybrid vibration PZT motor has been designed which with the advantages of three kinds of piezoelectric motors above mentioned.The main research contents are as follows:(1)The PZT effect,the characteristics of PZT and several important PZT parameters are introduced.According to the characteristics of the motor designed in this paper,the most suitable piezoelectric ceramics.(2)The action principle of the longitudinal-longitudinal hybride vibration piezoelectric motor is analyzed in detail,and the design idea of the separation-type bending-bending hybrid vibration piezoelectric motor is put forward.The action principle of the new piezoelectric motor driven by mechanical square wave is introduced in detail.The piezoelectric motor driven by square wave has better characteristics.Finally,the principle of synthetic square wave is explained from a theoretical point of view.(3)Two kinds of separation type bending-bending piezoelectric motors are designed.The method of matching the ratio of the first and the third order bending vibration frequency to be 1:3 is studied by the finite element method(FEM).Then the advantages and defects of the I type piezoelectric motor are analyzed,and the design defects are found.Based on this defect,we designed ? type piezoelectric motor.Finally,the finite element method is used to study how to reduce the accuracy requirement of the piezoelectric cantilever beam.(4)First,the methods to reduce the accuracy requirement of the piezoelectric cantilever beam are verified by experiments.Then the working characteristics of the piezoelectric motor with different driving position and driven position are studied,and the optimum driving position and the driven position are selected;the load characteristics of the motor driven by sinusoidal wave signal are studied.When the voltage of stator is 140V and the voltage of mover is 100V,the no-load speed is 3.35mm/s and the maximum traction force is 3.96N;the variation of the no-load characteristics of the piezoelectric motor driven by the approximate.square wave is investigated when the stator and the voltage are changed respectively;the experimental results show that the no-load speed of the motor increases with the increase of the excitation voltage of stator when the excitation voltage is certain(less than 180V).When the excitation voltage of stator is certain and the excitation voltage of mover is less than 180V,the motor speed increases with the increase of the voltage of mover,when the excitation voltage of the mover is greater than 180V,the no-load speed of the motor remains basically the same.The load characteristics of the motor is studied when the fundamental frequency excitation voltage of the stator and the mover are 140V and 100V,respectively.The no-load speed is 6.62mm/s and the maximum traction force is 3.6N.Finally,the load characteristics of the piezoelectric motor driven by sine wave and synthetic square wave are compared.When the load is relatively small,the piezoelectric motor driven by square wave has higher speed,and with the increase of load force,its speed decreases faster and its maximum load capacity is also smaller.The conclusion is verified that the efficiency of the piezoelectric motor driven by square wave is higher.