Inertial Piezoelectric Linear Motor Driven By A Single-phase Harmonic Wave With Automatic Clamping Mechanism

With the continuous development of micro-motors,piezoelectric motors have been widely used because of their low speed,high torque,anti-electromagnetic interference,high accuracy,high power density.Compared with other types of piezoelectric motors,inertial motors have the advantages of small size,simple structure and high precision.However,traditional inertial piezoelectric motors are usually driven by sawtooth waves and work in quasi-static state,which makes their output force and operation speed low.High friction loss in the step process makes their efficiency low.The stepping displacement of the traditional inertial piezoelectric motor has obvious backstepping distance,which leads to the unstable operation of the motor.In order to solve the above problems,researchers have put forward various solutions,but there are still many problems.A new type of automatic clamping linear inertial piezoelectric motor is presented in this paper to improve the output performance of the inertial motor,simplify the control strategy and reduce the friction loss.The main research contents:1)An automatic clamping mechanism consisting of piezoelectric bimorphs and flexible hinges in series is proposed.Simplified modeling of automatic clamping mechanism and dynamic simulation using Simulink are carried out.The modal and harmonic responses of automatic clamping mechanism are analyzed by Comsol.A test platform was built to measure the static and dynamic response of the automatic clamping mechanism.2)The working principle of automatic clamping inertial linear piezoelectric motor is described,and the dynamic model of the new motor is established.Simulink simulation is used to verify the feasibility of the driving scheme.Design the structure and pre-tightening mode of the new motor.3)Make principle prototype and test its performance.The maximum speed of the prototype is 3.178mm/s,the maximum output force is 4.25 N,the maximum resolution is 1.14 um,and the maximum working efficiency is 6.2%.The test results show that the new piezoelectric motor proposed in this paper has higher output force and work efficiency than the traditional inertial piezoelectric motor.