Research On The Two Degree Of Freedom Linear Motor Driven By Tian Type Piezoelectric Vibrator

At the beginning of development,linear ultrasonic motor has emerged all aspects of modern technology development due to its large thrust ratio,low noise,power failure,self locking and miniaturization.The purpose of this paper is to enrich the type of the linear ultrasonic motor,Based on the theory of ultrasonic motor,a Tian type ultrasonic motor is proposed,The following work has been completed:First,The development of linear ultrasonic motor in recent decades is summarized,and its research status and application fields at home and abroad are analyzed.The advantages and disadvantages of existing linear ultrasonic motor are analyzed,and its future development trend is predicted.Secondly,the inverse piezoelectric effect of piezoelectric material in ultrasonic motor is introduced theoretically,and the vibration theory of elastic body is analyzed.It is concluded that an inherent mode of elastic body must have a fixed frequency corresponding to the conclusion.At the same time,under the proper electric excitation,the piezoelectric material can resonate with the stator matrix and excite its natural mode,so as to get the desired mode of operation.Then,through the theoretical research of ultrasonic motor,a Tian type stator ultrasonic motor model is proposed.Based on the sensitivity analysis of the Tian type stator,the design size is 53.4mm×53.4mm×7.4mm.After the modal extraction is done,the strain and displacement curves of the piezoelectric material can be obtained,and the location of the piezoelectric material and the drive end can be obtained.Finally,the distribution setup of the piezoelectric material is given,and the trajectory of the driving end in a cycle is analyzed.According to the requirements of motor working environment,the types of stator matrix and piezoelectric material are defined,and the contact situation between dynamic stator is analyzed.The conclusion that the motor has the best preload force is the best driving state.Next,through the finite element simulation analysis of the stator structure,we get the elliptical motion track with a long axis of 1.5?m and a short axis of 1.3?m at the driving end when the excitation voltage is 250 V and the excitation frequency is32286 Hz.The response characteristics of the stator drive end are explored when the voltage,frequency and phase are different.Finally,under the condition of setting up the moving material,through thecontact model between the stator and the rotor,we get the preload of 150 N on the moving surface when the excitation voltage is 250 V and the excitation frequency is32286 Hz.The overall speed of the motor reaches 38mm/s.and the relationship between the speed of the motor and the pretightening force under the action of different pretightening forces is explored,and the existence of the best pretightening force is confirmed.