The Design And Research Of Rotating Ultrasonic Motor With Empty Rectangular Plate

Ultrasonic motor is a new type of micromotor,which has developed rapidly for decades since 1980 s.Ultrasonic motor is widely used in many fields,such as biomedical,aerospace,vehicle and so on,because of its advantages of miniaturization,no electromagnetic interference,fast response and good controllability.With the continuous development of technology and processing technology,different structures of ultrasonic motor are emerging to adapt to different working situations,so its application field is bound to continue to expand,and its application prospect is bound to be very broad.The working principle of ultrasonic motor is to use the converse piezoelectric effect of piezoelectric material to excite the piezoelectric vibrator to produce elongation or contraction deformation,and then transform the micro motion of the piezoelectric vibrator into the macro motion of the driving foot through the elastomer stator,and use the friction coupling to drive the rotor to rotate.Ultrasonic motor is a kind of mechanical and electrical integration product which covers many interdisciplinary subjects.Firstly,this paper systematically expounds the general situation,classification,research status at home and abroad and application fields of ultrasonic motor,summarizes the existing ultrasonic motor structures,and points out the advantages and disadvantages of ultrasonic motor.Then,the paper introduces the natural vibration and forced vibration of the side beam to meet the working mode of the stator of the ultrasonic motor,analyzes the characteristics and parameters of the piezoelectric vibrator of the rotary ultrasonic motor,and obtains that the transverse vibration mode of the piezoelectric vibrator will be excited under the voltage excitation of a certain frequency to realize the forced vibration of the elastomer.The working mechanism of the rotating type ultrasonic motor is designed: the intersection of two vertically distributed side beams in the stator assembly forms an elliptical motion track,and then drives the rotor to rotate.A rotating ultrasonic motor driven by four legs of rectangular plate is designed.The material of the stator component is selected.The sensitivity analysis of the structural parameters of the motor is carried out by using the optimization analysis component in workbench.The parameters of the stator structure,such as the width of the side beam,the height of the driving foot,the side length of the thin plate and the position of the driving foot,are optimized.The driving efficiency of the ultrasonic motor is improved The natural vibration mode of stator plate is determined.The finite element method is used to analyze the modal of the optimized stator assembly to find the natural vibration mode needed by the stator assembly.The harmonic response analysis is used to get the amplitude frequency characteristic curve of the stator assembly.The optimal driving frequency of the voltage is 26340 Hz.The transient analysis simulates the moving mode of the stator assembly in a moving cycle,and verifies the working mechanism of the ultrasonic motor.The contact analysis of the stator and rotor of the rotating ultrasonic motor designed in this paper is carried out,and the contact model of the stator and rotor is established by using the finite element software.In the finite element analysis software,the motion trace of the driving foot is simulated and analyzed to obtain the three-dimensional motion trace curve of the particle on the end face of the driving foot.Finally,the optimal pre tightening force for driving the rotor rotation is 4N by changing the pre tightening force.