Design And Experimental Research Of A Rotary Traveling Wave Ultrasonic Motor With Double-sided Staggered Teeth

Ultrasonic motor is an emerging science and technology involving many fields such as mechanics of materials,physics and electricity.The ultrasonic motor is a driving device that uses the converse piezoelectric effect of piezoelectric ceramics to convert electrical energy into mechanical energy.It breaks through the traditional driving concept of electromagnetic motor using magnetic field to generate torque.With a new drive theory,it has a place in the field of motors.Because its novel principles and structure,ultrasonic motors have many outstanding advantages such as large torque in the low speed range,good dynamic response,silent operation,fine positional accuracy and self-locking without applied electric power.Compared with electromagnetic motors,ultrasonic motors play an irreplaceable role in many fields.So far,the ultrasonic motor has gradually become the best choice in the fields of aerospace,camera auto-focus system,medical equipment,and precision instruments.Firstly,this article introduces the structure and working principle of the traditional traveling-wave ultrasonic motor,and analyzes the advantages and disadvantages of the existing traveling-wave ultrasonic motor under single-sided and double-sided driving.Based on this,the main research object of this paper is proposed——a rotary traveling wave ultrasonic motor with double-sided staggered teeth.Under the premise of double-sided drive design,the new staggered teeth configuration is used to ensure the overall structure of the motor,and further propose a new ceramic excitation method.By constructing a simplified model of the working state of the stator,the vibration trajectory equation of the particle on the end face of the stator driving tooth is established,and the motion trajectory of the particle on the end face of the motor driving tooth is deduced as an elliptical motion trajectory.The structural parameter sensitivity analysis is carried out for the stator of a rotary traveling wave ultrasonic motor with double-sided staggered teeth,and the modal analysis and transient analysis are carried out using ANSYS to study the influence of various structural parameters on the motor performance.By analyzing the resonance of the stator under different structural parameters,the frequency and the amplitude of the driving tooth mass point are used to determine the reasonable structural parameters.On the basis of the simulation analysis,the hidden dangers that may be caused by the later assembly of the motor were further considered,and the structural parameters of the motor stator were finally determined.According to the final structure parameters,the finite element model of the motor stator is established for modal analysis and the influence of the stator support plate on the vibration characteristics of the motor stator is analyzed.Then,through transient analysis,the motion trajectory of the particles on the different driving teeth of the stator is studied,which is compared with the previous theoretical analysis.The comparison of the results shows that the motion trajectory of the particle on the stator driving tooth is ellipse,which is consistent with the theoretical analysis result.For the rotary traveling wave ultrasonic motor with double-sided staggered teeth in this paper,experimental research is carried out,an experimental platform is built,the admittance/impedance characteristic test and vibration characteristic test of the motor are carried out,and the mechanical output characteristic test is finally carried out.The experimental results show that the maximum power,the maximum no-load maximum speed and maximum output torque of the prototype are 0.64 W,99 rpm and 0.19 N·m at a voltage of 150 Vp at a frequency of 28.25 k Hz.