Research On Hollow Traveling Wave Ultrasonic Motor

The working principle of the hollow traveling wave ultrasonic motor is to convert the electrical energy into the mechanical energy of the stator vibration by using the inverse piezoelectric effect of the piezoelectric ceramic piece,and to drive the rotation of the rotor by the frictional coupling between the stator and the rotor of the motor.In addition to its advantages of fast response,simple structure,self-locking of power failure and no electromagnetic interference,its hollow structure further expands the scope of use.It can be widely used in fields with high electromagnetic compatibility,optical,precision cameras,high-end automobiles,etc.However,there are still few studies on hollow traveling wave ultrasonic motors,and there is little torque.The shortcomings of poor heat dissipation and poor speed stability make it extremely urgent to design a traveling wave type ultrasonic motor with large driving torque,thinning and large hollow space.In this paper,a hollow traveling wave ultrasonic motor is innovatively designed for the optical focusing system.Based on the research on the structure of traveling wave ultrasonic motor at home and abroad,the corresponding mathematical model and finite element model are given by theoretical analysis and finite element simulation,and the parameters of the stator structure are optimized and tested.The research contents are as follows:1.Summarize the characteristics of ultrasonic motor different from electroma-gnetic motor and classification of ultrasonic motor.The current status of application of ultrasonic motor at home and abroad is elaborated.The development status of the hollow motor and the shortcomings of the current research are pointed out,and the advantages and application requirements of the hollow traveling wave ultrasonic motor designed in this paper are discussed.2.Analyze the principle of operation of hollow traveling wave ultrasonic motor.The formation mechanism of the traveling wave on the stator surface,the elliptical motion of the particle surface of the stator surface and the external factors affecting the elliptical motion of the particle are described in detail.3.According to the engineering requirements,the overall structural scheme of the hollow motor is innovatively designed,and the structural design of the motor stator is based on the overall structural scheme.The initial dimension design of the stator was carried out,and the modal analysis was carried out by using the ANSYS software to establish the electromechanical coupling dynamics model of the stator.The stator piezoelectric ceramic sheet is designed to be polarized,bonded,and applied with voltage.4.Using the APDL language in ANSYS,the stator is optimized by multiobjective optimization method.The total objective function is obtained by linear weighting of the subobjective function,so that the total target is reduced from the initial 9.603 to 3.595,and the mechanical performance is optimized.Finally,the optimized stator is subjected to dynamic analysis to verify the optimization per formance.5.Machining and assembling the motor prototype,and setting up the experimental platform of the motor for impedance matching,which improves the driving efficiency of the motor.The stator is subjected to frequency modulation and voltage regulation experiments to study the mechanical properties of the motor to meet the design requirements.