Design And Experimental Research On Deep-Sea Ultrasonic Motor Based On In-Plane Vibration

The deep sea contains a wealth of resources such as energy and minerals.The exploitation of marine resources plays a very important role in the development of the country.However,the deep sea environment is so harsh with high pressure and corrosiveness.Ordinary motors are difficult to adapt to the harsh environment of the deep sea.Ultrasonic motor is a actuator that convert electrical energy into mechanical energy by converse piezoelectric effect.Because of its high pressure resistance,it can be used in deep sea environment.It does not require an additional pressure balance device.It has a simple structure and strong environmental adaptability.The ultrasonic motor itself has self-locking power and high power density.And its response is quich.It is suitable for being used as a motor in deep sea environment due to its advantage.In this paper,a linear ultrasonic motor is designed by using the in-plane bending mode and radial extend mode of the ring for deep sea environment.First,the driving principle of the motor is analyzed and the equivalent circuit model of the motor was established.Then,the finite element analysis of the motor is carried out.The structural parameters of the motor are designed by modal analysis.The performance of the motor is predicted by harmonic response analysis.The motion path of the motor driven foot is obtained by transient analysis,and the driving principle of the motor is verified.Then,the finite element model is established for the ultrasonic motor after sealing and placed in water,and the vibration characteristics of the motor are analyzed by finite element analysis.Finally,the ultrasonic motor prototype was manufactured,and the corresponding experimental platform and deep sea environment simulation system of piezoelectric actuator were designed and built.To obtain the working mode shape and the corresponding natural frequency,the vibration mode test and impedance characteristic test of the piezoelectric actuator are carried out.The mechanical properties of the ultrasonic motor in air and water are experimentally tested by the experimental platform.In the air when the amplitude of the voltage which power motor is 150 V,the maximum speed of motor is 376mm/s and the maximum thrust motor can output is 2.5N.Under the water,when the amplitude of the voltage which power motor is 180 V,the maximum speed of motor is 346mm/s.