Development Of Micro Traveling Wave Type Ultrasonic Motor

Ultrasonic motor(USM), which starts from 1970s, has many good features contrast to conventional electromagnetic motor, such as large torque with low speed, immunity from electromagnetic interference. So USM can role as a complementarity of electromagnetic motor. After the invention of USM, many countries such as the Former Soviet Union, Japan, America, German, China and South Korea started the research of USM. And Japan leads authorities in USM's research. It possesses many patents relating to USM technology. And some types of USM have been made into mass industrial production. They are Shinsei company's traveling wave type USM and Cannon company's USM equipped in digital camera for auto focus lenses.In the end of 1980s, our country began to do research about USM. They are about twenty or more research institutes now. Kinds of prototype motor have been designed. Many research findings have been found. But we don't hear about any type of USM has been used for commercial use till now. We still have a lot to do to shorten the gap with other countries who is leading authorities in USM.We study traveling wave minitype ultrasonic motor mainly on this paper. Firstly, the history, classification, features and the applications of USM are introduced simply. Based of these the task of this paper is proposed.Secondly, the structure and working principle of USM is presented. These include the piezoelectric effect of piezoelectric ceramic, the generation of standing wave, the superposition of standing waves into traveling wave, the moving locus of the stator's surface particle, the require of driving circuit and affect factor of motor's performance and so on .Thirdly, we will introduce the application of ANSYS program in the design of USM. This includes the modal analysis and harmonic analysis and the results.Fourthly, the fabrication and assembling of the motor, the design of driving circuit and the design of position detect set are introduced.Fifthly, we will measure the fabricated motor. The position control result will be showed.Finally, summarize the whole paper. And propose the future work about the study of traveling wave type USM. The motor used another kind of ceramic, such as lead-free ceramic will be talked about.