Finite element analysis of stator vibration on ultrasonic motor driving fluid directly

The ultrasonic motor driving fluid directly solves some problems of the contact ultrasonic motors. Its stator doesn't contact with the rotor and the energy of the stator is transferred to the rotor through fluid medium. It becomes a new research direction in the field of the ultrasonic motors. Concerning differences of the stator vibration mode and the way of energy transfer from contact ultrasonic motor, a motor finite element model was presented in the paper. Through the modal analysis, harmonic response analysis and transient dynamic analysis when the motor is excited by voltage, the vibration frequency and the motion traces of some stator points were obtained, and the influence of stator vibration to motor running was discussed. The changes of the vibration frequency and amplitude produced by piezoceramic ring were studied in the paper, and the importance of choosing the appropriate thickness of piezoceramic ring was pointed out. In the end, the motor speed was measured when the voltage frequency and fluid height varied. The experimental results coincide with theory analysis.