Design and analysis of a cylindrical screw-type ultrasonic motor driven by six transducers

The screw-type ultrasonic motor was successfully used in fields of optical focusing system, medical instruments, and so on. In this paper, a cylindrical screw-type ultrasonic motor driven by six transducers is proposed. The motor mainly contains six fixed parts, twelve piezoelectric plates, six transducers, an elastomer and a screw shaft. The piezoelectric plates are bonded to the opposite outside surfaces of transducers and the d31 working mode is adopted. A traveling wave processing along circumferential direction of the elastomer is composited to drive screw shaft and the rotary-linear output motion is achieved without additional conversion mechanism. The motor is designed and its exciting mode is clarified in detail. The vibration performance of the motor is analyzed using Finite Element Method (FEM). The prototype is fabricated and tested. The testing results indicate that the vibration performance of the motor is in good agreement with the simulation results.