Driving Mechanism of a Travelling Wave Ultrasonic Motor(Travelling Wave on the Stator Surface Subjected to the External Excitation)
中山, 智了 ,
Nakayama, Tomoaki ,
山下, 清隆Yamashita, Kiyotaka
A travelling wave ultrasonic motor is an actuator that exploits vibration. Vibration in the ultrasonic range occurs in the stator, which is the oscillator of this motor. Because the vibration amplitude is extremely small, however, experimentation that employs the actual unit is difficult. In the research presented here, the stator of the ultrasonic motor was replaced by an elastic beam of finite length. A theoretical analysis of lateral vibrations of the beam, generated by imposing a forced displacement at the same frequency with a phase difference to both ends of this beam, was conducted. An apparatus was also fabricated with shakers installed on both ends of the beam. Appropriateness of the theoretical analysis was verified through experiments employing this apparatus. Consequently, generation of travelling waves, standing waves, and receding waves reliant upon the phase differences at the two ends became apparent through the theoretical analysis. The experimentation further confirmed undulations similar to the theoretical analysis results.