ULTRASONIC STEPPING MOTOR USING SPATIALLY SHIFTED STANDING VIBRATIONS

This paper proposes a novel configuration of ultrasonic stepping motor . It is based on the simple phenomena that an object on a vibrating bo dy moves to the nodal position of the vibration mode and rests there. The use of standing flexural vibrations of a ring simplifies both the structure of the motor itself and the driving circuit. To move the nod al point, several standing modes spatially shifted with respect to eac h other are excited one after another by switching the driving positio n on the stator ring at the timing of stepping clock. In this paper, a 60-step stepping motor is designed and fabricated for trial, where an optimum combination of the order of the mode used and the number of t he spatial phase shifts is discussed. The basic characteristics of the prototype motor is also studied experimentally.