Design and testing of rotors for a cylindrical micro-machined micro ultrasonic motor

In this paper, a design and testing of rotors for a micro ultrasonic motor using micro-machined cylindrical bulk piezoelectric vibrator is introduced. This motor consists of the vibrator, a glass case and a rotor. The diameter of the piezoelectric vibrator was 0.8 mm and that of the motor case was 1.8 mm. Since the stator transducer is fixed at the end of the cylinder, it is easy to support the vibrator and the structure of the motor was not complicated. In addition, the vibrator and rotor were supported by glass case. This is important for micro ultrasonic motor because it is difficult to support the vibrator when the vibrator was miniaturized. We have fabricated and evaluated some types of rotors for the cylindrical shaped traveling type micro ultrasonic motor using this vibrator.