Trial production of an ultrasonic motor using longitudinal and torsional vibrations of a rod vibrator driven by piezo-ceramic plates inserted in its axial direction

This paper deals with a rod-type ultrasonic motor using the first longitudinal and second torsional vibration modes of a rod vibrator driven by piezo-ceramic plates inserted in its axial direction; that is, metal blocks of rod vibrator are made as a quonset hut type. This construction is aimed at being suitable for miniaturization of a rod-type ultrasonic motor. Piezo-ceramics to excite longitudinal and torsional vibrations are rectangular in shape so that production of the motor is easy. By this construction of the motor, the mechanical strength of bonding the stator vibrator of motor is also made possible, because of the wide splicing surface of the metal blocks of the stater vibrator. In this paper, the authors investigate experimentally a prototype motor to confirm its operation and performance. It was found that the longitudinal and torsional mode vibrator newly proposed by the authors functioned as a stater vibrator for an ultrasonic motor, and the method of construction was also effective for the practical use of the motor.