ULTRASONIC MOTOR USING A LARGE-DIAMETER TORSIONAL VIBRATOR WITH SLANTSLITS

This paper deals with a large-diameter rod-type ultrasonic motor, in w hich only the torsional vibration is excited piezoelectrically. This n ew motor is designed to improve the performance of a relatively high-t orque motor by increasing the diameter of the stator vibrator. The cha racteristic feature of, the motor:construction is that many slits are cut aslant on the vibrator end-face in contact with a rotor in order t o form small slanted cantilever beams; that is, these cantilever beams operate in the bending vibration due. to coupling with the main torsi onal vibration of the stator and lift the rotor in the inclined direct ion to rotate it. Therefore, this motor operates fundamentally one-way , and thus its advantage is that it is easily driven with a single pow er source. The first part of this paper concerns the simulated results of an aslant slit torsional vibrator, especially on its slanted canti lever beam, and the second part describes the experimental investigati on of the prototype motor.