Ultrasonic driving motor

摘要

The Ultrasonic driving motor comprises an ultrasonic vibrator (10) having a center whole and a edge generating elliptically progressive waves, a contact member (18) contacting a plurality of divided parts with each other, a ring-like elastic member (19) for pressing the contact member (18) to the edge of the ultrasonic vibrator, a fixing member (11) fixed to the center hole of the ultrasonic vibrator (10), a rotor (15) mounted to rotate by a bearing (14) mounted to the fixing member (18), and a connection member (16) for connecting the contact member to the rotor (15). The control circuit for driving an ultrasonic driving motor comprises an encoder for detecting revolution number of the ultrasonic driving motor, a central processing unit for receiving an output of the encoder, a digital-to-analogue-converter for converting digital signals from the central processing unit to an analogue voltage, a voltage-to-frequency-converter for converting the analogue voltage to frequency signals, a phase control circuit for regulating the phase of the frequency signals by the output of the central processing unit, and a drive circuit for driving the ultrasonic driving motor by phase controlled signals from the phase control circuit.