A Novel High-Speed Rotary Ultrasonic Micro Motor

In this paper, a high-speed rotary ultrasonic motor based on out-of-plane flexural vibration mode is proposed, fabricated and characterized. This motor consists of one tapered rotor and one metal disk shaped stator. There are four piezoelectric plates bonded to the bottom face of the metal disk for exciting the stator's out-of-plane flexural vibration mode. The shaft is used to amplify the vibration amplitude of the metal disk. The rotor pressed on the conical surface of the shaft can be driven to rotate by the traveling wave propagation via the contact friction force. The preload between the stator and rotor is applied by one nut screwed to the solid shaft. The stator has a diameter of 22mm and weight of 13 gram. Experimental results show that the proposed motor can rotate at the maximum value of 7000 rpm applied with the driving voltage of 350 V
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