Patent ID: 7638926

Claim:
A piezoelectric ultrasonic motor comprising: a piezoelectric stator including a metal tube with an inner space and a plurality of piezoelectric elements mounted on the outer circumference of the metal tube, the piezoelectric stator straining with an electric field applied thereto; a rotary shaft including a rotation bar inserted into the inner space of the metal tube, a rotation member provided around the rotation bar in contact with the piezoelectric stator, the rotation member rotating in response to the strain of the piezoelectric stator, and a power transmission member provided at one portion of the rotation bar to transmit the rotation of the rotation member to an object to be transported; a power supply including terminals to apply a supply voltage necessary for the actuation of the piezoelectric stator; a housing to receive and encase the piezoelectric stator and the rotary shaft, wherein the housing has a hole to apply a supply voltage to the power supply and an opening to expose the power transmission member to the outside; and a separation preventing holder surrounding the piezoelectric stator and the terminals at a nodal point of the piezoelectric stator to prevent the terminals from being separated from the piezoelectric stator; wherein the rotation member is configured to contact with an upper surface or a lower surface of the piezoelectric stator.