Mechanism analysis and output characteristics experiments of an ultrasonic motor with circumferential surface drive

A kind of ultrasonic motor, whose rotor is driven by stator’s inner circumferential surface, has been designed and fabricated. The paper has analyzed the stator deformation characteristics under bending mode by using finite element method, identified the motor’s working mechanism with two-phase voltage drive, and studied the different functions of tangential and radial displacements of the stator’s inner circumference small teeth under bending mode and pointed that the above mentioned displacements along two directions of small teeth could drive the rotor continuously with single-phase voltage. The paper has discussed the motor’s rotary direction reversing and put forward a concrete scheme of reversing with single-phase voltage drive. The mode of the stator was obtained by experiment. Under two-phase and single-phase voltages, running experiments of the motor have been accomplished and the corresponding characteristics curves have been drawn. Taken above analysis result as driving mechanism, a kind of thin-type standing ultrasonic motor can be developed further.