Abstract: A kind of semi-analytical annular element is applied to mesh the inner web and outer annular plates of the stator of traveling wave type rotary ultrasonic motor (TRUM). In addition each tooth on the top of stator is modeled and its dynamical contribution to the substrate is calculated based on both dynamical substructure theory and Guyan method. Then the semi-analytical model of the stator is derived and possesses enough precision with the reduced DOFs. Furthermore the three-dimensional contact mechanism is investigated between the teeth of stator and friction layer glued on the bottom of rotor. Then the completed analytical model of the motor is derived with the integration of dynamic description of the motor’s rotor. The corresponding characteristic simulations by the proposed model are found to be in good agreement with the data from experiments. And it is investigated how geometric height of the teeth affects the characteristics of the motor. Finally it is pointed out that the slip friction in the radial direction leads to considerable waste of energy at the contact interface. On the other hand the measured characteristics could be inaccurate if the three dimension contact mechanism is simplified in the dynamic model. Thus the proposed model proves to be more accurate and can be used for the characteristics simulation and optimization design of the motor system.

Key words: Characteristics simulation, Dynamical substructure, Semi-analytical annular element, Traveling wave type rotary ultrasonic motor