Modelling of non-contact ultrasonic motor by means of boundary element method

Objective of this work is to study possibility of application of boundary element method (BEM) for modelling of non-contact ultrasonic motor (USM). Efficiency of modelling using BEM is studied on non-contact USM with asymmetric design of rotor based on standing-wave flexural vibrations of ring-shaped stator. Modelling is implemented using open source software OpenBEM. Results of modelling show that BEM can be used as efficient tool for design and modelling of USM complementary to finite element method (FEM) and experimental methods. Particularly, application of BEM provided additional results (in comparison with FEM) on effect of asymmetry on operation of the motor. Particularly, it is shown that non-periodic motion of the rotor (continuous rotary motion) is possible only in the case, when two kinds of asymmetry are present: structural asymmetry of the rotor and asymmetry of vibratory excitation of the stator.