Contact Force Numerical Analysis of a Wedge-Wave Ultrasonic Motor

Abstract

This study investigated the dynamic displacement response of an elastic friction layer under load by simplifying a circular cylindrical wedge-wave ultrasonic motor (WW-USM) to a two-dimensional (2D) contact problem through suitable assumptions. A model of contact friction between a stator and rotor was established using the finite element software 3dansys, and transient contact mechanics between the stator and rotor were simulated. Given actual displacement and external force boundary conditions, appropriate contact parameter values were determined, the convergence of the solution was tested, reasonable results were obtained, and the motor performance curve of revolution speed versus torque was estimated. Piezoelectric conduction was applied in the ultrasonic motor prototyping of measurement characteristics, and the control voltage applied to the rotor prestressing to replace the traditional compression spring caused by uneven force from the rotor was selected to avoid adversely affecting the motor performance. The 3dansys simulation results indicate that the parameter values selected for the model for contact friction between the stator and rotor are crucial to the determination of the real friction constant. A set of optimal contact friction model parameter values was obtained in this study and provided reference information for contact mechanics analysis and design improvements in transient response.