Investigation of the Contact Zone of Ultrasonic Motors at Different Modes of Exciter Vibrations

A polarization vector of the piezoceramic element and location of excitation electrodes on its surface determine the resonance modes of the high frequency vibration exciter. In its turn the modes of vibration play a key role in the functionality of ultrasonic motor. Two different regimes of operation are analyzed — when the contact zone of the resonator performs elliptic and unidirectional motions. Though the mechanical characteristics of the ultrasonic motor in both cases are comparable, detailed analysis of the contact surface shows very different wears. Computational simulation and experimental investigations are used to analyze the contact zone of ultrasonic motor. Laser holography is used to identify and control the regimes of motion. Atomic force microscopy is used for analysis of contact surfaces.