The study of adhesion layer in linear ultrasonic motors and its effect on output performance

Abstract Frictional wear at the stator/mover contact interface can lead to changes in friction characteristics and instability in motor operation, limiting their application. This study focuses on the frictional properties of the stator/mover contact, exploring the mechanism of adhesive layer formation and its impact on motor operating characteristics. Firstly, the operating mechanism of the motor and the formation mechanism of the adhesive layer are analyzed. Subsequently, based on mixed lubrication tribology theory, a friction coefficient estimation model is established, and the influence of adhesive layer thickness on the friction coefficient is investigated. Simultaneously, a dynamic model of the linear ultrasonic motor is constructed to analyze the impact of the friction coefficient on motor operating characteristics. Finally, methods for measuring the thickness of the adhesive layer are proposed, and experimental studies on the variation of adhesive layer thickness over time and its impact on the friction coefficient and motor operating characteristics are conducted. Experimental results show that the thickness of the adhesive layer increases over time, while the friction coefficient, operating speed, and thrust initially decrease and then increase.