Life Prediction Model for Friction Material of Traveling Wave Ultrasonic Motor

Aiming at the dynamic contact process between stator and rotor,it is proposed that wear of friction material is generated by the reciprocating scratch of wave crests on stator surface.The visco-elastic contact model of stator and rotor is used to deduce the functions of normal pressure distribution and relative sliding speed,which are introduced to the traditional wear equation-Archard equation.Then,the wear and life prediction model of TWUSM friction material is established.In the model,the special relationship between time and distance are used to analyze contact interval,and the change of friction material thickness is also considered.Based on this model,the wear and life prediction curve of a TWUSM friction material is simulated.As a result,the life prediction curve is consistent with the experiment which verifies the rationality of the prediction model.