Study of the tribological behavior of a thrust washer bearing

This study addresses the mechanisms that distress a flat-faced thrust washe r bearing system. This washer bearing system separates a helical gear and i ts carrier within a gearset. It was found that the bearing can experience d istress by the combination of rotational speed, axial load, and the sequenc e and rare of their application. Distress is defined as a sudden rise in th e real-time frictional torque and temperature. The various tests suggest the presence of hydrodynamic effects at certain r otational speeds and axial load combinations marked by decreases in the cal culated effective coefficient of friction with decreases in velocity. In th e tested cases, a distinct increase in the coefficient of friction occurs a t the instant of distress.