Investigation on dynamic behaviors of roller bearing in the planetary gear set under revolution-rotation coupled conditions

The planet bearing has become the component most likely to fail in the planetary gear set (PGS), especially for the revolution-rotation coupled (RRC) condition. However, the dynamics of the planet bearing in the PGS are still not revealed yet. To address it, this paper proposes a comprehensive dynamic model of the PGS, in which the gear mesh and roller contact excitations, as well as the centrifugal and Coriolis effect, are considered. On this basis, the dynamics of the planet bearing are investigated, particularly for the roller-cage contact. The results show that significant impacts between the roller and the cage would occur under RRC conditions and increase with the revolution speed. The most critical factor determining the roller-cage impact force is the revolution centrifugal force of the roller. The radial and cage pocket clearances show less effect but can still influence the roller-cage impact force.