A simulation analysis of the lubrication characteristics of the planetary cylindrical roller bearing in power coupling mechanism

The appropriate lubrication characteristics of the rotating components in the power coupling mechanism are crucial for ensuring its operational stability. In this paper, a computational fluid dynamics (CFD) numerical model of the cylindrical roller bearing considering the revolution of the planetary gear train is established. The global motion relationships of planetary cylindrical roller bearing (PCRB) are characterized through multiple reference frame (MRF) method. The volume of fluid (VOF) model is adopted to simulate the complex oil-air two-phase flow in the bearing cavity. The results indicate that the field distributions of the velocity vector, pressure and lubricating oil in PCRB are significantly migrated due to the centrifugal effect driven by the revolution of the planetary gear train. The outer side of the bearing cavity relative to the revolution center has relatively high lubricating oil content, while the inner side has relatively low content. This zonation phenomenon is further is intensified with the increasing rotational speed and temperature, resulting from enhanced centrifugal effect and reduced oil viscosity. This work can provide applicable guidance for the design of lubrication systems for planetary bearings.