Performance Analysis of Tilting Pad Journal Bearing Considering Base Flexibility

For the bearing-rotor system with flexible bearing base, the deformation of the base has important influence on the bearing lubrication performance. A lubrication analysis model of tilting pad journal bearings thinking about the flexibility of the bearing base is proposed in this paper. The fluid-structure coupling problem of lubricating oil-film and the bearing is solved by finite difference method (FDM) and finite element method (FEM). Firstly, the finite element model of the bearing pad and the bearing base is established on a three-dimensional scale. The oil-film pressure field of each pad obtained by the FDM was applied to the surface of the bearing pad to calculate the deformation of it. Then, the load capacity of pads is taken as a force which applies on the bearing base at the location corresponding to the pivot of bearing pads to get the deformation of the base. Finally, for special working condition, the oil-film thickness of bearings can be corrected by considering the deformation of pads and bearing base. The results indicate that the bearing load capacity of tilting pad bearings decreases if the deformation of the base is considered. Therefore, the flexibility of the bearing base cannot be ignored when the bearing is applied to high-speed and heavy-load occasions.