The Effects of Three-Dimensional Pad Deformations on Tilting-Pad Journal Bearings Under Dynamic Loading

Pad distortions are generally not taken into account for the dynamic study of tilting-pad journal bearings. The objective of this paper is both to show the influence of the three-dimensional (3-D) pad deformations due to the pressure field on the bearing response and to analyse the bearing behavior for various unbalance eccentricities. Similar orbits are obtained using 2-D or 3-D pad deformations; however, due to the axial profile of the film thickness, the minimum film thickness obtained with the 3-D model is about 40 percent lower than the one obtained with the 2-D model for the greatest unbalance eccentricity. The maximum pressure is decreased by about 16 percent when the 3-D model is used but that value is nearly similar to the one obtained without deformation. The dynamic behavior of the bearing is largely modified when the dynamic load is greater than the static load.