Influence of squeezing and interface slippage on the performance of water‐lubricated tilting‐pad thrust bearing during start‐up and shutdown

Abstract

AbstractThe film thickness varied because of the swing of the tilting‐pad thrust bearing, which introduced the squeezing effect in the start‐up and shutdown periods. The interface slippage might occur between the water and the pad surface, because of the effects of water polarity and surface energy of the material. To study the performance of the water‐lubrication tilting‐pad thrust bearing during start‐up and shutdown, a transient model considering the effects of squeezing and interface slippage was established. The effects of squeezing and interface slippage on film‐thickness distribution, nondimensional minimum film thickness, circumferential angle, and friction torque were studied. The theoretical friction torque was consistent with the experimental result quite well. The result demonstrated that the effect of squeezing was higher in the opening process than in the closing process; the interface slippage effect influenced the start‐up and shutdown significantly, blocking the formation of the water film. The friction torque of the bearings increased if the interface slippage existed, because the solid contact friction‐force increase was higher than the fluid shear‐force decrease in the mixed lubrication. When both effects worked simultaneously, the interface slippage dominated in the start‐up period. During the shutdown situation, as the rotational speed sustained a loss, the interface slippage was abated, where the influence of the squeezing effect dominated gradually.