Effects of Load Direction on Performance of Tiliting Pad Journal Bearings

At the previous works for tilting journal pad bearings( TPJBs),most TPJBs are designed to operate with the load either directly on-pad( LOP) or directly between-pad( LBP). However,in practice,in some cases,the load direction can change dramatically in operation. With the current requirements for the analysis of dynamic characteristics of the rotor-bearing systems,the effects of the load direction on the bearing performance must be known. So,in this paper,the effects of load direction on the static and dynamic characteristics of TPJBs are obtained with theoretical analysis based on the hydrodynamic lubrication theory,and the influence of load direction on the performance of TPJBs in different structure and operating parameters is also analysed. The results show that the load direction has considerable effects on the static and dynamic characteristics of the TPJBs,especially for the TPJBs that are operating under heavy load and high rotor speed. And for the operating condition that load direction changed rapidly,TPJBs with more pads,smaller length to diameter ratio,larger clearance ratio and smaller perload ratio can reduce the performance fluctuation with the variation of load direction.