Influence of Recess Dimensions and Jacking Oil Flow Rate on the Performance of Tilting Pad Journal Bearings with Jacking Oil Mechanism

Tilting pad journal bearings (TPJBs) often use externally pressurized oil to lift off journals for safe start and stop procedures and enhanced load capacity under heavy loads. This article presents an in-depth analysis of TPJBs with the jacking oil mechanism. The finite element method is used to solve the pressure distribution, and the Newton-Raphson technique is used to solve the resulting pad forces, pad moments, and oil flow rates in the pad's recess region. Excellent correlations with the archival test data validate the numerical model. Two sets of comprehensive parametric analyses are conducted to study the effects of jacking oil flow rate and recess geometry on the bearing's static and dynamic characteristics. It is found that the bearing performance improves with increasing jacking oil flow rate and decreasing recess area but at the expense of increased breakaway pressure. Thus, the selection of jacking oil flow rate and recess geometry must consider the bearing performance and breakaway pressure simultaneously.