Abstract

In rotating machines, tilting pad journal bearings (TPJBs) are widely used because of their enhanced design stability in comparison with alternative bearing configurations. In the present research, a thermohydrodynamic (THD) lubrication model for a tilting pad bearing with injection is developed. Within the THD lubrication model, the lubricant is also fed into each pad through a central injection orifice. The effects on the lubricant oil film pressures and temperatures and subsequent influences on the system dynamic behavior were investigated. Another important factor considered within the THD model is associated with the flexibility of the pivot of each pad and its impact on the behavior of the bearing when subjected to direct lubricant injection. The numerical model results are compared with the measurements of the rotor equilibrium position within the bearing and the pad temperatures obtained from the test rig designed specifically for the TPJB geometry with and without central pad injection. Pad temperatures are measured before the injection orifice position and after it. Agreement between experimental and model-predicted results provides confidence in the model’s ability to evaluate the dynamic behavior of the bearing and its effect on the complete system through the stiffness and damping coefficients.

摘要

在旋转机械中，可倾瓦轴颈轴承（TPJB）由于与其他轴承配置相比具有增强的设计稳定性而被广泛使用。在本研究中，开发了一种用于带注射的可倾瓦轴承的热流体动力学（THD）润滑模型。在THD润滑模型中，润滑剂还通过中央注入孔注入每个垫片。研究了对润滑油膜压力和温度的影响以及对系统动态行为的后续影响。在THD模型中考虑的另一个重要因素与每个轴瓦的枢轴的柔韧性及其在经受直接润滑剂喷射时对轴承性能的影响有关。将数值模型结果与轴承内转子平衡位置的测量值以及从专门为TPJB几何体设计的，带有和不带有中心衬套注射的试验台获得的衬套温度进行了比较。垫板温度在喷孔位置之前和之后进行测量。实验结果与模型预测结果之间的一致性为模型评估轴承的动态性能及其通过刚度和阻尼系数对整个系统的影响提供了信心。