极端工况静压支承润滑状态的微间隙油膜形貌表征

极端工况条件下静压支承运行过程中的极易发生摩擦学失效且润滑状态极难获得，为解决此技术难题，设计一种新型油垫可倾式静压支承结构，形成静动压混合推力轴承，提出利用微间隙油膜形貌来表征静压支承润滑状态的想法。针对新型双矩形腔油垫可倾式静压支承，建立温升和功耗、热固耦合变形、流固耦合变形及油膜形状等数学模型。分析极端工况下微间隙油膜温度场和油膜压力场分布特征，求得摩擦副热力耦合变形，获取三维油膜形貌，判断静压支承润滑状态。搭建油膜厚度测量装置，获得油膜厚度状态，验证理论分析和数值模拟所获得的油膜形貌的正确性。结果表明：极端工况下该结构润滑效果大大改善，轻载高速时热变形起主导作用，油膜厚度差异较大。低速重载时力变形占主导地位，油膜较平滑。油腔外侧封油边交角处变形最大，此处油膜最薄，易发生摩擦学失效。

Morphology Characterization of Micro-clearance Oil Film of Hydrostatic Bearing Under Extreme Conditions

During the operation process, the hydrostatic support is prone to tribological failure and the lubrication state is difficult to obtain under extreme conditions. In order to solve this technical problem, the new inclined oil pad of hydrostatic support structure was designed to form a static and dynamic pressure hybrid thrust bearing. There is a idea that use the micro-gap oil film morphology to characterize the lubrication state of the hydrostatic support. The equations such as temperature rise, power consumption, thermal-solid coupling deformation, fluid-solid coupling deformation and oil film shape are derived for the new double rectangular cavity hydrostatic bearing with tilting oil pad. In the first, the distribution characteristics of the oil film temperature and oil film pressure fields under extreme operating conditions are analyzed. In the second, the thermal-mechanical coupling deformation of the friction pairs and the three-dimensional oil film shape is obtained to judge the lubrication status of hydrostatic support. In the end, set up an oil film thickness measuring device to obtain the oil film thickness state and verify the correctness of the oil film morphology that obtained by theoretical analysis and numerical simulation. The results show that the lubricating performance of the structure is improved significantly under extreme working conditions. In the light load and high speed situation, the thermal deformation plays a leading role and the oil film thickness is uneven. Correspondingly, and the oil film is smoother when the force deformation dominates at low speed and heavy load situation. The greatest deformation appeared at the corners of the sealing oil edges on the outside of the oil cavity, where the oil film is the thinnest, which is prone to tribological failure.