Abstract:Under extreme working conditions, the lubricating oil film in the clearance of hydrostatic bearing is subjected to the combined action of strong extrusion pressure and strong shear force. Therefore, the temperature of lubricating oil increased, and the viscosity decreased, resulted in the oil film becomes thinner. During the operation, 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, and an idea that use the micro-gap oil film morphology to characterize the lubrication state of the hydrostatic support was proposed. The equations such as temperature rise, power consumption, thermal-solid coupling deformation, fluid-solid coupling deformation and oil film shape were derived for the new double rectangular cavity hydrostatic bearing with tilting oil pad. In the first, Solidworks software was used to establish the three-dimensional geometric model of hydrostatic support oil film, ANSYS ICEM software was used to carry out high-quality gap oil film structured mesh division, oil film mesh was introduced into ANSYS CFX to set the corresponding boundary conditions, and MATLAB was used to fit the viscose-temperature relation curve of 46^# lubricating oil for variable viscosity simulation. The distribution characteristics of the oil film temperature and oil film pressure fields under extreme operating conditions were solved and analyzed. In the second, the thermal-mechanical coupling deformation of the friction pairs and the three-dimensional oil film shape were obtained by data processing in MATLAB to judge the lubrication status of hydrostatic support. In the end, an oil film thickness measuring device was set up 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 showed 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.