Lubricating Performance Prediction Research Of High Speed And Heavy Load Hydrostatic Thrust Bearing

Large-scale heavy vertical lathe, representative products of China’s equipment manufacturing industry, is widely used in important industrial sectors of energy, transportation, heavy machinery, aviation, defense, shipbuilding and other countries. Hydrostatic thrust bearing is a core component for heavy NC equipment, its performance has a directly effect on the machining accuracy and operation efficiency, the main characteristics of the hydrostatic bearing is low friction coefficient, high carrying capacity, low starting torque, long working life. With the rapid development of high-speed cutting technology, rotating machinery must be more and more high-speed, high efficiency, and high-precision, also require high-precision and low-power bearing as a system support. The reliability and service life of hydrostatic thrust bearing have a significant impact on its performance, however under the conditions of high-speed heavy load, the shape of the oil film becomes very complex, the great change will occur in oil flow state, basic hypothesis and the boundary conditions. It is very difficult to accurately predict the lubricating properties of the oil film in the high-speed conditions through the classic lubrication theory performance formula, so it is necessary to predict the lubricating performance of the oil film considering the influence of thermal deformation and elastic deformation.By taking high speed and heavy load hydrostatic thrust bearing as the research object, three-dimensional model of hydrostatic thrust bearing is established and the parameter equations of oil cavity is given in this paper. According to static pressure technology and computational fluid dynamics, pressure field and temperature field of oil film is simulated through Ansys cfx software, convective heat transfer coefficient of hydrostatic bearing is calculated at different speeds. Based on tribology, theory of elastic-plastic deformation and heat transfer, taking one-twelfth of total model as the research object, elastic-plastic deformation of hydrostatic bearing is simulated, at last, prediction model of oil film is given according to total deformation of hydrostatic bearing as a basis for further study.The experiment of 5m vertical lathe worktable is operated in Qiqihar Heavy CNC Co., Ltd. The temperature data of rotary table and base are collected under different speeds. In order to verify the accuracy of simulation research, the simulation results and the experimental data are analyzed.