Lubrication Performance Prediction Of Hydrostatic Thrust Bearing Considering Deformation Of Friction Pairs

Hydrostatic thrust bearing is widely used in production and processing because of its high precision,bearing capacity and a series of advantages and it has become an indispensable part of CNC equipment.But high speed and heavy load machining equipment has higher requirements on bearing capacity and stability of hydrostatic thrust bearing.Hydrostatic thrust bearing often cause oil film deformation due to thermal deformation and force deformation which leads to friction pairs deformation and friction failure in the process of processing.So it is an urgent problem to research friction failure.In this thesis,Hydrostatic thrust bearing for vertical lathe is taken as the research object.The oil film prediction model for the deformation of the friction pairs is found by the method of theoretical analysis,numerical simulation and experiment.The lubrication performance is analyzed,and the friction failure is prevented.The basic equations of fluid lubrication are derived by theoretical calculation,and the bearing capacity and flow rate of the rectangular cavity oil pad of hydrostatic thrust bearing are prevented.Three-dimensional modeling software is used for constructing models and fabrication of film,oil pads,rotary table and base.The oil film model is meshed by ANSYS ICEM CFD software,and the divided mesh is imported into CFX and the boundary conditions are set.The temperature field and pressure field of oil film under different working conditions are calculated and solved by ANSYS software CFX.The oil film temperature field and pressure field are introduced into ANSYS Workbench and to predict the deformation of the oil film shape through the deformation analysis of rotating worktable and base.According to the prediction of oil film shape,the model of oil film,oil pad,base,rotary worktable and so on are built and assembled by using modeling software.The oil film of deformation model is meshed by ANSYS ICEM CFD software,and the divided mesh is imported into CFX and the boundary conditions are set.The temperature field and pressure field of oil film after deformation under different working conditions are calculated and solved by ANSYS CFX software.The calculated temperature and pressure fields of the deformed oil film are applied to the worktable and the base as the body load.The deformation of the friction pairs are calculated through ANSYS Workbench fluid structure coupling analysis.Prediction model of real shape of gap oil film considering deformation of friction pairs is obtained,according to the total deformation of worktable and base.It lays a good foundation for studying the mechanism of oil film lubrication and solving the deformation problem.With five meter vertical lathe hydrostatic pressure as the research object,,and experiments are carried out in Qiqihar Heavy CNC equipment Limited by Share Ltd.The oil film temperature is collected under different working conditions,and the influence of rotating speed and load on lubricant temperature is analyzed;The oil film thickness of the middle lateral edge of the oil film is measured by displacement sensor,and the oil film shape is predicted based on the measured data.By comparing the experimental data with the theoretical data,the correctness of theoretical calculation and numerical simulation is verified.