Research On Oil Film Pressure Loss Of Double Rectangular Hydrostatic Sliding Bearing

With the development of modern manufacturing industry towards the direction of intelligent and heavy-duty,hydrostatic sliding bearing,as an important part of large-scale processing equipment,is widely used because of its use of fluid lubrication,high bearing capacity,stable operation,small friction and other advantages.However,in continuous operation,the hydrostatic oil film will become thinner due to pressure loss,and local dry friction will occur in serious cases,which will lead to the failure of lubrication function.Therefore,it is of great significance to study the process of pressure loss of hydrostatic sliding bearing comprehensively and systematically to improve the machining accuracy of machine tools.In this study,double rectangular hydrostatic sliding bearing is taken as the research object,Firstly,the influencing factors of pressure loss are analyzed in detail.According to the theory of computational fluid dynamics,the bearing capacity equation,pressure loss equation and oil film thickness loss equation of double rectangular cavity hydrostatic oil pad are established,and the viscosity temperature relationship of No.32 hydraulic oil is fitted.The influencing factors of pressure loss are the decrease of viscosity of hydraulic oil caused by temperature rise and the rotation of turntable flow loss and pressure distribution changes.Using the finite element software for simulation analysis,the 3D model of the supporting oil film is created firstly.The mesh is divided in the finite element software ICEM,and the high quality mesh model is obtained.The boundary conditions are defined,and the pre-processing of the simulation is completed.The pressure loss value and pressure loss rate of hydrostatic oil film under different working conditions are obtained through the simulation analysis of variable viscosity in FLUENT.It is found that under the same initial oil film thickness and the same load,the higher the rotating speed is,the greater the oil film pressure loss and oil film thickness loss will be.When the rotating speed is the same,the pressure loss rate will increase with the decrease of the load.In this study,the maximum pressure loss rate is about 45% of the total pressure,in which the pressure loss rate caused by temperature is 33%,and the pressure loss rate caused by rotating speed is only 12%.The flow loss can be ignored by calculation.Based on the steady-state simulation results,the law of oil film thickness loss caused by pressure loss is obtained by using 6DOF dynamic grid method.It is found that under the condition of minimum load and maximum speed,the maximum oil film thickness loss value is about 18%,and the oil film thickness value under different conditions is obtained,which lays a foundation for experimental verification.Finally,through the experimental method,the experimental results are verified,and the experimental results are compared with the simulation results to verify the correctness of the research results.The research results have important scientific significance for the optimal design of hydrostatic equipment and the improvement of the bearing accuracy of hydrostatic sliding bearing.