Comparative Study On Lubrication Performance Of High Speed Hydrostatic Thrust Bearing At Center Loading And Eccentric Loading

With the rapid development of China's modern manufacturing industry,the demand for heavy machinery is increasing.Hydrostatic thrust bearing is the core component of heavy duty CNC machining equipment,and its performance directly affects the processing quality and operating efficiency of the equipment.Hydrostatic thrust bearing under ideal working conditions,the centroid of workpiece should be at the center of the rotary table,and then the workbench is subjected to the center load.However,in actual operation,sometimes the centroid of workpiece may not be at the center of the rotary workbench due to the influence of the workpiece shape and the clamping position,so the bearing will be tilted due to eccentric loading.If the workbench is tilted lightly,the workpiece quality will be reduced.If the workbench is tilted seriously,the local thickness of the oil film will become thinner.And even dry friction occurs,causing the hydrostatic thrust bearing to fail.It is very necessary for this subject to study the lubrication performance of hydrostatic thrust bearing under center load and eccentric load conditions.This paper takes double rectangular cavity multi-oil pad as the research object,studying the lubrication performance of high speed hydrostatic thrust bearing under center load and eccentric load conditions.Firstly,its structure and working principle are explained,and the flow equation,the bearing capacity equation,the oil film thickness equation,the oil film temperature rising equation and the viscosity-temperature relationship of lubricating oil of double rectangular cavity under center load and eccentric load conditions are deduced and calculated.Then the three-dimensional model of oil film under center load and eccentric load conditions was established by UG software,and the oil filmmesh is divided by ANSYS ICEM CFD software,and using ANSYS CFX software to set boundary conditions,solve calculations and execute post processing.Finally,through the method of controlling variables,temperature nephogram,pressure nephogram,average temperature and average pressure of oil film under center load and different eccentric load distance,center load and different eccentric load size conditions are is obtained,and the law of their change is obtained,providing a basis for the further optimization design of hydrostatic thrust bearing.In order to verify the correctness of theoretical calculations and simulation analysis,experimental verification is carried out in Qiqihar Heavy CNC equipment Limited Company.Taking double rectangular cavity hydrostatic thrust bearing as research object,experiment is carried out under a rotating speed of 100r/min,a load of 12 t and an eccentric load distance of 100 mm conditions.Finally,the experimental data is obtained to verify the correctness of the simulated and theoretical values.