Research On Influence Factors Of Stability Of Hydrostatic Rotary Table

As the core component of CNC machine tools,the hydrostatic rotary table directly affects the accuracy,processing quality and reliability of CNC machine tools.Under ideal working conditions,the hydrostatic rotary table should run smoothly and efficiently.However,in actual operation,changes in speed,temperature,additional load,flow and other factors can cause vibration,and then cause instability.The instability of the workbench will seriously affect the machining quality of the workpiece,and cause the local thickness of the oil film to become thin.In the worst case,dry friction will occur,making the hydrostatic rotary workbench invalid.Therefore,it is necessary to study the influence factors of the stability of the hydrostatic rotary table in this subject.Due to many factors affecting the stability of the hydrostatic rotary table.This article mainly analyzes three factors: speed,inlet temperature and load.Taking double rectangular cavity hydrostatic pressure rotary table as research object.Research methods using theoretical analysis,dynamic simulation and experimental testing.First,introduce the structure and working principle of the hydrostatic rotary table.Basic application equations such as viscosity-temperature equation,the oil film thickness equation,flow equation and so on are deduced and calculated.Select two symmetrical oil films to analyze the characteristics of steady state and disturbance state,respectively.Geometric modeling and structured meshing using software.Second,use the Visual Studio 2015 compiler to write UDF programs that control the boundary layer mesh motion and variable boundary conditions in C language.And achieve sinusoidal disturbance by changing the disturbance model of oil film inlet flow.Analyze the effects of rotation speed 10r/min?160r/min,inlet temperature20??35? and load 0t?32t on oil film temperature and pressure.Obtain the change curve of oil film temperature and pressure by establishing monitoringline.Finally,Derive the oil film stiffness equation,and use MATLAB to perform stable oil film stiffness analysis.Derive damping and displacement response equations,and establish a vertical disturbance model of the oil film system.Simulation of vibration response of disturbance oil film system using Simulink.By analyzing the amplitude of the oil film displacement response of the workbench under different working conditions,the change law is obtained.And provide theoretical basis for improving the stability of hydrostatic rotary table.In order to verify the correctness of the research results,experimental verification was carried out in the Institute of Lubrication Theory and Thrust Bearings.Taking the double-rectangular cavity hydrostatic rotary table as the research object,the experiment of oil film stability was carried under the conditions of 10r/min?160r/min and 12 t load.Finally,the experimental data are obtained,and the change trend is analyzed to verify the correctness of the theoretical and simulated values.