Prediction Of Friction Failure Of High Speed And Heavy Load Hydrostatic Thrust Bearing

Hydrostatic thrust bearing is an indispensable part of the heavy vertical CNC equipment.Thus,it is widely used for a series of advantages.With the appearance of high speed and heavy equipment,requirement of hydrostatic thrust bearing is higher and higher.However,friction failure of hydrostatic thrust bearing frequently occurs under the condition of high speed and heavy load.So it is an urgent problem to prevent friction failure and improve bearing capacity of hydrostatic.In this dissertation,hydrostatic bearing of high speed and heavy vertical lathe was taken as the research object,friction failure mechanism was searched by theoretical analysis,numerical simulation and experiments.Oil leakage,shear heating,temperature rise etc of lubricant oil under high speed and heavy load was obtained by theoretical calculation.The model of oil film,oil pad and worktable was constructed by modeling software and grid of the oil film model was generated using software of ANSYS ICEM CFD.Then,boundary parameters were set for simulation through of software of ANSYS CFX.In order to study effect law rotation speed on lubricant performance parameters,pressure field and temperature field was simulated under a constant load and different rotation speed.The factors contribute to friction failure are analyzed by these parameters.Fluid solid coupling analysis was done by software of ANSYS Workbench as pressure field and temperature field loaded to the bench and base.Deformation of worktable and base was calculated to predict actual deformation of oil film.The analysis of effect deformation of oil film on bearing capacity and lubrication performance provides theoretical reference for friction failure.In order to study the effect rotational speed on temperature of hydrostatic bearing,5 meter vertical hydrostatic lathe was taken as the research object,and a verification test was made in Qiqihar heavy CNC equipment co.ltd.Temperature acquisition of oil film in different rotational speeds is obtained,meanwhile,film thickness in different position was measured by displacement sensor to predict actual shape of oil film and deformation of hydrostatic bearing friction pair.Compared experimental results with theoretical calculation and numerical simulation,the results verify the validity of theoretical analysis and numerical simulation.Through the theoretical calculation,simulation and experiments,deformation law of hydrostatic oil pads under high pressure and high speed was obtained to prevent hydrostatic bearing from friction failure.