Study On Influence Of Oil Pad Geometric Characteristics On Performance Of Hydrostatic Thrust Bearing

Hydrostatic thrust bearing is an important part of vertical machine tool.It has the characteristics of low friction resistance,long service life and good anti vibration performance.As a load-bearing component,its bearing characteristics and temperature rise characteristics determine the machining efficiency and machining accuracy of the machine tool.In the hydrostatic thrust bearing,there are clearance oil films with different shapes in different oil pad geometric characteristics.In the actual working process,due to the influence of speed and load,the oil film is subject to shear and extrusion,and the hydrostatic thrust bearing will have different degrees of local thermal deformation and static pressure loss.Because of the above problems,taking the oil pad of hydrostatic thrust bearing as the research object,this thesis explores and analyzes the oil film bearing characteristics and temperature rise characteristics under the specified oil film thickness from the perspective of oil pad cavity shape,oil sealing edge size,oil return groove width and depth and the number of oil pads.Firstly,the flow equation,bearing capacity equation,temperature rise equation and load limit speed oil film thickness matching equation of single rectangular,double rectangular,trapezoidal and fan-shaped oil pads are deduced theoretically.According to the deduced theoretical equation,based on the existing double rectangular oil pad,the parameters of three different cavity shapes of oil pad are calculated by using the single control variable method.Secondly,SOLIDWORKS software is used to model the four different oil pads.In the numerical simulation process,the variable viscosity theory is used to fit the viscosity-temperature relationship curve of 46-HL lubricating oil with the help of MATLAB software.Use the ICEM-CFD module in ANSYS to divide the hexahedral structure mesh of four different oil pad gap oil film models,and set the boundary conditions.Then the CFX module in ANSYS is used to numerically solve the clearance oil film with different geometric characteristics.By analyzing the data of pressure field and temperature field,the influence laws of oil pad cavity shape,double rectangular cavity sealing oil edge size,oil return groove width and depth and oil pad number on the performance of hydrostatic thrust bearing are obtained,which provides a theoretical basis for selecting cavity shape in engineering practice.Finally,the hydrostatic thrust bearing test-bed is used to experiment with the working condition of 4t load and 0-160 r/min speed.The experimental data of hydrostatic oil film pressure and temperature are obtained,analyzed,and summarized to verify the feasibility and correctness of the numerical simulation method.