Research On The Dynamic Simulation Of Lubrication Performance Of Multi-Pad Hydrostatic Thrust Bearing

With the development of modern heavy-duty manufacturing industry towards to high-precision,high-efficiency and smarter,hydrostatic bearing,as a key component in heavy numerical control equipment,making sure it's running in high-speed and high-steady is important to improve the machining precision and efficiency under the condition of heavy load.Due to the change of working speed and the heat phenomenon caused by friction in internal fluid,the oil film becomes thinner,and that will affect the machining precision and operation reliability.So it has great significance for the technology process of NC machine tool to study the lubrication property of hydrostatic bearing under the condition of oil film thickness changing.This study selects the Q1-205 type of double-rectangular cavity hydrostatic thrust bearing as the research object,though theoretical analysis,dynamic simulation and experimental testing,the influence of oil film thickness variation on the temperature rise,flow characteristics and bearing characteristics of hydrostatic bearing under different inlet velocities and rotating speeds are analyzed.The main contents are as follows: firstly,based on the theory of fluid mechanics,friction and lubrication,the theoretical analysis model of supporting oil film is established,and the basin geometry model is established by using UG modeling software,then the hexahedral structure mesh of oil film model is divided though ICEM-CFD software.Secondly,though the dynamic mesh method,the C language compiler is used to edit the UDF program for controlling the movement of boundary layer grids,and the viscosity-temperature equation of No.32 oil is written into the program.By using the ANSYS/FLUENT software,the variable viscosity simulation of hydrostatic bearing fluid is carried out under the conditions of six inlet velocities and three working speeds,and the influence laws of oil film thickness variation on oil cavity temperature,oil cavity pressure,fluid velocity,flow,vorticity are obtained under different working conditions.Finally,the correctness of theoretical analysis and simulation are verified by designing the experimental scheme to test the changing of oil film thickness,oil cavity pressure and temperature under the conditions with different working speeds and certain inlet velocity.The results show that different inlet velocities and working speeds have different effect on oil cavity pressure,flow rate and temperature rise of oil-sealing edge under different oil film thicknesses.When the oil film thickness is high,the effect of working speeds on bearing lubrication is obvious;when the oil film thickness is low,the influence of inlet velocities on bearing lubrication characteristics is more prominent.