Research On The Load Performance And Flow Field Characteristics Of High-Speed Hydrostatic Gas Bearing With Micro-channel Grooves

Gas lubrication is one of the rapid development of scientific research technology in the age of science and technology.It is the key technology in the application of high speed and ultra precision equipment.Among them,the hydrostatic gas bearing is the most typical representative in the field of gas lubrication.Because of its characteristics of high speed,small temperature rise,low energy consumption and no pollution,it has an advantage in ultra precision machining.However,its load capacity is low and its stiffness is small,which has always been the weakness of the application of hydrostatic gas bearing.In this paper,by using the method of Computational Fluid Dynamics(CFD)method,the paper uses the most common Orifice hydrostatic gas bearing as the research object.By introducing the structure of micro-channel grooves,the influence rules of opening and geometric characteristics of grooves on the load performance and gas film flow field of hydrostatic gas bearing are studied,and the relationship between disturbance frequency,supply pressure and bearing dynamic characteristic coefficient is analyzed.The modal of the hydrostatic gas rotor is solved to improve the load performance of the hydrostatic gas bearing,improve its rotation accuracy and improve the limitation of its application.Based on CFD method,the study of gas film flow field and load capacity of hydrostatic gas bearing is an important topic in gas lubrication technology.It is of great value and significance for improving the performance of bearing,developing high speed equipment and ultra precision machining.This paper uses the Fluent software for the orifice hydrostatic gas bearing without the micro-channel groove,hydrostatic gas bearing with axial micro-channel grooves,hydrostatic gas bearing with circumferential micro-channel grooves,hydrostatic gas bearing with axial circumferential full-grooves.The flow field model was simulated to analyze the influence of the opening form of the micro-channel on the distribution of the gas film flow field of the hydrostatic gas bearing,and the variation law of the load capacity and stiffness of the four high speed bearing models under the same supply pressure was obtained.The mechanism of the influence of the channel on the static characteristics of the orifice hydrostatic gas bearing provides a reference for seeking the best way to open the microchannel.Based on the optimal form of the micro-channel grooves for hydrostatic gas bearing,the change law of the flow field of the gas film is studied by changing the circumferential angle of the micro-channel grooves;the change of load capacity and film stiffness of the bearing is analyzed by setting different groove depths and widths.Analysis by CFD simulation and comparison of micro-channel grooves of hydrostatic gas bearing model of rectangular and triangular,oval three section,find out the different gas film clearance,has high load performance of the optimum micro-channel grooves shape.The study of the geometrical characteristics of micro-channel grooves geometry on the effect of hydrostatic gas bearings is the basis for the search for ways to improve the performance of gas bearings.Using Fluent software to simulate the dynamic characteristics of the hydrostatic gas bearing,set the frequency of the unequal disturbance frequency,change the pressure of the supply air to obtain the dynamic stiffness coefficient and the dynamic damping coefficient of the hydrostatic gas bearing.The ANSYS Workbench software was used to perform modal analysis of the gas bearing rotor and solve the natural frequency of each mode.The analysis and solution of the static and dynamic characteristics of the hydrostatic gas bearing is of great importance for ensuring the high accuracy and stable working condition of the aerostatic bearing.Based on the analysis of the factors related to the bearing characteristics of the hydrostatic gas bearing based on the CFD method,the search for the best structural form and geometric parameters to improve the performance of the bearing is an important approach for the development of gas lubricating technology.