Research On Bearing Capacity And Stability Of Radial Gas Dynamic Bearings

Gas bearings have an absolute advantage in the four major application fields of high-speed support,support under special working conditions,low friction and low power consumption,and precision support.In these four application fields,rolling bearings and oil-lubricated bearings often face difficulties,giving gas bearings broad prospects in engineering applications.However,research and application of gas bearings in China is still limited,as their carrying capacity is limited and they are prone to instability under high-speed conditions,which to some extent constrains their application in actual products.Additionally,gas bearings require precision machining at the nanometer level,resulting in higher costs and slow progress in product application.Focusing on these situations,based on lubrication theory and dynamic characteristic analysis,this study explored the impact of various parameters on the carrying capacity and stability of spiral groove hydrodynamic gas bearings from both theoretical and practical perspectives.Comparative experiments were conducted to determine the effect of spiral grooves on the performance of air bearings,providing technical and theoretical support for the design and development of hydrodynamic gas bearings.The dynamic characteristics of hydrostatic and hydrodynamic gas bearings are the basis for studying the stability of the bearing-rotor system.This article establishes a finite element model to analyze the dynamic performance of the bearing,and analyzes the bearing parameters that affect carrying capacity,dynamic stiffness and damping.A physical model of the hydrostatic and hydrodynamic gas bearing is constructed.After dividing the model with ICEM CFD mesh,the pressure distribution of gas film under different eccentricities and aspect ratios is simulated using ANSYS CFX,and the pressure distribution cloud chart is obtained to analyze its influence on bearing carrying capacity.Based on the analysis of the carrying capacity,dynamic stiffness and damping of the gas bearings,the inherent frequency of the bearing-rotor system under different speeds was calculated,providing data support for the study of the critical mass and stability of the bearing.Based on the proposed stability criterion of the gas bearings,the stability analysis of the spiral groove hydrodynamic gas bearing-rotor system was conducted,and the influence of the diameter of the throttle hole,gas film thickness,aspect ratio,and supply pressure on bearing stability was analyzed.Finally,an air bearing performance test platform was built to compare and test the carrying capacity variation of spiral groove and non-groove air bearings with the change of rotational speed,to verify the influence of the spiral groove structure on the bearing carrying capacity performance,and to provide practical experience for subsequent research on the bearing processing.