Research On Lubrication Mechanism And Micro Texture Technology Of Aeroengine Elastic Gas Foil Bearing

Because of its high speed,no pollution,high reliability and long service life,the elastic foil bearing makes up for the shortcomings of traditional oil lubricated bearings,and has a broad application prospect in aerospace field.Compared with the foil radial bearing,the research on the foil thrust bearing is relatively less.In this paper,foil thrust bearing was considered as the research object,the influence of its parameters on the pressure distribution was analyzed,the influence of foil deformation and misalignment on the bearing performance was discussed,the surface texture technology was introduced to improve the bearing capacity,and the multigrid method was studied to improve the efficiency of numerical calculation.The lubrication model of foil gas bearing was established,which focused on the solution algorithm of lubrication model.The finite difference method was used to discrete Reynolds control equation,coupled with Newton iteration method to solve the gas film pressure,and then the bearing capacity and friction moment of the bearing were calculated.When the pitch ratio of the bearing is small,the pressure distribution is smooth.The increase of the minimum film thickness leads to the decrease of the pressure,and the increase of the rotating speed leads to the increase of the pressure.The deformation of the foil is not conducive to improving the performance of the bearing,and the misalignment of the bearing reduces the stability of the system.Based on the research of rectangular texture on the foil surface,the surface texture was designed accurately from the dimensions,arrangement and bottom morphology.The change of size has the greatest influence on the bearing performance.The constraint conditions and the film thickness equation of six texture shapes were established.The optimal texture shape is ellipse and the optimal texture density is 0.2.The arrangement of different directions of texture has different influence on the static performance of bearing.The time of lubrication numerical calculation increases with the increase of grid density.The multigrid method can be used to perform different iterations on different grid layers,which can reduce the calculation time,and the effect of multigrid method with different relaxation factors was analyzed.With the increase of convergence accuracy,the efficiency of this algorithm is higher and higher,which can reduce the computing time by 26.6%.