Abstract:With the continuous development of rotating machinery,foil aerodynamic bearings have developed into the fourth generation.Among them,multileaf bump foil aerodynamic bearing has a bright prospect for development because of its pre-tightening force and the application of high-temperature coating.Taking the multi-foil superposed elastic structure as the starting point,the top flat foil was equivalent to the cantilevered bending beam model and the linear spring model was used to simulate the supporting bump foil,and the film thickness equation different from the previous three generations of bearing’s was obtained.Based on the finite difference method,the gas film thickness equation and dynamic pressure Reynolds equation were coupled for iterative solution to obtain the static characteristics of multileaf bump foil aerodynamic bearing.The influence of rotating speed,eccentricity ratio and operating temperature on the static characteristics of the bearing was studied.The results show that the increase of eccentricity or rotating speed will increase the maximum film pressure and bearing capacity,and the influence of eccentricity is greater than that of rotating speed.The attitude angle decreases rapidly with the increase of eccentricity ratio,indicating the operation stability of bearing is improved with the increase of eccentricity.The increase of temperature will lead to the increase of the maximum film pressure and bearing capacity.Therefore,for the foil hydrodynamic bearing running at high speed,the aerodynamic thermal problem is an urgent problem to be solved.