Mechanical Performance and Fatigue Life Calculation Method of Sliding Beam Air Foil Bearing

Taking sliding beam air foil bearing as the research object, the mechanical model of the connecting part between the flat foil and the bottom foil sliding beam was established by using of the finite element method. The mechanical analysis of the sliding beam structure was conducted on the basis of the principle of virtual work. At the same time, a calculation model for foil deformation was established. The isothermal Reynolds equation was solved by using of the finite difference method, and a fluid structure coupling calculation model was constructed with the foil deformation calculation model. The calculation of the gas film pressure distribution of the bearing was carried out. And then a method for calculating the maximum stress of the sliding beam was established, and the fatigue life of the sliding beam and bearing was calculated based on linear fatigue damage theory. A new fatigue life calculation method for the sliding beam type air foil bearing was established. Based on a specific example, numerical calculations were conducted to study the fatigue life of bearings. It is shown that the maximum stress of the sliding beam is 106 MPa. With increasing foil thickness, sliding beam slope, bearing clearance, sliding beam row number, and decreasing sliding beam row number, the fatigue life of sliding beam foil bearings will increase. When the bearing clearance is 97 μm, the bearing life is about 9 a.