Influence of gas-film inertia force on the characteristics of an aerostatic thrust bearing with a singe gas supply hole

摘要

In order to analyze the pressure profile in externally pressurized gas bearings of the larger clearance, on the basis of the assumption that the temperature in clearance is constant and velocity distribution in a bearing clearance is a parabolic shape, conservation-modified Reynolds equations are established including the inertia force of a gas film and their boundary conditions. Pressure and velocity correction equations are derived, the SIMPLE algorithm was used to solve the governing equation and viscous force, inertia force, Mach number and pressure distribution in different gas supply pressures and different clearances are calculated. The theoretical results agree in general with the experimental results. From the analysis of theoretical results, with both gas supply pressure and clearance thickness increasing, the Mach number and inertia forces increase at the entrance of gas supply hole. The pressure in clearance drops rapidly following the entrance, and then rises again, finally falls away to the ambient pressure at the bearing periphery. The increase of the cross section of flow passage and the different trends of viscous force and inertia force lead a small resume of the pressure behind the throat. Due to the increase of clearance with decreasing load at fixed gas supply pressure, so conservation-modified Reynolds equations apply in the design of gas bearing in a wider clearance range.