A theoretical and experimental study on the stiffness of aerostatic thrust bearings with vacuum preloading
In this paper, the pressure distribution of aerostatic thrust bearings with vacuum pre-loading was investigated by solving the full Navier-Stokes equations based on the computational fluid dynamics method. The influences of the supply pressure, vacuum pressure, orifice diameter, and gas film thickness on the absolute pressure ratio were investigated. The finite difference method was used to study the effects of the vacuum chamber area, orifice diameter, orifice number, supply pressure, and vacuum pressure on the bearing stiffness. It is confirmed that the orifice diameter and film thickness had a great influence on the absolute pressure ratio, which increased with the reduction in the gas film thickness and the rise in the orifice diameter. The bearing stiffness can be improved by increasing the supply pressure, orifice number or vacuum chamber area or decreasing the orifice diameter or vacuum pressure, which provides useful guidance for the optimization design of aerostatic thrust bearings with vacuum preloading.