Design of Aerostatic Bearing Restrictor with Multi-loop Coupling Pocket

摘要

The shape and size of a pocket influences the pressure distribution on the working face of an aerostatic bearing and causes the vibration in normal direction of air gap. In order to analyze the pressure distribution on the working face of an aerostatic bearing caused by the shape of a pocket, an aerostatic bearing restrictor with multi-loop coupling pocket is proposed and double-loop and tricycle forms are taken as examples to illustrate the arrangements of a pocket and analyze the pressure-impedance relationship of a throttle system in different situations. Simulation is done using FLUENT, a computational fluid dynamics (CFD) software, to obtain the pressure distribution on the working face of an aerostatic bearing and the static performance curve with respect to the diameter of an orifice. The comparison between restrictors of aerostatic bearing with or without double-loop coupling pocket shows that the addition of a multi-loop pocket on the working face of an aerostatic bearing contributes to the improvement of surface pressure-averaging effect and static load carrying capability, and the reduction of air film vibration, thereby improving the measurement accuracy. These results are of practical significance for the design of key aerostatic bearing components.