Improving the stiffness of the aerostatic thrust bearing by using a restrictor with multi-orifice series

Abstract

To improve the stiffness of the orifice-type aerostatic bearing, a new construction of orifice restrictor with multiple orifices in series was proposed to enhance the restriction effect. The restriction effects of the restrictors with multiple orifices in series were studied numerically. Based on a circular aerostatic thrust bearing with a central feedhole, the effect of the bearing stiffness improved by the restrictors with multiple orifices in series was studied. The results show that the aerostatic bearing with the restrictors with multiple sub-orifices in series shows higher maximal bearing stiffness than the bearing with traditional simple orifice restrictor. For example, the maximal stiffness for aerostatic bearing with the restrictor of four sub-orifices in series is 57 N/µm, which is ∼11% larger than that of the bearing with simple orifice. With this construction, the restriction effect of the orifice restrictor can be enhanced by increasing the number of the sub-orifices, instead of decreasing the aperture of the orifice. This approach avoids the difficulty of manufacturing the orifice restrictor with too small aperture for achieving a high restriction effect. The feasibility of the restrictor with multiple sub-orifices in series proposed in this paper was verified with experimental studies.