狭缝节流气体静压轴承设计及其静态性能研究

Design and Static Performance of Slit Throttling Aerostatic Bearing

基于径向狭缝节流气体静压轴承,设计一种周向呈矩形,且槽型从节流孔到气膜方向由浅至深的槽结构。在Gambit中建立该槽结构气体静压轴承的CFD模型,进行数值计算,利用Fluent分析该径向槽结构参数(深度、数目、直径)和供气压力对气体静压轴承承载能力等静态特性的影响。研究表明相较于无均压槽气浮轴承,采用有均压槽的狭缝节流气体静压轴承可以提高承载能力和刚度。气浮轴承在其他参数一定的条件下,承载能力随着均压槽的各项参数的增加而减小,刚度则随着均压槽的各项参数的增加,呈现先增大后减小的趋势。文中槽型最大承载力对应的气膜厚度在5~10μm之间,最大刚度对应的最佳气膜厚度在10~15μm之间。当气膜厚度在10μm时,轴承的静态性能最佳。

Based on the radial slit throttling aerostatic bearing,a groove structure with rectangular circumference and are shallow to deep from orifice to gas film is designed in this paper.The CFD model of the aerostatic bearing with the groove structure is established in Gambit for numerical calculation.The effects of the radial groove structure parameters(depth,number,diameter)and air supply pressure on the static characteristics of the aerostatic bearing are analyzed by Fluent.The research shows that compared with the air bearing without pressure equalizing groove,the slit throttling aerostatic bearing with pressure equalizing groove can improve the bearing capacity and stiffness.Under certain other parameters,the bearing capacity of air bearing decreases with the increase of the parameters of pressure equalizing groove,and the stiffness increases first and then decreases with the increase of the parameters of pressure equalizing groove.In this paper,the gas film thickness corresponding to the maximum bearing capacity of the groove is 5~10μm,the optimum gas film thickness corresponding to the maximum stiffness is 10~15μm.When the film thickness is 10μm,the static performance of the bearing is the best.