小间隙下狭缝节流静压气体止推轴承静态性能的研究

Static Performance Analysis of Aerostatic Gas Bearings with Slot-restricted in Small Gap

减小气膜间隙可以提高气体轴承的刚度和承载,为研究小间隙下狭缝节流气体止推轴承静特性,运用FLUENT软件对小间隙下狭缝节流止推轴承进行流场仿真。采用滑移边界条件对小间隙下轴承流场进行计算,结果表明,随着气膜厚度的增加,滑移的影响逐渐减小,当膜厚大于等于4μm时滑移影响可以忽略。计算了狭缝结构对轴承静特性的影响,结果表明,在其他参数相同的条件下,轴承的承载力随狭缝的宽度的增加而增加;随着狭缝深度的增加而减小。在其它结构参数相同的条件下,随着狭缝宽度的减小,最大刚度值增加,最大刚度对应的气膜厚度逐渐减小;随着狭缝深度的增加,最大刚度值增加,最大刚度对应的气膜厚度逐渐减小。

The capacity and stiffness of gas bearings can be improved by reducing the gas film, in order to study the characteristic of aerostatic thrusting gas bearing with slot-restricted in small gap, the FLUENT software is used to simulate the flow field. The flow field of the gas bearing with discontinuous slot-restricted on the small clearance was calculated with the slip boundary conditions. The results show that the impact of slip is gradually reduced along with increasing of the air film thickness, when the film thickness 多4 ｜jLm, the impact of the boundary slip can be neglected. The slit structure influence on bearing static characteristics was calculated. The results show that under the same conditions as other parameters, the capacity of bearings increases with the increasing of the width of slot, and decreases with the increasing of the depth of slot. Under the same conditions as other structure parameters, with deceasing the width of slot, the maximum stiffness increases, gradually decreasing the maximum stiffness corresponding the gas film thickness. With increasing the depth of slot, the maximum stiffness increases, gradually decreasing the maximum stiffness corresponding the gas film thickness.