基于接触摩擦的多叶波箔型动压气体轴承静特性研究

Static Characteristics of Multi-Leaf Bump Foil Aerodynamic Bearing Based on Contact Friction

关键词:  多叶波箔轴承  接触摩擦  流固耦合  非线性刚度  静特性

Key words:  Mulit-leaf bump bearing  Contact friction  Fluid-structure interaction  Nonlinear stiffness  Static characteristic

摘要:

为揭示多叶波箔型动压气体轴承箔片间接触摩擦对轴承性能的影响机理，建立多平箔与波箔间接触约束下的力学分析模型，结合可压缩气体雷诺方程构建流固耦合计算方法。数值分析了接触摩擦下的箔片结构刚度变化及在不同轴承数下接触摩擦对轴承静特性的影响。结果表明：接触摩擦强化了箔片刚度随变形量变化的非线性效应和周向分布的非均匀性，随着箔片变形量的增加，接触摩擦对箔片刚度的影响越加显著。同时，随着摩擦系数的增大（η=0~0.5），在低轴承数时承载力呈现先增后减的规律，在高轴承数时承载力单调增加，且轴承数越大时，增速越快；偏位角随摩擦系数的增大而增大，且轴承数越大时，摩擦系数对偏位角的影响越明显。

Abstract:

In order to reveal the influence mechanism of foil contact friction on the multi-leaf bump aerodynamic foil bearing performance， a deformation simulation model is established under the contact constraint of multi top foils and bump foils， and the analysis of the fluid-structure interaction is established by combining with the Reynolds equation of compressible gas. The influence of the nonlinear variation of foil stiffness caused by contact friction on the static characteristics of the bearing under different bearing numbers is numerically analyzed. The results show that the foil stiffness increases nonlinearly with the foil deformation and presents the characteristic of circumferential non-uniformity. With the increase of the deformation of foil， the influence of contact friction on the foil stiffness is more significant. With the friction coefficient increases （η=0~0.5）， the bearing capacity increases first and then decreases when the bearing numbers is small， the bearing capacity increases monotonically when the bearing numbers is large， the higher the bearing numbers， the more significant the growth rate. The attitude angle increases with the increase of friction coefficient， and the larger the bearing numbers， the more significant the influence of friction coefficient on the attitude angle.