弹性箔片动压气体推力轴承承载性能研究

Theoretical Research on the Load Performance of Aerodynamic Compliant Foil Thrust Bearings

气弹耦合解是准确预测弹性箔片动压气体轴承承载性能的有效方法。通过引入箔片的弹性变形以及联立求解动压气体润滑Reynolds方程和弹性箔片的变形方程,给出了弹性箔片动压气体推力轴承的气弹耦合解。应用气弹耦合解理论,将顶层箔片的局部弹性变形纳入考虑范围,对弹性箔片动压气体推力轴承的承载性能进行了计算和分析。有限元数值仿真结果表明:顶层箔片在气膜压力作用下的局部弹性变形直接导致弹性箔片动压气体推力轴承承载能力的降低;根据轴承瓦块上气膜压力分布的特点合理设计支承拱箔的结构形式,可以减小顶层箔片的局部弹性变形,有效提高轴承的承载能力。得到了一种承载能力较高的弹性箔片动压气体推力轴承支承拱箔结构设计方案。

The elasto-aerodynamically coupled solution can be an eitective method for the load-performance prediction of aerodynamic compliant foil bearings. A generalized solution of the elasto-aerodynamically coupled lubrication for aerodynamic compliant foil thrust bearings was presented by introducing the elastic deformation of both the top foils and the bump foils and solving the gas-lubricated Reynolds equation with the deformation equations simultaneously. The presented theory was applied in the load-performance computation and analysis of some typical aerodynamic compliant foil thrust bearings and the deformation of the top foils was taken into account. The numerical results indicate that the deformation of the top foils under the pressure exerted by the gas film directly reduces the load capacity of an aerodynamic compliant foil thrust bearing. According to the distribution of the gas film pressure on the top foil pads, the configuration of the bump foils can be reasonably improved to decrease the deformation of the top foils and increase the bearing load capacity effectively. The design of the bump foils was discussed and the configuration of an aerodynamic compliant foil thrust bearing with higher load capacity was obtained.