波箔式气体轴承气膜流场分析

Analysis of Air Flow Field of Bump-Foil Type Gas Bearings

模拟在压力远场条件下,考虑气体可压缩性、平箔变形和端泄效应的箔片轴承三维气膜流场,得到轴承气膜压力和速度分布。刚性气体轴承的压力分布结果与文献结果吻合很好。研究考虑平箔变形情况下的承载力、端部泄漏流量等随转速和偏心率的变化关系,结果发现:在轴承端部存在出气的正压区和进气的负压区,与之前的文献端部为大气压的模拟结果不同;轴承两端的进气、出气是独立的,中心截面的流量为0;平箔变形使箔片轴承端部泄漏质量流量变大,承载力变小。

A three-dimensional bearing model, considering compressibility of air, top foil deformation and real ending leakage effect ,was developed to obtain distribution of pressure, velocity of gas film by using pressure far-field boundary condition. The result of pressure distribution of rigid bearing was compared with reference result and reasonable agreement was attained. The influences of rotor sPeed and eccentricity on load capacity, ending leakage mass flow rate were investiga- ted considering top foil deformation. The results show that there are exhausting positive pressure air zone and air-suetion negative pressure air zone at the end of bearing;the exhausting process and air-suction process of the two ends are inde- pendent, that is, the air mass flow of central cross-profile is zero;top foil deformation increases ending leakage mass flow rate ,but decreases load capacity.