新型波箔型径向气体轴承承载特性研究

Analysis of Load Capacity of New Bump-type Gas Foil Journal Bearings

基于波箔型轴承的结构特点,提出和设计平箔片与波箔片结构耦合的新型箔片轴承,包括波箔片覆盖轴承整个圆周、上半周和下半周的3种动压径向气体轴承。考虑气体的可压缩性,模拟箔片轴承的二维气膜流场,对新型箔片轴承的承载特性进行分析,并与刚性气体圆轴承的承载特性进行比较。结果表明,波箔片覆盖轴承下半周的下波箔片轴承的承载力明显优于其他轴承。通过改变下波箔片轴承波箔的波数、波宽、高度等结构参数来进一步模拟气膜流场变化。结果表明,在满足箔片结构稳定的情况下,下波箔片轴承承载力随波数及波宽的增加而增加,随波高的增大而呈现先急剧增大再缓慢减小的趋势。

Based on the structure characteristics of bump-type bearing,new bump-type gas foil journal bearings of cou- pling top foil and bump foil was proposed, including three kinds of gas journal bearings that the foil covers the whole circle, the upper half circle and the lower half circle of the bearing separately.Considering the compressibility of air, the twodimensional gas flow of the bump foil bearing was simulated, the bearing capacity of the foil bearing was analyzed and compared with that of the rigid gas bearing.It is found that the bearing capacity of the bearing with foil covering the lower half circle is optimal.By changing the foil number,foil width and foil height of the bearing with foil covering the lower half circle, the change of the gas membrane flow field was further simulated.The simulation results show that under the condition of satisfying the stability of foil structure, the bearing capacity of the bearing with foil covering the lower half circle is increased with the increasing of the foil number and foil width, and it shows a sharp increase and then a slow decrease with the increasing of the foil height.