为提高箔片轴承性能,提出一种新型的平箔片厚度轴向变化的波箔型箔片轴承.该新型箔片轴承的平箔片在轴承中间区域有一周向贯通的宽槽,凹槽深度在微米量级.考虑平箔片厚度的轴向变化,采用二维厚板有限元模型计算平箔片刚度.基于有限差分法和Newton-Raphson迭代法耦合求解压力控制方程及箔片变形方程,获得新型箔片轴承的气膜压力分布及承载力;基于小扰动法,计算轴承动力学特性系数.仿真研究平箔片宽槽深度对新型箔片轴承性能的影响.结果表明:与传统箔片轴承相比,平箔片厚度轴向变化的新型箔片轴承可有效减少润滑气体端泄,增大流体动压效果,提高轴承承载力并改善动力学特性;随着平箔片宽槽深度的增大,新型箔片轴承的承载力及主刚度进一步增大;平箔片宽槽深度为8μm的新型箔片轴承,其承载力和主刚度分别增大约11.8％、12.1％.%To improve the foil bearing performance, a novel foil journal bearing with top foil thickness variation in axial direction was proposed. A wide groove extending in circumferential direction, within micron magnitude, was manufactured in the mid-plane zone of top foil. To consider the top foil thickness variation, the 2D thick plate finite element model was employed to simulate the top foil deformation. Based on Newton-Raphson iterative method and finite difference method, the coupled pressure equation and foil deflection equation were solved, and the gas pressure distribution and load capacity of the novel foil bearing were obtained. The dynamic characteristics were solved using perturbation method and the influence of the wide groove depth on bearing performance was investigated theoretically. The results indicate that the novel foil bearing with top foil thickness variation axially can decrease the gas edge leakage and improve hydrodynamic pressure effectively, so the load capacity and dynamic characteristics are improved. Moreover, with the increment of the wide groove depth on top foil, the load capacity and direct stiffness are enhanced further. For the foil journal bearing with a wide groove depth of 8 μm, the load capacity and direct stiffness increase by about 11. 8％ and 12. 1％ respectively, compared with the traditional foil journal bearing.
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