Abstract:  Foil-magnetic hybrid bearing was a new type of high-performance active control bearing that might reduce the friction loss of foil bearing before take-off, and might improve the load-bearing and dynamics performance of magnetic bearings at high speeds. A design method of foil-magnetic hybrid bearings was proposed, and an experimental bench for supporting characteristics of foil-magnetic hybrid bearings and a rotor experimental bench for foil-magnetic hybrid bearings were designed and built. The influences of the magnetic-gas load ratio (which was the load distribution ratio between the gas foil bearings and the active magnetic bearings) on the supporting characteristics and rotor dynamics characteristics of foil-magnetic hybrid bearings were investigated through experiments. The experimental results show that the overall static stiffness and stiffness change rate of the foil-magnetic hybrid bearings are improved compared with the foil bearings. The structural stiffness of the foil-magnetic hybrid bearings increases with the increasing of frequency, and the equivalent viscous damping shows a trend of first decreasing and then increasing with the increasing of frequency. In addition, a suitable load ratio may reduce the take-off speed, improve friction loss, suppress sub-frequency vibrations, and help to improve the high-speed stability of the rotors.

Key words: foil-magnetic hybrid bearing, magnetic-gas load ratio, supporting characteristic, rotor dynamics

摘要： 箔片磁力混合轴承是一种能降低箔片轴承起飞前的摩擦损耗且可改善磁轴承高速时的承载和动力学性能的新型高性能主动控制型轴承。提出了一种箔片磁力混合轴承的设计方法，设计并搭建箔片磁力混合轴承支承特性实验台和箔片磁力混合轴承转子实验台，实验探究了磁气负载比（即气体箔片轴承和主动磁轴承之间的载荷分配比）对箔片磁力混合轴承支承特性和转子动力学特性的影响。实验结果表明：箔片磁力混合轴承比箔片轴承的总体静态刚度和刚度变化率有所提高。箔片磁力混合轴承结构刚度随频率的提高而增大，等效黏性阻尼随频率的提高呈现先降后增的趋势。此外，合适的负载比可以降低起飞转速，改善摩擦损耗，抑制次频振，有利于提高转子的高速稳定性。

关键词: 箔片磁力混合轴承, 磁气负载比, 支承特性, 转子动力学