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

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