多叶油润滑箔片轴承转子系统动力学特性研究

Research on dynamic characteristic analysis of multileaf oil-lubricated foil bearing system

用多叶油润滑箔片轴承取代超高速涡轮泵上的滚珠轴承具有高速、长寿命、高可靠等重要优点。将多叶箔片轴承的油膜刚度引入转子多叶箔片轴承系统运动方程中,运用传递矩阵法计算转子系统的临界转速,分析多叶箔片轴承的动态刚度对转子系统动力特性的影响。结合产品特点设计出了超高速油润滑多叶箔片轴承试验台,初步实现了80000转/分的运转速度。试验台轴系采用压缩气体驱动涡轮工作,径向轴承和止推轴承均设计为五叶箔片轴承。试验结果表明多叶油润滑箔片轴承能够实现高转速运行,具有良好的运转稳定性,且对转子的升降速适应性强、有一定的抗冲击能力、耐磨损性能。

Multileaf foil bearing, instead of ball bearing of super high-speed turbo-pump, has many important advantages including long life, high speed and higher reliability, etc. The oil-film stiffness were introduced into the movement equation of rotor system, the critical speed and unbalance response were computed by using transfer-matrix method. The influence on dynamic characteristics of rotor system was discussed by analyzing the dynamic stiffness of multileaf foil bearings. A special oil lubricated multileaf foil bearing test-bed has been designed in this paper, and achieved the speed of 80000rpm. The shaft of test-bed is driven by turbine which is driven by compressed air. The journal bearing and thrust beating are both designed as five-leaf foil bearings. Experimental results show that multileaf oil lubricated foil bearing can provide shaft with high speed and good rotating stability. Moreover, the multileaf oil lubricated foil bearing has better adaption of acceleration-reduction speed, the ability of against impact and abrasion.