滚动轴承-火箭发动机液氢涡轮泵转子系统的动力特性分析

 用有限元方法建立火箭发动机液氢涡轮泵转子的离散化模型,并提出考虑滚动轴承内间隙、运行表面波纹度和滚动体离心力等因素的二自由度滚动轴承模型,从而建立了滚动轴承－液氢涡轮泵转子系统的非线性动力学模型。通过数值仿真研究了液氢涡轮泵转子系统动力学问题集中的启动阶段的非线性动力特性。发现在启动阶段不但有同步共振,而且会发生亚谐共振。径向载荷的大小会显著影响同步及亚谐共振的起始时间。滚动体的离心力和滚动轴承的波纹度对转子系统的动力特性有明显影响。

Dynamic Properties Analysis of Ball Bearings-Liquid Hydrogen Turbopump Used in Rocket Engine

The discrete model of liquid hydrogen (LH_2) turbopump rotor is established using the finite element method. A two degrees of freedom model of ball bearing is presented for investigating the dynamic properties of the LH_2 turbopump rotor system supported by ball bearings. The model includes the effect of bearing internal clearance, bearing running surface waviness and ball centrifugal force. Thus, the ball bearings-LH_2 turbopump rotor system is modeled according to the discrete rotor model and the ball bearing model. The nonlinear dynamic characteristics in the start-up process are analyzed because the rotordynamic problems are concentrated in this process. Numerical results show that the subharmonic resonance as well as synchroresonance occurs in the start-up process. The radial load plays a significant role of the appearance of the subharmonic resonance and synchroresonance. The effects of ball centrifugal force and waviness are considerable.