航空发动机滚动轴承-双转子系统动态特性分析

在滚动轴承动力学和转子动力学分析基础上,建立了含滚动轴承动力学与转子动力学耦合以及高、低压转子间耦合的滚动轴承-双转子系统动力学方程,采用精细积分法和预估-校正Adams-Bashforth-Moulton多步法相结合的算法,对航空发动机滚动轴承-双转子系统非线性动力学方程进行求解,并对滚动轴承结构参数与转子动态特性的关系进行了理论分析.分析结果表明:①中介轴承径向游隙较小时转子系统振动量较小且转子运行较平稳,但中介轴承保持架打滑率会有所提高,应合理选取中介轴承的径向游隙值；中介轴承滚子数量对转子运转稳定性有较大影响,减小中介轴承滚子数量可降低保持架打滑率,但转子系统的振动量会增大；②支承轴承内、外沟曲率半径系数及径向游隙较小时转子系统的振动量较小,转子运转较稳定；支承轴承滚动体数量对转子运转稳定性有较大影响,滚动体数量增多有利于转子系统运行的平稳性.

Analysis on dynamic characteristics of aero-engine rolling bearing/dual-rotor system

The dynamic model of dual-rotor coupling system which included rolling bearing dynamics and rotor dynamics was established.Fine integral method and predict-correct Adams-Bashforth-Moulton multi-step method were used to solve the nonlinear dynamic equations of dual-rotor system.Then the influences of bearing structural parameters on dynamic response of rotors were studied.The result shows:(1)the displacement of rotors can be decreased and the stability of rotors can be improved by reducing radical clearance of inter-shaft bearing,but the slide ratio of cage would increase when the radial clearance decreases,so the radial clearance should be selected properly;the slide ratio of cage would decrease and the displacement of rotors would increase when the rollers of inter-shaft bearing are reduced;(2)the displacement and stability of rotors can be optimized when the groove curvature radius coefficients of rings and radial clearance of supporting bearings are decreased,and the stability of rotor would be improved when the rolling elements of bearings are increased.