根据大型旋转机械机电耦联特性,建立了水轮发电机组转子-轴承系统在不平衡磁拉力(Unbalanced Magnetic Pull,UMP)作用下定子与转子碰摩模型及其运动微分方程.利用数值积分方法,对系统由于励磁电流、转子质量偏心以及定子径向刚度变化引起的非线性动力学行为进行了研究,并给出了相应的分岔图、Poincaré映射图、时域图和频谱图.计算结果表明:UMP的存在使系统响应呈现出周期1、周期5、拟周期以及混沌等复杂的动力学现象并对其稳定性造成了明显影响；此外,较大的转子质量偏心以及定子径向刚度均有可能使局部碰摩发展为全周碰摩,对定子和转子造成巨大损害.%A dynamic model of a rub-impact rotor-bearing system with unbalanced magnetic pull (UMP) for a hydraulic generating set was established and the corresponding equations of motion were derived considering mechanical and electromagnetic coupling. Numerical integration method was adopted to investigate the nonlinear dynamic response of the system taking excitation current, rotor mass eccentricity and radial stiffness of stator as the control parameters and the corresponding bifurcation diagrams, Poincare maps, trajectories, time-histories and frequency spectra were obtained. Simulation results showed that the complex dynamic phenomena including period-one, period-five, quasi-period and chaotic motions are revealed and the system stability is obviously influenced by UMP; the larger rotor mass eccentricity or the stiffness of stator may lead to the full annular rubbing from the partial rubbing and then cause huger damage of the rotor and the stator.
展开▼
