含故障电磁轴承-转子系统的动态响应分析

ANALYSIS OF DYNAMIC CHARACTERISTICS OF FAULTY MAGNETIC BEARING-ROTOR SYSTEM

在综合考虑转轴裂纹、转子偏心量、电磁轴承电磁力、转轴与辅助轴承碰摩力相互耦合的条件下,运用龙格库塔数值积分法,得到了不同故障情况下电磁轴承-转子系统的分岔图、最大碰摩力分布图、轴心轨迹图、Poincaré映射图、时间响应图等,具体分析了不同故障对系统动态响应的影响;辨识了转轴与辅助轴承碰摩冲击现象和分岔特性。研究表明:发生裂纹-碰摩故障时,系统对应一阶临界转速、1/2、1/3和1/4临界转速、3倍临界转速阈值分岔特性发生改变,表现为系统的平稳性随裂纹系数Δk的增加而降低;转轴与辅助轴承的间隙d对系统的动力学特性产生显著的影响,较小间隙值时转轴与辅助轴承发生持续碰摩,间隙值增大后,系统的运动逐渐趋于平稳。

Consider the coupling of shaft cracks, rotor eccentricity, electromagnetic force of the electromagnetic bearing, and friction force between the rotating shaft and auxiliary bearing, the Runge-Kutta method is used to obtain the electromagnetic bearing-rotor system under different fault conditions. Bifurcation diagram, maximum friction force distribution diagram, axis trajectory diagram, Poincaré mapping diagram, time response diagram, etc., specifically analyze the impact of different faults on the dynamic response of the system;identify the rub-impact phenomenon and bifurcation of the rotating shaft and auxiliary bearing Characteristics. Research shows that when a crack-rub-impact fault occurs, the system corresponds to the first-order critical speed, 1/2, 1/3 and 1/4 critical speed, and 3 times the critical speed threshold bifurcation characteristics. The change shows that the stability of the system decreases with the increase of the crack coefficient;the clearance between the rotating shaft and the auxiliary bearing has a significant impact on the dynamic characteristics of the system. When the clearance is small, the rotating shaft and the auxiliary bearing will continue to rub-impact, and the clearance After increasing, the movement of the system gradually stabilizes.