转子—轴承系统受轴向摩擦时的振动

LATERAL VIBRATION OF A ROTOR/BEARING SYSTEM WITH AXIAL RUBS

研究轴向摩擦对单跨双盘转子—轴承系统横向振动的影响。盘与静子在不同位置发生轴向接触时 ,对盘的轴向压力由作用于两个轴端的力代替 ,轨迹切向摩擦力用单参数干摩擦力模型计算。数值模拟发现 ,轴颈位置、轨迹大小变化与轴向摩擦位置、程度和转速都有关系 ,因此表现为振动不稳定。另外 ,频谱中还包含倍频成分 ,且可能有比较复杂的运动形式如概周期运动。

The lateral vibration of a rotor/bearing system influenced by axial contact between disk and stator are investigated by numerical simulation. The contacting forces are equated by two parallel forces with equal magnitude, which act at two bearings laterally and form a couple. One-parametric model is then used to calculate the axial-contact-induced dry friction forces. Supposing the contact occurs at one of the two specified positions, lateral vibrations of the system are calculated at three values of speed which represent the states before and after the passage of the shaft's natural speed, and before the occurrence of the oil whirl, respectively. Results show that the sizes of the axle-necks' orbits can be enlarged and reduced as the initial compressing displacement is increased. When contacts occur at the edge of disk in horizontal plane, bifurcation diagrams reveal complicated behaviors of the axial-rubbed rotor/bearing system. These include motions with different values of period, quasi-periodic and even chaotic motion.