关键词: 非线性动力学耦合, 碰摩, 油膜, 分岔, Poincarè映射

Abstract: Discusses the nonlinear coupling characteristics of the oil film and impact/rub for a rigid rotor in short journal bearings by virtue of bifurcation diagram, Poincare mapping, and trajectory of rotor centre, supposing the impact/rub is of different intensities and the rotor is being rubbed in different directions. The numerical results show that the multifold-period bifurcation, aperiod motion even chaos are found with the increasing impact/rub intensity and the bifurcation diagram falls into two regions when the rotor is running at the interval of rotating speed that its response is period-doubling motion without impact/rub and the direction of impact/rub is far off 90° or 270° , and that the period-doubling characteristic of the rotor response remains unchanged when the direction of impact/rub is in the vicinity of 90° or 270° . When the rotor is running at the interval of rotating speed that its response is aperiodic/chaotic motion without impact/rub and the direction of impact/rub is in the vicinity of 90° or 270° , the rotor response is multifold period motion; and when the impact/rub intensity is smaller, the multiple of period in the vicinity of 90° is higher than that near 270° . However, both are down to period-doubling with the increasing impact/rub intensity, while the number of its response period increases even its response becomes aperiodic/chaotic motion if far off the two region, and the region of its period-doubling response will gradually be extended with the increasing impact/rub intensity.