Abstract: Impact forces of magnetic suspended dual-rotor systems(MSDS) in fixed-point rubbing processes were described with Lankarani-Nikravesh model. Vibration characteristics and contact processes of the MSDS with fixed-point rubbing were analyzed based on MSDS dynamic model established with finite element method. Research results indicate that, when rotation frequencies of inner rotors and outer rotors are integer multiple of the rotational frequency difference, integer frequency components of rotational frequency difference are observed when rubbing occurs. As the degree of rubbing increases, the fractional frequency components of rotational frequency difference appear. Maximum contact depth and impact forces in the rub-impact processes depend on initial impact speed. Moreover, suitable proportional coefficient making the system angular velocity speeds far away from critical angular velocity and large differential coefficient may significantly reduce the severity of the rub-impact.

Key words: dual-rotor system, active magnetic bearing, fixed-point rubbing, Lankarani-Nikravesh model

摘要： 采用Lankarani-Nikravesh模型描述了磁悬浮双转子系统定点碰摩过程中的法向冲击力，基于有限元法建立系统动力学模型，并对碰摩故障下的系统振动特性及接触过程进行了分析。研究结果表明:内外转子的转频是其转频差的整数倍时，碰摩发生时可观察到转频差的整数倍频率分量，随着碰摩程度的加剧，分数阶转频差频率分量出现；碰摩过程中的最大接触深度和法向冲击力取决于初始冲击速度；选择使系统运行角速度远离临界角速度的比例系数或较大的微分系数可显著减小系统碰摩的严重程度。

关键词: 双转子系统, 主动磁悬浮轴承, 定点碰摩, Lankarani-Nikravesh模型