有局部缺陷的滚动体中介轴承动力学建模及仿真研究

Dynamics modeling and simulation on intershaft bearing with local defect rolling element

在考虑径向间隙及滚动体缺陷通过内、外圈时接触变形量发生变化基础上,建立两种支承形式下滚动体含单一故障缺陷的中介轴承动力学模型。对比研究不同支承形式及内、外圈不同旋转方向对中介轴承振动影响。结果表明,采用内圈支承于高压转子、外圈支承于低压转子结构振幅大于内圈支承于低压转子、外圈支承于高压转子结构;内、外圈同向旋转振幅大于反向旋转;内、外圈反向旋转冲击振幅小不利于发现故障,反向旋转时缺陷冲击滚道频繁,同等运行条件下,反向旋转中介轴承潜在危险更大;保持架旋转频率为中介轴承振动信号的主要调制频率,且内、外圈反向旋转较同向旋转调制效果更强烈。

Considering the radial clearance and the change of contact deformation when a defect rolling element passing through inner and outer rings, the dynamic model of an intershaft bearing with local defect rolling element was established under two kinds of supporting conditions. The effects of different supporting condition and different rotating direction of inner and outer rings on the vibration were comparatively investigated. The results show that the vibration amplitude of the supporting structure with the inner ring mounted on the high-pressure rotor and the outer ring mounted on the low-pressure rotor is bigger than the supporting structure with the inner ring mounted on the low-pressure rotor and the outer ring mounted on the high-pressure rotor. Comparing with the case of counter-rotating of inner and outer rings, the vibration amplitude under the co-rotating of inner and outer rings is bigger. Although the repeated impact amplitude is small and it is not conducive to find fault in the counter-rotating case of inner and outer rings, the rolling element defect attacks the ring groove move frequently, so under the same operating condition, the counter-rotating intershaft bearing has a larger potential risk. The rotating frequency of cage is the main modulation frequency of intersbaft bearing vibration signals and compared to the co-rotating case of inner and outer rings, the modulation effect of the counter-rotating inner and outer rings is more intense.