Purpose

Detection of early faults such as misalignment, rotor rubbing, shaft crack and bearing fault is necessary to avoid harmful and even catastrophic influences on rotating machinery.

Methods

In this paper, the accelerating horizontal and pitching vibration responses of flywheel/flexible coupling model of an actual diesel generator, with angular misalignment and rubbing faults, are investigated using the smoothed pseudo-Wigner–Ville distributions (SPWVDs).

Results and Conclusions

Numerical simulations are performed through the dynamical equations of the flywheel/flexible coupling system; the results suggest that when an angular misalignment fault occurs, the super-harmonic resonance of order 3 can be found in the horizontal and pitching vibration signals. Meanwhile, both the 3fr and 5fr components (i.e., 3 and 5 times of the rotating frequencies) can also be found in SPWV distribution spectra. When rubbing fault occurs, more abundant sub- and super-harmonic frequency components can be observed in SPWV distribution spectra. Overall, the investigation shows that the smoothed pseudo-Wigner–Ville distribution spectra reveal obvious differences between the acceleration responses of the rotating system with different faults.

中文翻译：

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使用平滑伪维格纳-维勒分布的带有角度未对准和摩擦的旋转飞轮/柔性联轴器系统的振动分析

目的

为了避免对旋转机械产生有害甚至灾难性的影响，有必要对早期故障进行检测，例如未对准，转子摩擦，轴裂纹和轴承故障。

方法

在本文中，使用平滑的伪维格纳-维勒分布（SPWVDs）研究了实际柴油发电机的飞轮/挠性耦合模型的水平和俯仰振动响应，该模型具有角度失准和摩擦故障。

结果与结论

通过飞轮/挠性联轴器系统的动力学方程进行数值模拟。结果表明，当发生角度失准故障时，在水平和俯仰振动信号中可以发现3级的超谐共振。同时，在SPWV分布频谱中也可以找到3fr和5fr分量（即旋转频率的3倍和5倍）。当发生摩擦故障时，可以在SPWV分布频谱中观察到更丰富的次谐波和超谐波频率分量。总体而言，研究表明，平滑的伪Wigner-Ville分布谱揭示了具有不同故障的旋转系统的加速度响应之间的明显差异。