转子系统启动过程局部碰摩故障实验研究

Experimental Study on Local Rub-impact Faults Diagnosis of Rotor System in Startup Process

通过转子台启动过程实验模拟了局部碰摩故障发生的过程,基于Hilbert-Huang变换(HHT)得到了不同程度局部碰摩故障的时频分布特征,给出了单点碰摩与局部碰摩故障的区分方法。实验分析结果表明,单点局部碰摩故障时频分布特征表现为瞬时频率沿基频的规律性的突变与波动,其强度与碰摩程度有关,并且突变时刻与碰摩发生位置相对应;局部接触碰摩发生时,时频图上基频成分波动变化加剧,出现低频及规律变化的高频成分。基于HHT的时频分布可以在转子系统发生局部碰摩早期发现故障,与传统的频谱分析相比,能更准确地反映碰摩故障的特征。

The local rub-impact fault for rotor kit startup process was simulated. With Hilbert-Huang transform analysis, the time-frequency characteristics of rotor local rub-impact faults in different conditions were investigated. The single point and local rub-impact faults were distinguished by Hilbert time-frequency spectrum. The experimental analysis results show that the salient and fluctuation along the fundamental frequency in Hilbert spectrum represents the single point rub-impact process, and when local rub-impact occurs,low frequency and fluctuant regular high frequency component can be found in Hilbert spectrum. These features are conductive to diagnose and predict the rub-impact faults as early as possible. The Hilbert-Huang transform method is more exactly than Fourier transform in rubbing diagnosis.