谐波小波变换在转子-轴承系统多故障监测中的应用

以谐波小波变换为工具,分析了转子—轴承系统出现裂纹与碰摩耦合故障时的振动特征,并分别讨论了油膜力、裂纹与碰摩的影响,为工程实际中转子系统的多非线性故障监测和诊断提供一种方案。结果表明,支承滑动轴承的非线性油膜力对转子系统的影响比较大,且裂纹与碰摩引起的耦合故障不是单裂纹和单碰摩故障的线性叠加。因此,转子系统多故障监测和诊断过程中,各个非线性因素应该得到充分考虑,并应从时域和频域同时进行分析,才能取得更为合理的结果。

APPLICATION OF HARMONIC WAVELET TRANSFORM TO DETECTING MULTIFAULTS OF ROTOR BEARING SYSTEMS

Harmonic wavelet transform (HWT) is applied to the vibration analysis of a cracked rotor bearing system with rubs of its stators and rotors. Three nonlinear factors are taken into account. Using the time-frequency maps of HWT, the characteristics and energy distribution of rotor system can be described in detail. And the effect of the three nonlinear factors is investigated. Result shows that the nonlinear oil film force can weaken the faults characteristics, and the effect of the crack and rub-impact force must be considered simultaneously. In addition, the multi-nonlinear factors should be taken into account in both time domain and frequency domain to detect the faults of rotor bearing systems.