时频分析在油膜失稳与局部碰摩耦合故障中的应用

通过建立转子模型实验台, 模拟油膜失稳和局部碰摩耦合故障,把实验采集到的发生故障的振动信号,利用三维谱振图对转子升降速过程进行粗略分析.在频率成分较复杂的地方,利用小波尺度图和再分配小波尺度图进行细化分析.结果表明,再分配小波尺度图具有高的时频分辨率,可以清楚地识别出频率成分接近的低频分量;油膜失稳引起的转定子碰摩故障,会产生一些低频成分,油膜振荡会产生半频成分; 非线性油膜力是对系统起决定作用的重要因素,一般程度的碰摩对系统影响不大.

APPLICATION OF TIME-FREQUENCY ANALYSIS TO COUPLING FAULTS WITH OIL-FILM INSTABILITY AND PARTIAL RUB-IMPACT

A model test rig was set up to simulate coupling faults with oil-film instability and partial rub-impact.The collected vibration signals were roughly analyzed by 3-D waterfall spectra.In complicated frequency components domain,wavelet scalogram and reassigned wavelet scalogram were used to further analyze vibration signals.Results show that reassigned wavelet scalogram has higher time-frequency resolution than wavelet scalogram and can well identify such close low-frequency components.The analysis results also indicate rub-impact faults induced by oil-film instability can produce some low-frequency components with small amplitude and oil whip can produce half frequency component;rub-impact with a common extent exerts a light influence on rotor systems and nonlinear oil-film force plays a decisive role in rotor systems.