基于时频相干分析的曲轴主轴承磨损故障诊断研究

Wear fault diagnosis for crankshaft main bearing based on time-frequency coherence analysis

为了早期发现曲轴轴承磨损故障,提出一种基于时频相干分析的曲轴轴承磨损故障诊断方法。对曲轴主轴承座和机体振动信号进行分析,搞清曲轴轴承磨损故障振动信号产生机理;对故障源与机体信号进行时频相干估计,建立故障源振动传播模型;根据传播模型对机体振动信号进行故障特征提取与诊断识别。研究结果表明:该方法可以揭示曲轴磨损故障产生机理,建立故障源与机体振动之间的映射关系,为曲轴轴承磨损故障的不解体诊断提供理论依据。

To early detect crank-bearing wear faults,a fault diagnosis method was proposed based on timefrequency coherence analysis. Firstly,vibration signals measured from the main bearing cover and engine body were analyzed to find the vibration signals generation mechanism due to crank-bearing wear faults. Secondly,the timefrequency coherence between the fault source and engine body signals was estimated to build the fault source vibration propagation model. Finally,according the propagation model,the fault features were extracted from engine body vibration signals,they were diagnosed and identified. The results showed that the proposed method can reveal the generation mechanism of crank-bearing wear fault,establish the mapping relationship between the fault source and engine body vibration,and provide a theoretical basis for crank-bearing wear fault diagnosis without disassembly.