Multiband envelope spectrum array used for rotating machine fault diagnosis

Abstract

The invention belongs to the field of mechanical device vibration monitoring and fault diagnosis, and particularly relates to a multiband envelope spectrum array used for rotating machine fault diagnosis. Vibration signals of different frequency bands are obtained by conducting multi-narrow-band filtering on a rotating machine vibration signal which is picked up, the envelop demodulation analysis is conducted on the multiple sets of vibration signals of different frequency bands, and envelop spectrums of the multiple sets of signals are obtained and converted into the three-dimensional envelop spectrum array (graph) with vibration frequencies as x-axis coordinates, narrow-band filtering central frequencies as y-axis coordinates and vibration amplitudes as z-axis coordinates. On the basis of the spectrum envelope array, the fault modulation frequency, the fault occurrence part and the fault damage degree of a rotating machine can be rapidly and visually judged, and the intelligent fault diagnosis can be conveniently achieved.

Description

technical field [0001] The invention belongs to the field of vibration monitoring and fault diagnosis of mechanical equipment, and in particular relates to a multi-band envelope spectrum array used for fault diagnosis of rotating machinery. Background technique [0002] During the operation of rotating machinery, fault information usually exists in the vibration signal in the form of modulation, such as gear pitting, broken teeth, fatigue of rolling bearings, shaft bending and other faults. , frequency modulation and other modulation phenomena. The gear vibration is mainly generated by the meshing excitation of the gear pair. The signal contains the meshing frequency and harmonic components of the gears at all levels. When the gear fails, the periodic impact component generated will form a modulation effect in the vibration signal. Sidebands form around the meshing frequency. Use band-pass filter to extract the components near the gear meshing frequency to obtain narrow-ba...

AI Technical Summary

Problems solved by technology

However, for a complex mechanical system with multi-level gear transmission, the vibration energy of each level of transmission is quite different, and a large number of gears and bearings lead to more components that may fail, so it is difficult to accurately select the center frequency of narrow-band filtering

If the fault diagnosis of each gear pair is carried out, narrow-band envelope analysis needs to be done near the meshing frequency of the gear pair, which not only affects the real-time performance of analysis and diagnosis, but also limits the realization of automatic diagnosis program.

The actual analysis shows that the envelope analysis results of different filter center frequencies sometimes have great differences, which may lead to different fault diagnosis conclusions

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