Compound fault diagnosing method for planetary gearbox by using matrix wavelet transformation

Abstract

The invention discloses a compound fault diagnosing method for a planetary gearbox by using matrix wavelet transformation. The compound fault diagnosing method comprises the following steps of: firstly, transforming an acquired one-dimensional vibration signal of a planetary gearbox into a multi-dimensional input signal by using a repeated sampling pre-processing mode in matrix wavelet transformation; secondly, constructing an optimal matrix wavelet function by a lifting method, adaptively decomposing the multi-dimensional signals by using the constructed optimal matrix wavelet function, and decomposing a plurality of fault features into signals in different branches; and finally, extracting and identifying represented planetary gearbox faults in various frequency band signals by a spectrum enveloping method, and separating and diagnosing features of composite faults of the planetary gearbox according to failure mechanism analysis. The result of the method is reliable, and the real-time capability of the method is high. Moreover, the method is simple and practicable, and is applicable to diagnosing compound faults of planetary gearboxes of equipment transmission mechanisms such as a satellite communication antenna, a wind driven generator and a heavy-load crane.

Description

technical field [0001] The invention relates to a mechanical equipment fault diagnosis technology, in particular to a compound fault diagnosis method for a planetary gearbox. Background technique [0002] Engineering practice shows that the faults of planetary gearboxes are usually not single, and often manifest as compound faults such as pitting, peeling, wear, gluing, cracks, fractures, eccentricity, and modulation of gears and bearings. The so-called composite fault refers to the simultaneous occurrence of two or more faults that are interrelated and cross-affected. These composite faults occur simultaneously or in cascade, and their vibration signals often appear as mutual coupling of fault characteristics. The generation of composite faults brings more difficulties to fault diagnosis. At present, wavelet transform, second-generation wavelet transform and empirical mode decomposition are widely used in planetary gearbox fault diagnosis, but there is no effective signal...

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Problems solved by technology

[0003] The planetary gearbox is a typical epicyclic gear train, and the compound motion of the planetary gear includes rotation and revolution, so the vibration response of the planetary gearbox is more complicated than that of the fixed shaft transmission gearbox

Its complexity is manifested in: multi-mode confusion and complex vibration transmission path lead to weak fault response; large-scale instantaneous fluctuation of load causes strong non-stationarity of vibration; vibration mutual coupling of multiple pairs of gear meshes causes obvious nonlinear vibration; low-frequency characteristics The frequency component noise pollution is serious; the dynamic response signal spectrum distribution and characteristic frequency are complex

Existing fixed-axis gearbox fault diagnosis theory and technology are difficult to solve the problem of planetary gearbox fault diagnosis

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