Fault diagnosis method based on MED and fuzzy entropy for vibration signal of planetary gearbox

Abstract

The invention discloses a fault diagnosis method based on MED and fuzzy entropy for the vibration signals of a planetary gearbox, comprising steps of: build a wind turbine experiment device and collecting the vibration signals of the planetary gearbox through the wind turbine experiment device; denoising the vibration signals of the planetary gearbox with MED; performing EMD decomposition on the vibration signals of the planetary gearbox, eliminating the invalid components, and obtaining a plurality of effective IMF components, then calculating the fuzzy entropy value of each effective IMF component and retaining the IMF component with the smallest fuzzy entropy value; and performing the envelope spectrum analysis on the signals of the IMF components with the smallest fuzzy entropy value,to analyze the characteristic frequency of the fault. The fault diagnosis method based on MED and fuzzy entropy for the vibration signals of a planetary gearbox can effectively extract the characteristic frequency of the fault, and can effectively filter the interference of the noise on the characteristic frequency, thereby effectively eliminating the adverse effects of the modal aliasing and theend effect on the fault diagnosis of the planetary gearbox signals.

Description

technical field [0001] The invention belongs to the field of fault diagnosis of rotating machinery, in particular to a vibration signal fault diagnosis method of a planetary gearbox based on MED and fuzzy entropy. Background technique [0002] Compared with fixed-axis gearboxes, planetary gearboxes have the advantages of small size, light weight, strong carrying capacity, large transmission ratio and high transmission efficiency, so they are widely used in various transmission systems such as aviation, construction machinery, wind power, vehicles, etc. among. Since the planetary gearbox usually works in a low-speed and heavy-load environment, its surface is subject to alternating loads, so key parts are prone to failure. The vibration signal of the planetary gearbox is the coupling of various excitation factors, and its frequency components are very complex, including not only the rotation frequency of each component, the meshing frequency of the gear pair and its multiplie...

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Problems solved by technology

The vibration signal of the planetary gearbox is the coupling of various excitation factors, and its frequency components are very complex, including not only the rotation frequency of each component, the meshing frequency of the gear pair and its multiplier, but also the natural frequency of the equipment being excited; the planetary gear is both It meshes with the sun gear and meshes with other planetary gears. This meshing method leads to low characteristic frequencies; the relative position of the planetary gear and the sensor changes with the operation, and the vibration transmission path changes constantly. Installation and manufacturing errors, planetary gears pass through Effects, etc. will cause the amplitude or frequency modulation of the signal, resulting in complex sidebands. Coupled with the influence of environmental noise, the fault frequency is easily submerged, which brings great difficulties to vibration analysis.

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