Aero-engine intershaft bearing early weak fault diagnosis method

Abstract

The invention discloses an aero-engine intershaft bearing early weak fault diagnosis method, which belongs to the technical field of aero-engine fault detection. The method includes the following steps: the fault signal of the intershaft bearing is collected; an AR model is used to remove a deterministic signal generated by periodic rotation of the engine rotor; the processed fault signal is subjected to inverse MED filtering to enhance the shock component of the fault signal; a CEEMD method is used to decompose the processed fault signal, an effective modal component is screened according toa kurtosis value index and an autocorrelation function, and the intershaft bearing fault signal is subjected to noise reduction and reconstruction; and through a Teager energy operator, the output energy of the noise reduction signal is obtained, the envelope spectrum is calculated, and through analyzing the frequency component with a frequency component in the envelope spectrum, engine intershaftbearing early weak fault diagnosis is realized. The fault signal can be subjected to preprocessing, screening, reconstruction and demodulation, a fault characteristic signal reflecting the bearing fault is acquired, and the early weak fault of the intershaft bearing can be accurately diagnosed.

Description

Technical field [0001] The invention relates to the technical field of aero-engine fault detection, in particular to an early weak fault diagnosis method for an aero-engine intermediate bearing. Background technique [0002] In order to reduce weight, modern dual-rotor turbofan engine rotor systems generally use intermediate main bearings. The working conditions of the intermediate main bearings have the characteristics of high temperature, high speed, large load changes, and difficult to ensure lubrication conditions, resulting in fatigue spalling and spots during operation. Failure failures such as corrosion and wear. As a key component of the aero engine rotor support system, its failure will pose a great threat to flight safety. According to statistics, since 2001, due to the failure of the No. 5 intermediate bearing of a certain type of aero There have been 26 cases, resulting in 2 second-class flight accidents, causing direct economic losses of several billion yuan. The fa...

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Problems solved by technology

However, this invention aims to build a fault diagnosis model for engineering applications, which fails to reflect the effective fault characteristic signals of bearing faults and cannot solve the above technical problems

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