Abstract: Aiming at the problem that the fault information of the planetary gearbox was difficult to quantified and measured under the complicated working conditions, a fault diagnosis method of the planetary gearbox based on the harmonic effective index (HEI) to quantify the fault information was proposed. Firstly, the signal is analysed and processed, the RCMDE value of FSWT frequency sliced signal was calculated,the frequency band with more fault features was selected for signal reconstruction;MOMEDA was used to extract the fault impulse component of the reconstructed signal accurately. Then the fault information contained in the vibration signal was quantified by establishing the harmonic effective index(HEI), the fault diagnosis of planetary gearbox was realized.And the test data of the planetary gearbox tooth surface wear failure was used for verification.The research results show that the method can extract the fault characteristics in the vibration signal of the planetary gearbox; the planetary gear fault characteristic frequency fp=7.03Hz and its multiplication frequency nfp can be clearly observed in the frequency spectrum of the processed signal. The HEI value of fp in the experimental data is 3.47×10-6 which can be used as an effective index to measure the degree of failure of the planetary gearbox.

Key words:  harmonic effective index(HEI); planetary gearbox; fault diagnosis;fine composite multi-scale dispersion entropy (FCMDE);minimum entropy deconvolution (EDA)