According to the characteristics of fault signal of inter-shaft bearing

a new band optimization parameter-the peak factor of local envelope spectrum

was proposed

which can not only reflect the strength of impulse component in the signal

but also highlight the characteristics of periodic impulse. It was applied to optimize the frequency band of Morlet complex wavelet resonance demodulation of fault signal of inter-shaft bearing. In order to verify the superiority of this method

a double-rotor test-bed was built to simulate the outer ring and inner ring faults of inter-shaft bearings. The Morlet complex wavelet optimized by the local envelope spectrum peak factor band was used to analyze the collected test data. Taking the inter-shaft bearing with the inner and outer ring speeds of 600 r/min as an example

the theoretical value of the outer ring fault frequency was 88 Hz

and the outer ring fault frequency obtained by the local envelope spectrum peak factor band optimization was 8725 Hz. The results show that the index can extract the peak fault frequency of the inter-shaft bearing

effectively separate the fault information from the vibration signal

and realize the fault diagnosis of the inter-shaft bearing.