An insight concept to select appropriate IMFs for envelope analysis of bearing fault diagnosis

Traditional envelope analysis must examine all the resonant frequency bands during the process of bearing fault detection. To eliminate the above deficiency, this paper presents an insight concept based on the empirical mode decomposition to choose an appropriate resonant frequency band for characterizing feature frequencies of bearing faults by using the envelope analysis subsequently. By the band-pass filtering nature of the empirical mode decomposition, the resonant frequency bands are allocated in a specific intrinsic mode function. The inner or outer ring of bearings scratched intentionally is used to validate the feasibility of the proposed idea, and comparisons with the traditional envelope analysis are addressed. The experimental results show that the proposed insight concept can efficiently and correctly diagnose the bearing fault types.

► Combining EMD with run-up excitation enables to select an appropriate resonance frequency band.
► An IMF with the same high-energy frequency band as run-up excitation is selected.
► An appropriate IMF is used to proceed with the envelope analysis for bearing fault detection.
► The outer- and the inner-race defects were considered and used to justify the proposed technique.