Aimed at the drawback of blindly adding white noise occurring in the ensemble empirical mode decomposition（EEMD） when used to solver realistic problems

the iterative ensemble empirical mode decomposition（IEEMD） method is proposed.To begin with

the IEEMD method is introduced.Then

the EEMD method and the IEEMD method are used to analyze the signals from the realistic gearbox with a broken-tooth fault.As a result

the comparisons with the EEMD method show that the IEEMD method could produce HHT spectrum with higher time-frequency resolution and extract more and useful information from the signals.Moreover

it indicates that the IEEMD method greatly alleviates the drawback of the EEMD method and is suitable as a fault feature extraction method for gearboxes.