Abstract:Planetary gearboxes possess intricate transmission mechanisms. Upon the failure of the sun gear, its malfunction messages are frequently obscured by unrelated or interfering components, complicating the process of pinpointing specific fault characteristics; To effectively extract common features from vibration signals under fault conditions, the strategy of employing a co-source response for vibration source separation is adopted.; Based on the periodic and low-rank nature of internal excitation signals in rotating machinery, this approach identifies homologous response segments highly related to sun gear faults, thereby obtaining segments rich in fault information; The main components that best represent fault characteristics are then extracted to highlight fault information and reduce interference from irrelevant data; Building on traditional empirical Fourier decomposition, a frequency band segmentation threshold is set to prevent local spectral segmentation. The optimal decomposition components are adaptively selected through a fault feature ratio index, and the envelope spectrum is used to verify the effectiveness of fault feature extraction; Finally, the method's effectiveness is validated using both simulated vibration signals of sun gear crack faults and actual gearbox operational data, achieving clear extraction of sun gear crack fault features;