A novel event‑driven impact signal model for deep groove ball bearings with inner‑race defects

Vibration impact signals are pivotal for quantifying defect sizes in deep groove ball (DGB) bearings. However, conventional dynamic models often produce oversimplified responses that lack the characteristic impulses observed in test signals, primarily because they neglect the nuanced sequence of events during rolling element-defect interactions. To bridge this fidelity gap, this paper proposes a novel event-driven signal model that, based on the inner-race displacement under different bearing load conditions, for the first time deconstructs the rolling element's passage through an inner-race defect into three distinct physical phases: stress relief, first impact, and second impact. By calculating the time-varying load distribution and contact state transitions associated with each phase, the model synthesizes highly realistic impact impulses without relying on any resonance parameters, setting it apart from existing approaches. The key advantages of this model are its parametric simplicity, computational efficiency, and exceptional phase accuracy, enabling it to faithfully restore the transient impulse train. Experimental validation demonstrates remarkable consistency with test data. Furthermore, the model provides a clear analytical framework to investigate the influence of defect size and rotational speed on each impact event, offering profound insights for precise defect size evaluation and advancing the state-of-the-art in bearing fault simulation.