A robust hybrid estimation method for local bearing defect size based on analytical model and morphological analysis

This paper presents a robust hybrid method using an analytical model and morphological analysis for estimating defect sizes on bearings, addressing inaccuracies in traditional peak-based approaches. First, a spatial contact analytical model is developed to analyze roller movement through defects. Numerical results indicate that radial defect sizes significantly impact dual-impulse intervals for accurate estimation, while axial size has minimal effect. An analysis of contact deformation, force, and vibration response reveals that the defect entry aligns before the first low-frequency peak, and the exit aligns after the first high-frequency peak, preceding the second low-frequency peak. Finally, testing of the derived model on four samples, incorporating vibration characteristics and geometry, achieves a minimum estimation error of 0.03%, demonstrating high accuracy and practical value.