NURBS-based optimization of roller bearing profiles for enhanced performance under angular misalignment

Angular misalignment in roller bearings causes uneven contact pressure distribution, leading to reduced fatigue life and degraded performance. Existing roller profile designs, mostly based on logarithmic curves, suffer from limited adaptability due to their inherent geometric constraints. This paper proposes a novel optimization profile modification model utilizing Non-Uniform Rational B-Spline (NURBS) curves, which provide greater flexibility and broad theoretical applicability. A hybrid mechanical model is developed to accurately evaluate contact pressure distributions under misalignment while maintaining computational efficiency. An optimization framework is established with bearing fatigue life as the objective and NURBS control points as design variables, where geometric constraints on the NURBS profiles are incorporated to ensure design feasibility. Validation on a cylindrical roller bearing under various loading conditions demonstrates that the proposed model significantly improves tilt resistance and fatigue life compared to an enhanced logarithmic reference profile, especially under severe misalignment. Additionally, a simplified Line-Arc Optimized Fitting (LAOF) model is introduced to facilitate practical manufacturing without sacrificing performance.