Study on surface microstructure of cylindrical roller bearings for open-pit coal mine conveyors

To investigate the advantages of microstructure in enhancing multiple performance characteristics of conveyor idler bearings and other friction pairs in open-pit coal mines, this study conducted computational fluid dynamics (CFD) simulations on NU205 cylindrical roller bearing. Based on the structural features of prototype bearings, we designed an elliptical-opening offset parabolic microstructure (hereinafter referred to as EOOPT) configuration for the inner raceway surface. Response surface analysis was employed to investigate the influence patterns of microstructure characteristic parameters on bearing performance. Through multi-objective optimization design, optimal microstructure parameters were determined. Comparative analysis with prototype bearings demonstrated that the optimized microstructure significantly improved average bearing pressure by 15.58% while reducing average friction coefficient by 16.33%, temperature by 9.28%, and wear volume by 6.37%. Experimental studies revealed the influence of microstructure column count on vibration suppression characteristics, temperature stability, and torque variation. This study innovatively designs an elliptical-opening offset parabolic microstructure (EOOPT) for cylindrical roller bearings in open-pit coal mines-filling the gap in existing research that lacks exploration of non-simple microstructure opening shapes, cross-sectional depth optimization, and their integrated impact on bearing thermal stability; meanwhile, it establishes a multi-objective optimization model for EOOPT parameters, realizing the synergistic improvement of bearing load capacity, friction reduction, and vibration suppression, which is rarely reported in studies on mine conveyor bearings.