Wear Performance of Wind Turbine Gearbox Journal Bearings Considering Material Porosity from Laser Cladding: Numerical and Experimental Investigations

With the trend toward larger-scale wind turbines, planetary gear bearings in wind turbines are undergoing a transition from rolling bearings to laser-cladded journal bearings. Using a combined numerical and experimental approach, this study investigates the influence of material porosity induced by laser cladding on the lubrication and tribological performance of gearbox journal bearings. A computational model incorporating porous material properties was developed, taking into account pore morphology, elastic deformation, and contact pressure. The accuracy of the model was validated through experiments conducted at both the material level and the full-scale wind power bearing level. The results demonstrate that applied loads from 1000 to 2000 kN predominantly drive volumetric wear within the central bearing zone, whereas wear depth at the periphery exhibits reduced sensitivity to these load variations. Porosity analyses reveal three critical regimes: Low porosity exhibit negligible wear influence compared to surface roughness randomness. Moderate porosity disrupts hydrodynamic lubrication, generating stress concentrations that accelerate wear. High porosity significantly increases wear within central bearing zones through oil film fragmentation and intensified stress focusing.