Estimation of Smearing Damage Risk in Wind Turbine Main Bearings

In the global quest for sustainable energy, wind energy is a key renewable resource. The pursuit of lower costs for energy drives continuous innovation in wind turbine technology. Advances in drivetrain design have enabled higher capacity factor and improved turbine performance. Larger wind turbines have led to increasing demands on rolling bearings. Main bearings in particular must support greater loads as rotor diameters grow. Design standards focus on rolling contact fatigue and plastic deformation as primary failure mechanisms. However, damage such as adhesive wear also occurs in practice and can lead to wind turbine failure. Smearing damage in main bearings is an underrepresented failure mode in current design practices, despite its occurrence in the field. This study introduces a simulation-based methodology to assess and reduce smearing risk under realistic conditions. A multibody simulation model is developed to model the main bearing. Specifically, the model consists of a double-row tapered roller bearing with a pin-type cage. Due to the cage’s size, the model is extended to account for its flexibility. A screening study with realistic dimensions and load conditions identifies critical scenarios. Roller kinematics and contact forces are analyzed to reveal the damage mechanisms. In one specific load case, pronounced deceleration of the rolling elements is observed, caused by the roller being clamped between the cage and the ring riban effect not represented in existing quasi-static tools. A corrective measurean increased preloadis implemented and evaluated for effectiveness. The results show a significant reduction in the damage indicator without exceeding fatigue stress limits, demonstrating that the presented approach is capable of extending bearing life and improving system reliability.