Finite Element Analysis According to the Extreme Load Case of Pitch Bearing for Wind Turbine

This study was conducted to evaluate the safety of the bearing by analyzing the extreme load applied to the pitch bearing of a large wind turbine. NREL DG03 contact stress calculation and finite element analysis were performed for the maximum extreme load and 15% and 30% increased extreme load conditions applied to pitch bearings for large wind turbines. Using the calculated and analyzed results, safety evaluation was performed based on NREL DG03 guidelines. Based on the ball bearing static allowable stress of 4200 MPa from NREL DG03 guidelines, the safety factor of the finite element analysis was calculated and found to be 2.39 for the maximum extreme load, 1.73 for the 15% up extreme load, and 1.25 for the 30% up extreme load. Based on the minimum factor of safety of 1.5 in ISO 76, the results are above the minimum factor of safety up to 15% up extreme load, so the bearing design is considered safe.