Fatigue rating life calculation of the wind turbine yaw bearing

Four-point contact ball bearings are used as pitch and yaw bearing in wind turbines. This paper compares different life calculation methods of the wind turbine yaw bearing. Yaw bearing investigated in this paper belongs to a ۲.۵ MW wind turbine. International standards ISO ۲۸۱:۲۰۰۷ and ISO ۱۶۲۸۱:۲۰۰۸ are used as the primary references, and NREL DG ۰۳ as a valid guideline in this research. In modified rating life calculation based on ISO ۱۶۲۸۱, it is necessary to define internal load distribution. For this purpose, analytical and finite element (FE) methods are applied. A simplified FE model is created in ANSYS Workbench ۲۰۱۹ and utilized for internal load distribution determination. Evaluation of FE model and analytical results are conducted for assumed load case and good agreement are reached. In this study, the effect of support stiffness is not considered and rings are assumed to be rigid. Comparison of fatigue rating life calculated based on ISO ۲۸۱ and ISO ۱۶۲۸۱ standard approaches are made and it observed that ISO ۲۸۱ is slightly more conservative.

کلیدواژه ها:

four-point contact ball bearing ، fatigue loads ، numerical simulation ، wind energy