Fracture Failure Analysis on Pitch Bearing of Wind Turbine
Author(s): TAO Gangzheng, WANG Jianguo, WANG Yanfeng, Longyuan Wind Power Engineering Technology Co., Ltd., Liaoning Longyuan Wind Power Co., Ltd.
Pages: 240-242+245
Year: 2015 Issue: 8
Journal: Hot Working Technology
Keyword: wind turbine; pitch bearing; fracture; failure analysis;
Abstract: The pitch bearing of a wind turbine was broken in service leading to the blade drop. The broken bearing outer ring was subjected to inspections such as macroscopic inspection,fracture macroscopic analysis,microscopic analysis,chemical component analysis,mechanical property and hardness inspection and metallographic structure inspection. Based on the physics and chemistry experiments, the broken reasons for the bearing were analyzed by using micro-fracture mechanism.The results show that the corrosion pits exist at the bolt hole inner wall of the bearing outer ring. The cracks appear due to the stress concentration of the corrosion pit, and the cracks extend in the fatigue mode due to the alternatively various stress till the ring bearing is broken. Some advices were given for device security. Ameliorating the machining technics of the bearing and using improvable coating components can help improve the ability of defending corrosion fracture.
Pages: 240-242+245
Year: 2015 Issue: 8
Journal: Hot Working Technology
Keyword: wind turbine; pitch bearing; fracture; failure analysis;
Abstract: The pitch bearing of a wind turbine was broken in service leading to the blade drop. The broken bearing outer ring was subjected to inspections such as macroscopic inspection,fracture macroscopic analysis,microscopic analysis,chemical component analysis,mechanical property and hardness inspection and metallographic structure inspection. Based on the physics and chemistry experiments, the broken reasons for the bearing were analyzed by using micro-fracture mechanism.The results show that the corrosion pits exist at the bolt hole inner wall of the bearing outer ring. The cracks appear due to the stress concentration of the corrosion pit, and the cracks extend in the fatigue mode due to the alternatively various stress till the ring bearing is broken. Some advices were given for device security. Ameliorating the machining technics of the bearing and using improvable coating components can help improve the ability of defending corrosion fracture.
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