Failure analysis and thermochemical surface engineering of bearings for wind turbine drivetrains

摘要

Roller element bearings inside the drivetrain of a wind turbine are exposed to highly dynamic loads that can for instance originate from the wind field, the rotor, the drivetrain itself or the generator.This can lead to premature failure of these components and consequently to high economic maintenance costs.The mechanism behind the premature failures is not well understood but is associated with the formation of so called white etching cracks (WECs).Complementary microscopic techniques were used to analyse failed bearings and to characterize the morphology of white etching cracks.Deep nitriding was studied as a potential remedy to failures associated with WECs.Performance of nitrided rollers was evaluated by rolling contact fatigue testing under conditions known to provoke WEC failure.