An Experimental and Theoretical Investigation of Micropiiting in Wind Turbine Gears and Bearings

Kahraman, Ahmet

关键词: BEARINGS;    LUBRICANTS;    LUBRICATION;    ROLLING;    ROUGHNESS;    VALIDATION;    WIND TURBINES Wind turbine gearbox reliability;    micropitting;   

DOI  :  10.2172/1037344
RP-ID  :  DOE/EE0002735-1
PID  :  OSTI ID: 1037344
Others  :  TRN: US201208%%534

学科分类：再生能源与代替技术

美国|英语

来源: SciTech Connect

【 摘 要 】

In this research study, the micro-pitting related contact failures of wind turbine gearbox components were investigated both experimentally and theoretically. On the experimental side, a twin-disk type test machine was used to simulate wind turbine transmission contacts in terms of their kinematic (rolling and sliding speeds), surface roughnesses, material parameters and lubricant conditions. A test matrix that represents the ranges of contact conditions of the wind turbine gear boxes was defined and executed to bring an empirical understanding to the micro-pitting problem in terms of key contact parameters and operating conditions. On the theoretical side, the first deterministic micro-pitting model based on a mixed elastohydrodynamic lubrication formulations and multi-axial near-surface crack initiation model was developed. This physics-based model includes actual instantaneous asperity contacts associated with real surface roughness profiles for predicting the onset of the micro-pit formation. The predictions from the theoretical model were compared to the experimental data for validation of the models. The close agreement between the model and measurements was demonstrated. With this, the proposed model can be deemed suitable for identifying the mechanisms leading to micro-pitting of gear and bearing surfaces of wind turbine gear boxes, including all key material, lubricant and surface engineering aspects of the problem, and providing solutions to these micro-pitting problems.