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Title: Mitigation of Micropitting in Wind Turbine Main Shaft Bearings

In recent years, increasing evidence of failures has been reported from spherical roller main bearings used in three-point mounting (TPM) drivetrains of wind turbines. One of the leading causes has been micropitting, a failure mode that is possibly overlooked by design, selection and life-prediction tools. It remains to be seen if retrofitting problematic spherical roller bearings (SRBs) with improved bearing design solutions can improve their durability. Questions to ask might be: ‘Are the operating conditions of the main bearing well understood?’ and ‘Are the failures caused by deficient design practice or other unidentified external sources within the system?’ These questions fundamentally challenge the underlying design basis and encourage the need for a system analysis approach that is currently being undertaken by researchers from the National Renewable Energy Laboratory (NREL). Specifically, this article discusses a few potential design alternatives and system-level reassessment to circumvent micropitting in main bearings used in TPM drivetrains.
 [1] ;  [1] ;  [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
Publication Date:
OSTI Identifier:
Report Number(s):
DOE Contract Number:
Resource Type:
Journal Article
Resource Relation:
Journal Name: Windtech International; Related Information: WindTech International
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Wind and Water Technologies Office (EE-4W)
Country of Publication:
United States
17 WIND ENERGY; Spherical roller bearing; envelope; clearance; tapered roller bearing; trunnion; drivetrain; failure; NREL