Insights on Wind Turbine Maintenance From the Usage History of a General Electric Transportation Systems Gearbox

Although damage to the gears occurs less frequently than damage to the bearings in wind turbine gearboxes (Sheng 2017), gear damage still presents a reliability challenge. Micropitting is a form of hertzian fatigue damage that occurs on gear teeth. It appears as ultrafine cracks on the surface of the flank, with the resulting loss of material looking like gray staining. Recently, micropitting that occurred in a wind turbine gearbox (Keller, Michaud, and Lambert 2020) was used as a case study in the International Organization for Standardization (ISO) technical specification (TS) ISO/TS 6336-22 (Olson, Michaud, and Keller 2020a; Olson, Michaud, and Keller 2020b). This specification contains a proposed calculation of risk of micropitting in gear sets in terms of a safety factor based on the ratio of the minimum to the permissible specific lubricant film thickness. The case study only examined the simplified computation in Method B in the technical specification that evaluates points on the path of contact, and micropitting was not predicted to occur (Olson, Michaud, and Keller 2020a). The case study is currently being extended to include the more detailed Method A that evaluates the specific film thickness across the entire contact zone, but more accurate knowledge of the operational history of the gearbox is needed. This report summarizes the operational history of the gearbox.

• Record URL:
  • https://www.nrel.gov/docs/fy22osti/82704.pdf
• Corporate Authors:

  National Renewable Energy Laboratory

  Golden, CO  United States  80401
• Authors:
  • Keller, Jonathan
  • Graham, Syenna
  • Guo, Yi
• Publication Date: 2022-7

Language

• English

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; Photos; References; Tables;
• Pagination: 17p

Subject/Index Terms

• TRT Terms: Gears; Maintenance; Pitting; Turbines; Wind power generation
• Subject Areas: Bridges and other structures; Maintenance and Preservation; Transportation (General);

Filing Info

• Accession Number: 01854996
• Record Type: Publication
• Report/Paper Numbers: NREL/TP-5000-82704
• Contract Numbers: DE-AC36-08GO28308
• Files: TRIS
• Created Date: Aug 18 2022 3:06PM