Dear Jason Jonkman,
I reviewed the following documents of the reference 5-MW wind turbine but could not find helpful data for the structural analysis of the gearbox. The gears are designed based on ISO 6336-2, ISO 6336-3, and ISO 6336-6 and with the load and safety factors recommended by IEC 61400-4. KISSsoft 2014 was also used to initial gear sizing. As known, the gear standards hold some critical values for the safety factors associated with bending and contact stress but are not specified in the documents. The safety factors that were obtained for the bending and surface pitting of planetary and helical gears are very important from the aspects of design and its optimization. What are the allowable bending and contact stress numbers used in the analyses? Could you share a datasheet or document to have detailed knowledge about the procedure tracked for the gearbox design?
- Nejad, A. R., Guo, Y., Gao, Z., & Moan, T. (2016). Development of a 5 MW reference gearbox for offshore wind turbines. Wind Energy, 19(6), 1089-1106.
- Jonkman J, Butterfield S, Musial W, Scott G, Definition of a 5-MW reference wind turbine for offshore system development, Technical Report NREL/TP-500-38060, National Renewable Energy Laboratory (NREL), Golden, Colorado, USA, 2009.