For wind turbine main gearboxes (MGBs) with about 1 MW or higher power, gearbox designs with multiple power paths are used. They handle several mega-Newton-meter of torque economically. Earlier wind turbines with lower power ratings used parallel shaft gearboxes with only one power path but soon they were superseded by planetary gearboxes having typically three to five planets per stage. This paper describes experiences using planetary gears where “Flexpins” are used to improve the load sharing between the individual planets—representing the multitude of power paths—and along the planet’s face width.

2023 is shaping up to be our planet’s hottest year on record, and the wind energy industry is feeling the heat. The GWEC (Global Wind Energy Council) says that the rate of wind turbine installations will need to quadruple globally by the end of the decade if we’re to achieve the IRENA’s (International Renewable Energy Agency) goal of net zero carbon emissions by 2050—and keep the average annual temperature worldwide from increasing more than the predicted 1.5° C. Fortunately, “net zero” commitments are gathering global momentum. Before year’s end, total global windpower is expected to reach a historic milestone of 1 TW of installed capacity, eliminating 1.2 billion tons of CO2 annually, roughly the equivalent of all the carbon emissions of South America.