The subject matter described herein relates generally to methods and systems for wind turbines, and more particularly, to methods and systems relating to gearboxes for wind turbines.
At least some known wind turbines include a tower and a nacelle mounted on the tower. A rotor is rotatably mounted to the nacelle and is coupled to a generator by a shaft. A plurality of blades extend from the rotor. The blades are oriented such that wind passing over the blades turns the rotor and rotates the shaft, thereby driving the generator to generate electricity.
At least some known wind turbines include gearboxes to transmit torque from a rotor shaft to a high speed shaft. The rotor shaft is driven by the rotor blades of the wind turbine. The high speed shaft is coupled to the generator.
In recent years wind turbines having an increased nominal power have been developed. Increased nominal power demands gearboxes having an increased outer diameter for transmitting the torque from the rotor blades to the generator. Gearboxes become increasingly expensive as their outer diameter grows. Furthermore, available space in a nacelle of a wind turbine is restricted. US 2010/0120573 A1 discloses a planetary gear box having multiple sun pinions with a limited balance of the load split between the load paths.
Therefore, it is desirable to have gearboxes capable of transmitting torque from a rotor shaft to a high speed shaft with a way around the growing outer diameter for high torques using a split load arrangement with a balanced splitting of the load between at least two gear sets.