Patent ID: 8487470

Claim:
A vertical wind turbine comprising: a support base defined about an axis; a bearing assembly comprising a fixed ring and a rotating ring, the fixed ring coupled to the support base; a drive shaft having a proximal end and an opposing distal end, the drive shaft coupled to the rotating ring of the bearing assembly; a multistage axial flux generator comprising a rotor assembly coupled to the drive shaft and a stator assembly coupled to the support base, the rotor assembly comprising a plurality of permanent magnets, the stator assembly comprising a plurality of coils defining at least two voltage output stages, wherein the permanent magnets on the rotor assembly are close-coupled to the coils on the stator assembly, wherein the stator assembly further comprises a second plurality of windings defining at least two voltage output stages, and the vertical wind turbine system further comprises a second rotor assembly defined about the axis and coupled to the drive shaft, the second rotor assembly comprising a second plurality of permanent magnets secured to a planar face thereof, the second plurality of permanent magnets being close-coupled to the second plurality of windings on the stator assembly; and a plurality of sails coupled to the drive shaft.