Patent ID: 6975045

Claim:
A wind power generating system, comprising: a generator housing mounted on a fixed base so as to be rotatable around a vertical axis; an outer rotor including a hollow cylindrical member supported by the generator housing so as to be rotatable around a horizontal axis and a plurality of permanent magnets attached to an inner circumferential surface of the cylindrical member at a regular angular interval, the cylindrical member including a coaxial extension having a reduced diameter; an inner rotor including a shaft disposed coaxially with the cylindrical member in a freely rotatable manner, a plurality of core teeth arranged circumferentially along an outer circumferential surface of the shaft, and a coil wound around each core tooth, the shaft including a free end that coaxally extends out of the coaxial extension of the cylindrical member; a slip ring arrangement for electrically connecting the coils of the inner rotor to an external circuit; a first turbine including a plurality of turbine blades mounted to the free end of the shaft of the inner rotor; a second turbine including a plurality of turbine blades mounted on the coaxial extension of the cylindrical member, the turbine blades of the second turbine being provided with a pitch angle that is opposite in sense from those of the first turbine but otherwise similar in shape as those of the first turbine; wherein the first turbine is axially spaced from the second turbine at least by three times the axial width of the turbine blades.