Patent ID: 8192322

Claim:
A wind turbine drive ( 1 ), comprising: a nacelle ( 4 ); a rotor ( 2 ) with a rotor shaft ( 3 ); and a transmission box ( 8 ) with a planetary gear unit ( 12 ) connected to the rotor shaft ( 3 ), the planetary gear unit ( 12 ) comprising a planet carrier ( 13 ), the transmission box ( 8 ) supported by a far end of the rotor shaft ( 3 ), the rotor shaft ( 3 ) bearing-mounted with i) a first rotor bearing ( 5 ), the first rotor bearing ( 5 ) directly fixed to the nacelle ( 4 ), and ii) a second rotor bearing ( 6 , 22 ), the second rotor bearing ( 6 , 22 ) being one of i) fixed to the nacelle ( 4 ) in case of a direct rotor bearing, ii) a part of the transmission box ( 8 ) in case of an indirect rotor bearing, the transmission box ( 8 ) provided with a reaction arm ( 21 ), wherein during working of the planetary gear unit ( 12 ), the reaction arm ( 21 ) transmits a reaction torque round the rotor shaft ( 3 ) from the transmission box ( 8 ) to the nacelle ( 4 ) sufficient to prevent the transmission box ( 8 ) from turning along with the rotor shaft ( 3 ), the planet carrier ( 13 ) of the planetary gear unit ( 12 ) bearing-mounted in the transmission box ( 8 ) by only one planet carrier bearing ( 22 , 23 ) at the most, and the reaction arm ( 21 ) arranged adjacent the planet carrier bearing ( 22 , 23 ).