Wind turbine

Abstract

A wind turbine is described. The turbine includes a hub with one or more blades. The hub is rotatably mounted on a frame and operatively coupled to a shaft through a coupling plate mounted on the shaft. The shaft is provided at least partially internally to the frame, and the shaft is a substantially tubular hollow shaft.

1 - 17 . (canceled) 
     
     
         18 . A wind turbine comprising:
 a hub with one or more blades, the hub being rotatably mounted on a frame, and operatively coupled to a shaft through a coupling plate mounted on the shaft, wherein the shaft is provided at least partially internally of the frame, and the shaft is a substantially tubular hollow shaft made by forming a thin metal plate into a tube.   
     
     
         19 . The wind turbine according to  claim 18 , wherein the coupling plate is adapted to transmit a torque about a rotational axis of the hub from the hub to the shaft while substantially limiting the transmission of other loads. 
     
     
         20 . The wind turbine according to  claim 19 , wherein the coupling plate comprises a center piece from which a plurality of spokes extends radially, and wherein the hub is provided with a plurality of circumferentially arranged axial protrusions, and wherein flexible elements are arranged to connect the spokes to the protrusions. 
     
     
         21 . The wind turbine according to  claim 19 , wherein the coupling plate comprises a center piece, the center piece comprising a substantially circular disc, the circular disc being connected to the hub through a plurality of circumferentially arranged axial bolts, wherein the bolts are arranged within the circular disc with a plurality of flexible bushings. 
     
     
         22 . The wind turbine according to  claim 18 , wherein the coupling plate comprises a substantially tubular flange and is mounted on the shaft through a shrink disc. 
     
     
         23 . The wind turbine according to  claim 22 , wherein the shaft is of gradually increasing external diameter in the region where the coupling plate is mounted on the shaft. 
     
     
         24 . The wind turbine according to  claim 18 , wherein the shaft comprises a reinforcement substantially in or near a portion of the shaft where the coupling plate is mounted. 
     
     
         25 . The wind turbine according to  claim 24 , wherein the local reinforcements comprise a plurality of annular discs mounted internally to the shaft, the annular discs being welded to the inside of the shaft. 
     
     
         26 . The wind turbine according to  claim 24 , wherein the one or more local reinforcements comprise a cylindrical insert mounted internally to the shaft. 
     
     
         27 . The wind turbine according to  claim 26 , wherein the local reinforcements further comprise an annular disc mounted internally to the cylindrical insert. 
     
     
         28 . The wind turbine according to  claim 27 , wherein the annular disc is welded to the inside of the cylindrical insert. 
     
     
         29 . A wind turbine comprising:
 a hub with one or more blades, the hub being rotatably mounted on a frame, surrounding the frame, and operatively coupled to a shaft through a coupling plate mounted on the shaft,   wherein the shaft is provided at least partially internally of the frame and is a thin-walled and substantially tubular shaft.   
     
     
         30 . The wind turbine according to  claim 29 , wherein the shaft is made by forming a thin metal plate into a tube and welding along a longitudinal axis of the tube. 
     
     
         31 . The wind turbine according to  claim 29 , wherein the shaft is formed in a forging or casting process. 
     
     
         32 . The wind turbine according to  claim 29 , wherein the coupling plate is adapted to transmit a torque about a rotational axis of the hub from the hub to the shaft while substantially limiting the transmission of other loads. 
     
     
         33 . The wind turbine according to  claim 31 , wherein the coupling plate comprises a center piece, the center piece comprising a substantially circular disc, the circular disc being connected to the hub through a plurality of circumferentially arranged axial bolts, wherein the bolts are arranged within the circular disc with a plurality of flexible bushings. 
     
     
         34 . A wind turbine comprising:
 a hub with one or more blades, the hub being rotatably mounted on a frame and operatively coupled to a shaft through a coupling plate mounted on the shaft,   the shaft being a substantially tubular hollow shaft, and   the shaft is formed in a forging or casting process.   
     
     
         35 . The wind turbine according to  claim 34 , wherein the hub is rotatably mounted on the frame through a plurality of bearings. 
     
     
         36 . The wind turbine according to  claim 35 , wherein the hub surrounds the frame. 
     
     
         37 . The wind turbine according to  claim 34 , wherein the shaft comprises a reinforcement substantially in or near a portion of the shaft where the coupling plate is mounted.