Wind turbine anchor element

Abstract

An anchor element for a tower includes an anchor plate element including an upper surface, a lower surface, and at least one first through-hole extending between the upper surface and the lower surface; and at least one first nut having a female thread, the at least one first nut being provided at the at least one first through-hole at the lower surface of the anchor plate element so as to cover the at least one first through-hole, wherein the at least one first nut is non-releasably connected to the lower surface of the anchor plate element.

1 . An anchor element for a tower, comprising:
 an anchor plate element comprising an upper surface, a lower surface, and at least one first through-hole extending between the upper surface and the lower surface; and   at least one first nut having a female thread, said at least one first nut being provided at the at least one first through-hole at the lower surface of the anchor plate element so as to cover the at least one first through-hole,   wherein said at least one first nut is non-releasably connected to the lower surface of the anchor plate element.   
     
     
         2 . The anchor element according to  claim 1 , wherein
 the at least one first nut is connected to the lower surface of the anchor plate element such that a lower portion of the at least one first through-hole is sealed from the space below the lower surface of the anchor plate element.   
     
     
         3 . The anchor element according to  claim 1 , wherein
 a shape of the anchor plate element is an ring sector.   
     
     
         4 . The anchor element according to  claim 1 , wherein
 a shape of the anchor plate element is a closed ring.   
     
     
         5 . The anchor element according to  claim 1 , wherein
 the at least one first nut is closed at the end distal from the anchor plate element.   
     
     
         6 . The anchor element according to  claim 1 , wherein
 the at least one first nut is a cap nut.   
     
     
         7 . The anchor element according to  claim 6 , wherein the cap nut further comprises
 a torque member adapted for anchoring the cap nut in concrete when the anchor element is embedded within a tower foundation.   
     
     
         8 . The anchor element according to  claim 7 , wherein
 a cap of the cap nut has a convex shape and the torque member comprises a plate which is tangent to the cap of the cap nut.   
     
     
         9 . The anchor element according to  claim 7 , wherein
 the torque member comprises a plate attached to an outer surface of the cap nut and extending at least partially in an axial direction of the cap nut.   
     
     
         10 . The anchor element according to  claim 1 , wherein
 the at least one first nut is integrally formed with the lower surface of the anchor plate element.   
     
     
         11 . The anchor element according to  claim 1 , wherein
 at least one first washer is provided between the lower surface of the anchor plate element and the at least one first nut, the at least one first washer being non-releasably connected to both the lower surface of the anchor plate element and the at least one first nut.   
     
     
         12 . The anchor element according to  claim 1 , wherein
 the at least one first nut is integrally formed with a washer.   
     
     
         13 . The anchor element according to  claim 1 , further comprising:
 a tower base plate provided above the anchor element, the tower base plate having an upper surface, a lower surface, and at least one second through-hole extending between the upper surface of the tower base plate and the lower surface of the tower base plate;   at least one conduit extending between the lower surface of the tower base plate and the upper surface of the anchor plate element and connecting said at least one first and at least one second through holes; and   at least one anchor bolt accommodated within the at least one conduit, a lower portion of the anchor bolt being screwedly fixed to the female thread of the at least one first nut and an upper portion of the at least one anchor bolt protruding from the upper surface of the tower base plate and being fixed to a second nut provided at the upper surface of the tower base plate.   
     
     
         14 . A wind turbine comprising:
 a tower having a lower portion;   a foundation having an upper surface;   an anchor comprising:   a lower anchor member within the foundation and comprising an upper surface,   a lower surface, and a plurality of first through-holes connecting the upper and the lower surface of the lower anchor member, a plurality of lower nuts, each lower nut being provided at a respective first through-hole at the lower surface of the lower anchor member so as to cover said first through-hole and being non-releasably connected to the lower surface of the lower anchor member;   an upper anchor member comprising an upper surface, a lower surface, and a plurality of second through-holes connecting the upper and the lower surface of the upper anchor member, each second through-hole being substantially vertically aligned with one of the first through-holes;   a plurality of guide tubes, each guide tube connecting a pair of first and second through-holes;   a plurality of anchor bolts, each anchor bolt being accommodated within one of the guide tubes, a lower portion of said anchor bolt being screwedly engaged with an inner thread of a corresponding lower nut and an upper portion of said anchor bolt protruding from the upper surface of the upper anchor member; and   a plurality of upper nuts, each upper nut fixing an upper portion a corresponding anchor bolt;   wherein the lower portion of the tower is rigidly connected to the upper surface of the upper anchor member.   
     
     
         15 . The wind turbine according to  claim 14 , further comprising:
 a plurality of first washers, each first washer being provided between the lower surface of the lower anchor member and one of the lower nuts and being non-releasably connected to both the lower surface of the lower anchor member and said lower nut.   
     
     
         16 . The wind turbine according to  claim 14 , wherein
 at least one of the lower anchor member and the upper anchor member is a plate having a ring shape.   
     
     
         17 . The wind turbine according to  claim 14 , wherein
 said lower nuts are cap nuts.   
     
     
         18 . A method for replacing an anchor bolt of a wind turbine, comprising:
 (a) loosening and removing an upper nut at an upper anchor member,   (b) removing said anchor bolt by unscrewing a lower portion of said anchor bolt from a lower nut which is non-releasably connected to a lower anchor member and pulling said anchor bolt out of a conduit extending between the lower anchor member and the upper anchor member,   (c) inserting an exchange anchor bolt into said conduit and screwing together a lower portion of said exchange anchor bolt and said lower nut,   (d) forming a rigid connection between the upper and lower anchor members by fastening said upper nut at an upper portion of said exchange anchor bolt.   
     
     
         19 . The method according to  claim 18 , wherein the rigid connection is formed by prestressing the anchor bolt. 
     
     
         20 . The method according to  claim 19 , wherein prestressing the bolt includes pulling said exchange anchor bolt into an axial direction thereof such that a gap is formed between the upper nut and the upper anchor member;
 tightening the upper nut; and   releasing the pulling force.