Repair of rotor blade roots

Abstract

A method for repairing a wind turbine is described. The method may include preparing the surface of the blade, removing a plurality of mounting bolts, and replacing the mounting bolts with rod members. The rod members may be bonded to the blade root thereby strengthening the blade root and/or repairing any damaged or weakened regions. This repair may be performed on blades and blade coupling regions of various characteristics as well in modular fashion using pre-molded sections attached together around the blade root. The method of repair may be performed while the blade is still attached to the turbine hub. Wind turbines repaired according to these methods are also described. The method may also be used for attaching and otherwise handling new turbine blades and new wind turbines.

1 . A wind turbine comprising:
 a blade root having a flange configured for securing the blade root to a turbine hub; and   a load shifting structure housed on the flange and attached to the blade root, the load shifting structure positioned around an outer surface of the blade root and configured to vary a path of loading on the blade root when the blade is in use.   
     
     
         2 . The wind turbine of  claim 1 , wherein the load shifting structure comprises a threaded attachment bonded to the outer surface of the blade root. 
     
     
         3 . The wind turbine of  claim 2 , wherein the load shifting structure comprises a threaded attachment, the threaded attachment including a threaded rod and a complimentary nut configured to provide a coupling force on the flange for coupling the blade root to the turbine hub. 
     
     
         4 . The wind turbine of  claim 2 , wherein the threaded attachment is bonded to the outer surface of the blade root by a bonding material including fiberglass, epoxy, or vinyl ester resin. 
     
     
         5 . The wind turbine of  claim 2 , wherein the load shifting structure further comprises a plurality of threaded attachments positioned around the blade root so as to circumscribe the blade root, the threaded attachments being bonded to the outer surface of the blade root. 
     
     
         6 . The wind turbine of  claim 5 , the plurality of threaded attachments being angularly spaced substantially uniform distances apart so as to uniformly circumscribe the blade root. 
     
     
         7 . The wind turbine of  claim 6 , the plurality of threaded attachments being bonded to the outer surface of the blade root by a bonding material, the bonding material substantially covering the plurality of the threaded attachments and forming a collar of bonding material about the outer surface of the blade root. 
     
     
         8 . The wind turbine of  claim 2 , wherein the load varying structure is bonded to the outer surface of the blade root with a bonding material including elastonite. 
     
     
         9 . The wind turbine of  claim 1 , the load shifting structure comprising a plurality of pre-molded sections bonded together and to the outer surface of the blade root to form a securing collar. 
     
     
         10 . The wind turbine of  claim 9 , each of the pre-molded sections having a convex exterior and concave interior surface complimentary in curvature to the outer surface of the blade root. 
     
     
         11 . The wind turbine of  claim 9 , each of the pre-molded sections comprising attachment elements configured for complimentary fit to the securing structure of a turbine hub. 
     
     
         12 . A method for repairing a blade of a wind turbine, comprising the steps of:
 preparing an outer surface of a blade root of a blade for repair; and   attaching a load shifting structure around an outer surface of the blade root, the load shifting structure configured to vary a load path of the blade when in use.   
     
     
         13 . A method of installing a blade, comprising the steps of:
 securing blade attachment hardware to a blade root to form a securing collar and securing a blade to a wind turbine by attaching the securing collar to a hub of the wind turbine.   
     
     
         14 . The method of installing a blade of  claim 13 , wherein the step of securing blade attachment hardware to a blade root to form a securing collar further comprises, securing a plurality of pre-molded sections together and to an outer surface of the blade root. 
     
     
         15 . The method of installing a blade of  claim 14 , wherein the plurality of pre-molded sections are bonded together and to the outer surface of the blade root. 
     
     
         16 . The method of installing a blade of  claim 14 , further comprising the steps of modifying one of a coning angle, blade pitch angle, number of attachments or orientation of attachments. 
     
     
         17 . The method of installing a blade of  claim 13 , wherein the securing collar is configured to enable a new blade to be attached to the hub of the wind turbine.