Integrated shear webs for wind turbine blades

Abstract

The present invention includes a method for fabricating elongated wind turbine blades and wind turbine blades formed by the method. The method includes providing a first shell reinforcing fiber structure. At least one shear web reinforcing fiber structure is positioned adjacent to the first shell reinforcing fiber structure. The method includes infusing the first shell reinforcing fiber structure and shear web reinforcing fiber structure with a matrix material and curing the matrix material to form a unitary composite first shell component. Thereafter a composite second shell component is attached to the composite first shell component to form an elongated composite airfoil suitable for use as a wind turbine blade. The wind turbine blades formed include unitary components providing reduced number of adhesive joints.

1 . A method for fabricating elongated airfoils for wind turbines comprising:
 providing a first spar reinforcing fiber structure, a second spar reinforcing structure and a shear web reinforcing fiber structure;   positioning the first spar reinforcing fiber structure and the second spar reinforcing fiber structure adjacent the shear web reinforcing fiber structure;   infusing the first shell reinforcing fiber structure and shear reinforcing fiber structure with a matrix material and curing the matrix material to form a unitary composite web spar; and   attaching the web spar to each of a first composite first shell component and a composite second shell component to form an elongated composite airfoil structure.   
     
     
         2 . The method of  claim 1 , wherein the infusing step comprises a technique selected from the group consisting of resin transfer molding, vacuum assisted resin transfer molding, resin film infusion, resin infusion or combinations thereof 
     
     
         3 . The method of  claim 1 , wherein the positioning includes providing a mold conforming to the desired geometry of a shear web portion of the unitary composite first shell component. 
     
     
         4 . The method of  claim 1 , wherein at least one of the first shell reinforcing fiber structure, the second shell reinforcing fiber structure or the shear web reinforcing fiber structure includes a stiffener material. 
     
     
         5 . The method of  claim 4 , wherein the stiffener material is balsa or foam. 
     
     
         6 . A wind turbine blade comprising
 a first shell portion; and   a second shell portion adhered to the first shell portion;   wherein the first shell portion comprises at least one shear web, the first shell portion and integral shear web being a unitary composite component.   
     
     
         7 . The wind turbine blade of  claim 6 , wherein the unitary composite component includes a plurality of shear webs. 
     
     
         8 . The wind turbine blade of  claim 6 , wherein the wind turbine blade comprises a length of greater than about  20  meters. 
     
     
         9 . The wind turbine blade of  claim 6 , wherein the wind turbine blade comprises a length of greater than about  50  meters. 
     
     
         10 . The wind turbine blade of  claim 6 , wherein the second shell portion includes the second shell portion and integral shear web being a unitary composite component. 
     
     
         11 . A wind turbine blade comprising
 a first shell portion and a second shell portion enveloping a web spar, the web spar comprising:   a first spar portion;   a second spar portion; and   at least one shear web between the first spar portion and the second spar portion;   wherein the first spar portion and the shear web are a unitary composite component.   
     
     
         12 . The wind turbine blade of  claim 11 , wherein the unitary composite component includes a plurality of shear webs 
     
     
         13 . The wind turbine blade of  claim 11 , wherein the wind turbine blade comprises a length of greater than about  20  meters. 
     
     
         14 . The wind turbine blade of  claim 11 , wherein the wind turbine blade comprises a length of greater than about  50  meters. 
     
     
         15 . The wind turbine blade of  claim 11 , wherein the first spar portion, shear web and second spar portion are a unitary composite component. 
     
     
         16 . The wind turbine blade of  claim 11 , wherein the web spar includes a “T” shaped geometry. 
     
     
         17 . The wind turbine blade of  claim 11 , wherein the web spar includes a “I” shaped geometry.