Rotor blade for a wind turbine and method for manufacturing it

Abstract

Rotor blade (100; 300; 400; 500; 600) for a wind turbine (10), wherein the rotor blade (100; 300; 400; 500; 600) has: a body (106) which is at least partially formed from a core material (126), wherein the body (106) defines a pressure side (108) and a suction side (110) which extend between a front edge (112) and a rear edge (114); several shear elements (128) extending between the pressure side (108) and the suction side (110), each of the plurality of shear elements (128) comprising a first end (132) and a second end (134); several stiffening elements (130) spaced apart across the pressure side (108) and the suction side (110), each of the plurality of stiffening elements (130) being arranged at the first end (132) or at the second end (134) of one of the plurality of shear elements (128); and a skin (120) extending around an outer circumference of the body (106), furthermore the rotor blade (100; 300; 400; 500; 600) further comprises a plurality of transverse elements (580) extending diagonally between at least two adjacent stiffening elements (130) of the plurality of stiffening elements (130), each of the plurality of transverse elements (580) being arranged adjacent to the skin (120), or Each of the plurality of shear elements (128) of the rotor blade (100; 300; 400; 500; 600) has a plurality of strut elements (682) which extend diagonally between opposing stiffening elements (130) of the plurality of stiffening elements (130).

Description

[0001] The present subject matter relates generally to wind turbines and more specifically to rotor blades of wind turbines and methods for manufacturing such rotor blades.

[0002] Wind power is considered one of the cleanest, most environmentally friendly energy sources currently available, and wind turbines have garnered increasing attention in this regard. A modern wind turbine typically consists of a tower, a generator, a gearbox, a nacelle, and one or more rotor blades. The rotor blades capture the kinetic energy of the wind using well-known airfoil principles and transfer this energy, via rotational energy, to a gearbox or, if no gearbox is used, directly to a generator. The generator then converts the mechanical energy into electrical energy, which can be fed into a power grid.

[0003] Manufacturing rotor blades generally requires the use of specialized tools and / or molds. For example, the blade halves of a conventional rotor blade are typically formed in large molds custom-made for the specific size or shape of the blade being produced. Consequently, new molds must be sourced or otherwise manufactured for each blade size and shape produced, significantly increasing the manufacturing cost. Additionally, conventional methods for manufacturing rotor blade halves typically involve an inlay process, in which layers of reinforcing material are manually inserted into the custom-made molds. This process is very labor-intensive and greatly increases the time required to produce a rotor blade.

[0004] US 2011 / 0223032A1 discloses generally an improved method for manufacturing wind turbine rotor blades that reduces production costs and increases the speed at which the blades can be produced. In particular, the application discloses that rotor blades can be manufactured by providing a blade blank consisting of a filler material. The blade blank can be machined or otherwise shaped into the aerodynamic shape or profile of the rotor blade. An outer skin can then be applied to an outer circumference of the shaped blade blank to form the outer surface of the rotor blade and to provide a protective coating for the filler material.However, while the methods described in such an application offer significant advantages, the disclosure does not provide for the assembly of substantial components within the rotor blade to impart stiffness and / or strength to the blade.

[0005] Accordingly, a method for manufacturing rotor blades that improves upon the method described above by providing a rotor blade with increased stiffness and / or strength would be desirable in the technology.

[0006] Aspects and advantages of the invention are partly described in the following description, or can be recognized from the description, or can be learned by implementing the invention.

[0007] In one aspect, the present subject matter discloses a rotor blade for a wind turbine. The rotor blade can generally comprise a body that is at least partially formed from a core material. The body can generally define a pressure side and a suction side extending between a leading edge and a trailing edge. The rotor blade can also comprise a plurality of shear elements and a plurality of stiffening elements. The shear elements can generally extend between the pressure and suction sides of the body and can each comprise a first end and a second end. The stiffening elements can be spaced apart from one another (distributed) over the pressure and suction sides of the body, with each stiffening element being arranged at the first end or at the second end of one of the shear elements. Additionally, the rotor blade can comprise a skin extending around an outer circumference of the body.

[0008] In another aspect, the present subject matter discloses a method for manufacturing a rotor blade for a wind turbine. The method may generally comprise assembling a blade blank with a plurality of shear elements spaced apart within a volume of core material, shaping the blade blank to form a body with a pressure side and a suction side extending between a leading edge and a trailing edge, arranging a plurality of stiffening elements over the pressure and suction sides such that at least two stiffening elements of the plurality of stiffening elements are aligned with each of the plurality of shear elements, and arranging a skin around an outer circumference of the body.

[0009] These and other features, aspects, and advantages of the present invention will be better understood with reference to the following description and the accompanying claims. The accompanying drawings, which are incorporated into the description and form part of it, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0010] A complete and executable disclosure of the present invention, including its best embodiment, to a person skilled in the art, is described in the description, which refers to the accompanying drawings, of which: Fig. 1 represents a perspective view of an embodiment of a wind turbine; Fig. 2 represents a perspective view of an embodiment of a rotor blade according to aspects of the present subject matter; Fig. 3 a cross-sectional view of the in Fig. 2 shows the rotor blade cut along line 3-3; Fig. 4 represents a flowchart of an embodiment of a method for manufacturing a rotor blade according to aspects of the present subject matter; Fig. 5 a cross-sectional view of an embodiment of a sheet mold suitable for use in the manufacture of the in the Fig. 2 and Fig. 3 shown rotor blade is, represents; Fig. 6 a cross-sectional view along the span of an embodiment of the in Fig. 5 leaf form shown, after it has been shaped according to aspects of the present subject; Fig. 7 a cross-sectional view of the in Fig. 6 of the shaped leaf forms shown were cut represents, in particular, an expansion- represents the guidance form of channels that are formed around the pressure and suction sides of the rotor blade; Fig. 8 a perspective partial view of the in Fig. 6 and Fig. 7 shows a shaped blade form with stiffening elements installed within the channels formed around the pressure and suction sides of the rotor blade; Fig. 9 a cross-sectional view of another embodiment of a sheet mold suitable for use in the manufacture of the in the Fig. 2 and Fig. 3 shown rotor blade is, represents; Fig. 10 represents a cross-sectional view of another embodiment of a rotor blade according to aspects of the present subject matter; Fig. 11 represents a cross-sectional view of a further embodiment of a rotor blade according to aspects of the present subject matter; Fig. 12 a perspective partial view of yet another embodiment of a rotor blade according to aspects of the present subject matter; and Fig. 13 represents a perspective partial view of a further embodiment of a rotor blade according to aspects of the present subject matter.

[0011] Extensive reference will now be made to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is given to illustrate the invention and not to limit it. Indeed, those skilled in the art will recognize that various modifications and variations of the present invention can be made without departing from the scope of protection or the basic concept of the invention. For example, features shown or described as part of one embodiment can be used with another embodiment to produce yet another embodiment. Therefore, the present invention is intended to cover such modifications and variations, provided they fall within the scope of protection of the appended claims and their equivalents.

[0012] In general, the present subject matter relates to improved methods for manufacturing rotor blades for wind turbines and also to rotor blades manufactured according to such methods. In particular, the disclosed rotor blades may comprise a body formed from a core material (e.g., a foam) that is designed to be machined or otherwise shaped into the aerodynamic form or profile of the rotor blade. Additionally, a plurality of components (e.g., shear elements, stiffening elements, and the like) may be arranged within and / or around the body to impart increased strength and / or stiffness to the rotor blade. The rotor blade may also include a covering skin extending around the outer circumference of the body, forming the outer surface of the rotor blade and providing a protective coating for the core material.

[0013] As can be seen from the description given herein, the disclosed methods generally enable the production of rotor blades without the use of special tools and molds and without labor-intensive processes of manually inserting layers of laminate into such molds. In particular, the rotor blade can be manufactured from the inside out by assembling a blade blank that can be machined or otherwise shaped into the aerodynamic form or profile of the rotor blade. Therefore, the manufacturing costs and the time required to produce a rotor blade can be significantly reduced, thereby improving the efficiency of developing new rotor blade designs and the speed at which rotor blades can be brought to market.Furthermore, due to the inclusion of the various components, the manufactured rotor blade can have a structural configuration that increases the strength and / or stiffness of the blade.

[0014] Furthermore, it should be recognized that in various embodiments, the disclosed methods can be particularly advantageous for the rapid and efficient production of prototype rotor blades for testing new airfoil designs and the like. Therefore, new airfoil shapes and / or other blade configurations / features (e.g., aero-elastic trimmed blades, winglets, and the like) can be manufactured and tested immediately without the additional time required for producing and / or sourcing such specialized molds. However, the disclosed methods can also be used to manufacture rotor blades for field applications. For example, rotor blades manufactured according to the disclosed methods can be used as the main and / or auxiliary rotor blades of a wind turbine.

[0015] Referring to the drawings, states Fig. Figure 1 shows a perspective view of a wind turbine 10. The wind turbine 10 comprises a tower 12 with a nacelle 14 attached to it. A plurality of rotor blades 16 are attached to a rotor hub 18, which in turn is connected to a main flange that rotates a main rotor shaft. The wind turbine's energy generation and control components are housed within the nacelle 14. It should be noted that the wind turbine 10 of the Fig. Figure 1 is given for illustrative purposes only, to place the present invention within an exemplary field of use. Therefore, a person skilled in the art should understand that the invention is not limited to any particular type of wind turbine configuration.

[0016] With reference to Fig. 2 and Fig. Section 3 presents an embodiment of a rotor blade 100 according to aspects of the present subject matter. In particular, it presents Fig. Figure 2 shows a perspective view of rotor blade 100. Additionally, it shows Fig. Figure 3 shows a cross-sectional view of the in Fig. 2 shows rotor blade 100 cut along line 3-3.

[0017] As shown, the rotor blade 100 includes a blade root 102, which is used to mount the rotor blade 100 to the rotor hub 18 of a wind turbine 10 ( Fig. 1) is arranged, and a blade tip 104 is positioned opposite the blade root 102. A body 106 of the rotor blade 100 can extend between the blade root 102 and the blade tip 104 and can generally define the aerodynamic shape of the rotor blade 100. For example, in some embodiments, the body 106 is manufactured to define an airfoil-shaped cross-section, such as by forming it as a symmetrical or cambered airfoil shape. Thus, as in Fig. As shown in Figure 3, the body 106 comprises a compression side 108 and a suction side 110, extending between a leading edge 112 and a trailing edge 114. Additionally, the body 106 can generally include a span 116, defining the entire length between the blade root 102 and the blade tip 104, and a chord line 118, defining the entire length between the leading edge 112 and the trailing edge 114. As is generally understood, the length of the chord line 118 can vary with respect to the span 116, since the body 106 extends from the blade root 102 to the blade tip 104.

[0018] It should be noted that the body 106 of the rotor blade 100 may also have additional aerodynamic features. For example, in one embodiment, the body 106 may be aeroelastically shaped, such as by bending and / or twisting in generally one direction of the airfoil chord (i.e., in a direction generally parallel to the airfoil chord 118) and / or in generally one direction of the span (i.e., in a direction generally parallel to the span 116).

[0019] Furthermore, the rotor blade 100 can generally include a skin 120 that surrounds the aerodynamically shaped body. In particular, as in Fig. Figure 3 shows that the skin 120 generally comprises an outer surface 122, which defines the outer surface of the rotor blade 100, and an inner surface 124, which generally delimits the outer circumference of the body 106. It should therefore be clear that the skin 120 can generally be configured to fit the profile or shape of the aerodynamic body 106 such that the outer surface 122 of the skin 120 generally defines the aerodynamic profile of the rotor blade 100.

[0020] As especially in Fig. As shown in Figure 3, the body 106 can be formed at least partially from a core material 126. In some embodiments, the body 106 can be formed substantially from the core material 126. "Formed substantially from the core material 126" means that more than 50% of the volume of the body 106 (i.e., the volume of the rotor blade 100 defined within the inner surface 124 of the skin 120) is filled with or otherwise occupied by the core material 126, such as more than 60% of the volume of the body 106, more than 75% of the volume of the body 106, more than 85% of the volume of the body 106, and all other sub-areas in between. In alternative embodiments, however, less than 50% of the body 106 can be formed from the core material 126. For example, significant parts and / or all of the core material 126 may be removed from the interior of the rotor blade 100.

[0021] In general, the core material 126 can comprise any suitable material capable of being machined or otherwise formed into the aerodynamic shape or profile of the body 106. For example, in some embodiments of the present product, the core material 126 can comprise a relatively lightweight, low-density material. Thus, in a particular embodiment, the core material 126 can comprise a low-density foam material. Suitable low-density foam materials may include, but are not limited to, polystyrene (e.g., expanded polystyrene foams), polyurethane foams, other foam rubber / resin-based foams, and various other open-cell or closed-cell foams. Alternatively, the filler material 126 can comprise other suitable low-density materials, such as balsa wood, cork, and the like.

[0022] Referring to still Fig. 2 and Fig. 3. The rotor blade 100 can also comprise a plurality of components 128, 130 designed to bear the loads acting on the rotor blade 100 during the operation of the wind turbine 10. For example, as in Fig. As shown in Figure 3, the rotor blade 100 has a plurality of shear elements 128 spaced apart from one another in the direction of the airfoil chord. Generally, each shear element 128 can be configured to extend longitudinally within the body 106 along at least one section of the span 116. Additionally, as shown, each shear element 128 can be configured to extend generally perpendicular to the direction of the airfoil chord between the pressure and suction sides 108, 110 of the body 106, for example by extending between a first end 132, which is generally adjacent to the pressure side 108 of the body 106, and a second end 134, which is generally adjacent to the suction side 110 of the body 106.Therefore, the shear elements 128 can define a shear path between the pressure and suction sides 108, 110 of the body 106, thereby allowing the shear elements 128 to bear any shear forces acting on the rotor blade 100.

[0023] Furthermore, as in Fig. As shown in Figure 3, each shear element 128 can generally be configured as a solid, continuously extending component defining a rectangular cross-sectional shape. However, it should be noted that in alternative embodiments, the shear elements 128 may have any other suitable configuration and define any other suitable cross-sectional shape that allows such elements 128 to function as described herein. For example, as shown below with reference to Fig. As described in Figure 13, each shear element 128 has a plurality of strut elements 682 extending between the pressure and suction sides 108, 110 of the body 106.

[0024] In addition to the shear elements 128, the rotor blade 100 can also include a plurality of stiffening elements 130 extending longitudinally along at least one section of the span 116 of the body 106. Generally, the stiffening elements 130 can be spaced apart across the pressure and suction sides 108, 110 of the body 106 to support loads acting on the blade in the direction of the span (e.g., bending loads). Furthermore, in some embodiments, the stiffening elements 130 can be arranged within the rotor blade 100 such that they are aligned with the shear elements 128, for example, by being positioned between the skin 120 and each end 132, 134 of the shear elements 128. Such an arrangement of the stiffening elements 130 can generally benefit from the shear path generated by the shear elements 128, thereby increasing the load-bearing capacity of the stiffening elements 130.

[0025] It should be noted that the shear elements 128 and the stiffening elements 130 can generally be formed from any suitable stiff and / or durable material that can impart stiffness and / or strength to the rotor blade 100. For example, such elements 128, 130 can be formed from any suitable composite materials (e.g., fiber-reinforced composites), polymers (e.g., high-strength plastic), metals (e.g., aluminum), wood, or any other suitable material or combination of materials. Additionally, it should be noted that although the disclosed rotor blade 100 is shown to comprise five shear elements 128 and a corresponding number of stiffening elements 130, the rotor blade 100 can generally comprise any suitable number of shear elements 128 and / or stiffening elements 130.

[0026] With reference to Fig. 4 is a flowchart of an embodiment of a method 200 for producing the in the Fig. 2 and Fig. The rotor blade 100 shown in section 3 is described in accordance with aspects of the present document. As shown, the method 200 generally comprises assembling a blade blank having a plurality of shear elements spaced apart within a volume of core material 202, shaping the blade blank to form a body with a pressure side and a suction side extending between a leading edge and a trailing edge 204, arranging a plurality of stiffening elements over the pressure and suction sides such that at least two stiffening elements of the plurality of stiffening elements are aligned with each of the plurality of shear elements 206, and arranging a skin around an outer circumference of the body 208. It should be noted that, although the Fig. The four different process steps 202, 204, 206, 208 shown in a specific order are generally performed in any sequence and / or order in accordance with the disclosure provided herein. For example, as described below, the stiffening elements 130 of the rotor blade 100 can be aligned with the shear elements 128 before or after the blade forming 136 ( Fig. 5) is shaped to form body 106.

[0027] As indicated above, such a process 200 can generally offer a reduction in both production costs and the time required to manufacture a rotor blade. Accordingly, new rotor blade designs can be manufactured with greater efficiency, thereby improving product development and increasing the speed at which rotor blades can be brought to market. Furthermore, by incorporating components such as the shear elements 128 and the stiffening elements 130 within the rotor blade 100, the manufactured blade can exhibit improved strength and / or stiffness.

[0028] With reference to Fig. Figure 5 is a cross-sectional view of an embodiment of a blade blank 136, which can be assembled according to the disclosed method 200, as shown in the present subject matter. In general, the blade blank 136 can have a volume of core material 126 that is configured to be machined or otherwise formed into the aerodynamic shape or profile (indicated by the dashed line 138) of the rotor blade body 106. It should therefore be noted that in various embodiments of the blade blank 136, any suitable shape with dimensions equal to or greater than the maximum chord length 140, the maximum height 142 (i.e., the maximum height between the pressure and suction sides 108, 110 of the body 106), and the span 116 ( Fig. 2) of the body 106, such that parts of the leaf form 136 can be removed to define the aerodynamic shape or profile of the body 106. For example, in one embodiment, a width 144 of the leaf form 136 can generally be equal to or greater than the maximum chord 140 of the body 106, and a height 146 of the leaf form 136 can generally be equal to or greater than the maximum height 142 of the body 106. Similarly, a length (a dimension in the side) of the leaf form 136 can generally be equal to or greater than the wingspan 116 of the body 106. In alternative embodiments, the leaf shape 136 can be formed in segments, each segment having a width 144, a height 146 and / or a length (not shown) corresponding to a fraction of the maximum profile chord 140, the maximum height 142 and / or the span 116 of the body 106.

[0029] In some embodiments, the shear elements 128 of the rotor blade 100 can also be contained within the blade shape 136. In particular, as shown in Fig. Figure 5 shows that the sheet-formed blank 136 has a layered structure, wherein the shear elements 128 are spaced between a plurality of core material segments 148, each containing individual blocks or sections of the core material 126. In general, the layered structure of the sheet-formed blank 136 can be assembled or otherwise formed using any suitable means and / or method known in the prior art. In some embodiments, the core material segments 148 and the shear elements 128 can comprise separate, prefabricated components that can be attached or otherwise assembled to form the sheet-formed blank 136.For example, the core material segments 148 and the shear elements 128 can be stacked on top of each other and then joined, glued, bound, fastened, or otherwise attached to one another using any suitable means and / or method known in the prior art. Alternatively, the shear elements 128 can be formed directly onto or within the core material segments 148. For example, in one embodiment, each shear element 128 can be formed directly onto a core material segment 148 by laying or otherwise assembling a plurality of layers of a composite material (e.g., a fiber-reinforced composite material). Once the shear element 128 has been formed onto the core material segment 148, another core material segment 148 can then be mounted onto the top of the shear element 128, with the process being repeated to form the entire sheet forming 136.

[0030] It should be noted that the width of each core material segment 148 and the spacing between the shear elements 128 can generally vary between different blade shapes 136 depending on numerous factors, such as, but not limited to, the size (e.g., the width of the maximum chord line 140) and the number of shear elements 128 to be contained within the rotor blade 100. Additionally, it should be noted that in one embodiment, the shear elements 128 can be evenly spaced from one another within the blade shape 136. Alternatively, the spacing between each of the shear elements 128 can be varied. For example, each of the core material segments 148 can define a different width, so that the spacing between the shear elements 128 within the blade shape 136, and thus within the rotor blade 100, is varied.Furthermore, as shown in the illustrated embodiment, each of the core material segments 148 has a solid volume of the core material 126. In alternative embodiments, however, some or all of the core material segments 148 may be non-solid and / or non-continuous. For example, air gaps and / or spaces may be defined in and / or between the core material segments 148 used to form the sheet mold 136.

[0031] It should also be noted that in some embodiments various other components of the rotor blade 100 may be contained within the blade formwork 136. For example, as described below with reference to Fig. As described in section 9, the stiffening elements 130 are arranged between each core material segment 148 when the sheet forming 236 is assembled.

[0032] With reference to Fig. 6 and Fig. 7 are cross-sectional views of an embodiment of the in Fig. The blade formwork 136 shown in section 5 is depicted after it has been formed into the aerodynamic body 106 of the rotor blade 100. In particular, it represents Fig. Figure 6 shows a cross-sectional view in the direction of the span of the shaped body 106. Additionally, it shows Fig. Figure 7 shows a cross-sectional view in the direction of the profile chord of the shaped body 106.

[0033] In general, the leaf form can be 136 ( Fig. 5) be formed into the desired shape or profile using any suitable forming means / method known in the prior art that allows parts of the sheet blank 136 to be removed to define the aerodynamic shape of the body 106, such as by removing parts of the core material segments 148 and the shear elements 128 to form the aerodynamic contour and profile of the pressure side 108, the suction side 110, the leading edge 112, and the trailing edge 114 of the body 106. For example, in one embodiment, the sheet blank 136 can be machined using any suitable machining process and / or any suitable machining machine, such as a computer numerical control (CNC) machine or any other precision machining machine.Alternatively, the sheet forming 136 can be formed using other suitable tools and / or machines, such as various manual and electric power tools. For example, the sheet forming 136 can be formed using cutting tools (e.g., knives, saws, and the like), grinding / sanding machines (e.g., electric grinders, electric sanders, sandpaper, and the like), and / or any other suitable tools / machines known in the prior art.

[0034] In one embodiment, in addition to shaping the blade blank 136 to define the aerodynamic shape of the body 106, the blade blank 136 can also be shaped to accommodate the stiffening elements 130 of the rotor blade 100. In particular, a plurality of grooves or channels 150 can be formed in the blade blank 136 to allow the stiffening elements 130 to be arranged around the pressure and suction sides 108, 110 of the body 106. For example, as in Fig. As shown in Figure 7, the channels 150 are formed over the pressure and suction sides 108, 110 to be aligned with the ends 132, 134 of each shear element 128. Therefore, if the stiffening elements 130 are arranged within the channels 150, each pair of opposing stiffening elements 130 can be arranged adjacent to the first and / or second ends 132, 134 of each shear element 128.

[0035] It should be noted that the channels 150 can be formed during the same manufacturing step that is carried out to form the leaf blank 136 into the aerodynamic profile of the body 106, or in a separate manufacturing step. For example, in one embodiment, the aerodynamic profile of the body 106 can initially be formed in the leaf blank 136, with the channels 150 subsequently being formed in the leaf blank 136 as a separate manufacturing step.

[0036] Furthermore, in several embodiments of the present object, a root sleeve 152 can be attached to the leaf root 102 ( Fig. 2) of the rotor blade 100 is installed after the blade mold 136 has been formed. In particular, as shown in Fig. Figure 6 shows the root sleeve 152 being installed at a root end 154 of the shaped body 106. The root sleeve 152 can generally be described as an attachment mechanism for attaching the rotor blade 100 to the rotor hub 18 of a wind turbine 10 ( Fig. 1) serve. Thus, it should be noted that the root sleeve 152 can generally be shaped to have any suitable size, shape, and / or configuration that allows the root sleeve 152 to be attached to a rotor hub 18. For example, in one embodiment, the root sleeve 152 can define a substantially cylindrical or round shape with a diameter or height 156 that generally corresponds to the diameter or height of the component of the rotor hub 18 to which the rotor blade 100 is designed to be attached (e.g., a pitch bearing). Additionally, the root sleeve 152 can include a plurality of annularly spaced holes 158 that define a screw hole pattern that generally corresponds to the screw hole pattern defined in the corresponding component of the rotor hub 18 (e.g., the pitch bearing).Therefore, the root sleeve 152 can be attached to the rotor hub 18 using suitable screws, threaded rods and / or the like.

[0037] In general, the root sleeve 152 can be made of any suitable material. However, in some embodiments, the root sleeve 152 can be made of a relatively stiff and / or durable material. For example, the root sleeve 152 can be made of any suitable composite materials (e.g., fiber-reinforced composites), polymers (e.g., high-strength plastic), metals (e.g., aluminum), wood, or any other suitable materials or combinations of materials capable of withstanding the load that typically occurs along the attachment point of the hub 18 and the rotor blade 100 during the operation of a wind turbine 10. Additionally, in one embodiment, the root sleeve 152 can have a prefabricated component designed to be mounted onto the root end 154 of the molded body 106.Alternatively, the root sleeve 152 can be formed directly onto the foot end 156 of the shaped body 106. For example, in a particular embodiment of the present article, the root sleeve 152 can be formed directly onto the root end 154 by placing or otherwise assembling a plurality of layers of a composite material (e.g., a fiber-reinforced composite material).

[0038] It should be noted that the root end 154 of the formed body 106 can generally be machined or otherwise shaped to receive the root sleeve 152. For example, in one embodiment, an additional quantity of the core material 126, corresponding to the width 160 of the root sleeve 152, can be removed from the leaf form 136 at the root end 154 to allow the root sleeve 152 to subsequently be arranged, mounted, or formed onto the root end 154. Additionally, in a particular embodiment, the width 160 of the root sleeve 152 can generally taper as the root sleeve 152 extends away from the leaf root 102. Thus, as described in Fig. Figure 6 shows that the root end 154 of the shaped body 106 is generally machined or otherwise shaped to include a corresponding tapered profile to accommodate the tapered width 160 of the root sleeve 152.

[0039] It should also be noted that in some embodiments of the present product, it is not necessary to initially machine or otherwise form the entire aerodynamic profile of the body 106 into the blade mold 136. For example, in one embodiment, only the root end 154 of the body 106 may initially be machined or otherwise formed. In such an embodiment, the root sleeve 152 can be arranged, mounted, or formed onto the root end 154 before the remainder of the aerodynamic profile of the body 106 is formed into the blade mold 136.

[0040] With reference to Fig. Figure 8 shows a perspective partial view of the shaped body 106 of the rotor blade 100 after the stiffening elements 130 have been installed in the channels 150 ( Fig. 7) were arranged at each end 132, 134 of the shear elements 128. As stated above, the stiffening elements 130 can generally be configured to impart strength and / or stiffness to the rotor blade 100 by bearing any load in the span direction (e.g., compressive and / or tensile-bending loads) acting on the blade formwork 100 during the operation of a wind turbine 10. Thus, it should be noted that the stiffening elements 130 can generally have any suitable shape, size, and / or configuration that allows the stiffening elements 130 to function as described herein. For example, as shown in the illustrated embodiment, the stiffening elements 130 generally have bars extending in the span direction with a semicircular cross-sectional shape.In alternative embodiments, however, the stiffening elements 130 may have a circular, rectangular, triangular and / or any other suitable cross-sectional shape and may be solid or hollow.

[0041] It should also be noted that in some embodiments, the stiffening elements 130 may comprise separate, prefabricated components that can be attached or otherwise mounted within the channels 150. For example, the stiffening elements 130 may initially be formed within the channels 15 and then subsequently joined, bonded, screwed, fastened, or otherwise secured using any suitable means and / or methods known in the prior art. In particular, in one embodiment, the stiffening elements 130 may be prefabricated from a suitable composite material (e.g., a fiber-reinforced composite) using a drawing process and then installed in the channels 150.In another embodiment, the stiffening elements 130 can be formed from a pre-impregnated composite material that can be cured after being installed in the channels 150. Alternatively, the stiffening elements 130 can be formed directly onto and / or within the channels 150. For example, in one embodiment, the stiffening elements 130 can be formed by placing or otherwise assembling a suitable reinforcing material (e.g., glass and / or carbon fibers) within the channels 150 and subsequently casting a suitable matrix material (e.g., a suitable resin) around the reinforcing material.

[0042] In addition, in several embodiments, the stiffening elements 130 can be shaped or otherwise designed so that the pressure and suction sides 108, 110 of the body 106 form a continuous, aerodynamic surface. For example, as in Fig. As shown in Figure 8, an outer surface 162 of each stiffening element 130 can be generally shaped or otherwise formed such that the surface forms a continuation of the aerodynamic profile of the body 106. Therefore, a smooth transition can be defined at the interface between the outer surface 162 of each stiffening element 130 and an outer surface 164 of each shaped core material segment 148.

[0043] Referring back to Fig. As mentioned above, the rotor blade 100 can also include a skin 120 that defines the outer surface of the rotor blade 100. In general, the skin 120 can be designed to fit and be positioned around the outer circumference of the body 106 and, in some embodiments, the root sleeve 152, so that a smooth, aerodynamic profile is defined by the rotor blade 100. Additionally, as an outer coating, the skin 120 can provide support and protection (e.g., impact protection) to the core material 126.

[0044] It should be noted that the skin 120 can generally comprise any suitable material and can be formed using any suitable method and / or process. For example, in one embodiment, the skin 120 can comprise a composite material (e.g., a fiber-reinforced composite) formed around the outer circumference of the body 106 using a manual lay-up process or any other suitable layering process. In another embodiment, the skin 120 can have a spray-on surface coating, such as a polyurethane elastomer spray compound. In yet another embodiment, the skin 120 can comprise a thermoplastic-based coating formed using a heat-shrink sleeve process and / or a heat-shrink tubing process.

[0045] With reference to Fig. Figure 9 shows a cross-sectional view of another embodiment of a sheet-shaped blank 236 corresponding to aspects of the present subject matter, which can be assembled according to the disclosed method 200. In particular, in contrast to the embodiment referred to in Fig. In the embodiment described above (5-7), the stiffening elements 130 of the rotor blade 100 are installed within the blade blank 236 before the blade blank 236 is formed. Thus, as shown, the blade blank 236 can have a layered structure, with the shear elements 128 and the stiffening elements 130 arranged between the core material segments 148.

[0046] It should be noted that the layered structure of the sheet-shaped component 236 can be assembled or otherwise formed using any suitable means and / or methods known in the prior art. For example, in some embodiments, the core material segments 148 can be shaped to accommodate the shear elements 128 and / or the stiffening elements 130. In particular, as shown in Fig. As shown in Figure 9, each core material segment 148 comprises a recessed surface 266 for receiving each shear element 128 and a groove or channel 250 for receiving each stiffening element 130. Therefore, the shear elements 128 and the stiffening elements 130 can be arranged between the core material segments 148 when the sheet forming 236 is assembled.

[0047] Similar to the embodiment described above, in one embodiment the core material segments 148, the shear elements 128, and / or the stiffening elements 130 can comprise separate, prefabricated components that can be attached to one another or otherwise assembled to form the sheet metal component 236. Alternatively, the shear elements 128 and / or the stiffening elements 130 can be formed directly onto or within the core material segments 148 to form the sheet metal component 236. For example, in one embodiment the shear elements 128 and / or the stiffening elements 130 can be formed directly onto a core material segment 148 by laying or otherwise joining a plurality of layers of a composite material (e.g., a fiber-reinforced composite material).Once the shear element 128 and / or the stiffening element 130 has been formed onto the core material segment 148, another core material segment 148 can then be assembled on top of the shear element 128 and / or the stiffening element 130, repeating the process to form the entire sheet forming 236.

[0048] Once the blade mold 236 is assembled, the blade mold 236 can then be shaped to achieve the aerodynamic profile (indicated by the dashed line 138 in Fig. 9) of the rotor blade body 106. For example, as described above, the blade blank 236 can be machined or otherwise processed to remove parts of the core material segments 148, the shear elements 128 and / or the stiffening elements 130 in order to shape the aerodynamic contours and profile of the pressure side 108, the suction side 110, the leading edge 112 and the trailing edge 114 ( Fig. 3) to form the body 106. When forming the leaf model 236, the skin 120 ( Fig. 3) then arranged around the outer circumference of the body 106 to form the outer surface of the rotor blade 100.

[0049] With reference to Fig. Figure 10 shows a cross-sectional view of another embodiment of a rotor blade 300 according to aspects of the present subject matter. In particular, it shows Fig. 10 examples of different components 370, 372, 374, which may optionally be included within the rotor blade 300.

[0050] As shown in the illustrated embodiment, the rotor blade 300, in addition to the shear elements 128 and stiffening elements 130 described above, also comprises a pair of edge stiffening elements 370, 372, which are designed to bear edge loads acting on the rotor blade 300 and also to improve the buckling strength of the rotor blade 300 (particularly at the trailing edge 114). In particular, the rotor blade 300 comprises a first edge stiffening element 370, which is arranged adjacent to the leading edge 112, and a second edge stiffening element 372, which is arranged adjacent to the trailing edge 114, each edge stiffening element 370, 372 extending longitudinally along at least one section of the span 116 ( Fig. 2) of the rotor blade 300 extends.

[0051] It should be noted that the edge stiffening elements 370, 372 can generally be configured in the same or a similar way to the stiffening elements 130 described above. Thus, the edge stiffening elements 370, 372 can generally have any suitable shape, size, and / or configuration that allows them to function as described herein. For example, as shown in the illustrated embodiment, the first edge stiffening element 370 generally has a semicircular cross-sectional shape, while the second edge stiffening element 372 has a cross-sectional shape that generally corresponds to the aerodynamic profile of the rotor blade 300 at the trailing edge 114. In alternative embodiments, however, the edge stiffening elements 370, 372 can have any other suitable cross-sectional shape and can be solid or hollow.

[0052] Furthermore, the edge stiffening elements 370, 372 can generally be made of any suitable stiff and / or durable material that allows such elements to impart stiffness and / or strength to the rotor blade 300. For example, in one embodiment, the edge stiffening elements 370, 372 can be made of any suitable composite materials (e.g., fiber-reinforced composite material), polymers (e.g., high-strength plastic), metals (e.g., aluminum), wood, or any other suitable materials or combinations of materials. Furthermore, the edge stiffening elements 370, 372 can be installed within the rotor blade 300 using any suitable means and / or method. For example, the edge stiffening elements 370, 372 can be installed similarly to those described above with reference to… Fig. 5-7 described embodiment are installed after the leaf forming 136 ( Fig. 5) was formed, for example by forming grooves or channels (not shown) on the leading and trailing edges 112, 114 during the forming of the sheet blank 136 and subsequently incorporating the edge stiffening elements 370, 372 within such channels (e.g., by incorporating prefabricated edge stiffening elements within the channels or by assembling the edge stiffening elements within the channels). Alternatively, similar to the above, with reference to Fig. In the embodiment described in 9, the edge stiffening elements 370, 372 are installed before the sheet forming 236 is formed, for example by installing the edge stiffening elements 370, 372 within the core material segments 148 during the assembly of the sheet forming 236.

[0053] Still with reference to Fig. 10. The rotor blade 300 can also comprise at least one auxiliary stiffening element 374, which is arranged at one or more locations along the height of each shear element 128. In particular, as shown in the illustrated embodiment, a single auxiliary stiffening element 374 is arranged between the first and second ends 132, 134 of each shear element 128. In alternative embodiments, however, the rotor blade 300 can comprise two or more auxiliary stiffening elements 374, which are spaced apart between the first and second ends 132, 134 of each shear element 128. By arranging such auxiliary stiffening element(s) 374 along the height of each shear element 128, the auxiliary stiffening element(s) 374 can generally increase the ability of the rotor blade 300 to bear lateral loads by reducing the unsupported distance along the shear element 128.Furthermore, each auxiliary stiffening element 374 can also impart buckling resistance to the rotor blade 300.

[0054] Similar to the edge stiffening elements 370, 372, the auxiliary stiffening elements 374 can generally be designed in the same or a similar way to the stiffening elements 130 described above. Thus, the auxiliary stiffening elements 374 can generally have any suitable shape, size, and / or configuration that allows such auxiliary stiffening elements 374 to function as described herein. For example, as shown in the illustrated embodiment, the auxiliary stiffening elements 374 generally define a circular cross-sectional shape. However, in alternative embodiments, the auxiliary stiffening elements 374 can have a semicircular, rectangular, triangular, and / or any other suitable cross-sectional shape and can be solid or hollow. In addition, the auxiliary stiffening elements 374 can be made of any suitable stiff and / or durable material (e.g.,any suitable composite materials, polymers, metals, wood, and the like) and can be installed within the rotor blade 300 using any suitable means and / or method known in the prior art. For example, in one embodiment, the auxiliary stiffening elements 374 can be installed after the blade mold 136, 236 has been assembled, such as by preforming grooves or channels within the core material segments 148 to allow the auxiliary stiffening elements 374 to be installed along the shear elements 128 after the blade mold 136, 236 has been assembled and / or formed. Alternatively, similar to the above with reference to . Fig. In the embodiment described in 9, the auxiliary stiffening elements 374 are installed during the assembly of the sheet forming 236, for example by assembling or forming the shear elements 128, the stiffening elements 130 and / or the auxiliary stiffening elements 374 between each core material segment 148.

[0055] In particular, in one embodiment the shear elements 128, the stiffening elements 130 and / or the auxiliary stiffening elements 374 can be formed together by placing or otherwise joining a plurality of layers of a composite material (e.g. a fiber-reinforced composite material) directly between each core material segment 148.

[0056] It should be noted that the rotor blade 300 can generally comprise any combination of the components 128, 130, 370, 372, 374 described above and therefore may not be exactly as shown in Fig. 10 must be designed. For example, the auxiliary stiffening elements 374 can be included within the rotor blade 300 additionally or as an alternative to the edge stiffening elements 370, 372.

[0057] With reference to Fig. Figure 11 shows a cross-sectional view of a further embodiment of a rotor blade 400 according to aspects of the present subject matter. In particular, it represents Fig. Figure 11 shows an example of another component that may optionally be included within the rotor blade 400.

[0058] As shown, in addition to the shear elements 128 and stiffening elements 130 described above, the rotor blade 400 also includes one or more transverse stiffening elements 476, which are generally oriented perpendicular to the shear elements 128. For example, in the illustrated embodiment, the rotor blade 400 includes a single transverse stiffening element 476 extending in the direction of the airfoil chord from generally adjacent to the leading edge 112 to generally adjacent to the trailing edge 114. In alternative embodiments, however, the rotor blade 400 can include any suitable number of transverse stiffening elements 476 spaced apart within the rotor blade 400. The transverse stiffening element(s) 476 can impart edge stiffness and / or buckling resistance to the rotor blade 400 and / or can generally improve the structural integrity of the rotor blade 400.

[0059] It should be noted that, similar to the other components 128, 130, 370, 372, 374 described herein, the cross-stiffening element(s) 476 may generally be made of any suitable stiff and / or durable material that allows such cross-stiffening elements 476 to impart stiffness and / or strength to the rotor blade 400. For example, the cross-stiffening element(s) 476 may be made of any suitable composite materials (e.g., fiber-reinforced composites), polymers (e.g., high-strength plastic), metals (e.g., aluminum), wood, or any other suitable materials or combinations of materials. Furthermore, the cross-stiffening element(s) 476 may be installed within the rotor blade 400 using any suitable means and / or method known in the prior art.Thus, in some embodiments, the transverse stiffening element(s) 476 can be installed during the assembly of the sheet form 136, 236. For example, each of the above with reference to . Fig. 5 described core material segment 148 horizontal (e.g. along the in Fig. 5 shown dashed line 478) are divided so that the illustrated transverse stiffening element 476 can be assembled into the sheet form 136, for example by placing the (transverse stiffening element(s) 476 between the divided core material segments 148.

[0060] It should also be noted that the transverse stiffening element(s) 476 may be included within the rotor blade 400 in addition to, or as an alternative to, the edge stiffening elements 370, 372 and / or the auxiliary stiffening elements 374. For example, in one embodiment, the transverse stiffening element(s) 476 may be configured to extend generally in the direction of the airfoil chord between the edge stiffening elements 370, 372 and / or between each auxiliary stiffening element 374.

[0061] With reference to Fig. Figure 12 shows a partial, perspective view of another embodiment of a rotor blade 500 according to aspects of the present subject matter. In particular, it shows Fig. Figure 12 shows the rotor blade 500 with the skin 120 removed to show another example of components that may optionally be included within the rotor blade 500.

[0062] As shown, in addition to the shear elements 128 and stiffening elements 130 described above, the rotor blade 500 also includes a plurality of transverse elements 580 extending between adjacent stiffening elements 130 on the pressure and suction sides 108, 110 of the body 106. The transverse elements 580 can generally be configured to impart torsional stiffness to the rotor blade 500. Furthermore, by arranging the transverse elements 580 around the outer circumference of the body 106 (i.e., adjacent to and / or in the plane of the skin 120 (not shown)), the transverse elements 580 can reduce the shear and torsional loads that the skin 120 must bear.

[0063] As in Fig. As shown in Figure 12, the transverse elements 580 generally extend diagonally between each pair of adjacent stiffening elements 130, with pairs of transverse elements 580 intersecting to form a cross or “X” pattern. In another embodiment, however, the transverse elements 580 may be configured to extend diagonally between adjacent stiffening elements 130 without intersecting, for example, by forming a zigzag pattern between the stiffening elements 130. Alternatively, the transverse elements 580 may have any other orientation between each pair of adjacent stiffening elements 130. For example, in one embodiment, the transverse elements 580 may extend perpendicularly between adjacent stiffening elements 130 (e.g., in the direction of the profile chord) and may be spaced apart from each other in the direction of the span along the length of the stiffening elements 130.In another embodiment, the transverse elements 580 can be aligned both vertically and diagonally, for example by forming a “Z” pattern between each pair of adjacent stiffening elements 130.

[0064] It should be noted that the transverse elements 580 can generally be designed in the same or a similar way to the stiffening elements 130 described above. Thus, the transverse elements 580 can generally have any suitable shape, size, and / or configuration that allows such transverse elements 580 to function as described herein. Additionally, the transverse elements 580 can be formed from any suitable stiff and / or durable material that allows such transverse elements 580 to impart stiffness and / or strength to the rotor blade 500. For example, the transverse element(s) 580 can be formed from any suitable composite materials (e.g., fiber-reinforced composites), polymers (e.g., high-strength plastic), metals (e.g., aluminum), wood, or any other suitable materials or combinations of materials.

[0065] It should also be recognized that the transverse elements 580 can be installed within the rotor blade 500 using any suitable means and / or method known in the prior art. For example, with reference to the above, Fig. In the embodiment described in Figures 5-7, in addition to the channels 150 formed in the body 106 to accommodate the stiffening elements 130, suitable grooves or channels may also be formed in the pressure and suction sides 108, 110 of the body 106 for receiving the transverse elements 580. Therefore, the transverse elements 580 can be installed before, after, or simultaneously with the installation of the stiffening elements 130.

[0066] Additionally, it should be noted that the transverse elements 580 can be installed within the rotor blade 500 in combination with any of the other components 128, 130, 370, 372, 374, 476 described herein. For example, in one embodiment, the transverse elements 580 can be installed within the rotor blade 500 together with the edge stiffening elements 370, 372 described above. In such an embodiment, additional transverse elements 580 can also be installed within the rotor blade to connect each edge stiffening element 370, 372 to the adjacent stiffening elements 130 arranged on the pressure and suction sides 108, 110 of the body 106.

[0067] With reference to Fig. Figure 13 shows a perspective partial view of a further embodiment of a rotor blade 600 according to aspects of the present subject matter. In particular, it shows Fig. 13 represents the rotor blade 600, with the skin 120 ( Fig. 3) is removed and part of the body 106 is cut away to show a variation of the components that can be used to form each of the shear elements 128 described above.

[0068] As shown, each shear element 128 is configured as a plurality of strut elements 682 extending between each pair of opposing stiffening elements 130 arranged along the pressure and suction sides 108, 110 of the body 106. In the illustrated embodiment, the strut elements 682 extend diagonally between each pair of opposing stiffening elements 130, with pairs of strut elements 682 intersecting to form a cross or “X” pattern. In another embodiment, however, the strut elements 682 can be configured to extend diagonally between opposing stiffening elements 130 without intersecting, for example, by forming a zigzag pattern between the stiffening elements 130. Alternatively, the strut elements 682 can have any other orientation between each pair of opposing stiffening elements 130.For example, in one embodiment, the strut elements 682 can extend perpendicularly between the opposing stiffening elements 130 and can be spaced apart from each other in the direction of the span along the length of the stiffening elements 130. In another embodiment, the strut elements 682 can be oriented both perpendicularly and diagonally, for example by forming a “Z” pattern between each pair of opposing stiffening elements 130.

[0069] It should be noted that the strut elements 682 can generally be designed in the same or a similar way to the stiffening elements 130 described above. Thus, the strut elements 682 can generally have any suitable shape, size, and / or configuration that allows such strut elements 682 to impart stiffness and / or strength to the rotor blade 600. Additionally, the strut elements 682 can be made of any suitable stiff and / or durable material. For example, the strut element(s) 682 can be made of any suitable composite materials (e.g., fiber-reinforced composites), polymers (e.g., high-strength plastic), metals (e.g., aluminum), wood, or any other suitable materials or combinations of materials.

[0070] It should also be noted that the strut elements 682 can be installed within the rotor blade 600 using any suitable means and / or method known in the prior art. For example, similar to the one described above with reference to Fig. In the embodiment described in section 9, the strut elements 682 are installed during the assembly of the sheet forming 236, for example by assembling or forming the strut elements 682 and stiffening elements 130 between each core material segment 148. In particular, in one embodiment, the strut elements 682 and stiffening elements 130 can be formed together by placing or otherwise assembling a plurality of layers of a composite material (e.g., a fiber-reinforced composite material) directly between each core material segment 148.

[0071] Additionally, it should be recognized that the strut elements 682 can be installed within the rotor blade 600 in combination with any of the other components 128, 130, 370, 372, 374, 476, 580 described herein.

[0072] This written description uses examples to disclose the invention, including the best embodiment, and also to enable any person skilled in the art to carry out the invention, including manufacturing and using any devices or systems and performing any methods contained therein. The patentable scope of the invention is defined by the claims and may include other examples that would be recognized by those skilled in the art. Such other examples shall fall within the scope of the claims if they include structural elements that do not differ from the exact wording of the claims, or if they include equivalent structural elements with insignificant differences from the exact wording of the claims.

[0073] A rotor blade for a wind turbine is disclosed. The rotor blade can generally comprise a body that is at least partially formed from a core material. The body can generally define a pressure side and a suction side extending between a leading edge and a trailing edge. The rotor blade can also comprise a plurality of shear elements and a plurality of stiffening elements. The shear elements can generally extend between the pressure and suction sides of the body and can each comprise a first end and a second end. The stiffening elements can be spaced apart over the pressure and suction sides of the body, with each stiffening element being arranged at the first end or the second end of one of the shear elements. Additionally, the rotor blade can comprise a skin extending around an outer circumference of the body. REFERENCE MARK LIST: 10 wind turbines 12 Tower 14 gondolas 16 rotor blades 18 Rotor hub 100 rotor blades 102 Leaf root 104 Leaf tip 106 bodies 108 printed page 110 Suction side 112 Leading edge 114 trailing edge 116 wingspan 118 Profile tendon 120 skin 122 outdoor area 124 interior surface 126 core material 128 shear elements 130 stiffening elements 132 First End 134 Second Ending 136 leaf form 138 Dashed line 140 Profile tendon 142 Height 144 width 146 Height 148 segments 150 channels 152 Root sleeve 154 Root end 156 Height 158 holes 160 width 162 outdoor area 164 outdoor area 200 procedures 202 Procedure step 204 Procedure step 206 Procedure step 208 Procedure step 236 Leaf Formation 250 channel 266 Recessed surface 300 rotor blades 370 first edge stiffening element 372 second edge stiffening element 374 Auxiliary stiffening element 400 rotor blades 476 Cross-stiffening element 500 rotor blades 580 transverse elements 600 rotor blades 682 strut elements

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