Positioning device for a wind turbine blade

Abstract

A positioning device is provided for positioning a plurality of inserts within an end of a wind turbine blade portion having a partial or full aerofoil profile during manufacture of the blade portion, the inserts each having at least one threaded bushing for embedding in a blade shell of the blade portion. The positioning device comprises a mounting body having a first side and a second side and a plurality of through holes extending between the first side and the second side. The through holes are each configured to receive a respective threaded fastener for connecting the positioning device to the plurality of inserts by engaging the threaded fasteners with the threaded bushings. Each of the plurality of through holes defines a fastener hole axis for receiving the respective threaded fastener. At least two of the through holes have fastener hole axes that are non-parallel relative to each other.

Description

[0001] POSITIONING DEVICE FOR A WIND TURBINE BLADE

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a positioning device for positioning a plurality of inserts within an end of a wind turbine blade portion; a wind turbine blade portion mould assembly having the positioning device; and a method of forming a wind turbine blade portion with the positioning device.

[0004] BACKGROUND OF THE INVENTION

[0005] There is a continued drive to produce larger wind turbine blades, due to the increased energy production that is produced. Yet, as the size of wind turbine blades continues to increase, wind turbine blades may become more complex to transport, at least onshore. It has become desirable to manufacture and transport blades as a ‘split blade’ having separate blade portions and to construct the blades closer to the wind turbine site by connecting the blade portions. A blade portion may have a plurality of inserts embedded in the end of the blade portion, each insert used to couple to another insert of another blade portion to form the connection between the blade portions.

[0006] Forming a wind turbine blade portion with the inserts embedded therein can be complicated, since the inserts are not perpendicular to the blade split (if the inserts are to follow the blade geometry) because of the double curved geometry of the blade (blade section at the split has an aerofoil profile and the blade thickness and chord length are decreasing towards tip). As a result, it is an aim to provide a means of positioning the inserts in the blade portion, to facilitate effective positioning of the inserts to provide effective support along the blade portion and across the joint between blade portions.

[0007] SUMMARY OF THE INVENTION

[0008] According to an aspect of the invention, there is provided a positioning device for positioning a plurality of inserts within an end of a wind turbine blade portion having a partial or full aerofoil profile during manufacture of the wind turbine blade portion, the inserts each having at least one threaded bushing for embedding in a blade shell of the wind turbine blade portion, the positioning device comprising: a mounting body having a first side and a second side and a plurality of through holes extending between the first side and the second side, the through holes each configured to receive a respective threaded fastener for connecting the positioning device to the plurality of inserts by engaging the threaded fasteners with the threaded bushings; wherein each of the plurality of through holes define a fastener hole axis for receiving the respective threaded fastener; and wherein at least two of the plurality of through holes have fastener hole axes that are non-parallel relative to each other.

[0009] Advantageously, the positioning device can facilitate effective embedding of inserts within an end of a wind turbine blade portion having an aerofoil profile. This is particularly challenging when manufacturing split blades (i.e. that are split chordwise along the spanwise length of the blade to define multiple blade portions). It will be understood that a wind turbine blade portion does not have a constant profile, and rather defines an aerofoil profile that will taper toward the tip end of the blade in both the thickness and chordwise directions. In this way, providing fastener hole axes that are non-parallel relative to each other in the positioning device allows inserts connected to the positioning device to be individually angled relative to one another. In this way, once the blade shell of the blade portion is formed around the inserts, the inserts align with the blade geometry and load path and thus provide effective support to a split wind turbine blade.

[0010] Optionally, the plurality of through holes may each have fastener hole axes that are non-parallel relative to each other.

[0011] Each fastener hole axis defines an individual angle (e.g. relative to the first side of the mounting body), resulting in each insert in the blade portion extending along an individual angle (e.g. relative to an end of the blade portion). This allows the inserts to align with the blade geometry so as to provide improved support to the wind turbine blade.

[0012] Optionally, each through hole may have a bushing arrangement which defines the respective fastener hole axis. The through holes themselves may have axes which are parallel to each other, but the bushing arrangement defines respective fastener hole axes that are non-parallel relative to each other. This advantageously simplifies the manufacture of the positioning device. Optionally, the bushing arrangement may include a first bushing adjacent the first side of the mounting body and a second bushing adjacent the second side of the mounting body.

[0013] Advantageously, the bushing arrangement provides additional support to the fastener in the through hole.

[0014] Optionally, the first bushing has a first hole centre and the second bushing has a second hole centre. The respective fastener hole axis may be aligned with the first hole centre and the second hole centre.

[0015] Optionally, at least one of the plurality of through holes has an internal diameter, and the internal diameter varies between the first side and the second side of the mounting body.

[0016] Advantageously, such a configuration facilitates the use of a fastener with a complementary variation in outer diameter, and / or to provide clearances between the fastener and the through hole between the bushings.

[0017] Optionally, at least one of the first bushing and second bushing defines a non-planar surface facing away from the mounting body for centring a fastener on the respective fastener hole axis.

[0018] Such an arrangement provides control over the angle of insertion of the fastener and, consequently, the angle at which the insert coupled to the positioning device extends into the wind turbine blade portion.

[0019] Optionally, the mounting body forms an integral part of a wind turbine blade portion mould.

[0020] Optionally, the mounting body is configured to be mounted to a wind turbine blade portion mould.

[0021] Optionally, the mounting body has a fixing arrangement for mounting the mounting body to the wind turbine blade portion mould. Optionally, the fixing arrangement is configured to removably secure the positioning device to the mould.

[0022] Optionally, the fixing arrangement comprises a set of fastener receiving holes in the mounting body.

[0023] Advantageously, the fixing arrangement can allow the positioning device to be fixed in place in a mould. Removably securing the positioning device in the mould allows the positioning device to be reused in the same or similar moulds (i.e. to form multiple blade portions).

[0024] Optionally, the mounting body has a generally plate-like form.

[0025] Optionally, the mounting body has a shape generally corresponding to at least a portion of the aerofoil profile of the wind turbine blade portion.

[0026] Optionally, the positioning device includes a plurality of mounting bodies.

[0027] Optionally, one or more of the mounting bodies together have a shape corresponding to the partial aerofoil profile of a wind turbine blade portion half shell for use with a wind turbine blade portion half shell mould.

[0028] Optionally, one or more of the mounting bodies has a shape corresponding to the full aerofoil profile of a complete wind turbine blade portion shell for use with a wind turbine blade portion full shell mould.

[0029] The positioning device can comprise one or multiple mounting bodies. A single mounting body per blade shell or half shell may advantageously make it easier to seal off the end of the mould for containing infused resin.

[0030] Optionally, the mounting body is for mounting parallel with the aerofoil profile of the end of the wind turbine blade portion. At least one of the plurality of fastener hole axes may be angularly offset to extend in the thickness and / or chordwise direction away from normal to the aerofoil profile of the end of the wind turbine blade portion. Advantageously, the angular offset of the fastener hole axis / axes results in inserts within a blade portion that are inclined in the thickness and / or chordwise direction of the wind turbine blade portion. This results in inserts that align with the blade geometry and thus provide effective support along the load-path of the blade.

[0031] Optionally, at least two of the fastener hole axes are offset relative to each other by an angle less than about 2°.

[0032] Optionally, the plurality of through holes are arranged relative to one another along a curve generally corresponding to the aerofoil profile of the end of the wind turbine blade portion.

[0033] Advantageously, the arrangement of through holes can result in an effective arrangement of inserts within a wind turbine blade portion having an aerofoil profile.

[0034] According to a further aspect of the invention, there is provided a wind turbine blade portion mould assembly comprising: a mould having a cavity for forming a wind turbine blade portion having a partial or full aerofoil profile; a positioning device as described herein, wherein the mounting body of the positioning device forms an integral part of the mould, or is mounted to the mould; and a plurality of threaded fasteners received in the respective through holes of the mounting body for connecting the positioning device to a plurality of inserts arranged in the cavity by engaging the threaded fasteners with threaded bushings of the inserts.

[0035] The mould assembly may benefit from the advantages of the positioning device as noted above.

[0036] Optionally, the wind turbine blade portion mould assembly further comprises a plurality of inserts arranged within the cavity. The inserts may each have at least one threaded bushing for embedding in a blade shell of a wind turbine blade portion having a partial or full aerofoil profile. The plurality of threaded fasteners received in the respective through holes of the mounting body may connect the positioning device to the plurality of inserts by engaging the threaded fasteners with threaded bushings of the inserts.

[0037] Optionally, the wind turbine blade portion mould assembly further comprises a wind turbine blade portion having a blade shell arranged within the cavity, the wind turbine blade portion having a partial or full aerofoil profile. The plurality of inserts may be embedded in the blade shell. The inserts may be for securing the wind turbine blade portion to another wind turbine blade portion.

[0038] Optionally, the threaded bushings of each insert are aligned with the respective fastener hole axes of the positioning device.

[0039] Advantageously, each insert is positioned so as to be embedded within a wind turbine blade portion such that the insert aligns with the blade geometry and therefore loadpath.

[0040] Optionally, the cavity extends in a lengthwise direction to define a span of the wind turbine blade portion.

[0041] The positioning device may be located at an end of the cavity.

[0042] Advantageously, such a mould assembly can form a split portion of a wind turbine blade.

[0043] Two positioning devices may be provided that are located along the length of the cavity so as to divide the cavity into a first section up to a first one of the positioning devices and a second section up to a second one of the positioning devices. Two such wind turbine blade portions each having a blade shell may be arranged within the cavity, the wind turbine blade portions each having a partial or full aerofoil profile. The plurality of inserts may be embedded in each of the blade shells.

[0044] Advantageously, such a mould assembly can form an entire blade having two portions.

[0045] According to a further aspect of the invention, there is provided a method of forming a wind turbine blade portion, the method comprising: providing a mould having a cavity for forming a wind turbine blade portion having a partial or full aerofoil profile, providing a positioning device as described herein, wherein the mounting body of the positioning device forms an integral part of the mould, or is mounted to the mould; laying up a wind turbine blade portion in the mould, including blade shell material and a plurality of inserts such that the blade shell material substantially surrounds the plurality of inserts in the mould, wherein the inserts each have at least one threaded bushing; inserting a plurality of threaded fasteners through respective through holes of the mounting body to connect the positioning device to the plurality of inserts by engaging the threaded fasteners with threaded bushings of the inserts such that the threaded bushings of each insert are aligned with the respective fastener hole axes of the positioning device; providing resin to the mould; and curing the wind turbine blade portion in the mould; wherein the inserts are for securing the wind turbine blade portion to another wind turbine blade portion.

[0046] The method may benefit from the advantages of the positioning device as discussed herein.

[0047] Optionally, the method further comprises detaching the wind turbine blade portion from the positioning device by removing the plurality of threaded fasteners from the plurality of inserts.

[0048] Optionally, the method further comprises machining an end of the wind turbine blade portion after detaching the wind turbine blade portion from the positioning device. Machining may remove an exposed portion of at least one of the inserts such that the end of the wind turbine blade portion defines a substantially planar surface.

[0049] Advantageously, the end of the blade portion may include sections of inserts projecting therefrom. It will be understood that a planar end surface of the blade shell portion is advantageous to facilitate connection with other components, e.g. another blade shell portion. As such, machining the end of the blade shell portion to define a substantially planar surface can improve the connection between the blade shell portion and other wind turbine components.

[0050] BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

[0052] Figure 1 shows a front view of a wind turbine; Figure 2 shows an isometric view of a wind turbine blade;

[0053] Figure 3 shows a profile view of a blade portion;

[0054] Figure 4 shows a detailed view of a joint connecting two blade portions;

[0055] Figure 5 shows an isometric view of an insert;

[0056] Figure 6A shows a front view of a positioning device;

[0057] Figure 6B shows a front view of an alternative positioning device;

[0058] Figure 7A shows a cross-sectional view of a positioning device;

[0059] Figure 7B shows a cross-sectional view of the positioning device of Figure 7A with the inserts coupled thereto;

[0060] Figure 8A shows a mould assembly; and

[0061] Figure 8B shows an alternative mould assembly.

[0062] DETAILED DESCRIPTION OF EMBODIMENT(S)

[0063] In this specification, terms such as leading edge, trailing edge, pressure surface, suction surface, thickness, and chord are used. While these terms are well known and understood to a person skilled in the art, definitions are given below for the avoidance of doubt.

[0064] The term leading edge is used to refer to an edge of the blade which will be at the front of the blade as the blade rotates in the normal rotation direction of the wind turbine rotor.

[0065] The term trailing edge is used to refer to an edge of a wind turbine blade which will be at the back of the blade as the blade rotates in the normal rotation direction of the wind turbine rotor.

[0066] The chord of a blade is the straight line distance from the leading edge to the trailing edge in a given cross section perpendicular to the blade spanwise direction. The term chordwise is used to refer to a direction from the leading edge to the trailing edge, or vice versa.

[0067] A pressure surface (or windward surface) of a wind turbine blade is a surface between the leading edge and the trailing edge, which, when the blade is in use, has a higher pressure than a suction surface of the blade. A suction surface (or leeward surface) of a wind turbine blade is a surface between the leading edge and the trailing edge, which will have a lower pressure acting upon it than that of a pressure surface, when the blade is in use.

[0068] The thickness of a wind turbine blade is measured perpendicularly to the chord of the blade and is the greatest distance between the pressure surface and the suction surface in a given cross section perpendicular to the blade spanwise direction.

[0069] The term spanwise is used to refer to a direction from a root end of a wind turbine blade to a tip end of the blade, or vice versa. When a wind turbine blade is mounted on a wind turbine hub, the spanwise and radial directions will be substantially the same.

[0070] The term outboard refers to a radial direction from the hub of the blade towards the tip end of the blade. The term inboard refers to a radial direction from the tip end towards the hub.

[0071] A view which is perpendicular to both of the spanwise and chordwise directions is known as a planform view. This view looks along the thickness dimension of the blade.

[0072] Figure 1 shows a wind turbine 1 according to an example. The wind turbine 1 includes a tower 2 and a nacelle 3 mounted on the tower 2. A hub 4 is mounted rotatably on the nacelle 3, and carries three wind turbine blades 5 projecting outwardly from the nacelle 3. While the example shown in Figure 1 has three blades 5, it will be appreciated that other numbers of blades 5 are possible. When wind blows against the wind turbine 1 , the wind turbine blades 5 generate a lift force which causes a generator (not shown) within the nacelle 3 to generate electrical energy.

[0073] It will be appreciated that the wind turbine 1 depicted may be any suitable type of wind turbine 1. The wind turbine 1 shown is an upwind wind turbine, although it will be appreciated the wind turbine 1 may be a downwind wind turbine. The wind turbine 1 may be an onshore wind turbine such that the foundation is embedded in the ground, or the wind turbine 1 may be an offshore installation in which case the foundation would be provided by a suitable marine platform.

[0074] Figure 2 shows an isometric view of one of the wind turbine blades 5. The wind turbine blade 5 includes an inboard wind turbine blade portion 6 and an outboard wind turbine blade portion 7 for joining together by a joint 8. Advantageously, providing the wind turbine blade 5 as two portions may help to simplify transport of the wind turbine blade

[0075] 5, especially onshore.

[0076] Figure 3 shows a profile view of the end 9 of the outboard wind turbine blade portion 7. A corresponding profile view of the end 9 of the inboard wind turbine blade portion 6 may be a mirror image of the end 9 shown in Figure 3 about a vertical plane. However, the end of the inboard wind turbine blade portion may have a different profile shape. In the following, anything discussed in relation to the end 9 of the outboard wind turbine blade portion 7 is applicable to the end 9 of the inboard wind turbine blade portion 6 unless stated otherwise. Each of the inboard and outboard wind turbine blade portions

[0077] 6, 7 has an end 9 with a partial or full aerofoil profile.

[0078] Each respective wind turbine blade portion 6, 7 has a leading edge 17, a trailing edge 19, a leeward side 60 extending between the leading edge 17 and the trailing edge 19 and a windward side 61 extending between the leading edge 17 and the trailing edge 19. The aerofoil profile of the ends 9 of the respective wind turbine blade portions 6, 7 may have any suitable aerofoil shape.

[0079] The end 9 of each of the respective wind turbine blade portions 6, 7 has a plurality of inserts 12 embedded therein. Each insert 12 has an end portion 13 having a connection for coupling the insert 12 to other components (e.g. to another of the inserts 12 across the joint 8).

[0080] Corresponding inserts 12 on the windward sides 61 of the ends 9 of the respective wind turbine blade portions 6, 7 are coupled to each other across the joint 8. Likewise, corresponding inserts 12 on the leeward sides 60 of the ends 9 of the respective wind turbine blade portions 6, 7 are coupled to each other across the joint 8. The end 9 of each of the respective wind turbine blade portions 6, 7 may have an identical number of inserts 12. The inserts 12 each extend generally along a spanwise direction of the wind turbine blade 5. Figure 4 shows a spanwise cross-sectional view through an exemplary joint 8 in the wind turbine blade 5.

[0081] The joint 8 may include a joint member 30 between the inboard wind turbine blade portion 6 and the outboard wind turbine blade portion 7. The inserts 12 of the inboard blade portion 6 may be fastened to one side of the joint member 30 and the inserts 12 of the outboard blade portion 7 may be fastened to the other side of the joint member 30. In other examples, thejoint 8 may comprise a direct connection between the inserts of the inboard and outboard blade portions 6, 7.

[0082] At least one of the inserts 12 may have a bushing 32 for receiving a fastener 16. The bushing 32 may be provided in the end portion 13 of at least one of the inserts 12. The bushing may define a threaded bore 18 (shown in Figure 5) for receiving a threaded fastener 16. The fastener 16 may form the connection for joining the wind turbine blade portions 6, 7 together. In some arrangements, all of the inserts 12 include a bushing 32 such that all of the inserts 12 are configured to connect the blade portions 6, 7 together.

[0083] Each fastener 16 may be received through a hole 34 in the joint member 30 and the bushing 32 of one of the inserts 12 to secure the insert 12 to the joint member 30. The joint member 30 may be made of a metal, such as steel, via a casting process. In alternative examples, the joint member 30 may be made from any suitable material (such as fibre reinforced composite) via any suitable process. Advantageously, joining the inboard wind turbine blade portion 6 and the outboard wind turbine blade portion 7 together via thejoint 8 enables the blade portions 6, 7 to be transported separately and assembled at the site of the wind turbine 1 .

[0084] The plurality of inserts 12 may be sandwiched between or embedded in fibre reinforced composite layers forming a shell 42 of the wind turbine blade 5. Alternatively the inserts may be bonded or otherwise attached to the inside of the blade shell 42. The inserts may be bonded to the neighbouring fibre reinforced composite layers so as to transfer load between the insert and the fibre reinforced composite layers of the blade shell 42.

[0085] Each insert 12 may include an extension portion 14 which extends away from the end portion 13 to a tip 15. The extension portion 14 may provide a large surface area for transferring load between the insert and the fibre reinforced composite layers of the shell 42 of the wind turbine blade portion. This aids in preventing pull out of the insert under high tensile load across the joint. The extension portion 14 tapers (e.g. in the blade shell thickness direction) from the end portion 13 to the tip 15, which aids in smoothly transferring load between the insert 12 and the fibre reinforced composite layers, avoiding stress concentrations. Figure 5 shows an isometric view of an example of one of the inserts 12. Embedding the inserts 12 within an end 9 of a wind turbine blade portion 7 having a partial or full aerofoil profile can be challenging, since the inserts are not perpendicular to the blade split (if the inserts are to follow the blade geometry) because of the doubly curved geometry of the blade (the blade section at the split has an aerofoil profile and the blade thickness and chord length are decreasing towards tip). The profile of such a blade portion 7 is not constant, and instead defines a profile that will taper toward the tip end of the blade portion 7 in both a thickness and chordwise direction. Correctly positioning the inserts 12 relative to one another to provide effective support to the wind turbine blade portion 7 and to facilitate connection to anotherwind turbine blade portion 6 is important to maximise efficiency of load transfer across the joint 8. Each insert will therefore have an individual out of perpendicular (angle) relative to the split. For this reason, a positioning device 20 may be utilised during manufacture of the wind turbine blade 5. The positioning device 20 may be located in a mould in some arrangements, with the wind turbine blade portion 6, 7 formed around the positioning device 20 in the mould.

[0086] The positioning device 20 will now be discussed with reference to Figures 6A to 7B. The positioning device 20 may be for positioning a plurality of inserts 12 within an end 9 of a wind turbine blade portion 6, 7 having a partial or full aerofoil profile during manufacture of the wind turbine blade portion 6, 7. The positioning device 20 may be used during manufacture of the inboard and / or outboard wind turbine blade portion 6, 7. As discussed above, the inserts 12 may each include at least one bushing 32, e.g. a threaded bushing 32, for embedding in a blade shell 42 of the wind turbine blade portion 6, 7.

[0087] The positioning device 20 includes a mounting body 22 having a first side 22a and a second side 22b. A plurality of through holes 24 extend between the first side 22a and the second side 22b. The through holes 24 are each configured to receive a respective fastener 26 (see Figure 7B), e.g. a threaded fastener 26, for connecting the positioning device 20 to the plurality of inserts 12 by engaging the threaded fasteners 26 with the threaded bushings 32 of the inserts 12. Any number of through holes 24 may be provided. Each through hole 24 may correspond to a desired position of an insert 12 within the blade portion 6, 7. In some arrangements, the number of through holes 24 may correspond to the number of inserts 12 to be provided in the blade portion 6, 7. The fastener 26 may be any suitable fastener including a screw, a bolt, or the like. The fastener 26 may be substantially the same as the fastener 16 used to connect the blade portions 6, 7 to the joint 8, but may only be used in the manufacturing process of the blade.

[0088] The plurality of through holes 24 may be arranged relative to one another along a curve generally corresponding to the aerofoil profile of the end 9 of the respective wind turbine blade portion 6, 7. Such an arrangement of through holes 24 can result in an effective arrangement of inserts 12 within a wind turbine blade portion 6, 7 having an aerofoil profile. The plurality of through holes 24 may arranged side by side or immediately adjacent one another along the curve in some arrangements. This may increase the number of inserts 12 that are present in the resulting blade portion 6, 7. In alternative arrangements, the through holes 24 may be spaced apart on the mounting body 22, e.g. spaced apart along the curve corresponding to the aerofoil profile of the respective blade portion 6, 7.

[0089] As can be best seen in Figures 7A and 7B, each of the plurality of through holes 24 define a fastener hole axis 28 for receiving the respective threaded fastener 24. At least two of the plurality of through holes 24 have fastener hole axes 28 that are non-parallel relative to each other. Providing at least two through holes 24 having fastener hole axes 28 that are non-parallel relative to each other in the positioning device 20 allows inserts 12 in the respective blade portion 6, 7 to be individually angled relative to one another. For example, the inserts 12 connected to the positioning device 20 will define a non-zero angle relative to one another. In this way, once the blade shell 42 of the respective blade portion 6, 7 is formed around the inserts 12, the inserts 12 align with the blade geometry and load path and thus provide effective support to a split wind turbine blade 5.

[0090] Figures 7A and 7B indicate two adjacent through holes 24 of the plurality of through holes 24 each defining a respective fastener hole axis 28. As can be seen, the respective fastener hole axes 28 each define a different angle cu and 02 relative to a side 22a, 22b of the mounting body 22. The fastener hole axes 28 of the through holes 24 are angularly offset relative to each other. At least two of the fastener hole axes are offset relative to each other by an angle less than about 10°, optionally less than about 5°, optionally less than about 2°. The offset may be decrease with an increased number of through holes 24, e.g. more through holes 24 may result in a smaller angular offset between adjacent through holes 24, e.g. an offset of less than 2°. In some arrangements, each or all of the plurality of through holes 24 have fastener hole axes 28 that are non-parallel relative to each other. The fastener hole axis 28 of each through hole 24 may define an individual angle (e.g. relative to the first side 22a of the mounting body 22) that is different to the respective angle defined by the faster hole axes 28 of the other through holes 24. Such an arrangement may result in each insert 12 in the blade portion 6, 7 extending along an individual angle (e.g. relative to an end 9 of the blade portion 7). Following manufacture of the blade portion 6, 7, each insert 12 extends along an axis that is coaxial to the fastener hole axes 28 defined by the through hole 24 to which the insert 12 was connected. The angles defined by the axes 28 are selected such that the resulting inserts 12 can align with blade geometry to provide improved support to the blade 5. In some arrangements, the angles defined by each through hole 24 may be offset relative to one another such that inserts 12 in the blade portion 6, 7 are angularly offset relative to one another in the thickness and / or chordwise direction of the wind turbine blade portion 6, 7.

[0091] The mounting body 22 may be configured for mounting parallel with the aerofoil profile of the end 9 of the wind turbine blade portion 6, 7. At least one of the plurality of fastener hole axes 28 may be angularly offset to extend in the thickness and / or chordwise direction away from normal to the aerofoil profile of the end 9 of the wind turbine blade portion 6, 7. The angular offset of the fastener hole axis / axes 28 results in inserts 12 within a blade portion 6, 7 that are inclined in the thickness and / or chordwise direction of the wind turbine blade portion 6, 7. This results in inserts 12 that align with the blade geometry and thus provide effective support along the load-path of the blade 5.

[0092] The positioning device 20 may be configured differently depending on the blade portion 6, 7 being manufactured. As can be clearly seen in Figure 2, the inboard blade portion 6 and outboard blade portion 7 define a different profile in at least one direction, e.g. in the spanwise and / or chordwise direction. This may result in the inserts 12 being required to extend in different directions depending on which blade portion 6, 7 is being manufactured. For this reason, different positioning devices may be required depending on the blade portion 6, 7 being manufactured. For example, the angles defined by the through holes 28 may be different in a positioning device 20 for locating inserts in the inboard blade portion 6 than in a positioning device 20 for locating inserts in the outboard blade portion 7. As will be discussed in more detail with reference to Figures 8A and 8B, the positioning device 20, in particular the mounting body 22, may form an integral part of a wind turbine blade portion mould 44. In some arrangements, the mounting body 22 may be welded to the mould 44. In alternative arrangements, the mounting body 22 may be configured to be otherwise mounted to a wind turbine blade portion mould 44.

[0093] The mounting body 22 may be configured to be removeably mounted to a wind turbine blade portion mould 44. The mounting body 22 may have a fixing arrangement 46. The fixing arrangement 46 may be configured to removeably secure the positioning device 20 to the mould 44. Removeably securing the positioning device 20 in the mould allows the positioning device to be reused in subsequent moulds 44 (i.e. to form multiple blade portions 6, 7). As can be seen in Figure 6A and 6B, the fixing arrangement 46 may include one or more fastener receiving holes 48 in the mounting body 22. The fastener receiving holes 48 may have a threaded internal profile in some arrangements. The fixing arrangement 46 may include a set of fastener receiving holes 48. The set of fastener receiving holes 48 may be distributed about the mounting body 22. It will be appreciated that any suitable means of securing the mounting body 22 to the mould 44 may be utilised, e.g. clamping, adhesive, fasteners, or the like.

[0094] The mounting body 22 may have a generally plate-like form. The mounting body 22 may be larger in a width and / or length direction than in a thickness direction between the first and second sides 22a, 22b. The mounting body 22 may have a shape generally corresponding to at least a portion of the aerofoil profile of the wind turbine blade portion 6, 7. The mounting body 22 may be formed as a single, unified body.

[0095] The mounting body 22 of Figure 6A has a shape corresponding to the full aerofoil profile of a complete wind turbine blade portion shell for use with a wind turbine blade portion full shell mould. An opening 54 may be provided through the mounting body 22. The mounting body 22 may enclose the opening. In this way, the mounting body 22 may correspond to the shape of a wind turbine blade portion shell 42 (e.g. with a hollow centre). In alternative arrangements, the opening 54 may not be present.

[0096] The mounting body 22 of Figure 6B has a shape corresponding to the partial aerofoil profile of a wind turbine blade portion half shell for use with a wind turbine blade portion half shell mould. The mounting body 22 of Figure 6B may be utilised with another mounting body 22 having a shape corresponding to the partial aerofoil profile of a wind turbine blade portion half shell, such that the two mounting bodies together define a shape corresponding to a full aerofoil profile (e.g. corresponding to the mounting body 22 of Figure 6A). In this case, the two mounting bodies may be utilised in a full shell mould.

[0097] A single mounting body 22 per blade shell or half shell may advantageously make it easier to seal off the end of the mould 44 for containing resin used to infuse the fibre layers of the blade shell to form the blade shell 42. In alternative arrangements, multiple mounting bodies 22 or mounting body portions may be connected or otherwise coupled together to form the positioning device 20, e.g. having a full or partial aerofoil shape. In some arrangements, the mounting body 22 may not have a shape that corresponds exactly to an aerofoil or partial aerofoil profile of a wind turbine blade portion. In this case, the through holes 24 may be arranged through the mounting body 22 such that the through holes 24 together define a substantially aerofoil or partial aerofoil profile.

[0098] As can be best seen in the cross-sectional view of Figures 7A and 7B, each through hole 24 may include a bushing arrangement 36 which defines the respective fastener hole axis 28. The bushing arrangement 36 may include a first bushing 38 adjacent the first side 22a of the mounting body 22 and a second bushing 40 adjacent the second side 22b of the mounting body 22. The first bushing 38 and the second bushing 40 may be positioned in the through hole 24 so as to be spaced apart from each other. The first bushing 38 may have a first hole centre and the second bushing 40 may have a second hole centre. The respective fastener hole axis 28 may be aligned or coaxial with the first hole centre and the second hole centre. The bushing arrangement 36 may provide additional support to the fastener 26 in the mounting body 22.

[0099] At least one of the plurality of through holes 24 may have an internal diameter that varies between the first side 22a and the second side 22b of the mounting body 22. Such a configuration may facilitate the use of a fastener 26 with a complementary variation in outer diameter. The configuration may also be beneficial in providing clearances between the fastener 26 and the through hole 24 between the bushings 38, 40 as can be seen in Figure 7B. In some arrangements, all of the through holes 24 are configured to define a varying internal diameter.

[0100] At least one of the first bushing 38 and second bushing 40 defines a non-planar surface 40a facing away from the mounting body 22 for centring a fastener 26 on the respective fastener hole axis 28. The non-planar surface 40a provides control over the angle of insertion of the fastener 26 and, consequently, the angle at which the insert 12 coupled to the positioning device 20 extends into the respective wind turbine blade portion 6, 7. The non-planar surface 40a may include a tapered or a conical inner surface. As can be seen in Figure 7B, an end of the fastener 26 may have an outer surface that is complementary to the non-planar surface 40a, e.g. similarly tapered or conical. In the illustrated arrangement, an internal surface of the second bushing 40 defines the non- planar surface 40a. In such an arrangement, the fastener 26 may be inserted into the respective through hole 24 until the end of the fastener abuts against the non-planar surface 40a. The non-planar surface 40a may be configured to guide the fastener along the fastener hole axis 28 through the through hole 24 from the second side 22b to the first side 22a of the mounting body 22.

[0101] Figure 7B shows an example arrangement of the positioning device 20 in use. The fastener 26 may be configured to extend through the mounting body 22 and beyond the first end 22a of the mounting body 22. The fastener 26 may be received in the insert 12, for example in the threaded bore 18 defined by the insert bushing 32 in the end 13 of the insert 12. The fastener 26 extends through the mounting body 22 via the respective through hole 24 and into the bushing 32 of the insert 12. The insert 12 is connected to the positioning device 20 via the fastener 26. The end 13 of the insert 12 may be positioned so as to generally abut or face the first side 22a of the mounting body 22. A portion of the fastener 26 may be exposed or accessible at the second side 22b of the mounting body 22. This may facilitate simple disconnection of the positioning device 20 from the inserts 12 once the blade portion 6, 7 has been formed and the inserts 12 are embedded therein, e.g. by removing the fastener 26 from the through hole 24 via contact with the exposed portion at the second side 22b. In this way, the positioning device 20 can be re-used to form subsequent blade portions 6, 7.

[0102] A wind turbine blade portion mould assembly 50 will now be described with reference to Figures 8A and 8B. Figure 8A shows a cross-sectional view of a mould assembly 50, in which an outboard wind turbine blade portion 7 has been formed. Figure 8B shows a similar mould assembly 50, in which an inboard wind turbine blade portion 6 and an outboard wind turbine blade portion 7 has been formed.

[0103] The mould assembly 50 includes a mould 44 having a cavity 52 for forming at least one wind turbine blade portion 6, 7 having a partial or full aerofoil profile. The cavity is represented in dashed lines in the figures for purposes of clarity. The mould 44 may be a hollow structure with the cavity 52 being defined by an internal surface of the mould 44. The cavity 52 of Figure 8A is configured to define the shape of the outboard wind turbine blade portion 7. It will be appreciated that a mould assembly to form the inboard wind turbine blade portion 6 may be substantially the same as that of Figure 8B, with the cavity being configured to define the shape of the inboard wind turbine blade portion

[0104] 6 instead. As such, any discussion regarding the mould assembly of Figure 8A may also apply to a mould assembly configured to form the inboard wind turbine blade portion 6. The cavity 52 of Figure 8B is configured to define the shape of both the inboard and outboard wind turbine blade portion 6, 7. The cavity 52 is configured for receiving a blade material, e.g. fibrous material and resin, to form the blade portion 7. The mould 44 may be formed from two halves that are connected (e.g. clamped) together during the manufacturing process.

[0105] The mould assembly 50 includes the positioning device 20. The mounting body 22 of the positioning device 20 may form an integral part of the mould 44 or be mounted to the mould 44. The mould assembly 50 includes a plurality of threaded fasteners 26 received in the respective through holes 24 of the mounting body 22 for connecting the positioning device 20 to a plurality of inserts 12 arranged in the cavity 52 by engaging the threaded fasteners 26 with threaded bushings 32 of the inserts 12.

[0106] The cavity 52 may extend in a lengthwise direction to define a span of the wind turbine blade portion 7. In the arrangement of Figure 8A, the positioning device 20 is located at an end of the cavity 52 (e.g. the end corresponding to the end 9 of the resulting wind turbine blade portion 7). Such an arrangement results in the manufacture of a portion

[0107] 7 of a split wind turbine blade 5.

[0108] In Figure 8B, two positioning devices 20 are located along the length of the cavity 52 so as to divide the cavity into a first section 52a up to a first one of the positioning devices 20 and a second section 52b up to a second one 20 of the positioning devices. The two positioning devices 20 may be positioned to correspond with a respective end 9 of the wind turbine blade portion 6, 7 into which the positioning device 20 is positioning inserts 12 into. In this arrangement, two such wind turbine blade portions 6, 7 each having a blade shell 42 are arranged within the cavity 52. The wind turbine blade portions 6, 7 may each have a partial or full aerofoil profile. A plurality of inserts 12 may be embedded in each of the blade shells 42. The first section 52a of the cavity 52 may be configured to correspond to the inboard wind turbine blade portion 6. The second section 52b of the cavity 52 may be configured to correspond to the outboard wind turbine blade portion 7. The positioning devices of Figure 8B may be different from each other such that the inserts 12 align with the geometry of the respective blade portion 6, 7 in which they are embedded. For example, the through holes of each positioning device may be distributed differently or may define different fastener hole axes 28.

[0109] The mould assembly 50 may include a plurality of inserts 12 arranged within the cavity 52. The inserts 12 may be substantially the same as those described herein. Each insert 21 may have at least one threaded bushing 32 for embedding in a blade shell of a wind turbine blade portion 6, 7 having a partial or full aerofoil profile. The plurality of threaded fasteners 26 received in the respective through holes 24 of the mounting body 22 may connect the positioning device 20 to the plurality of inserts 12 by engaging the threaded fasteners 26 with threaded bushings 32 of the inserts 12, e.g. as shown in Figure 7B. The threaded bushings 32 of each insert 12 may be aligned with the respective fastener hole axes 28 of the positioning device 20. Put another way, the threaded bushings 32 may define a central axis that is coaxial with the fastener hole axis 28 of the respective through hole 24. In this way, each insert is positioned so as to be embedded within a respective wind turbine blade portion 6, 7 such that the insert aligns with the blade geometry and therefore load-path.

[0110] The mould assembly 50 may include a wind turbine blade portion 6, 7 having a blade shell 42 arranged within the cavity 52. The wind turbine blade portion 6, 7 may have a partial or full aerofoil profile. The plurality of inserts are embedded in the blade shell 42. The inserts 12 may be configured for securing the wind turbine blade portion 7 to another wind turbine blade portion 6.

[0111] A method of forming a wind turbine blade portion 7 will now be described. The method may be configured to form an inboard wind turbine blade portion 6 or an outboard wind turbine blade portion 7. The method may include one or more of the following steps:

[0112] (a) providing a mould 44 having a cavity 52 for forming a wind turbine blade portion 6, 7 having a partial or full aerofoil profile, (b) providing a positioning device 20 as described herein, the mounting body 22 of the positioning device 20 may form an integral part of the mould 44, or may be mounted to the mould 44;

[0113] (c) laying up a wind turbine blade portion 6, 7 in the mould 44, including blade shell material and a plurality of inserts 12 such that the blade shell material substantially surrounds the plurality of inserts 12 in the mould 44. The inserts each have at least one threaded bushing 32;

[0114] (d) inserting a plurality of threaded fasteners 26 through respective through holes 24 of the mounting body 22 to connect the positioning device 20 to the plurality of inserts 18 by engaging the threaded fasteners 26 with threaded bushings 32 of the inserts 12 such that the threaded bushings 32 of each insert 12 are aligned with the respective fastener hole axes 28 of the positioning device 20;

[0115] (e) providing resin to the mould 44; and

[0116] (f) curing the wind turbine blade portion 6, 7 in the mould 44.

[0117] The inserts 12 may be configured for securing the wind turbine blade portion 6, 7 to another wind turbine blade portion 6,7 (e.g. made via the same method).

[0118] Step (c) may include introducing layers of composite material into the cavity 52 of the mould 44. The blade shell material may include fibreglass and / or carbon fibre material (e.g. carbon fibre reinforced plastic). Other materials may be utilised in some arrangements. Layers of the material are introduced into the mould. The layers may be arranged at different angles to provide strength to the wind turbine blade portion 6, 7 in different directions.

[0119] Step (e) may include providing resin to the mould 44 (e.g. to the cavity 52) such that the resin fills any gaps between the material that forms the blade portion 6, 7 and the inserts 14. Step (e) may include infusing the blade portion material with resin using a vacuum assisted resin transfer moulding process. This allows infusion of resin between the inserts 12 to bond the inserts 12 together during manufacture of the blade portion 6, 7, e.g. by vacuum assisted resin transfer moulding.

[0120] Step (f) may include curing under heat and / or pressure. This step is configured to harden or cure the resin so as to create a strong and rigid blade portion 7. This step may reduce the presence of air pockets or voids in the resin. Once this step is completed, the wind turbine blade portion 7 has been formed in the mould 44. The wind turbine blade portion 7 may then be removed from the mould 44.

[0121] The method may optionally include introducing additional components to the mould 44, e.g. before or after infusing the resin. This may include the addition of internal supports throughout the mould 44 to provide additional rigidity to the blade portion 7. In some arrangements, one or more shear webs and / or spar caps may be introduced into the mould 44.

[0122] The mould 44 may be a wind turbine blade portion half shell mould or wind turbine blade portion full shell mould. In the case of the half shell mould, the two half shells may be attached together by any suitable means after curing. The mould 44 may include two half shell cavities that are connectable prior to curing so as to define a full shell mould, e.g. two half shell cavities that are pivotably connected.

[0123] The method may include detaching the wind turbine blade portion 6, 7 from the positioning device 20 by removing the plurality of threaded fasteners 26 from the plurality of inserts 12. This step may be performed after curing the wind turbine blade portion 6, 7 in the mould 44. This step may be performed after removing the wind turbine blade portion 6, 7 from the mould 44. This step may result in a wind turbine blade portion 6, 7 having a plurality of inserts 12 embedded therein. The inserts include threaded bores 18 extending therein following the removal of the threaded fasteners 26.

[0124] The blade portion 6, 7 may include surface imperfections or excess material following removal from the mould 44. For this reason, the method may include the additional step of machining the surface of the wind turbine blade portion 6, 7 after removal from the mould 44. This may result in a smooth outer surface of the blade portion 6, 7.

[0125] In some arrangements, an end 9 of the blade portion 6, 7 (i.e. the end to which the positioning device 20 is attached) may include sections of inserts 12 projecting therefrom following removal of the blade portion 7 from the mould 44. For this reason, the method may include the step of machining an end 9 of the wind turbine blade portion 6, 7 after detaching the wind turbine blade portion 6, 7 from the positioning device 20. Machining the end 9 may remove an exposed portion of at least one of the inserts 12 such that the end 9 of the wind turbine blade portion 6, 7 defines a substantially planar surface. It will be understood that a planar end surface 9 of the blade portion 6, 7 is advantageous to facilitate connection with other components, e.g. another blade shell portion 6, 7. As such, machining the end of the blade shell portion 6, 7 to define a substantially planar surface can improve the connection between the blade shell portions 6, 7. Machining the surface of the wind turbine blade portion 6, 7 may include trimming excess material (e.g. the inserts 12), sanding the surface, or the like.

[0126] In some arrangements, the mould 44 may be arranged as in Figure 8A, such that the method forms a portion 6, 7 of the wind turbine blade 5. In this case, another mould 44 may be utilised to form the other portion 6, 7 of the wind turbine blade 5 via a similar method. In alternative arrangements, the mould 44 may be arranged as shown in Figure 8B. In this case, two positioning devices 20 may be provided, as discussed above. This may result in the formation of two wind turbine blade portions 6, 7 in a single mould 44. Each blade portion 6, 7 includes embedded inserts 12 having a bushing 32. This may be beneficial, as only a single resin introduction step (step (e)) and / or curing step (step (f)) may be required to form the blade portions 6, 7 in a single mould 44.

[0127] Following the formation of the two blade portions 6, 7 (e.g. via separate moulds or a single mould) and the removal of the respective positioning devices 20, the blade portions 6, 7 can be connected via the joint 8. A fastener 16 may be introduced into the bushing 32 of one or more inserts 12 in each blade portions 6, 7. This may result in the formation of a wind turbine blade 5, e.g. as shown in Figures 3 and 4. It will be understood that the wind turbine blade portions 6, 7 may be connected by any suitable means. The connection of the blade portions 6, 7 may occur at a different location to the location at which the method is performed. For example, the blade portions 6, 7 made according to the method may be transported to a site of the wind turbine 1 separately before being connected during assembly of the wind turbine 1.

[0128] Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

Claims

CLAIMS1. A positioning device (20) for positioning a plurality of inserts (12) within an end (9) of a wind turbine blade portion (6, 7) having a partial or full aerofoil profile during manufacture of the wind turbine blade portion (6, 7), the inserts (12) each having at least one threaded bushing (32) for embedding in a blade shell (42) of the wind turbine blade portion (6, 7), the positioning device (20) comprising: a mounting body (22) having a first side (22a) and a second side (22b) and a plurality of through holes (24) extending between the first side (22a) and the second side (22b), the through holes (24) each configured to receive a respective threaded fastener (26) for connecting the positioning device (20) to the plurality of inserts (12) by engaging the threaded fasteners (26) with the threaded bushings (32); wherein each of the plurality of through holes (24) defines a fastener hole axis (28) for receiving the respective threaded fastener (26); and wherein at least two of the plurality of through holes (24) have fastener hole axes (28) that are non-parallel relative to each other.

2. A positioning device (20) according to claim 1 , wherein the plurality of through holes (24) each have fastener hole axes (28) that are non-parallel relative to each other.

3. A positioning device (20) according to claim 1 or claim 2, wherein at least one of the plurality of through holes (24) has an internal diameter, and the internal diameter varies between the first side (22a) and the second side (22b) of the mounting body (22).

4. A positioning device (20) according to any preceding claim, wherein each through hole (24) has a bushing arrangement (36) which defines the respective fastener hole axis (28), and wherein the bushing arrangement (36) includes a first bushing (38) adjacent the first side (22a) of the mounting body (22) and a second bushing (40) adjacent the second side (22b) of the mounting body (22).

5. A positioning device according to claim 4, wherein at least one of the first bushing (38) and second bushing (40) defines a non-planar surface (40a) facing awayfrom the mounting body (22) for centring a fastener (26) on the respective fastener hole axis (28).

6. A positioning device (20) according to any preceding claim, wherein the mounting body (22) is for mounting parallel with the aerofoil profile of the end (9) of the wind turbine blade portion (6, 7), and wherein at least one of the plurality of fastener hole axes (28) is angularly offset to extend in the thickness and / or chordwise direction away from normal to the aerofoil profile of the end (9) of the wind turbine blade portion (6, 7).

7. A positioning device (20) according to any preceding claim, wherein the plurality of through holes (24) are arranged relative to one another along a curve generally corresponding to the aerofoil profile of the end (9) of the wind turbine blade portion (6, 7).

8. A wind turbine blade portion mould assembly (50) comprising: a mould (44) having a cavity (52) for forming a wind turbine blade portion (6, 7) having a partial or full aerofoil profile; a positioning device (20) according to any preceding claim, wherein the mounting body (22) of the positioning device forms an integral part of the mould (44), or is mounted to the mould (44); and a plurality of threaded fasteners (26) received in the respective through holes (24) of the mounting body (22) for connecting the positioning device (20) to a plurality of inserts (12) arranged in the cavity (52) by engaging the threaded fasteners (26) with threaded bushings (32) of the inserts (12).

9. A wind turbine blade portion mould assembly (50) according to claim 8, further comprising: a plurality of inserts (12) arranged within the cavity (52), the inserts (12) each having at least one threaded bushing (32) for embedding in a blade shell (42) of a wind turbine blade portion (6, 7) having a partial or full aerofoil profile; wherein the plurality of threaded fasteners (26) received in the respective through holes (24) of the mounting body (22) may connect the positioning device (20) to the plurality of inserts (12) by engaging the threaded fasteners (26) with threaded bushings (32) of the inserts (12).

10. A wind turbine blade portion mould assembly (50) according to claim 9, wherein the threaded bushings (32) of each insert (12) are aligned with the respective fastener hole axes (28) of the positioning device (20).

11. A wind turbine blade portion mould assembly (50) according to any of claims 8 to 10, wherein the cavity (52) extends in a lengthwise direction to define a span of the wind turbine blade portion (6, 7), and wherein the positioning device (20) is located at an end of the cavity (52).

12. A wind turbine blade portion mould assembly (50) according to any of claims 8 to 10, wherein the cavity (52) extends in a lengthwise direction to define a span of the wind turbine blade portion (6, 7), and wherein two positioning devices (20) are located along the length of the cavity (52) so as to divide the cavity (52) into a first section (52a) up to a first one of the positioning devices (20) and a second section (52b) up to a second one of the positioning devices (20), and wherein two such wind turbine blade portions (6, 7) each having a blade shell (42) are arranged within the cavity (52), the wind turbine blade portions (6, 7) each having a partial or full aerofoil profile, and wherein the plurality of inserts (12) are embedded in each of the blade shells (42).

13. A method of forming a wind turbine blade portion (6, 7), the method comprising: providing a mould (44) having a cavity (52) for forming a wind turbine blade portion (6, 7) having a partial or full aerofoil profile, providing a positioning device (20) according to any of claims 1 to 7, wherein the mounting body (22) of the positioning device forms an integral part of the mould (44), or is mounted to the mould (44); laying up a wind turbine blade portion (6, 7) in the mould, including blade shell material and a plurality of inserts (12) such that the blade shell material substantially surrounds the plurality of inserts (12) in the mould (44), wherein the inserts (12) each have at least one threaded bushing (32); inserting a plurality of threaded fasteners (26) through respective through holes (24) of the mounting body (22) to connect the positioning device (20) to the plurality of inserts (12) by engaging the threaded fasteners (26) with threaded bushings (32) of the inserts (12) such that the threaded bushings (32) of each insert (12) are aligned with the respective fastener hole axes (28) of the positioning device (20); providing resin to the mould (44); and curing the wind turbine blade portion (6, 7) in the mould (44);wherein the inserts (12) are for securing the wind turbine blade portion (6, 7) to another wind turbine blade portion (6, 7).

14. A method according to claim 13, further comprising: detaching the wind turbine blade portion (6, 7) from the positioning device (20) by removing the plurality of threaded fasteners (26) from the plurality of inserts (12).

15. A method according to claim 14, further comprising: machining an end (9) of the wind turbine blade portion (6, 7) after detaching the wind turbine blade portion (6, 7) from the positioning device (20), wherein machining removes an exposed portion of at least one of the inserts (12) such that the end of the wind turbine blade portion (6, 7) defines a substantially planar surface.

Images