Moulding apparatus

Abstract

There is provided moulding apparatus for moulding a wind turbine blade shear web comprising a longitudinally-extending web panel and a web flange extending transverse to the web panel along a longitudinal edge of the web panel. The web flange comprises a first portion that extends on a first side of the web panel and defines at least part of a mounting surface for connecting the shear web to a wind turbine blade shell. The moulding apparatus defines a mould length. The moulding apparatus comprises a main mould comprising a longitudinally-extending main mould surface shaped to form at least part of the web panel, a tooling surface extending transverse to the main mould surface at a first inclination angle and shaped to form at least part of the first portion of the web flange, and a support surface extending transverse to the tooling surface at a second inclination angle. The moulding apparatus further comprises at least one mould element comprising a base surface for arrangement with the support surface of the main mould and a moulding surface extending transverse to the base surface at a third inclination angle. The moulding surface is shaped to form at least part of the mounting surface of the web flange. The first inclination angle varies along the mould length. The second inclination angle is substantially constant along the mould length. The third inclination angle is substantially constant along the mould length.

Description

[0001] Moulding apparatus

[0002] Technical field

[0003] The present invention relates to wind turbine blades and more particularly to moulding apparatus for moulding a wind turbine blade shear web.

[0004] Background

[0005] Modern wind turbine blades typically have an aerodynamic outer shell that is supported by one or more shear webs that extend longitudinally inside the shell. The outer shell of a wind turbine blade may be twisted along its length to enable effective and efficient energy capture from wind incident on the blade in use. To facilitate a strong and uniform bond between the shear web and the outer shell, the web may be configured with a web flange that varies along its length to substantially correspond to the varying geometry of the shell to which it is connected.

[0006] Wind turbine blades may be designed for specific turbines, specific wind conditions, and specific locations. Accordingly, a blade manufacturing facility may produce multiple different blade designs. Each blade design typically requires a specific shear web design to fit inside the outer shell and provide the requisite structural support. A blade manufacturing facility may therefore require multiple sets of shear web manufacturing equipment to form the different shear web designs. This can be expensive and also takes up floor space in the blade manufacturing facility.

[0007] Additionally, some components of the shear web manufacturing equipment may be susceptible to damage because of the frequency with which they are used, assembled / disassembled, and moved around. To reduce cost and production downtime, the blade manufacturing facility may therefore also have equipment for manufacturing replacement components for the shear web manufacturing equipment. However, because the shear web manufacturing equipment is specific to each shear web design, the blade manufacturing facility may need multiple sets of equipment for manufacturing the replacement components. Again, this is expensive and takes up further floor space in the manufacturing facility.

[0008] It is against this background that the present invention has been developed. Summary

[0009] According to a first aspect of the present invention there is provided moulding apparatus for moulding a wind turbine blade shear web comprising a longitudinally-extending web panel and a web flange extending transverse to the web panel along a longitudinal edge of the web panel. The web flange comprises a first portion that extends on a first side of the web panel and defines at least part of a mounting surface for connecting the shear web to a wind turbine blade shell. The moulding apparatus defines a mould length. The moulding apparatus comprises a main mould comprising a longitudinally-extending main mould surface shaped to form at least part of the web panel, a tooling surface extending transverse to the main mould surface at a first inclination angle and shaped to form at least part of the first portion of the web flange, and a support surface extending transverse to the tooling surface at a second inclination angle. The moulding apparatus further comprises at least one mould element comprising a base surface for arrangement with the support surface of the main mould and a moulding surface extending transverse to the base surface at a third inclination angle. The moulding surface is shaped to form at least part of the mounting surface of the web flange. The first inclination angle varies along the mould length. The second inclination angle is substantially constant along the mould length. The third inclination angle is substantially constant along the mould length.

[0010] For example, the substantially constant second inclination angle and substantially constant third inclination angle may each vary at a rate of less than 1.57m, preferably less than 17m, and more preferably less than 0.57m along the mould length. In some preferred examples, the second inclination angle may be the same, i.e. may not vary at all, along the mould length. Further, in some preferred examples the third inclination angle may be the same, i.e. may not vary at all, along the mould length.

[0011] The mould length is a portion of the moulding apparatus in which the first inclination angle varies, and in which the second inclination is substantially constant, and in which the third inclination angle is substantially constant. In some examples, the mould length may be defined by the length of the mould element, i.e. the length of the mould element may be the same as the mould length. Additionally or alternatively, the mould length may be defined by the length of the support surface, in some examples, i.e. the mould length may extend along the full length of the support surface. Further, in some examples the mould length may additionally or alternatively be defined by the length of the tooling surface of the main mould, i.e. the mould length may extend along the full length of the tooling surface. Accordingly, it will be appreciated that in some examples the mould length may be substantially the same as the length of each of the mould element, the support surface, and the tooling surface.

[0012] In some examples, the or each mould element may have substantially the same cross- sectional profile along the mould length. For example, the mould element may comprise a substantially L-shaped cross-sectional profile defined by the base surface and the moulding surface extending transverse to the base surface.

[0013] Further, in some examples the or each mould element may have substantially the same cross-sectional profile along its length. In some examples, the base surface of the mould element may be defined between two longitudinally extending edges that extend continuously along the length of the mould element. This may provide a stiff base along the length of the mould element to maintain the consistent geometry of the mould element despite the variation in the orientation of the support surface against which the base surface of the mould element is arranged. The longitudinally extending edges may be a heel edge and a toe edge of the mould element. When the mould element is arranged with the main mould, the heel edge may be proximal to the tooling surface and the toe edge may be distal from the tooling surface. Further, the heel edge may define part of the moulding surface of the mould element.

[0014] In some examples, the or each mould element may be configured to provide heat to the moulding surface. For example, the mould element may comprise a heating element, such as an electric resistive heating element, in or adjacent to the moulding surface to provide heat to the moulding surface. Additionally or alternatively, the mould element may comprise a cavity or channel configured to receive a flow of heated fluid. Such a mould element may be configured to conduct heat from the fluid in the cavity or channel to the moulding surface. Accordingly, in some examples the mould element may be formed of a heat conductive material, such as metal for example. Providing heat to the moulding surface of the mould element may help to cure resin supplied to fibre material arranged between the moulding surface and the tooling surface of the main mould during manufacture of a shear web. This may help to reduce cycle time, and may also help to facilitate more even curing of resin throughout the mould when forming a shear web therein.

[0015] In some examples, the or each mould element may be removably fastened to the support surface of the main mould. For example, the mould element may be removably fastened to the main mould by fixing means, such as a bolted connection, extending through the base surface of the mould element. Advantageously such a configuration does not interfere with the shear web flange formed between the moulding surface of the mould element and the tooling surface of the main mould. The fixing means, for example bolts, may extend through the support surface at least partially into the main mould.

[0016] In some examples, the main mould may comprise a main mould body and one or more tooling shims arranged with the main mould body to define at least part of the tooling surface. A shim may also be referred to as a mould insert. The or each shim may be formed of metal or polymer, in some examples. Alternatively, in some examples the or each shim may be formed of a composite material, such as laminated glass fibre reinforced polymer. Dependent on the material of the or each shim, examples for attaching the or each shim to the main mould body include welding, bonding or overlaminating. The use of one or more shims facilitates fine tuning of the mould to form the shear web accurately. Additionally or alternatively, the use of one or more shims may facilitate the configuration and reconfiguration of the mould for forming different shear web designs.

[0017] In some examples, the or each tooling shim may be configured to provide heat to the tooling surface. For example, the or each tooling shim may comprise a heating element, such as an electric resistive heating element, in or adjacent to the tooling surface to provide heat to the tooling surface. In some examples, the or each tooling shim may be formed of a heat conductive material, such as metal for example. In some examples, the or each tooling shim may comprise aluminium. Providing heat to the tooling surface may help to cure resin supplied to fibre material arranged between the tooling surface and the moulding surface of the mould element during manufacture of a shear web. This may help to reduce cycle time, and may also help to facilitate more even curing of resin throughout the mould when forming a shear web therein.

[0018] In some examples, the main mould body may have substantially the same cross-sectional profile along the mould length. In such an example, the tooling shim may have a variable cross-sectional profile along the mould length to define the varying first inclination angle. Such a configuration facilitates simple and repeatable manufacture of the main mould body whilst still enabling the specific mould configuration to be achieved by using one or more tooling shims having a varying cross-sectional profile. In particular, the main mould body may be reused to manufacture various different shear web designs simply by implementing different variable tooling shims with the main mould body. In some examples, the mould length may be defined by the length of the main mould body. Accordingly, in some examples main mould body may have substantially the same cross- sectional profile along its length.

[0019] In some examples, the main mould may comprise a main mould body and one or more support shims arranged with the main mould body to define at least part of the support surface. In some examples, the or each support shim may have a variable cross-sectional profile along the mould length to maintain a substantially constant second inclination angle between the support surface defined by the support shim and the variable inclination of the tooling surface.

[0020] In some examples, the or each shim, i.e. the or each tooling shim and / or the or each support shim, may be removably attached to the main mould body. For example, the or each shim may be bolted to the main mould body. Accordingly, the shims may be interchangeable and may therefore facilitate the use of the same mould element and main mould body with different shims to form differently shear web designs.

[0021] In some examples, a support shim may be sandwiched between the main mould body and the base surface of the mould element, and the mould element may be attached to the main mould body via fixing means extending through the base surface of the mould element, through the support shim and into the main mould body. Accordingly, the support shim in such an example may be clamped in position between the base surface and the main mould body.

[0022] In some examples, the moulding apparatus may be configured for moulding a shear web that has a web flange comprising a second portion that extends on a second side of the web panel and also defines part of the mounting surface. In such an example, the moulding surface of the mould element may have a greater height than the tooling surface. Accordingly, the moulding surface of the mould element may extend above the main mould surface when the mould element is arranged with the support surface of the main mould. It will be appreciated that the height of the moulding surface of the mould element is measured from the base surface of the mould element, and the height of the tooling surface of the main mould is measured from the support surface of the main mould.

[0023] In some examples, the first inclination angle may vary within a range of 45 degrees to 160 degrees, preferably between 60 degrees and 150 degrees. Further, the substantially constant second inclination angle may be less than 180 degrees and may preferably be between 45 degrees and 135 degrees. The substantially constant third inclination angle may be less than 180 degrees and may preferably be between 45 degrees and 135 degrees. In some examples, the first inclination angle may vary at a rate of between 1 ,57m and 107m. Accordingly, it will be appreciated that the first inclination angle varies at a significantly higher rate than any slight variation in the substantially constant second and third inclination angles. Configuring the moulding apparatus with inclination angles in these ranges may be advantageous for removing the mould element from the main mould and demoulding a shear web formed in the mould.

[0024] It will be appreciated that the inclination of the support surface also varies relative to the main mould surface along the mould length as a result of the substantially constant relation between the support surface and the tooling surface and the variable relation between the tooling surface and the main mould surface.

[0025] In some examples, the substantially constant third inclination angle between the base surface and the moulding surface of the mould element may be the same as the substantially constant second inclination angle between the support surface and the tooling surface of the main mould. The moulding surface of the mould element and the tooling surface may therefore be substantially parallel. Such a configuration may therefore form a first portion of the web flange that has a substantially constant thickness when viewed in cross section.

[0026] In some examples, the or each mould element may be formed of a composite material. For example the mould element may be formed of fibre reinforced composite material. In some examples, the mould element may be a pultruded composite component, i.e. the mould element may be formed in a pultrusion process. A pultrusion process may be a particularly cost-effective method for manufacturing a mould element having substantially the same cross-sectional profile along its length.

[0027] Alternatively, in some preferred examples the mould element may be a laminated composite component. A laminated composite mould element may be advantageously flexible such that the base surface of the mould element conforms to the contours of the support surface when the mould element is arranged with the main mould whilst still having the requisite rigidity to maintain the intended geometry for accurately forming a shear web in the mould. In another aspect of the present invention there is provided a method of manufacturing a shear web using the moulding apparatus described herein. The method comprises arranging one or more layers of fibre material on the main mould surface, arranging the mould element with the main mould such that the base surface of the mould element is arranged on the support surface of the main mould, and arranging one or more layers of fibre material between the moulding surface of the mould element and the tooling surface of the main mould. The method further comprises supplying resin to the fibre material, and curing the resin to fix the fibre material in a cured resin matrix.

[0028] It should be appreciated that arranging the base surface on the support surface is not limited to direct physical contact between the base surface and support surface. In some examples the base surface of the mould element may be arranged on the support surface with one or more other components or layers of material arranged between the base surface and the support surface. For example, as previously described, in some examples a support shim may be arranged between the base surface of the mould element and the support surface of the main mould.

[0029] After curing the resin to fix the fibre material in a cured resin matrix, the method may comprise removing the mould element from the main mould and subsequently demoulding the shear web from the main mould.

[0030] In some examples, the method may include arranging a panel of core material on the main mould surface to form the web panel. The core material may comprise polymer foam or balsa wood, for example.

[0031] In some examples, supplying resin to the fibre material may comprise a vacuum assisted resin transfer moulding process wherein the fibre material is infused with resin under vacuum pressure. Additionally or alternatively, in some examples the fibre material may comprise pre-preg fibre material that is pre-impregnated with resin prior to arrangement in the mould.

[0032] In some preferred examples, the one or more layers of fibre material may be arranged on the main mould surface before the mould element is arranged with the main mould. Further, in some examples one or more layers of fibre material may be arranged on the tooling surface before the mould element is arranged with the main mould. Further still, in some examples, fibre material may be arranged on both the main mould surface and on the tooling surface of the main mould before the mould element is arranged with the main mould.

[0033] In some examples, arranging one or more layers of fibre material between the moulding surface of the mould element and the tooling surface of the main mould may comprise arranging a fibre material preform between the moulding surface and the tooling surface. For example a fibre material preform may comprise a plurality of layers of fibre material pre-arranged in a stack.

[0034] In some examples, the method may comprise pre-arranging one or more layers of fibre material with the moulding surface of the mould element and subsequently arranging the mould element and the fibre material with the main mould. Accordingly, in such an example the one or more layers of fibre material may be arranged between the moulding surface and the tooling surface simultaneously with the arrangement of the mould element with the main mould.

[0035] The or each layer of fibre material may be pre-arranged with the moulding surface by releasably fixing the fibre material to the mould element, for example by clamping, bonding or taping the fibre material to the mould element. Further, in some examples the method may comprise pre-arranging a fibre material preform with the moulding surface of the mould element prior to arranging the mould element with the main mould.

[0036] Brief description of the drawings

[0037] Examples of the present invention will now be described by way of non-limiting example(s) only, with reference to the accompanying figures, in which:

[0038] Figure 1 is a schematic exploded view of an example of a wind turbine blade comprising a shear web;

[0039] Figures 2a to 2c show different schematic cross-sectional views of moulding apparatus for moulding the shear web taken at different positions along the moulding apparatus;

[0040] Figures 3a to 3c are schematic cross-sectional views of moulding apparatus comprising a plurality of shims;

[0041] Figure 4 is a schematic perspective view of a mould element; Figure 5 is a schematic perspective view of a stage in a method of making a wind turbine blade shear web using the moulding apparatus; and

[0042] Figures 6a to 6c show schematic cross-sectional views of another example of apparatus for forming a shear web.

[0043] Detailed description

[0044] Figure 1 is a schematic exploded view of an example of a wind turbine blade 10. The blade extends longitudinally in a spanwise direction (S) between a root end 12 and a tip end 14, and in a chordwise direction (C) between a leading edge 16 and a trailing edge 18. The blade comprises a shell which may be formed of a first half shell 20a and a second half shell 20b which are joined together.

[0045] The wind turbine blade 10 further comprises a shear web 22. The shear web 22 extends longitudinally in the spanwise direction (S) and forms part of a spar structure which is configured to absorb bending and torsional loads experienced by the blade 10 in use. The shear web 22 comprises a longitudinally-extending web panel 24 and one or more web flanges 26 configured for connecting the shear web 22 to the shell of the blade 10. As shown in Figure 1 , in some examples the shear web 22 may comprise two web flanges 26.

[0046] The web flange 26 extends along a longitudinal edge 28 of the web panel 24 and transverse to the web panel 24. The web flange 26 comprises a first portion 30 that extends on a first side of the web panel 24. The first portion 30 of the web flange 26 defines at least part of a mounting surface 32 for connecting the shear web 22 to the shell of the wind turbine blade 10. As shown in Figure 1 , in some examples the web flange 26 may comprise a second portion 34 that extends on a second side of the web panel 24, and the second portion 34 may also define part of the mounting surface 32. The mounting surface 32 of the shear web flange 26 is preferably substantially parallel to an inner surface of the outer shell to facilitate a strong and substantially uniform bond along the length of the shear web 22.

[0047] As described by way of background, the wind turbine blade 10 may be twisted along its length. Conversely, the shear web panel 24 is substantially planar in order to absorb the shear loads experienced by the blade 10 most effectively. Accordingly, an angle (not shown) between the shear web panel 24 and inner surface of the outer shell may vary along the length of the shear web 22. It follows that the shear web 22 may be configured such that an angle A defined between the web panel 24 and the web flange 26 varies along the length of the shear web 22 in order to maintain the mounting surface 32 substantially parallel to the inner surface of the outer shell along its length.

[0048] Brief reference is now made to Figures 6a to 6c which show an example of apparatus 100 that may be used to form a shear web 22. The apparatus 100 may include a mould 102 that defines a panel-forming surface 104 for forming the shear web panel 24 and a flangeforming surface 106 for forming part of the web flange 26. The apparatus 100 may also include a plurality of removable mould components 108a, 108b, 108c which are configured with a respective shaping surface 110 to form part of the flange 26 of the shear web 22. The mould components 108a-c may be located on a process flange 112 of the mould 102. A bottom surface 114 of each mould component 108a-c may be seated on the process flange 112. The process flange 112 may be substantially parallel to the panel-forming surface 104 of the mould 102 for ease of manufacture.

[0049] As previously described, the web flange 26 of the shear web 22 may be inclined at a varying angle A along the length of the shear web 22. To form a shear web 22 with a twisted or varying web flange 26, the flange-forming surface of the mould 102 may be inclined at a varying angle relative to the panel-forming surface 104 along the length of the mould 102. Additionally, the mould components 108a-c may be configured such that the shaping surface 110 of each mould component is inclined at a different angle D relative to its respective bottom surface. This means that the inclination D between the surfaces of each mould component 108a-c is different for the different mould components 108a-c arranged along the length of the mould 102, and this in turn may help to form a web flange 26 that is inclined at a varying angle A along the length of the shear web 22. Each of the mould components 108a-c is different, i.e. individual, so the mould components 108a-c must be arranged in a specific order to correctly form a shear web 22 with a flange 26 that twists along its length as intended for a particular shear web design.

[0050] Improved moulding apparatus 36 for moulding the shear web 22, and a method of manufacturing the shear web 22, will now be described with reference to Figures 2a to 5.

[0051] Reference is made initially to Figures 2a to 2c, which show schematic cross-sectional views of the moulding apparatus 36 and an outline of the shear web 22 formed therein. Whilst not shown in the accompanying figures, the moulding apparatus 36 defines a mould length, and each of the cross-sectional views 2a to 2c are taken at different positions along the moulding apparatus 36 within the mould length. The moulding apparatus 36 comprises a main mould 38 and a mould element 40. The main mould 38 includes a main mould surface 42 that is shaped to form at least part of the shear web panel 24. Accordingly, the main mould surface 42 extends in a longitudinal direction, which is into the plane of the page in Figure 2a.

[0052] The main mould 38 also comprises a tooling surface 44 shaped to form at least part of the first portion 30 of the web flange 26. The tooling surface 44 extends transverse to the main mould surface 42 at a first inclination angle X. The main mould 38 also comprises a support surface 46 which extends transverse to the tooling surface 44 at a second inclination angle Y. The support surface 46 is configured for supporting the mould element 40 during manufacture of a shear web 22.

[0053] Referring still to Figures 2a to 2c, it follows that the mould element 40 comprises a base surface 48 for arrangement with the support surface 46 of the main mould 38. The mould element 40 also comprises a moulding surface 50 which extends transverse to the base surface 48 at a third inclination angle Z. The third inclination angle is substantially constant along the mould length. The moulding surface 50 is shaped to form at least part of the mounting surface 32 of the web flange 26. At least the first portion 30 of the web flange 26 may therefore be formed between the tooling surface 44 of the main mould 38 and the moulding surface 50 of the mould element 40 as will be described in more detail later with reference to Figure 5.

[0054] As described previously, the shear web 22 may comprise a second portion 34 extending on the second side of the web panel 24. In such an example, as shown in Figure 2a, the moulding surface 50 of the mould element 40 may have a greater height than the tooling surface 44. Accordingly, when the mould element 40 is arranged with the support surface 46 of the main mould 38, the moulding surface 50 of the mould element 40 may extend above the main mould surface 42. The second portion 34 of the shear web flange 26 may be formed, at least in part, by a portion 51 of the mould element 40 that extends above the main mould surface 42.

[0055] As will now be described with reference to Figures 2a to 5, the moulding apparatus 36 is configured to form a shear web 22 having a web flange 26 that is inclined at a varying angle A relative to the web panel 24 along its length. With reference to Figures 2a to 2c in particular, it can be seen that the first inclination angle X between the main mould surface 42 and the tooling surface 44 varies along the mould length. That is to say, throughout the mould length, the tooling surface 44 is inclined at various different angles relative to the main mould surface 42.

[0056] Conversely, the relation between the tooling surface 44 and the support surface 46 of the main mould 38, i.e. the second inclination angle Y, is substantially constant along the mould length. Accordingly, any variation in the inclination of the tooling surface 44 relative to the main mould surface 42 (i.e. the first inclination angle X) also results in a variation of the inclination of the support surface 46 relative to the main mould surface 42. With the mould element 40 comprising a substantially constant third inclination angle Z between the base surface 48 and the moulding surface 50 along the mould length, it follows that the varying first inclination angle ultimately also results in a variation of the inclination of the moulding surface 50 relative to the main mould surface 42, when the mould element 40 is arranged with the support surface 46 of the main mould 38.

[0057] As previously described, the main mould surface 42 is shaped to form the web panel 24, and the tooling surface 44 and moulding surface 50 are configured to form the first portion 30 of the web flange 26 of a shear web 22. It should therefore be understood that the web flange 26 of a shear web 22 formed using the moulding apparatus 36 is inclined relative to the web panel 24 at a varying angle A as a direct result of the variation of the first inclination angle X between the main mould surface 42 and the tooling surface 44. Accordingly, various different shear web designs can be manufacturing using the same mould element 40 design in combination with different main mould designs, because the variation in the resultant shear web geometry is dictated by the configuration of the main mould 38 and not the mould element 40.

[0058] As described by way of background, mould elements 40 may be used and moved frequently, and a blade or shear web manufacturing facility may therefore also manufacture mould elements 40 to replace old or damaged mould elements 40. Advantageously, a manufacturing facility set up to manufacture a plurality of different shear web designs using moulding apparatus 36 as described herein may only require apparatus configured to manufacture a single replacement mould element design to replace any old or damaged mould elements 40. This may save both cost and floor space in the manufacturing facility. Further still, in some examples the moulding apparatus 36 may be configured to facilitate the manufacture of different shear web designs in the same moulding apparatus 36. For example, as will now be described with reference to Figures 3a to 3c, the main mould 38 may comprise a main mould body 52 and one or more shims that define the geometry of the main mould 38.

[0059] Figures 3a to 3c again show schematic cross-sectional views of an example of the moulding apparatus 36 at different positions along the moulding apparatus 36 within the mould length. The main mould 38 may comprise a main mould body 52 and one or more tooling shims 54 arranged with the main mould body 52 to define at least part of the tooling surface 44. In some examples, the main mould body 52 may have substantially the same cross-sectional profile along the mould length, and the tooling shim 54 may have a variable cross-sectional profile along the mould length. The varying first inclination angle X between the tooling surface 44 and the main mould surface 42 may therefore be defined by the variable cross-sectional profile of the tooling shim 54, in such an example.

[0060] Further, in some examples the moulding apparatus 36 may include one or more support shims 56 arranged with the main mould body 52. A support shim 56 may define at least part of the support surface 46 on which the mould element 40 is arranged when manufacturing a shear web 22. The support shim 56 may have a varying cross-sectional profile along the mould length to maintain the substantially constant second inclination angle Y between the tooling surface 44 and the support surface 46 as described previously.

[0061] With reference to Figures 3a to 3c, it should be appreciated that the main mould 38 may be reconfigured to form different shear web designs by using the same main mould body 52 in combination with different tooling shims 54 and / or support shims 56. To facilitate simple reconfiguration of the main mould 38, the or each shim 54, 56 may be removably attached to the main mould body 52, for example by bolts (not shown).

[0062] Brief reference is now made to Figure 4 which shows a schematic perspective view of an example of a mould element 40. The mould element 40 may have substantially the same cross-sectional profile along the mould length. For example, as shown in Figure 4, the mould element 40 may comprise a substantially L-shaped cross-sectional profile, and the mould element may be substantially L-shaped along the mould length. Whilst the mould element 40 may twist along its length when arranged with the main mould 38, it will be appreciated that the mould element 40 maintains a substantially constant cross-sectional profile, such as an L-shaped profile, along the mould length. In particular, it will be appreciated that the third inclination angle Z between the base surface 48 and the moulding surface 50 remains substantially constant along the mould length. In some examples, the mould element 40 may have substantially the same cross-sectional profile along its length Configuring the mould element 40 with substantially the same cross- sectional profile along its length may simplify manufacture of the mould element 40 whilst also providing the mould element 40 with the requisite structural rigidity to maintain its shape during manufacture of a shear web 22.

[0063] Further, in some examples, the base surface 48 of the mould element 40 may be defined between two longitudinally extending edges 60, 62 that extend continuously along the length of the mould element 40. This configuration may provide a sufficiently rigid base 64 that twists to conform to the support surface 46 against which it is arranged, whilst still providing the requisite support to a moulding upstand 66 that defines the moulding surface 50.

[0064] The mould element 40 may be formed of a composite material. For example, the mould element 40 may comprise glass fibre reinforced plastic (GFRP). The composite material may allow the mould element 40 to twist along the mould length whilst still maintaining the requisite geometry, including the substantially constant third inclination angle Z, to accurately form the shear web 22. Further, a composite mould element 40 may be manufactured in a simple and inexpensive manner by laminating, i.e. moulding, the composite material on a relatively simple mould (not shown). As described previously, a blade or shear web manufacturing facility may only require a single mould for manufacturing mould elements 40 suitable for forming a plurality of different shear web designs using examples of the moulding apparatus 36 described herein.

[0065] A method of manufacturing the shear web 22 will now be described with reference to Figure 5 which again shows a schematic cross-sectional view of an example of the moulding apparatus 36 described previously. Features described previously with reference to Figures 2a to 4 will not be repeated here for conciseness, and it should be understood that the method may be implemented using any of the examples of moulding apparatus 36 described previously.

[0066] As shown in Figure 5, the method includes arranging at least one layer of fibre material 68 on the main mould surface 42. The fibre material 68 may comprise glass fibre and / or carbon fibre, and in some examples the fibre material 68 may be bi-axial fibre material. Optionally, in some examples the method may additionally include arranging a panel of core material 70, such as polymer foam or balsa wood, on the main mould surface 42 to form the web panel 24.

[0067] The method further includes arranging the mould element 40 with the main mould 38. As described previously, the base surface 48 of the mould element 40 is arranged on the support surface 46 of the main mould 38. In some examples the mould element 40 may be removably fastened to the support surface 46 of the main mould 38, for example using bolts 72, as shown in Figure 5.

[0068] One or more layers of fibre material 74 are arranged between the moulding surface 50 of the mould element 40 and the tooling surface 44 of the main mould 38. This fibre material 74 forms at least part of the first portion 30 of the shear web flange 26. In some examples the fibre material 74 may be pre-arranged with the moulding surface 50 of the mould element 40 before the mould element 40 is arranged with the main mould 38. Accordingly, the fibre material 74 may be arranged between the moulding surface 50 and the tooling surface 44 when the mould element 40 is arranged on the support surface 46 of the main mould 38. Such a process may help to expedite the manufacturing method and may also reduce the risk of forming wrinkles in the fibre material 74 when arranging it between the tooling and moulding surfaces 44, 50.

[0069] As previously described, in some examples the moulding apparatus 36 may be used to form a shear web 22 having a web flange 26 that extends on both a first and second side of the web panel 24. Accordingly, the moulding apparatus 36 may be configured with a mould element 40 having a portion 51 that extends above the main mould surface 42 when the mould element 40 is arranged on the support surface 46. It follows that to form the second portion 34 of the web flange 26, the method may include arranging fibre material 76 with the moulding surface 50 of the mould element 40, namely with a portion of the mould surface 50 defined by the portion 51 of the mould element 40 that extends above the main mould surface 42. In some preferred examples, the fibre material 76 for forming the second flange portion 34 may be arranged with the moulding surface 50 after the mould element 40 is arranged with the main mould 38.

[0070] The method also includes supplying resin (not shown) to the fibre material 68, 74 arranged on the main mould surface 42 and between the tooling and moulding surfaces 44, 50. Resin may also be supplied to the fibre material 76 arranged with the portion 51 of the mould element 40 that extends above the main mould surface 42 to form the second portion 34 of the web flange 26. In some examples the resin may be supplied in an infusion process, or alternatively the resin may be supplied with the fibre material 68, 74 if the fibre material 68, 74 comprises pre-preg fibre material.

[0071] The resin is cured to fix the fibre material 68, 74, 76 in a cured resin matrix, thereby forming the shear web 22. Optionally, the resin may be cured by supplying heat to the material laid up in the moulding apparatus 36. For example, the main mould 38 may comprise heating elements (not shown) to supply heat to the main mould surface 42. Further, in some examples the mould element 40 and / or the main mould 38 may be configured to respectively supply heat to the moulding surface 50 and / or to the tooling surface 44. This may help to ensure that the resin throughout the moulding apparatus 36 cures at a substantially similar rate which is beneficial for the longevity and load-bearing performance of the resultant shear web 22.

[0072] It will be appreciated that the description provided with reference to the accompanying figures serves to provide a plurality of non-exclusive examples of the invention defined by the appended claims. Accordingly, it should be appreciated that other examples that are not shown in the accompanying figures may form part of the invention, in some examples.

[0073] For example, Figures 2a to 5 have been described with reference to moulding apparatus 36 comprising a mould element 40. However, it should be understood that in some examples, the moulding apparatus 36 may include a plurality of mould elements 40 arranged end to end on the support surface 46 of the main mould 38. Accordingly, in some examples the mould length may extend over a greater length than the length of a single mould element 40, and a plurality of mould elements 40 may be arranged at least partially within the mould length. In examples comprising a plurality of mould elements 40, the mould elements 40 may all be of substantially the same design. Accordingly, even in examples where the moulding apparatus 36 comprises a plurality of mould elements 40, such mould elements 40 are again simple and cost effective to manufacture because they are all the same design which reduces both part count and the equipment required for manufacturing the mould elements 40. Further, assembly of the moulding apparatus 36 is simplified, because there is no specific order in which the mould elements 40 must be arranged, because all of the mould elements 40 are the same. This helps to reduce cycle time for manufacturing a shear web 22 because the mould elements 40 can be arranged quickly, and this also reduces the risk of configuring the moulding apparatus 36 incorrectly. Whilst not specifically identified in the accompanying figures, the main mould 38 and mould element 40 may be configured to simplify disassembly of the moulding apparatus 36 and demoulding of the shear web 22 from the main mould 38 after moulding. For example, the varying first inclination angle X between the main mould surface 42 and the tooling surface 44 may vary within a range of 45 degrees to 160 degrees, and preferably between 60 degrees and 150 degrees. Further, the substantially constant second inclination angle Y between the tooling surface 44 and the support surface 46 may be less than 180 degrees, for example between 45 degrees and 135 degrees. The substantially constant third inclination angle Z may also be less than 180 degrees, for example between 45 degrees and 135 degrees.

[0074] It will be appreciated that features described in relation to any of the examples above may be readily combined with any other features described with reference to different examples without departing from the scope of the invention as defined in the appended claims.

Claims

Claims1. Moulding apparatus (36) for moulding a wind turbine blade shear web (22) comprising a longitudinally-extending web panel (24) and a web flange (26) extending transverse to the web panel along a longitudinal edge (28) of the web panel, the web flange comprising a first portion (30) that extends on a first side of the web panel and defines at least part of a mounting surface (32) for connecting the shear web to a wind turbine blade shell, the moulding apparatus defining a mould length and comprising: a main mould (38) comprising a longitudinally-extending main mould surface (42) shaped to form at least part of the web panel, a tooling surface (44) extending transverse to the main mould surface at a first inclination angle X and shaped to form at least part of the first portion of the web flange, and a support surface (46) extending transverse to the tooling surface at a second inclination angle Y; at least one mould element (40) comprising a base surface (48) for arrangement with the support surface of the main mould and a moulding surface (50) extending transverse to the base surface at a third inclination angle Z, the moulding surface being shaped to form at least part of the mounting surface of the web flange; wherein the first inclination angle X varies along the mould length; wherein the second inclination angle Vis substantially constant along the mould length; and wherein the third inclination angle Z is substantially constant along the mould length.

2. The moulding apparatus (36) of any preceding claim, wherein the or each mould element (40) has substantially the same cross-sectional profile along the mould length.

3. The moulding apparatus (36) of Claim 1 or Claim 2, wherein the base surface (48) of the mould element (40) is defined between two longitudinally extending edges (60, 62) that extend continuously along the length of the mould element.

4. The moulding apparatus (36) of any preceding claim, wherein the or each mould element (40) is configured to provide heat to the moulding surface (50).

5. The moulding apparatus (36) of any preceding claim, wherein the or each mould element (40) is removably fastened to the support surface (46) of the main mould (38).

6. The moulding apparatus (36) of any preceding claim, wherein the main mould (38) comprises a main mould body (52) and one or more tooling shims (54) arranged with the main mould body to define at least part of the tooling surface (44).

7. The moulding apparatus (36) of Claim 6, wherein the or each tooling shim (54) is configured to provide heat to the tooling surface (44).

8. The moulding apparatus (36) of Claim 6 or Claim 7, wherein the main mould body (52) has substantially the same cross-sectional profile along the mould length, and wherein the tooling shim (54) has a variable cross-sectional profile along the mould length to define the varying first inclination angle9. The moulding apparatus (36) of any preceding claim, wherein the main mould (38) comprises a main mould body (52) and one or more support shims (56) arranged with the main mould body to define at least part of the support surface (46).

10. The moulding apparatus (36) of any of Claims 6 to 9, wherein the or each shim (54, 56) is removably attached to the main mould body (52).

11. The moulding apparatus (36) of any preceding claim, wherein the web flange (26) comprises a second portion (34) that extends on a second side of the web panel (24) and also defines part of the mounting surface (32), and wherein the moulding surface (50) of the mould element (40) has a greater height than the tooling surface (44) such that the moulding surface of the mould element extends above the main mould surface (42) when the mould element is arranged with the support surface (46) of the main mould (38).

12. The moulding apparatus (36) of any preceding claim, wherein the first inclination angle X varies within a range of 45 degrees to 160 degrees, wherein the substantially constant second inclination angle V is less than 180 degrees and preferably between 45 degrees and 135 degrees, and wherein the substantially constant third inclination angle Z is less than 180 degrees and preferably between 45 degrees and 135 degrees.

13. The moulding apparatus (36) of any preceding claim, wherein the or each mould element (40) is formed of a composite material.

14. A method of manufacturing a shear web (22) using the moulding apparatus (36) of any preceding claim, the method comprising: arranging one or more layers of fibre material (68) on the main mould surface (42); arranging the mould element (40) with the main mould (38) such that the base surface (48) of the mould element is arranged on the support surface (46) of the main mould; arranging one or more layers of fibre material (74) between the moulding surface (50) of the mould element and the tooling surface (44) of the main mould; supplying resin to the fibre material; and curing the resin to fix the fibre material in a cured resin matrix.

15. The method of Claim 14, wherein one or more layers of fibre material (74) are pre-arranged with the moulding surface (50) of the mould element (40) and the mould element and fibre material (74) are subsequently arranged with the main mould (38).

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