GB2636112A

GB2636112A - Shear webs

Info

Publication number: GB2636112A
Application number: GB2318214.0A
Authority: GB
Inventors: Paul Schroder Henning; Buhl Thomas
Original assignee: Gurit UK Ltd
Current assignee: Gurit UK Ltd
Priority date: 2023-11-29
Filing date: 2023-11-29
Publication date: 2025-06-11
Also published as: WO2025114067A1; GB202318214D0

Abstract

A wind turbine blade shell (100, fig.1) with a shear web assembly 344, that typically runs from the blade root to the blade tip. The assembly has multiple sandwich panels 324, connected to one another at lateral edges 336, 338, to form a series of sandwich panels. Along the top 350 and bottom 352 edges of the series of sandwich panels there are top 348 and bottom 354 connectors. In the upper and lower portions of the blade shell, upper and lower connectors extend lengthways on corresponding upper 316 or lower 320 spar caps. The length of the series of sandwich panels matches the length of the wind turbine blade shell and is aligned longitudinally. The top connector is in the upper connector on the upper spar cap and the bottom connector is in the lower connector of the lower spar cap. The connectors on the assembly may have concave profiles to correspond with convex profile connectors on the spar caps. There may be channels for adhesive to join the assembly to the connector. A method of manufacture on site and installation is also included.

Description

SHEAR WEBS

The present invention relates to a wind turbine blade shell comprising a shear web assembly, a method of manufacturing a shear web assembly for a wind turbine blade shell, and a method of installing a shear web assembly into a wind turbine blade shell.

Background

Shear webs are structural elements in wind turbine blades that, in use, enable a wind turbine blade to withstand shear forces.

It is known to manufacture wind turbine blades in a kitted fashion, where components of the wind turbine blade are provided in a kit. Shear webs and/or parts of shear webs may be provided as part of the kit. In this way, the shear webs or parts of shear webs will be pre-manufactured "off-site" from the blade assembly site, and then transported to the blade assembly site as part of a kit. Accordingly, the shear web assembly and/or parts of the shear web assembly must be pre-manufactured to a specified structure for any given wind turbine blade. This may increase manufacturing complexity and may for example increase the size of a bill of materials and inventory where a manufacturer needs to produce a range of wind turbine blade sizes.

W02022/112151A1 discloses a blade part, such as a shear web, for a wind turbine blade, and a method for making a shear web. The disclosed method comprises providing a panel section as a sandwich construction made of a fibre-reinforced thermoplastic or thermoset material and comprising a core material sandwiched between a first fibre-reinforcement sheet and a second fibre-reinforcement sheet. The method also comprises shaping at least a first side segment at a first side of the panel section to form a mounting flange of the shear web for mounting to another blade part such as a spar cap. However, the process for shaping the side segment to form a mounting flange is complicated.

The present inventors have attempted to address or at least mitigate the above-mentioned problems and have aimed to provide a wind turbine blade shell comprising a shear web assembly, a method of manufacturing a shear web assembly for a wind turbine blade shell, and a method of installing a shear web assembly into a wind turbine blade shell where the shear web assembly can be assembled, configured and fitted in the blade on-site, to correspond with a shape of the blade, in an efficient manner.

Summary

Accordingly, in a first aspect the present invention provides a method of installing a S shear web assembly into a wind turbine blade shell, according to claim 1.

In a second aspect the present invention provides a wind turbine blade shell assembly, according to claim 16.

In a third aspect the present invention provides a method of manufacturing a shear web assembly for a wind turbine blade shell, according to claim 30.

Preferred features of these aspects of the present invention are defined in the respective dependent claims.

Brief description of Figures

Figure 1 is a perspective view of a known wind turbine blade; Figure 2 is a cross-sectional view of a known wind turbine blade; Figure 3 schematically shows some parts of a process flow of installing a shear web assembly in to a wind turbine blade, according to an embodiment of the present invention; Figure 4 is a schematic cross-sectional view of a shear web assembly, according to an embodiment of the present invention; Figure 5 is a schematic side view of some parts of a shear web assembly, according to an embodiment of the present invention; Figure 6 is a schematic plan view of some parts of a shear web assembly, according to an embodiment of the present invention; Figure 7 is a schematic side view of some parts of a shear web assembly, according to an embodiment of the present invention; Figure 8 is a schematic side view of some parts of a shear web assembly, according to an embodiment of the present invention; Figure 9 is a schematic side view of a shear web assembly in a manufacturing jig, according to an embodiment of the present invention; Figure 10 is a schematic plan view of a wind turbine blade assembly site, according to an embodiment of the present invention; Figure 11 schematically shows some parts of a process flow of manufacturing a shear web assembly for a wind turbine blade, according to an embodiment of the present invention; and Figure 12 schematically shows some parts of a process flow of manufacturing a shear web assembly for a wind turbine blade, according to an embodiment of the present invention.

Detailed description

Figures 1 and 2 are schematic diagrams showing some parts of a known wind turbine blade, to aid with understanding the current invention.

Figure 1 is a perspective view of a wind turbine blade 100, partially shown in cut-away in the region of the dashed line in Figure 1, and Figure 2 shows the wind turbine blade 100 in cross section. The wind turbine blade 100 extends between a root region 102 and a tip region 104, and comprises an upper shell 106 and a lower shell 108. A shear web 110 is located in the wind turbine blade 100. The shear web 110 typically runs from or proximate to the root portion 102 up to or proximate to the tip portion 104. The shear web 110 has a top edge 114 that is joined to an upper spar cap 116 of the wind turbine blade 100, and a bottom edge 118 that is attached to a lower spar cap 120 in the wind turbine blade 100. Typically, the shear web 110 is attached to the upper spar cap 116 and the lower spar cap 118 with an adhesive. A purpose of the shear web 110 is to withstand shear forces that the wind turbine blade 100 is subjected to during use, and to maintain the shape of the wind turbine blade 100.

A wind turbine blade shell comprising a shear web assembly, a method of manufacturing a shear web assembly for a wind turbine blade shell, and a method of installing a shear web assembly into a wind turbine blade shell will now be described in more detail according to some illustrative embodiments of the present invention.

Figure 3 is a process diagram schematically showing a method of installing a shear web assembly into a wind turbine blade shell, according to an embodiment of the present invention.

At step (a), the method comprises providing a plurality of sandwich panels 322 and 324. In Figure 3 two sandwich panels 322 and 324 are shown for the purpose of explanation, but in practice more than two sandwich panels may be provided. Each sandwich panel comprises a core sandwiched between opposite outer skins. By way of example the core may be made from a polymeric material such as polyethylene terephthalate (PET) cellular foam, or balsa wood. The opposite outer skins may have any suitable composition and/or structure.

For example, the outer skins may comprise a fibre reinforced resin matrix material with any suitable resin composition (thermoset or thermoplastic), fibre/fabric composition (glass, carbon, polymeric, natural fibres) and weave, and thickness and/or areal weight known to those skilled in the art.

Each sandwich panel comprises a top edge and a bottom edge. In Figure 3, sandwich panel 324 comprises top edge 328 and bottom edge 330, and sandwich panel 326 comprises top edge 332 and bottom edge 334. Each sandwich panel also comprises lateral edges that extend between the top and bottom edges. In Figure 3, sandwich panel 324 comprises lateral edges 336 and 338, and sandwich panel 326 comprises lateral edges 340 and 342.

At step (b), the method comprises connecting the plurality of sandwich panels 324 and 326 to each other at lateral edges of adjacent sandwich panels to form a sandwich panel assembly 344. For example, lateral edge 338 of sandwich panel 324 is joined to lateral edge 340 of sandwich panel 326. Where the panels 324 and 326 are joined may be termed an interface region 346. The sandwich panel assembly 344 may be considered to comprise an elongate series of sandwich panels. The sandwich panel assembly 344 has a top edge 350 and a bottom edge 352. Top edge 350 of the sandwich panel assembly 344 comprises top edges 328 and 332 of sandwich panels 324 and 326. Bottom edge 352 of the sandwich panel assembly 344 comprises bottom edges 330 and 334 of sandwich panels 324 and 326.

At step (c) the method comprises providing at least one top connector 348 along at least a portion of the top edge 350 of the sandwich panel assembly 344. In some examples, the at least one top connector 348 straddles interface region 346 between adjacent sandwich panels 324 and 326. In some examples, a same top connector may straddle three or more sandwich panels that are in series. In other examples, one top connector may engage one sandwich panel only.

At step (d) the method comprises providing at least one bottom connector 354 along at least a portion of the bottom edge 352 of the sandwich panel assembly 344. In some examples, the at least one bottom connector 354 straddles interface region 346 between adjacent sandwich panels 324 and 326. In some examples, a same bottom connector may straddle three or more sandwich panels that are in series. In other examples, one bottom connector may engage one sandwich panel only.

It is to be noted that although in some examples the at least one top connector 348 and the at least one bottom connector 354 may provide a joining force between adjacent sandwich panels (where the top and/or bottom connectors straddle adjacent sandwich panels), this is not a primary purpose of the top and bottom connectors. Rather, a primary purpose of the at least one top connector 348 and the at least one bottom connector 354 is to enable connection to the wind turbine blade shell (explained in more detail below).

At step (e) the method comprises providing at least one upper connector 356 that extends longitudinally on an upper spar cap 316 in an upper portion 315 of the blade shell 300. For example, the at least one upper connector 356 may be joined to the upper spar cap 316 with an adhesive. At this stage, the upper portion 315 of the blade shell may be located in an upper blade shell mould.

At step (f) the method comprises providing at least one lower connector 358 that extends longitudinally on a lower spar cap 320 in a lower portion 319 of the blade shell. For example, the at least one lower connector 358 may be joined to the lower spar cap 320 with an adhesive. At this stage, the lower portion 319 of the blade shell may be located in a lower blade shell mould.

At step (g), the method comprises locating the sandwich panel assembly 344 in to the wind turbine blade shell 300, so that the at least one top connector 348 of the sandwich panel assembly 344 locates in the upper connector 356 on the upper spar cap 316 and the at least one bottom connector 354 of the sandwich panel assembly 344 locates in the at least one lower connector 358 of the lower spar cap 320. The sandwich panel assembly 344 has a length which corresponds, in a longitudinal direction, to a length of the wind turbine blade shell and the sandwich panel assembly 344 is aligned along the longitudinal direction of the wind turbine blade shell 300. In Fig. 3, the length of the sandwich panel assembly is denoted by Lsw and the length of the blade shell is denoted by Les. Where it is said that the length of the sandwich panel assembly corresponds to a length of the wind turbine blade shell this may mean, but does not necessarily mean, that they are exactly the same length. Rather, it may in some examples be considered that the length Lsw of the sandwich panel assembly 344 spans or substantially spans the length Les of the blade shell.

In some examples, step (g) may comprise a sub step of (i) locating the at least one bottom connector 354 of the sandwich panel assembly 344 in the at least one lower connector 358 of the lower spar cap 320 whilst the lower portion 319 of the blade shell is in a lower blade mould (for example by lifting and then lowering sandwich panel assembly 344 into the lower blade mould, for example with a crane). Alternatively, sub-step (i) may comprise lifting and then lowering the sandwich panel assembly into a lower blade shell that has been removed from a lower blade mould. In some examples step (g) comprises a sub step (ii) of closing an upper blade mould over the lower blade mould so that the at least one top connector 348 of the sandwich panel assembly 344 locates in the upper connector 356 on the upper spar cap 316. Alternatively, sub-step (ii) may comprise lifting and then lowering an upper blade shell (that has been removed from an upper blade shell mould) on to the sandwich panel assembly 344 and the lower blade shell.

Figure 4 is a schematic end view (i.e. looking along the length of a wind turbine blade) showing some aspects of the shear web assembly 344 and how the shear web assembly 344 attaches to the spar caps of the wind turbine blade shell.

The top connector 348 comprises a top channel portion 360 for receiving the top edge 350 of the sandwich panel assembly 344. For example, the top edge 350 of the sandwich panel assembly 344 may be a friction or relaxation fit in to the channel portion 360 of the top connector 348, and/or the top edge 350 of the sandwich panel assembly 344 may be adhesively bonded in the top channel portion 360 of the top connector 348. The top connector 348 also comprises a concave profile portion 362. The upper connector 356 on the upper spar cap comprises a convex profile portion 364. The concave profile portion 362 of the at least one top connector 348 on the sandwich panel assembly 344 is configured to guide and receive the convex profile portion 364 of the at least one upper connector 356 on the upper spar cap 316, during the process of locating the sandwich panel assembly 344 in the blade shell 300.

In some examples, it may be considered that the at least one top connector 348 defines a top longitudinally extending elongate channel 363 and the at least one upper connector 356 comprises a longitudinally extending elongate member which is received in the channel 363. In some examples, it may be considered that the top elongate channel 363 is generally U-shaped in cross-section.

In some examples it may be considered that the longitudinally extending elongate channel 363 forms an elongate reservoir for containing an adhesive 366 therein. The adhesive may be a structural adhesive, in some examples. During step (g) of locating the sandwich panel assembly 344 in the blade shell, the at least one upper connector 356 on the upper spar cap 316 displaces the adhesive 366 up an inner edge 368 of the longitudinally extending elongate channel 363 of the top connector 348. This provides an increased adhesive interface area between the at least one top connector 348 on the sandwich panel assembly 344 and the at least one upper connector 356 on the upper spar cap 316. In other words, it may be considered that the adhesive 366 is squeezed between the at least one upper connector 356 and the at least one top connector 348, and therefore pushed up the sides of the U-shaped profile of the top connector 348 and around the convex outer profile of the upper connector 356. This provides a relatively large bonding surface area between the upper connector 356 and the top connector 348.

The at least one bottom connector 354 comprises a bottom channel portion 366 for receiving the bottom edge 352 of the sandwich panel assembly 344. For example, the bottom edge 352 of the sandwich panel assembly 344 may be a friction or relaxation fit in to the bottom channel portion 366 of the bottom connector 354, and/or the bottom edge 352 of the sandwich panel assembly 344 may be adhesively bonded in the bottom channel portion 366 of the bottom connector 354. The at least one bottom connector 354 on the sandwich panel assembly 344 comprises a convex profile portion 368, and the at least one lower connector 358 on the lower spar cap 320 comprises a concave profile portion 370. The concave profile portion 370 of the at least one lower connector 358 on the lower spar cap 320 is configured to guide and receive the convex profile portion 368 of the at least one bottom connector 354 on the sandwich panel assembly 344 during the process of locating the sandwich panel assembly 344 in the blade shell.

In some examples it may be considered that the at least one lower connector 358 on the lower spar cap 320 defines a lower longitudinally extending elongate channel 371 and the at least one bottom connector 354 comprises a bottom longitudinally extending elongate member which is received in the lower longitudinally extending elongate channel 371. In some examples, it may be considered that the lower elongate channel 371 is generally U-shaped in cross-section.

According to some examples the lower longitudinally extending elongate channel 371 forms an elongate reservoir for containing an adhesive 372 therein, wherein during step (g) of locating the sandwich panel assembly 344 in the blade shell, the at least one bottom connector 354 on the bottom edge of the sandwich panel assembly 344 displaces the adhesive 372 up an inner edge 374 of the lower longitudinally extending elongate channel to provide an increased adhesive interface area between the at least one bottom connector 354 on the sandwich panel assembly 344 and the at least one lower connector 358 on the lower spar cap 320. In other words, it may be considered that the adhesive 372 is squeezed between the at least one bottom connector 354 and the at least one lower connector 358, and therefore pushed up the sides of the U-shaped or concave profile of the lower connector 358 and around the convex outer profile of the at least one bottom connector 354. This provides a relatively large bonding surface area between the lower connector 358 and the bottom connector 354.

Reference is now made to Figure 5, which is a schematic side view of sandwich panel assembly 344. According to some examples, the at least one top connector 348 on the sandwich panel assembly 344 comprises at least first and second top connectors 348 and 349 adjacent each other. There is a longitudinal upper spacing Lu between the first and second top connectors 348 and 349. The longitudinal upper spacing Lu prevents the sandwich panel assembly 344 from becoming excessively stiff. For example, this may enable some degree of flex of the sandwich panel assembly 344 which can assist the at least one top connector 348 on the sandwich panel assembly 344 locating in the at least one upper connector 356 on the upper spar cap 316. In some examples the longitudinal spacing Lu is in a range of from 1mm to 10mm.

As also shown in Figure 5, according to some examples the at least one bottom connector 354 on the sandwich panel assembly 344 comprises at least first and second bottom connectors 354 and 355 adjacent each other. According to some examples there is a longitudinal lower spacing LI_ between the first and second bottom connectors 354 and 355.

The longitudinal lower spacing LI_ prevents the sandwich panel assembly 344 from becoming excessively stiff. For example, this may enable some degree of flex of the sandwich panel assembly 344 which can assist the at least one bottom connector 354 on the sandwich panel assembly 344 locating in the at least one lower connector 358 on the upper spar cap 320. In some examples the longitudinal spacing Lis in a range of from 1mm to 10mm.

According to some examples, the at least first and second top connectors 348 and 349 and longitudinal upper spacing L. are aligned with the at least first and second bottom connectors 354 and 355 and longitudinal lower spacing Lt, along the length of the sandwich panel assembly 344. According to another example, the at least first and second top connectors 348 and 349 and longitudinal upper spacing L. are offset from the at least first and second bottom connectors 354 and 355 and longitudinal lower spacing Lt, along the length of the sandwich panel assembly 344.

Figure 6 is a schematic plan view to illustrate one way in which the step (b) of connecting the plurality of sandwich panels to each other at lateral edges of adjacent sandwich panels, to form a sandwich panel assembly 344 comprising an elongate series of the sandwich panels, can be achieved. Figure 6 shows, in plan view, first sandwich panel 324 and second sandwich panel 326. Figure 6 also shows lateral edge 338 of sandwich panel 324 and lateral edge 340 of sandwich panel 326.

According to some examples, the step (b) of Figure 3 comprises connecting adjacent sandwich panels 324 and 326 to each other with at least one elongate coupling member 376.

The elongate coupling member 376 is arranged to contact and extend along the lateral edges 338 and 340 of the adjacent sandwich panels 324 and 326. To this end, the coupling member 376 has first and second opposite sides 380 and 382 which are configured to mate with the lateral edges 338 and 340 of respective first and second sandwich panels 324 and 326.

According to some examples, the method further comprises a step (h), which is carried out before step (b) of Figure 3, of cutting into the lateral edges 338 and 340 of the sandwich panels 324 and 326 respective elongate grooves 384 and 386 which extends at least partly along the lateral edges 338 and 340 of the respective sandwich panels. The elongate groove 384 is located between a pair of elongate edge parts 383 and 385 of the lateral edge 338. The elongate groove 386 is located between a pair of elongate edge parts 387 and 389 of the lateral edge 340.

The coupling member 376 comprises a pair of elongate recesses 375 and 377 on opposite sides of respective central reinforcement portions 381 and 391 that extend longitudinally along the at least one coupling member 376. The method further comprises a step (i), which is carried out after step (h) and before step (b), of disposing an adhesive 379 in the elongate recesses 375 and 377 and/or the elongate grooves 384 and 386, pressing the pair of elongate edge parts 383 and 385 of the first of the adjacent sandwich panels 324 into the elongate recesses 375 on the first side 380 of the coupling member 376 and simultaneously pressing the central reinforcement portion 381 on the first side 380 of the coupling member 376 into the elongate groove 384 of the first sandwich panel 324, and pressing the pair of elongate edge parts 387 and 389 of the second of the adjacent sandwich panels 326 in to the elongate recesses 377 on the second side 382 of the coupling member 376 and simultaneously pressing the central reinforcement portion 391 on the second side 382 of the coupling member 376 into the elongate groove 386 of the second sandwich panel 326.

It is to be noted that Figure 6 schematically shows sandwich panels 324 and 326 before they are fully pressed into contact with elongate coupling member 376.

According to some examples, the at least one elongate coupling member comprises at least first and second coupling members. This is schematically shown in Figure 7, which is a side view of sandwich panels 324 and 326 when joined together, and shows first and second elongate coupling members 376 and 392. The first and second elongate coupling members 376 and 392 are laterally aligned along common edges of the first and second sandwich panels 324 and 326 and connect first sandwich panel 324 to second sandwich panel 326. The first and second coupling members 376 and 392 are mutually spaced to provide a laterally extending spacing between the first and second coupling members 376 and 392. In Figure 7 this spacing between coupling members is denoted as Lc. It may therefore be considered that the at least one coupling member connection between the first sandwich panel 324 and second sandwich panel 326 is not continuous from top to bottom of the shear web assembly. This avoids having an excessively stiff connection between leeward and windward sides of the blade shell. In some examples, the spacing Lc is in a range of from 1mm to 10mm.

According to some examples, step (b) i.e. connecting the plurality of sandwich panels to each other at lateral edges of adjacent sandwich panels, to form a sandwich panel assembly comprising an elongate series of the sandwich panels, comprises bonding adjacent sandwich panels to each other. This is schematically shown in Figure 8 which shows sandwich panel assembly 344 where the plurality of sandwich panels (e.g. sandwich panels 324 and 326) are bonded, on at least one or both faces of the sandwich panel assembly 344, by a fibre-reinforced resin matrix composite layer 396 applied to the interface region 346. The interface region 346 comprises opposed lateral edges 338 and 340 of adjacent sandwich panels 324 and 326. According to some examples the fibre reinforced resin matrix composite layer comprises a curable thermosetting resin. According to some examples, the curable thermosetting resin is curable by UV light. According to some examples, step (b) comprises applying UV light to the curable thermosetting resin to cure the resin.

In some examples, step (b) of the method may comprise one or both of: (i) connecting adjacent sandwich panels to each other with at least one elongate coupling member that contacts and extends along the lateral edges of the adjacent sandwich panels (i.e as shown in Figures 6 and 7); (ii) bonding, on at least one or both faces of the sandwich panel assembly, a fibre reinforced resin matrix composite layer to an interface region comprised of opposed lateral edges of adjacent sandwich panels (i.e. as shown in Figure 8).

Figure 9 schematically shows a shear web assembly 344 during manufacture or upon completion of manufacture. A jig 400 is schematically shown at 400. The jig 400 is configured to hold the shear web assembly 344 or at least a portion of the shear web assembly 344 in place during manufacture of the shear web assembly 344. In some examples one or more processes of constructing the shear web assembly 344 are carried out while the shear web assembly 344 is held in the jig 400. In some examples the shear web assembly 344 is held in place in the jig 400 while performing the bonding of the fibre reinforced matrix composite layer (see Figure 9) to the interface regions on the shear web assembly 344. In some examples, multiple machines are provided for performing the bonding of the fibre reinforced matrix composite layer, so that the fibre reinforced matrix composite layer can be applied to multiple interface regions simultaneously to speed up the overall process of producing the shear web assembly 344. In some examples, the jig 400 supports the shear web assembly 344 at or proximate to its top edge 350.

Figure 10 schematically shows a wind turbine blade production facility or site 500. A blade mould station is schematically shown at 502. In some examples, the jig 400 is positioned adjacent to the blade mould station 502. Then, once the shear web assembly 344 has been completed, the completed shear web assembly 344 can be lifted (for example by an overhead gantry crane) directly from the jig 400 to be located in to the blade shell, as discussed above.

There will now be discussed a method of manufacturing a shear web assembly for a wind turbine blade shell with reference to Figures 11 to 12.

Figure 11 provides a schematic overview of some parts of the process.

At step (a), the method comprises production of a sandwich panel 601 in a continuous manner. The continuously produced sandwich panel may comprise a foam core 602. The foam core 602 may be formed using a foam extrusion machine 604. The foam core may comprise PET (polyethylene terephthalate) foam, in which case a supply of PET foam pellets 606 are fed in to the extrusion machine 604. First and second outer skins 608 and 610 are applied to the foam core 602 at an outer skin applying station 612. One or more pairs of nip rollers 609 and 611 may assist in drawing off the outer skin materials 608 and 610 from respective rolls 613 and 615 of skin forming material 617 and 619. The nip rollers 609 and 611 (and/or one or more further rollers) may also assist in pressing the skin forming materials 617 and 619 against the core 602. The skin-forming material 617, 619 are unwound to supply a continuous length of the skin-forming material 617, 619 which is applied to a respective opposite outer surface 621, 623 of the foam core 602. The outer skins 608 and 610 may comprise a multi-axial material. For example the multi-axial material may comprise a bi-axial material. In some examples the outer skins 608 and 610 are formed from a pre-impregnated composite material, otherwise referred to as a "pre-preg". The first and second outer skins 608 and 610 may be bonded to the foam core 602 at a bonding station 614. For example, the bonding may comprise heating the outer skins 608 and 610 to a temperature so that they fuse or weld to the foam core 602. When pre-pregs are used, the resin in the pre-preg can be at least partly cured at the bonding station 614 or at a downstream curing station (not shown) if the resin is a thermosetting resin, e.g. an epoxy resin, and the curing can be achieved by thermal curing or by UV curing. The resin alternatively may be a thermoplastic resin which is thermally bonded at the bonding station 614. In an alternative embodiment, the skin-forming material 617, 619 comprises a fabric layer which has been coated with a liquid resin upstream of the outer skin applying station 612, and then the liquid resin is solidified by curing or drying to bond the outer skins 608, 610 to be adhered to the foam core 602.

That the sandwich panel is produced in a "continuous manner" will be understood to mean that the sandwich panel can be produced to any length so long as the constituent raw materials are supplied and the machinery such as extrusion machine 604 and the skin applying station 612 are running. It will therefore be understood that the phrase "in a continuous manners' refers to an extending length of sandwich panel being produced as the foam core is extruded and the outer skins are laid thereon. The phrase "in a continuous manner" does not preclude that the process of producing the extending length of sandwich panel can be started and stopped (for example for maintenance or at the start/end of a shift). In practice, the main restriction to the overall length of sandwich panel that can be produced in the continuous manner is the length of the production facility.

Step (b) comprises cutting the sandwich panel 601 which has been produced in a continuous manner in to a plurality of sandwich panel sections, schematically shown at 624 and 626. For example, a cutting machine 616 may perform the cutting operation.

Step (c) comprises joining of the sandwich panel sections 624, 625 and 626 in series to form a shear web assembly 634. Step (c) takes place at a shear web assembly station 700 prior to locating the shear web assembly 634 in a wind turbine blade shell 800 that the shear web assembly 634 is configured for. The shear web assembly 634 has a longitudinal direction LwA that corresponds with a length direction Lwr of the wind turbine blade shell. The shear web assembly 634 has a width direction WwA that corresponds with a width direction Wwr of the wind turbine blade shell.

The shear web assembly 634 is arranged for joining with upper and lower spar caps of the wind turbine blade shell. Whilst not limited thereto, arranging the shear web assembly 634 for joining with upper and lower spar caps of the wind turbine blade shell 800 may, for example, be performed as described with respect to Figure 4.

In some examples, each sandwich panel 624, 625, 626 in the shear web assembly 634 has a length dimension Lp (which extends in the length direction LwA) and a width dimension Wp (which extends in the width direction WwA). In some examples, one or more of the sandwich panels are rectangular. In some examples, one or more of the sandwich panels has an angled or tapered top and/or bottom edge that extends in the longitudinal direction LwA, to account for a corresponding tapering width Wwf along the length of the wind turbine blade shell 800.

In some examples, at least one of the sandwich panel sections 624, 625, 626 has a length Lp and/or width Wp dimension that differs from a respective length Lp and/or width Wp dimension of another at least one sandwich panel section 624, 625, 626 in the shear web assembly 634.

Figure 12 schematically illustrates how a sequence of sandwich panel sections may be prepared for joining into a shear web assembly, for insertion in to a wind turbine blade shell.

A length of sandwich panel that has been produced in the continuous manner is schematically shown in plan view at 601. The length direction of the sandwich panel is shown at [WA and the width direction of the sandwich panel is shown at WwA. To aid explanation, an outline of a wind turbine blade shell 800 is schematically shown, in an underlaid fashion. The length direction of the wind turbine blade shell is shown at Lw-r and the width direction of the wind turbine blade shell is shown at \NWT. A root end of the wind turbine blade shell is shown at 802 and a tip end of the blade shell is shown at 804. The shear web assembly 634 has a corresponding root end portion 633 configured to be fitted to the root end 802 of the blade shell and a tip end portion 635 configured to be fitted to the tip end 804 of the blade shell.

Each sandwich panel section (e.g. sandwich panel sections 624, 625, 626 and so on) may be supplied to the shear web assembly station 700 in a supply direction schematically shown as Dsup in Figure 12.

When forming the root end portion 633 of the shear web assembly 634, at least one sandwich panel section at the root end portion 633 is aligned with the supply direction Dsup.

That is, when in the shear web assembly 634 it may be considered that a sandwich panel section at the root end portion 633 has a length dimension that is oriented perpendicular to the longitudinal direction of the shear web assembly and of the wind turbine blade.

When forming the tip end portion 635 of the shear web assembly 634, at least one sandwich panel section at the tip end portion 635 is rotated through 90 degrees relative to the supply direction Dsup. Then, when in the shear web assembly 634 it may be considered that such a sandwich panel section at the tip end portion 635 has a length dimension that is oriented parallel to the longitudinal direction of the shear web assembly and of the wind turbine blade.

As noted above, the outer skins 608 and 610 may comprise a multi-axial material.

According to examples, the multi-axial material is laid on the foam core 602 at an orientation such that each sandwich panel can be rotated through 90 degrees whilst maintaining shear strength properties of the shear web assembly 634.

Cutting the continuously formed sandwich panel 601 at step (b) provides a sequence or series of cut sandwich panel sections. In some examples, a sandwich panel section may itself be cut into two or more further sandwich panel sections, as mentioned above.

As shown in Figure 12, the continuously formed sandwich panel 601 may first be cut at point C, to provide sandwich panel section 624. The offcut section or part of the offcut section may then be used as another sandwich panel section 625 in the shear web assembly 634. For the purpose of explanation, in this instance the sandwich panel section 624 may be considered a first sandwich panel section and the sandwich panel section 625 may be considered a second sandwich panel section. Dependent on the dimensions of the cut sandwich panel sections and dimensions of the blade shell the method may comprise either of: installing the first and second sandwich panel sections adjacent to each other in the shear web assembly; (ii) installing the first and second sandwich panel sections in the shear web assembly in a manner such that the first and second sandwich panel sections are not adjacent to each other in the shear web assembly.

In some examples, when forming the tip end portion 635 of the shear web assembly 634, after the rotation of the sandwich panel section a side part or edge of a first tip panel section can be cut generally in the longitudinal direction of the blade, and the cut-off portion can be used for an adjacent or non-adjacent second tip panel section. This is shown schematically in Figure 12, where at tip end portion 635 sandwich panel sections 629 and 631 are formed from sandwich panel 627 which has been cut in the longitudinal direction of the blade shell 800.

This efficiently utilises the produced sandwich panel 601 and minimises wastage.

It will also be understood that the disclosed method enables the continuously produced sandwich panel 601 to be treated as a commodity which can be produced and cut on-site, as required. The disclosed method therefore obviates or mitigates a requirement for sandwich panels to have to be produced off-site, then supplied in a kitted form specific for particular wind turbine blades.

The examples described herein are to be understood as illustrative examples of embodiments of the invention. Further embodiments and examples are envisaged. Any feature described in relation to any one example or embodiment may be used alone or in combination with other features. In addition, any feature described in relation to any one example or embodiment may also be used in combination with one or more features of any other of the examples or embodiments, or any combination of any other of the examples or embodiments. For example, one or more features of the examples described with respect to Figures 11 and 12 may be combined with one or more features of the examples described with respect to Figures 3 to 10. For example, sandwich panels produced in the continuous manner as shown in steps (a) and (b) of Figure 11 may be attached to a wind turbine blade shell as shown in steps (b) to (g) of Figure 3 and Figures 4 to 10.

Various modifications to the preferred embodiments of the present invention, as defined by the appended claims, will be apparent to those skilled in the art.

Claims

Claims 1. A method of installing a shear web assembly into a wind turbine blade shell, comprising the steps of: (a) providing a plurality of sandwich panels; (b) connecting the plurality of sandwich panels to each other at lateral edges of adjacent sandwich panels, to form a sandwich panel assembly comprising an elongate series of the sandwich panels; (c) providing at least one top connector along at least a portion of a top edge of the sandwich panel assembly; (d) providing at least one bottom connector along at least a portion of a bottom edge of the sandwich panel assembly; (e) providing at least one upper connector that extends longitudinally on an upper spar cap in an upper portion of the blade shell; (f) providing at least one lower connector that extends longitudinally on a lower spar cap in a lower portion of the blade shell; (g) locating the sandwich panel assembly into the wind turbine blade shell, the sandwich panel assembly having a length which corresponds to a length, in a longitudinal direction, of the wind turbine blade shell and the sandwich panel assembly being aligned along the longitudinal direction of the wind turbine blade shell, so that the at least one top connector of the sandwich panel assembly locates in the upper connector on the upper spar cap and the at least one bottom connector of the sandwich panel assembly locates in the at least one lower connector of the lower spar cap.
2. A method according to claim 1, wherein the at least one top connector on the sandwich panel assembly comprises a concave profile, and the at least one upper connector on the upper spar cap comprises a convex profile, wherein the concave profile of the at least one top connector on the sandwich panel assembly is configured to guide and receive the convex profile of the at least one upper connector on the upper spar cap during the process of locating the sandwich panel assembly in the blade shell.
3. A method according to claim 2, wherein the at least one top connector defines a top longitudinally extending elongate channel and the at least one upper connector comprises an upper longitudinally extending elongate member which is received in the top longitudinally extending elongate channel.
4. A method according to claim 3, wherein the top longitudinally extending elongate channel forms an elongate reservoir for containing an adhesive therein, wherein during step (g) of locating the sandwich panel assembly in the blade shell, the at least one upper connector on the upper spar cap displaces the adhesive up an inner edge of the longitudinally extending elongate channel to provide an increased adhesive interface area between the at least one top connector on the sandwich panel assembly and the at least one upper connector on the upper spar cap.
S. A method according to any of claims 1 to 4, wherein the at least one bottom connector on the sandwich panel assembly comprises a convex profile, and the at least one lower connector on the lower spar cap comprises a concave profile, wherein the concave profile of the at least one lower connector on the lower spar cap is configured to guide and receive the convex profile of the at least one bottom connector on the sandwich panel assembly during the process of locating the sandwich panel assembly in the blade shell.
6. A method according to claim 5, wherein the at least one lower connector on the lower spar cap defines a lower longitudinally extending elongate channel and the at least one bottom connector comprises a bottom longitudinally extending elongate member which is received in the lower longitudinally extending elongate channel.
7. A method according to claim 5 or claim 6, wherein the lower longitudinally extending elongate channel forms an elongate reservoir for containing an adhesive therein, wherein during step (g) of locating the sandwich panel assembly in the blade shell, the at least one bottom connector on the bottom edge of the sandwich panel assembly displaces the adhesive up an inner edge of the lower longitudinally extending elongate channel to provide an increased adhesive interface area between the at least one bottom connector on the sandwich panel assembly and the at least one lower connector on the lower spar cap.
8. A method according to any of claims 1 to 7, wherein the at least one top connector on the sandwich panel assembly comprises at least first and second top connectors adjacent each other, there being a longitudinal upper spacing between the first and second top connectors.
9. A method according to any of claims 1 to 8, wherein the at least one bottom connector on the sandwich panel assembly comprises at least first and second bottom connectors adjacent each other, there being a longitudinal lower spacing between the first and second bottom connectors.
10. A method according to any of claims 1 to 9 wherein step (b) comprises connecting adjacent sandwich panels to each other with at least one elongate coupling member that contacts and extends along the lateral edges of the adjacent sandwich panels, wherein the at least one elongate coupling member has first and second opposite sides which are configured to mate with the lateral edge of respective first and second sandwich panels.
11. A method according to claim 10, wherein the method further comprises step (h), which is carried out before step (b), of cutting into the lateral edges of the sandwich panels an elongate groove which extends at least partly along the lateral edges of the sandwich panels, the elongate groove being located between a pair of elongate edge parts of the respective lateral edge, and wherein each of the first and second opposite sides of the coupling member comprises a pair of elongate recesses on opposite sides of a central reinforcement portion that extends longitudinally along the at least one coupling member, and the method further comprises step (i), which is carried out after step (h) and before step (b), of disposing an adhesive in the elongate recesses and/or the elongate grooves, pressing the pair of elongate edge parts of a first of the adjacent sandwich panels into the elongate recesses on the first side of the coupling member and simultaneously pressing the central reinforcement portion on the first side of the coupling member into the elongate groove of the first sandwich panel and pressing the pair of elongate edge parts of a second of the adjacent sandwich panels in to the elongate recesses on the second side of the coupling member and simultaneously pressing the central reinforcement portion on the second side of the coupling member into the elongate groove of the second sandwich panel.
12. A method according to claim 10 or claim 11, wherein the at least one elongate coupling member comprises first and second elongate coupling members which are laterally aligned along common edges of the first and second sandwich panels and connect together the adjacent first and second sandwich panels, the first and second coupling members being mutually spaced to provide a laterally extending spacing between the first and second coupling members.
13. A method according to any of claims 1 to 12, wherein in step (b) the plurality of sandwich panels are connected to each other by bonding, on at least one or both faces of the sandwich panel assembly, a fibre reinforced resin matrix composite layer to an interface region comprised of opposed lateral edges of adjacent sandwich panels.
14. A method according to claim 13, wherein the fibre reinforced resin matrix composite layer comprises a curable thermosetting resin.
15. A method according to claim 14, wherein the curable thermosetting resin is curable by UV light and step (b) further comprises applying UV light to the curable thermosetting resin to cure the resin.
16. A wind turbine blade shell assembly comprising: an upper portion of the blade shell; a lower portion of the blade shell; a shear web assembly, wherein the shear web assembly comprises: a plurality of sandwich panels, wherein the plurality of sandwich panels are connected to each other at lateral edges of adjacent sandwich panels, to form a sandwich panel assembly comprising an elongate series of the sandwich panels; at least one top connector positioned along at least a portion of a top edge of the sandwich panel assembly; at least one bottom connector positioned along at least a portion of a bottom edge of the sandwich panel assembly; at least one upper connector that extends longitudinally on an upper spar cap in the upper portion of the blade shell; at least one lower connector that extends longitudinally on a lower spar cap in the lower portion of the blade shell; wherein the sandwich panel assembly has a length which corresponds to a length, in a longitudinal direction, of the wind turbine blade shell and the sandwich panel assembly is aligned along the longitudinal direction of the wind turbine blade shell, and wherein the at least one top connector of the sandwich panel is located in the upper connector on the upper spar cap and the at least one bottom connector of the sandwich panel assembly is located in the at least one lower connector of the lower spar cap.
17. A wind turbine blade shell according to claim 16, wherein the at least one top connector on the sandwich panel assembly comprises a concave profile, and the at least one upper connector on the upper spar cap comprises a convex profile, wherein the concave profile of the at least one top connector on the sandwich panel assembly is shaped to guide and receive the convex profile of the at least one upper connector on the upper spar cap.
18. A wind turbine blade shell according to claim 17, wherein the at least one top connector defines a top longitudinally extending elongate channel and the at least one upper connector comprises an upper longitudinally extending elongate member which is received in the top longitudinally extending elongate channel.
19. A wind turbine blade shell according to claim 18, wherein the at least one top longitudinally extending elongate channel forms an elongate reservoir containing an adhesive which extends up an inner edge of the top longitudinally extending elongate channel and adheres the at least one top connector of the sandwich panel assembly to the at least one upper connector on the upper spar cap.
20. A wind turbine blade shell according to any of claims 16 to 19, wherein the at least one bottom connector on the sandwich panel assembly comprises a convex profile, and the at least one lower connector on the lower spar cap comprises a concave profile, wherein the concave profile of the at least one lower connector on the lower spar cap is shaped to guide and receive the at least one bottom connector on the sandwich panel assembly.
21. A wind turbine blade shell according to claim 20, wherein the at least one lower connector on the lower spar cap defines a lower longitudinally extending elongate channel and the at least one bottom connector comprises a bottom longitudinally extending elongate member which is received in the lower longitudinally extending elongate channel.
22. A wind turbine blade shell according to claim 21, wherein the lower longitudinally extending elongate channel forms an elongate reservoir containing an adhesive which extends up an inner edge of the lower longitudinally extending elongate channel and adheres the at least one bottom connector of the sandwich panel assembly to the at least one lower connector on the lower spar cap.
23. A wind turbine blade shell according to any of claims 16 to 22, wherein the at least one top connector on the sandwich panel assembly comprises at least first and second top connectors adjacent each other, there being a longitudinal upper spacing between the first and second top connectors.
24. A wind turbine blade shell according to any of claims 16 to 23, wherein the at least one bottom connector on the sandwich panel assembly comprises at least first and second bottom connectors adjacent each other, there being a longitudinal bottom spacing between the first and second bottom connectors.
25. A wind turbine blade shell according to any of claims 16 to 24, wherein adjacent sandwich panels are connected to each other with at least one elongate coupling member that contacts and extends along the lateral edges of the adjacent sandwich panels, wherein the at least one elongate coupling member has first and second opposite sides which are configured to mate with the lateral edge of respective first and second sandwich panels.
26. A wind turbine blade shell according to claim 25, wherein the lateral edges of the sandwich panels comprise an elongate groove which extends at least partly along the lateral edges of the sandwich panels, the elongate groove being located between a pair of elongate edge parts of the respective lateral edge, and each of the first and second opposite sides of the at least one coupling member comprises a pair of elongate recesses on opposite sides of a central reinforcement portion that extends longitudinally along the at least one coupling member, there being an adhesive disposed in the elongate recesses and/or the elongate grooves, wherein the pair of elongate edge parts of a first of the adjacent sandwich panels are located in the elongate recesses on the first side of the coupling member and the pair of elongate edge parts of a second of the adjacent sandwich panels are located in the elongate recesses on the second side of the coupling member.
27. A wind turbine blade shell according to claim 25 or claim 26, wherein the at least one elongate coupling member comprises first and second elongate coupling members which are laterally aligned along common edges of the first and second sandwich panels and connect together the adjacent first and second sandwich panels, the first and second coupling members being mutually spaced to provide a laterally extending spacing between the first and second coupling members.
28. A wind turbine blade shell according to any of claims 16 to 27, comprising an interface region composed of opposed lateral edges of adjacent sandwich panels, there being a fibre reinforced resin matrix composite layer bonded to the interface region.
29. A wind turbine blade shell according to claim 28, wherein the fibre reinforced resin matrix composite layer comprises a curable thermosetting resin.
30. A method of manufacturing a shear web assembly for a wind turbine blade shell, the method comprising the steps of: (a) production of a sandwich panel in a continuous manner; (b) cutting of the sandwich panel to form a plurality of sandwich panel sections; (c) joining of the sandwich panel sections in series to form a shear web assembly at a shear web assembly station prior to locating the shear web assembly in the wind turbine blade shell, wherein the shear web assembly has a longitudinal direction that corresponds with a length direction of the wind turbine blade shell and a width direction that corresponds with a width direction of the wind turbine blade shell, wherein the shear web assembly is arranged for joining with upper and lower spar caps of the wind turbine blade shell.
31. A method according to claim 30, wherein each of the plurality of sandwich panel sections comprises a length dimension and a width dimension.
32. A method according to claim 31, wherein at least one of the sandwich panel sections has a length and/or width dimension that varies from a respective length and/or width of another at least one sandwich panel section in the shear web assembly.
33. A method according to any of claims 30 to 32, wherein the shear web assembly has a tip end portion configured to be fitted at a tip portion of the wind turbine blade shell and a root end portion configured to be fitted to a root portion of the wind turbine blade shell, wherein the root end portion has a greater width than the tip end portion.
34. A method according to claim 33, wherein each sandwich panel section is supplied to the shear web assembly station in a supply direction, and in forming the tip end portion of the shear web assembly at least one sandwich panel is rotated through 90 degrees relative to the supply direction, and in forming the root end portion at least one sandwich panel is aligned with the sandwich panel supply direction.
35. A method according to claim 34, wherein the supply direction to the assembly station is parallel to a direction in which the sandwich panel is continuously formed.
36. A method according to any of claims 30 to 35, comprising cutting at least one of the sandwich panel sections into at least first and second sandwich panel sections.
37. A method according to claim 36, wherein the method comprises installing the first and second sandwich panel sections adjacent to each other in the shear web assembly.
38. A method according to claim 36, wherein the method comprises installing the first and second sandwich panel sections in the shear web assembly in a manner such that the first and second sandwich panel sections are not adjacent to each other in the shear web assembly.
39. A method according to any of claims 30 to 38, wherein the production of a sandwich panel in a continuous manner comprises extruding a foam core from an extruder, and bonding first and second outer skins to the foam core, downstream of the extruder.
40. A method according to claim 39, wherein the first and second outer skins comprise a multi-axial material.
41. A method according to claim 40, wherein the multi-axial material comprises a bi-axial material.
42. A method according to claim 40 or claim 41, wherein the multi-axial material is laid on the foam core at an orientation such that each sandwich panel can be rotated through 90 degrees whilst maintaining shear strength properties of the shear web assembly.