Fixation for a wind turbine blade to the hub

Abstract

The blade root or the internal structure of the blade comprise joining elements for joining to the hub disposed between lamination sheets, consisting of a plurality of inserts, designed to receive a fixing element related to the hub, which facilitate the coupling of the blade to the wind turbine hub. It incorporates fibre bands of compact, elongated and enveloping configuration which grip the inserts configuring assemblies embedded between the lamination sheets, wherein the fibre bands guarantee the progressive progression of stresses between blade and hub.

Claims

1. A wind turbine blade comprising: a blade root formed by lamination sheets, joining elements comprising: a plurality of inserts wherein each one of said inserts comprises: at least one elongated body provided with at least one longitudinal bore provided with one opening, a gripping sector, fibre bands of compact, elongated and enveloping configuration which grip the inserts, said fibre bands comprising: an upper section, a lower section, a joining section located between the lower and upper section which grips the gripping sector of the insert, wherein the fibre bands additionally grip, between the upper section and the lower section, at least one of said lamination sheets.

2. The wind turbine blade of claim 1, further comprising insertion blocks situated between the inserts which give continuity to the inserts and to the fibre bands.

3. The wind turbine blade of claim 1 wherein the inserts are each all first inserts disposed parallel with respect to the blade root, wherein the elongated body is single, the bore is a blind threaded bore, and the gripping sector is formed by a handle defined in a side of the elongated body opposite the opening of the threaded bore.

4. The wind turbine blade of claim 1 wherein the inserts are each all second inserts disposed parallel with respect to the blade root, wherein the elongated body is single, the bore is a blind threaded bore, the gripping sector is formed by lateral extensions which perpendicularly extend on both sides of the elongated body.

5. The wind turbine blade of claim 1 wherein the inserts are each all third inserts disposed transversally to the blade root comprising elongated bodies formed by separate bushings opposed at their ends, wherein the bores are through-bores and the gripping sector is formed by a cylindrical outer surface of said bodies.

6. A wind turbine blade comprising: a blade root an internal structure, formed by lamination sheets joining elements comprising: a plurality of inserts wherein each one of said inserts comprising: at least one elongated body provided with at least one longitudinal bore provided with one opening, and a gripping sector, fibre bands of compact, elongated and enveloping configuration which grip the inserts, said fibre bands comprising: an upper section, a lower section, a joining section located between the lower and upper section which grips the gripping sector of the insert, wherein the fibre bands additionally grip, between the upper section and the lower section, at least one of said lamination sheets.

7. The wind turbine blade of claim 6, further comprising insertion blocks situated between the inserts which give continuity to the inserts and to the fibre bands.

8. The wind turbine blade of claim 6 wherein the inserts are each all first inserts disposed parallel with respect to the internal structure, wherein the elongated body is single, the bore is a blind threaded bore and the gripping sector is formed by a handle defined in a side of the elongated body opposite the opening of the threaded bore.

9. The wind turbine blade of claim 6 wherein the inserts are each all second inserts disposed parallel with respect to the internal structure, wherein the elongated body is single, the bore is a blind threaded bore, and the gripping sector is formed by lateral extensions which perpendicularly extend on both sides of the elongated body.

10. The wind turbine blade of claim 6 wherein the inserts are each all third inserts disposed transversally to the internal structure comprising elongated bodies formed by separate bushings opposed at their ends, wherein the bores are through-bores and the gripping sector is formed by a cylindrical outer surface of said bodies.

Description

DESCRIPTION OF THE DRAWINGS

(1) To complement the description being made and in order to aid towards a better understanding of the characteristics of the invention, in accordance with a preferred example of practical embodiment thereof, a set of drawings is attached as an integral part of said description wherein, with illustrative and non-limiting character, the following has been represented:

(2) FIG. 1.—Shows a perspective view of a detail of the root of a blade wherein the inserts are situated, configured according to a first embodiment of the insert, with the inserts spaced, in longitudinal disposal and gripped by the fibre bands between a lower sheet and upper laminated sheet.

(3) FIG. 2.—Shows a view of the embodiment of the insert of the previous figure gripped by the fibre band.

(4) FIG. 3.—Shows a perspective view of only the insert of the previous figures.

(5) FIG. 4.—Shows a perspective view of a second embodiment of the joining insert.

(6) FIG. 5.—Shows a view of the second embodiment representing the insert with the fibre band gripping the lateral gripping sectors.

(7) FIG. 6.—Shows a perspective view of a detail of the root of a blade wherein the inserts configured according to the second embodiment are located, wherein insertion blocks situated between inserts have also been represented.

(8) FIG. 7.—Shows an enlarged detail of the previous figure.

(9) FIG. 8.—Shows a view similar to that of FIG. 1 wherein, unlike the former, the insertion blocks have been incorporated between inserts.

(10) FIG. 9.—Shows a perspective view of a detail of the root of a blade wherein the inserts configured according to a third embodiment are located, where the insert appears in transversal disposal with respect to the longitudinal shaft of the blade.

(11) FIG. 10.—Shows a view similar to that of the previous figure wherein the upper laminated sheet has been partially eliminated for a better view of the fibre bands which grip the inserts.

(12) FIG. 11.—Shows a perspective view of the third embodiment, wherein the fibre band gripping the bushings which form the insert is observed, with the pin introduced in said bushings.

(13) FIG. 12.—Shows a detailed view of FIG. 11 according to section A-A.

(14) FIG. 13.—Shows a perspective view wherein the root of the blade and the internal structure or core of the blade is observed, wherein the third embodiment of the insert has been incorporated with the fibre band gripping the end of the internal structure of the blade.

(15) FIG. 14.—Shows a perspective view wherein the root of the blade and the internal structure or core of the blade is observed, wherein the third embodiment of the insert has been represented with the fibre bands between different sheets of the internal structure of the blade.

PREFERRED EMBODIMENT OF THE INVENTION

(16) In light of figures, a series of preferred embodiments of the wind turbine blade object of this invention is described.

(17) The blade incorporates an aerodynamic portion, not represented in the figures, a root (1) which can be observed in FIGS. 1 and 6 to 10 adapted for its coupling to the wind turbine hub, which has not been represented either, and an internal structure (17) or stiffening core of the blade which is only shown in FIGS. 13 and 14.

(18) According to the invention, in a first solution it has been provided that the joining means for joining the blade to the hub are associated to the external covering of the root (1), and in a second solution that the joining means are associated to the internal structure (17) of the blade.

(19) The root (1) comprises an external covering which also comprises lamination sheets (2, 3), which are represented in FIGS. 1 and 6 to 10, wherebetween the joining means are found.

(20) The joining means proposed in this invention are designed to be embedded between lamination sheets (2, 3, 18, 19) which form part of the blade, as can be observed in FIGS. 1 and 14, for example, and comprise a plurality of inserts (4.1, 4.2, 4.3), wherein each one of said inserts (4.1, 4.2, 4.3) comprise at least one elongated body (5.1, 5.2, 5.3) which is provided with at least one longitudinal bore (6.1, 6.2, 6.3) which is designed to receive a fixing element related to the hub, which facilitate the coupling between the blade and the wind turbine hub.

(21) Unlike other solutions, the joining means also comprise fibre bands (7) of compact, elongated and enveloping configuration, as observed, for example, in FIGS. 2, 5 and 11, which grip the inserts (4.1, 4.2, 4.3) by a gripping sector (8.1, 8.2, 8.3) defined in the inserts (4.1, 4.2, 4.3).

(22) The fibre band (7), as observed in FIGS. 2, 5 and 11 is defined by an upper section (10), a lower section (11) and a joining section (12) which joins both upper (10) and lower (11) sections, normally curved, wherein the lower (11) and upper (10) sections start from a common or rear side of the fibre band (7) until the opposite or front side wherein the joining section (12) is found, which constitutes the section of the fibre band (7) which grips the gripping sector (8.1, 8.2, 8.3) of the insert (4.1, 4.2, 4.3).

(23) FIGS. 2, 5 and 11 show that the joining means additionally comprise at least one intermediate block (9) for each fibre band (7), which is intercalated within the fibre band (7) between the upper section (10) and the lower section (11). Said intermediate block (9) has in this case a wedge shape.

(24) In an alternative embodiment the joining means lack said intermediate block (9) and the fibre bands (7) directly grip, between the upper section (10) and the lower section (11), the ends of at least one of the lamination sheets, as occurs in FIG. 13 for example, wherein the fibre bands (7) grip the lamination sheet (19) between the upper section (10) and the lower section (11), or in the case of FIG. 10 wherein fibre bands grip the lamination sheet (2) between the upper section (10) and the lower section (11).

(25) As observed in FIGS. 6, 7 and 8, the blade root (1) can also incorporate insertion blocks (13) situated between the inserts (4.1, 4.2, 4.3) which give continuity to the inserts (4.1, 4.2, 4.3) and to the fibre bands, and facilitate the transmission of transversal loads.

(26) In the figures three alternative solutions have been represented of inserts (4.1, 4.2, 4.3) with their particular configuration adapted to facilitate the coupling of the fixing element which connects the hub to the blade root (1).

(27) In the case of FIGS. 1 to 3 and 8, the first embodiment of insert (4.1) is observed comprising a single elongated body (5.1), wherein the bore (6.1) is a blind threaded bore and the gripping sector (8.1) whereof consists of a handle defined in the side of the body (5.1) opposite the opening of the threaded bore (6.1). In this case the fixing element is a screw, not represented, designed to thread in the threaded bore (6.1). On the other hand, FIG. 2 shows that the fibre band (7) which grips this insert (4.1) extends with progressively increasing width towards its rear side, in the same way as the intermediate block (9).

(28) In the case of FIGS. 4 to 7, the second embodiment of insert (4.2) is observed comprising a single elongated body (5.2), wherein the bore (6.2) is a blind threaded bore and the gripping sector (8.2) consists of different lateral extensions which perpendicularly extend on both sides of the body (5.2). In this case the fixing element is also a screw, not represented, designed to thread in the threaded bore (6.2). For this insert (4.2), in FIG. 5 the possibility has been represented that the fibre band (7) extends around intermediate block (9) divided in two sectors, one for each gripping sector (8.2), sectors which are connected in the rear side of the fibre band (7), distant from the insert (4.2).

(29) In the case of FIGS. 9 to 11, the third embodiment of the insert (4.3) is observed comprising different bodies (5.3) consisting of bushings opposing by one of their ends, which are disposed transversally to the longitudinal shaft of the blade root (1), as observed in said figures, wherein each one of said bushings has a bore (6.3) opposite that of the other bushing, as observed in FIG. 12, and the gripping sector (8.3) is formed by the cylindrical outer surface of said bodies (5.3). In this case the fixing element consists of a pin (15).

(30) As observed in FIG. 11, a central opening (16) is defined in the fibre band (7) and in the intermediate block (9) located between the bodies (5.3) which is designed for example to incorporate a lug of the hub, not represented, which would be connected to the insert (8.3), after penetrating between the bodies (5.3) in said central opening (16) and after the later insertion of the pin (15) which would traverse the bodies (5.3) and the opening of the lug.

(31) FIGS. 13 and 14 represent the end of the internal structure (17) of the blade which is observed in correspondence with the blade root, the internal structure (17), instead of the covering of the root (1), being responsible for establishing the connection of the blade to the hub.

(32) Likewise, said figures show the fibre bands (7) which grip the inserts (4.3) and which are disposed, in the case of FIG. 13, gripping the lamination sheet (19) which forms part of the internal structure (17), or in the case of FIG. 14 they are situated between lamination sheets (18,19) gripping an intermediate block (9).

(33) Although FIGS. 13 and 14 have only represented the joining system with the insert (4.3), any of the previously shown solutions with the inserts (4.1, 4.2) can be equally valid for the internal structure (17).