Connection of a rotor blade to the rotor hub of a wind turbine

Abstract

A rotor blade for a wind turbine, to a rotor for a wind turbine, to a wind turbine, to a method for producing a rotor blade, to a method for connecting a rotor blade to a rotor hub and to a method for repairing a rotor of a wind turbine. The rotor blade has a connection interface, the connection interface having at least one cutout for receiving a tension element for connecting the rotor blade to a further element of a wind turbine, an outer circumferential surface of the cutout being formed of a connection material and having an internal thread.

Claims

1. An assembled rotor blade, comprising: a first rotor blade segment made of a rotor blade material; and a second rotor blade segment made of the rotor blade material, the first rotor blade segment comprising a connection interface having a cutout for receiving a tension element for connecting the first rotor blade segment to the second rotor blade segment, the cutout being formed in the rotor blade material and having an internal thread; the second rotor blade segment comprising a connection interface having a cutout for receiving a tension element for connecting the second rotor blade segment to the first rotor blade segment, the cutout being formed in the rotor blade material and having an internal thread; a first tension element received in the cutout of the first rotor blade segment and anchored in the second rotor blade segment; and a second tension element received in the cutout of the second rotor blade segment and anchored in the first rotor blade segment.

2. The assembled rotor blade as claimed in claim 1, wherein at least one of the cutouts of the first and second rotor blade segments is a blind hole.

3. The assembled rotor blade as claimed in claim 1, wherein at least one of the cutouts of the first and second rotor blade segments has a depth that is a multiple of a diameter of the respective cutout.

4. The assembled rotor blade as claimed in claim 3, wherein at least one of the cutouts of the first and second rotor blade segments has a depth that corresponds to at least three times the diameter of the respective cutout.

5. The assembled rotor blade as claimed in claim 1, wherein the rotor blade material is a fiber-reinforced composite material.

6. The assembled rotor blade as claimed in claim 5, wherein the fiber-reinforced composite material is a fiber-plastic composite material or a glass-fiber-reinforced epoxy resin composite material.

7. The assembled rotor blade as claimed in claim 1, wherein the rotor blade material has a stiffness that is lower than a stiffness of a material of the tension element of the first and second rotor blade segments, wherein an elastic modulus or a shear modulus of the rotor blade material and the material of the tension element of the first and second rotor blade segments are used as a measure of the stiffness.

8. The assembled rotor blade as claimed in claim 1, wherein the rotor blade material has a stiffness that is many times lower than a stiffness of a material of the tension element of the first and second rotor blade segments, wherein an elastic modulus or a shear modulus of the rotor blade material and the material of the tension element of the first and second rotor blade segments are used as a measure of the stiffness.

9. The assembled rotor blade as claimed in claim 1, wherein the connection interfaces of the first and second rotor blade segments have a plurality of cutouts.

10. A rotor for a wind turbine, comprising: a rotor hub and at least one rotor blade fastened to the rotor hub, wherein the at least one rotor blade is the assembled rotor blade as claimed in claim 1.

11. The rotor as claimed in claim 10, wherein the first and second tension elements are adhesively bonded in the respective cutouts.

12. A wind turbine, comprising: a tower; and a nacelle arranged on the tower, the nacelle having the rotor as claimed in claim 10.

13. A method for repairing the rotor of the wind turbine as claimed in claim 10, comprising: releasing a third tension element from a third cutout of a connection of the at least one rotor blade to the rotor hub, enlarging the third cutout to a larger diameter and forming an internal thread, and fastening the rotor blade to the rotor hub by screwing a tension element with a larger diameter into the third cutout.

14. A method comprising: assembling the rotor blade as claimed in claim 1, the assembling comprising: forming the first rotor blade segment with the connection interface, forming the cutout in the connection interface of the first rotor blade segment by drilling and forming the internal thread, forming the second rotor blade segment with the connection interface, and forming the cutout in the connection interface of the second rotor blade segment by drilling and forming the internal thread.

15. A method, comprising: connecting the assembled rotor blade as claimed in claim 1 to a rotor hub.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

(1) Preferred embodiments of the invention will be described by way of example on the basis of the appended figures. In the figures:

(2) FIG. 1 shows a schematic illustration of a wind turbine having a rotor blade according to the invention;

(3) FIG. 2 shows a schematic illustration of a detail of an embodiment of a rotor blade having a connection interface with a plurality of cutouts, into which cutouts a respective tension element has been introduced;

(4) FIG. 3 shows a schematic longitudinal section through a cutout in a connection interface with tension element introduced;

(5) FIG. 4 shows a schematic longitudinal section through a cutout in a connection interface; and

(6) FIG. 5 shows an enlarged detail from an example of an assembled rotor blade.

DETAILED DESCRIPTION

(7) FIG. 1 shows a schematic illustration of a wind turbine according to the invention. The wind turbine 100 has a tower 102 and a nacelle 104 on the tower 102. On the nacelle 104 there is provided an aerodynamic rotor 106 with three rotor blades 108 and a spinner 110. When the wind turbine is in operation, the aerodynamic rotor 106 is set in rotation by the wind and thus also turns an electrodynamic rotor of a generator, which is coupled directly or indirectly to the aerodynamic rotor 106. The electric generator is arranged in the nacelle 104 and generates electrical energy. The pitch angles of the rotor blades 108 can be changed by pitch motors of the respective rotor blades 108. The rotor blades 108 are fastened by means of the solution described here.

(8) FIG. 2 shows a schematic illustration of a detail of an embodiment of a rotor blade 200 having a connection interface 210 with a plurality of cutouts 211, into which cutouts a respective tension element 220 has been introduced. The outer circumferential surface of the respective cutouts 211 is formed by the connection material. The openings of the cutouts 211 lie in the end surface 212 of the connection interface 210. The diameter of the cutout 211 preferably corresponds to approximately a third, preferably about 10 to 50%, in particular about 20 to 40%, of the extent D.sub.F of the connection interface 210 orthogonal to a longitudinal axis of the cutout 211 and/or of the rotor blade 200.

(9) FIG. 3 shows a schematic longitudinal section through a cutout 311 in a connection interface 310 with tension element 320 introduced, said tension element having a diameter D and a total length which consists of the length L.sub.B1 of that part which is received in the cutout 311 and of the length L.sub.B2 of that part which protrudes out of the cutout 311. The outer circumferential surface of the cutout 311 is formed by the connection material. The cutout 311 is configured in the form of a blind hole, and the opening lies in the end surface 312 of the connection interface 310. Adhesive material 330 is introduced into the cutout.

(10) The cutout 311 is of substantially cylindrical configuration and has a substantially cylindrical shaft part 311a with a first diameter D.sub.B and has a widened head part 311b, which adjoins the opening, with a second diameter D.sub.E, the second diameter D.sub.E being larger than the first diameter D.sub.B. In the longitudinal direction of the cutout, the shaft part 311a is many times longer than the head part 311b with a length L.sub.E. Overall, the cutout 311 has a basic length L.sub.G and a total length L.sub.B. Said longitudinal extent of the cutout 311 along the longitudinal axis is longer than the length L.sub.B1 of that part of the tension element 320 which is to be received therein, and corresponds to a multiple of the diameter D.sub.B of the cutout 311. The diameter D.sub.B of the cutout 311 preferably corresponds to approximately a third, preferably about 10 to 50%, in particular about 20 to 40%, of the extent D.sub.F of the connection interface 310 orthogonal to a longitudinal axis of the cutout 311 and/or of the rotor blade.

(11) Embodiments with multi-row connections can also be preferred.

(12) The tension element 320 received in the cutout 311 has an external thread, the internal thread of the cutout 311 and the external thread of the tension element 320 being configured to engage with one another.

(13) FIG. 4 shows a schematic longitudinal section through a cutout 411 in a connection interface 410. The outer circumferential surface of the cutout 411 is formed by the connection material. The cutout 411 is configured in the form of a blind hole, and the opening lies in the end surface 412 of the connection interface 410. The cutout 411 is of substantially cylindrical configuration and has a substantially cylindrical shaft part 411a with a first diameter D.sub.B and has a widened head part 411b, which adjoins the opening, with a second diameter D.sub.E, the second diameter D.sub.E being larger than the first diameter D.sub.B. A transition portion 411c is configured between the widened head part 411b and the shaft part 411a, said portion preferably having an angle of inclination α of 30 to 60°, in particular of 45°. An end portion 411d is configured at the closed end of the blind hole, said portion preferably having an angle of inclination β of 60 to 120°. The shaft part 411a has an internal thread 413 which is cut directly into the connection material.

(14) In the longitudinal direction of the cutout, the shaft part 411a with a length L.sub.V is many times longer than the head part 411b with a length L.sub.E. The longitudinal extent of the cutout 411 along the longitudinal axis corresponds to a multiple of the diameter D.sub.B of the cutout 311. The diameter D.sub.B of the cutout 311 preferably corresponds to approximately a third, preferably about 10 to 50%, in particular about 20 to 40%, of the extent D.sub.F of the connection interface 410 orthogonal to a longitudinal axis of the cutout 411 and/or of the rotor blade.

(15) The connection interfaces 210, 310, 410 preferably comprise a connection material which is identical to a rotor blade material. Further preferably, the connection interfaces 210, 310, 410 are each manufactured integrally with the rotor blade and/or are each configured in one piece with the rotor blade.

(16) The diameter D.sub.E is preferably approximately 1.25 times the diameter D.sub.B. Further preferably, the length D.sub.E is preferably approximately 1.5 times the diameter D.sub.B. Preferably, the length L.sub.V is approximately 6 times the diameter D.sub.B.

(17) FIG. 5 shows an enlarged detail from an example of an assembled rotor blade 1000 having a first rotor blade segment 1100 and a second rotor blade segment 1200. Both rotor blade segments 1100, 1200 are configured as described herein.

(18) The first rotor blade segment 1100 comprises a connection interface 1110 with a plurality of tension element anchors 1130 which comprise openings 1131. Anchoring elements 1132 which are configured in the form of D-bolts are arranged in the openings 1131 of the tension element anchors 1130. Cutouts for receiving tension elements are arranged in each case between the tension element anchors 1130. Said cutouts are not visible in FIG. 5, since it is not a sectional illustration. However, the cutouts are configured as described herein, and the outer circumferential surface of the cutouts is formed by the connection material of the connection interface 1110.

(19) The second rotor blade segment 1200 is constructed in a corresponding manner. The second rotor blade segment 1200 comprises a connection interface 1210 with a plurality of tension element anchors 1230 which comprise openings 1231. Anchoring elements 1232 which are configured in the form of D-bolts are arranged in the openings 1231 of the tension element anchors 1230. Cutouts for receiving tension elements are arranged in each case between the tension element anchors 1230. Said cutouts are not visible in FIG. 5, since it is not a sectional illustration. However, the cutouts are configured as described herein, and the outer circumferential surface of the cutouts is formed by the connection material of the connection interface 1200.

(20) The two end surfaces of the connection interfaces 1110, 1210 meet each other at the joint T.

(21) In the cutouts of the first rotor blade segment 1100, tension elements 1120 are introduced, which are anchored in the tension element anchors 1230 of the second rotor blade segment 1200. In the cutouts of the second rotor blade segment 1200, tension elements 1220 are introduced, which are anchored in the tension element anchors 1130 of the first rotor blade segment 1100. The introduction and anchoring of tension elements of the first and second rotor blade segments 1100, 1200 is thus effected alternately here, with other arrangements also being possible, however.

(22) Said connection of rotor blade segments of an assembled rotor blade saves a lot of weight and space, and makes it possible, for example, to arrange a multiplicity of tension elements in a confined space. Corresponding connections are possible not only between rotor blade segments but also, in principle, between a rotor blade and a further element of a wind turbine, such as, for example, a rotor blade hub and/or a rotor blade adapter.