ROTOR FOR A WIND TURBINE, AND METHOD

Abstract

A rotor for a wind turbine, to a rotor blade for a wind turbine, to a blade-fastening element for the fastening of a rotor blade, to a wind turbine, and to a method for mounting a rotor. A rotor for a wind turbine, comprising at least one rotor blade which extends from a blade tip to a face side, a hub having a blade-fastening element which, at the rotor-blade side thereof, has a blind hole for receiving a longitudinal bolt for the fastening of a rotor blade to the blade-fastening element, wherein the rotor blade has a fastening region which is of tubular form and which is arranged adjoining the face side, wherein the fastening region has at its outer circumferential surface and/or at its inner circumferential surface at least one thickened portion.

Claims

1. A rotor for a wind turbine, comprising: a rotor blade which extends from a blade tip to a face side, a hub having a blade-fastening element having a blind hole for receiving a longitudinal bolt for fastening the rotor blade to the blade-fastening element, wherein the rotor blade has a fastening region which is tubular shaped and arranged at the face side, wherein at least one surface chosen from an outer circumferential surface and an inner circumferential surface of the fastening region has at least one thickened portion, wherein a passage opening extends through the at least one thickened portion wherein the passage opening has first and second opposite ends, wherein the first end of the passage opening is arranged on the face side of the rotor blade, and wherein a longitudinal bolt is arranged in the blind hole and in the passage opening for fastening the rotor blade to the blade-fastening element.

2. The rotor as claimed in claim 1, wherein the fastening region has a tapering portion at a face side-averted side of the thickened portion, wherein the tapering portion tapers from the face side-facing end to a face side-averted end.

3. The rotor as claimed in claim 2, wherein the tapering portion has a fastening cutout extending from a first end to a second end.

4. The rotor as claimed in claim 3, wherein a surface normal of an opening cross section of a second end of the fastening cutout and a surface normal of an opening cross section of a first end of the fastening cutout include an angle.

5. The rotor as claimed in claim 3, wherein a diameter of the fastening cutout is greater than a diameter of the passage opening.

6. The rotor as claimed in claim 3, wherein a diameter of the fastening cutout is arranged and configured for receiving a counterpart element for connection to the longitudinal bolt.

7. The rotor as claimed in claim 2, wherein the thickened portion and the tapering portion are annular shaped.

8. The rotor as claimed in claim 1, wherein, on a bearing side, which is averted from the rotor-blade side, the blade-fastening element has a bearing groove with a groove width, a groove base surface, an outer groove side surface, an inner groove side surface, and a groove opening.

9. The rotor as claimed in claim 8, wherein: the groove base is spaced apart from a blind hole base in an axial direction, and/or a radial spacing between the outer groove side surface and a blind hole axis is at least two times smaller than the blind hole diameter, and/or a radial spacing between the inner groove side surface and a blind hole axis is at least two times smaller than the blind hole diameter, and/or a blind hole longitudinal axis intersects the groove base.

10. The rotor as claimed in claim 1, wherein: the rotor blade has in the fastening region a transverse bolt cutout which extends substantially radially with respect to a passage direction of the fastening region, a transverse bolt with a transverse bolt opening is arranged in the transverse bolt cutout, and the transverse bolt opening forms a part of the passage opening, and the longitudinal bolt extends through the transverse bolt opening.

11. The rotor as claimed in claim 1, wherein the blade-fastening element is a hub adapter or a blade flange bearing.

12. A rotor blade for a wind turbine, comprising: a body that extends from a blade tip to a face side, and a fastening region that is tubular shaped and arranged adjoining the face side, wherein the fastening region fastens the rotor blade to a blade-fastening element of a rotor hub, wherein at least one thickened portion is arranged at an outer circumferential surface and/or at an inner circumferential surface of the fastening region, and wherein the at least one thickened portion includes a passage opening with first and second ends, wherein the first end is arranged on the face side.

13. A rotor blade segment for a rotor blade for a wind turbine, comprising: a rotor blade segment extending from a blade end to a fastening side, a fastening region of a tubular shape and arranged adjoining the fastening side, wherein the fastening region is configured to fasten the rotor blade segment to another rotor blade segment for forming a rotor blade, wherein the fastening region includes at least one thickened portion arranged at an outer circumferential surface and/or at an inner circumferential surface of the fastening region, and wherein the at least one thickened portion is extended through by a passage opening, with two opposite ends, wherein a first end is arranged at the fastening side.

14. A blade-fastening element for the fastening of a rotor blade to a hub of a rotor for a wind turbine, comprising: a blind hole for receiving a longitudinal bolt for fastening to the blade-fastening element of the rotor blade segment as claimed in claim 12.

15. A wind turbine comprising the rotor as claimed in claim 1.

16. A method for mounting the rotor as claimed in claim 1 to a blade-fastening element, the method comprising: fastening a longitudinal bolt in a blind hole of the blade-fastening element, leading a portion of the longitudinal bolt that projects from the blind hole through the passage opening, wherein the face side of the rotor blade at least sectionally abuts against a rotor-blade side of the blade-fastening element, and fastening in the region of the fastening cutout, through attachment of a counterpart, an end of the longitudinal bolt that projects from the passage opening.

17. The rotor as claimed in claim 4, wherein the surface normal of the opening cross section of the second end of the fastening cutout and a longitudinal axis of the fastening cutout include an angle.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0054] Preferred embodiments of the invention will be discussed by way of example on the basis of the appended figures. In the figures:

[0055] FIG. 1 shows a schematic three-dimensional view of an exemplary embodiment of a wind turbine;

[0056] FIG. 2 shows a schematic two-dimensional view of a detail of a rotor known in the prior art;

[0057] FIG. 3 shows a schematic two-dimensional view of a detail of an exemplary embodiment of a rotor;

[0058] FIG. 4 shows a schematic two-dimensional partial view of an exemplary embodiment of a rotor blade;

[0059] FIG. 5 shows a schematic three-dimensional partial view of the rotor blade from FIG. 4;

[0060] FIG. 6 shows a schematic two-dimensional partial view of a further exemplary embodiment of a rotor blade;

[0061] FIG. 7 shows a schematic three-dimensional partial view of the rotor blade from FIG. 6;

[0062] FIG. 8 shows a schematic three-dimensional view of an exemplary embodiment of a fastening region;

[0063] FIG. 9 shows a schematic three-dimensional view of the fastening region from FIG. 8;

[0064] FIG. 10 shows a schematic three-dimensional view of a further exemplary embodiment of a rotor;

[0065] FIG. 11 shows a schematic three-dimensional view of a further exemplary embodiment of a rotor.

[0066] In the figures, identical or substantially functionally identical or similar elements are denoted by the same reference signs.

DETAILED DESCRIPTION

[0067] FIG. 1 shows a schematic three-dimensional view of an exemplary embodiment of a wind turbine. FIG. 1 shows in particular a wind turbine 100 with a tower 102 and with a nacelle 104. A rotor 106 having three rotor blades 108 and having a spinner 110 is arranged on the nacelle 104. During operation, the rotor 106 is set in rotational motion by the wind and in this way drives a generator in the nacelle 104.

[0068] At least one of the rotor blades 108 of the rotor 106 extends from a blade tip 108a to a face side 108b, wherein the rotor blade 108 has a fastening region which is of tubular form and which is arranged adjoining the face side 108b, wherein the fastening region has at its outer circumferential surface and/or at its inner circumferential surface at least one thickened portion, wherein the at least one thickened portion is extended through by a longitudinal bolt cutout, in the form of a passage opening, with two opposite ends, wherein a first end of the longitudinal bolt cutout is arranged on the face side 108b of the rotor blade 108. The rotor 106 furthermore comprises a hub having a blade-fastening element which, at the rotor-blade side thereof, has a blind hole for receiving a longitudinal bolt for the fastening of the rotor blade 108 to the blade-fastening element. Furthermore, a longitudinal bolt is arranged in the blind hole and in the longitudinal bolt cutout for the fastening of the rotor blade to the blade-fastening element.

[0069] Alternatively or additionally, at least one of the rotor blades 108 of the rotor 106 may be formed as a two-part, in particular (as here) longitudinally split, rotor blade having two rotor blade segments 109a, 109b. The rotor blade segment 109a extends from a blade end, specifically the blade tip, to a fastening side and comprises a fastening region which is of tubular form and which is arranged adjoining the fastening side, wherein at least one thickened portion is arranged at an outer circumferential surface and/or at an inner circumferential surface of the fastening region, the at least one thickened portion being extended through by a longitudinal bolt cutout, in the form of a passage opening, with two opposite ends, wherein a first end is arranged at the fastening side. The rotor blade segment 109b extends from a blade end, specifically the blade end close to the hub, to a fastening side and comprises a fastening region which is of tubular form and which is arranged adjoining the fastening side, wherein at least one thickened portion is arranged at an outer circumferential surface and/or at an inner circumferential surface of the fastening region, the at least one thickened portion being extended through by a longitudinal bolt cutout, in the form of a passage opening, with two opposite ends, wherein a first end is arranged at the fastening side.

[0070] The two rotor blade segments 109a, 109b together form a rotor blade. For this purpose, the two mutually facing fastening sides are fastened to one another at the rotor-blade fastening point or ends 109c.

[0071] That end of the rotor blade segment 109b which is close to the hub may preferably have a face side 109d, which corresponds to the face side 108b described for the fastening of a rotor blade to a hub of a rotor for a wind turbine.

[0072] FIG. 2 shows a schematic two-dimensional view of a detail of a rotor known in the prior art. The connecting point between the rotor blade 5 and the hub has a fastening region 10 on the side of the rotor blade 5. The rotor blade 5 adjoins a U-bearing 42 of the hub by way of the fastening region 10. The fastening region 10 has an outer rotor blade-side longitudinal bolt cutout 22. The fastening region 10 furthermore has a transverse bolt cutout 12 in which a transverse bolt 14 is arranged. Furthermore, the transverse bolt 14 has an outer transverse bolt opening 26 which, with corresponding arrangement of the transverse bolt 14 in the transverse bolt cutout 12, is arranged aligned with the outer rotor blade-side longitudinal bolt cutout 22.

[0073] The U-bearing 42 has an outer hub-side longitudinal bolt cutout 24 which, with corresponding arrangement of the rotor blade 5 on the U-bearing 42, is oriented aligned with the outer rotor blade-side longitudinal bolt cutout 22 and aligned with the outer transverse bolt opening 26. An outer longitudinal bolt 16 is arranged within the outer transverse bolt opening 26, the outer rotor blade-side longitudinal bolt cutout 22 and the outer hub-side longitudinal bolt cutout 24. The longitudinal bolt 16 preferably has at its second end 20, which faces the rotor blade, a thread. Furthermore, the transverse bolt 14 preferably has in its outer transverse bolt opening 26 an inner thread which is formed in a manner corresponding to the outer thread on the longitudinal bolt 16, so that the longitudinal bolt 16 can be screwed into the transverse bolt 12.

[0074] The longitudinal bolt extends from a first end 18, which faces the hub, to the second end 20. The longitudinal bolt 16 projects with the first end 18 out of the outer hub-side longitudinal bolt cutout 24. The longitudinal bolt 16 has an outer thread on a portion adjoining the first end 18. A nut 25 is screwed onto said outer thread, so that, by means of the screwing of the longitudinal bolt 16 into the transverse bolt 12 and by means of the screwing-on of the nut 25, a fastening of the rotor blade 5 to the U-bearing 42 is realized.

[0075] Analogously to the outer side, an inner rotor blade-side longitudinal bolt cutout 34, an inner transverse bolt opening 38 and an inner hub-side longitudinal bolt cutout 36 are arranged on an inner side of the fastening region. An inner longitudinal bolt 28 is arranged therein and extends from a first end 30 to a second end 32 in a longitudinal direction. The longitudinal direction of the longitudinal bolt 28 is substantially parallel to a longitudinal extent of the rotor blade 5 and/or to a passage direction of the fastening region 10. The longitudinal bolt 28 is screwed into a thread of the inner transverse bolt opening 38 and is secured at its first end 30 by means of a nut 40. The U-bearing 42 has a hub element 48 which is mounted in a groove of the U-bearing 42 by means of rolling bodies 44, 46.

[0076] FIG. 3 shows a schematic two-dimensional view of a detail of an exemplary embodiment of a rotor. The tubular fastening region 200 arranged on a rotor blade on a face side is shown. The fastening region 200 is arranged on a blade-fastening element 300 on a face side. FIG. 3 shows in particular a section through a wall in a radial direction of the fastening region 200. Furthermore, a part of the rotor blade wall 206 is shown on the left-hand side of the figure. The wall is thickened in the fastening region 200 in that an outer thickened portion 202 is arranged on an outer circumferential surface and an inner thickened portion 203 is arranged on an inner circumferential surface. The outer thickened portion 202 and the inner thickened portion 203 are connected integrally to the rotor blade wall 206. The rotor blade extends in particular from the fastening region 200 to a rotor blade tip (not shown) in a longitudinal direction L.

[0077] The fastening region 200 has an outer tapering portion 204 on a face side-averted side of the outer thickened portion 202, wherein the outer tapering portion 204 tapers from a face side-facing end to a face side-averted end. The outer tapering portion 204 has a cross section whose surface normal is arranged parallel to the ring direction and/or tangential direction of the fastening region 200. The cross section of the outer tapering portion 204 is triangular, wherein a first cathetus adjoins the thickened portion 202 and a second cathetus adjoins the rotor blade wall 206. The hypotenuse is in the form of a straight line.

[0078] An inner tapering portion 205 analogously adjoins the inner thickened portion 203. The tapering portions 204, 205 are connected integrally to the rotor blade wall 206 and to the respective thickened portions 202, 203. Due to the triangular geometry of the outer tapering portion 204, a surface normal of an opening cross section of a second end of the fastening cutout 240, which second end is averted from the face side, and a surface normal of an opening cross section of a first end of the fastening cutout 240 include an angle. Furthermore, a surface normal of an opening cross section of the second end of the fastening cutout 240 and a longitudinal axis of the fastening cutout 240 include an angle. It can furthermore be seen that the diameter of the fastening cutout 240 is greater than the diameter of the longitudinal bolt cutout 211.

[0079] An outer longitudinal bolt cutout 210 and an inner longitudinal bolt cutout 211 extend through the outer thickened portion 202 and the inner thickened portion 203 in each case from a first end, which is arranged on the face side, in each case to a second end, wherein the second ends of the longitudinal bolt cutouts 210, 211 adjoin the tapering portions 204, 205. A transverse bolt 212 is furthermore arranged between the longitudinal bolt cutouts 210, 211 and the tapering portions 204, 205. The transverse bolt 212 has an outer transverse bolt opening 214 and an inner transverse bolt opening 215 which extend coaxially with respect to the outer longitudinal bolt cutout 210 and the inner longitudinal bolt cutout 211, respectively. The outer transverse bolt opening 214 and inner transverse bolt opening 215 may be understood as being part of the outer longitudinal bolt cutout 210 and inner longitudinal bolt cutout 211, respectively. The second end, averted from the hub, of the outer longitudinal bolt cutout 210 and a first end, facing the hub, of the fastening cutout 240 adjoin one another.

[0080] As already described, the longitudinal bolt cutouts 210, 211 adjoin the tapering portions 204, 205 at their second ends. An outer fastening cutout 240 extends through the outer tapering portion 204 parallel to the longitudinal direction L from the second end of the outer longitudinal bolt cutout. Analogously, an inner fastening cutout 241 extends through the inner tapering portion 205 in the longitudinal direction L. The fastening cutouts 240, 241 preferably extend coaxially with respect to the longitudinal bolt cutouts 210, 211.

[0081] The blade-fastening element 300 has a U-bearing 320 and a hub element 310. The hub element 310 is mounted within a bearing groove 350 of the U-bearing 320 by means of rolling bodies 321, 322. The bearing groove 350 has two side surfaces which face the outer circumferential surface and the inner circumferential surface, a groove base which faces the rotor blade, and an open side which is averted from the rotor blade. The U-bearing 320 has a rotor-blade side which faces the face side of the rotor blade.

[0082] The U-bearing 320 has an outer blind hole 330 and inner blind hole 340 on the rotor-blade side. In the mounted state, the outer blind hole 330 is arranged coaxially with respect to the outer longitudinal bolt cutout 210. Furthermore, the inner blind hole 340 is arranged coaxially with respect to the inner longitudinal bolt cutout 211. The outer longitudinal bolt cutout 210, the outer fastening cutout 240 and the outer blind hole 330 form a passage and are arranged in a coaxial manner. The blind holes 330, 340 are spaced apart from the groove 350 in the direction of the rotor blade in the longitudinal direction L. Furthermore, the side walls of the groove 350 are spaced apart in such a way that their spacing is larger than a spacing of the blind holes 330, 340 to one another.

[0083] For the purpose of fastening the rotor blade by way of its fastening region 200 to the blade-fastening element 300, an outer longitudinal bolt 220 is arranged within the outer blind hole 330, the outer longitudinal bolt cutout 210 and the outer fastening cutout 240. The first end, facing the hub, of the longitudinal bolt cutout 210 adjoins the blind hole 330. The outer longitudinal bolt 220 extends from a first end 222 as far as a second end 224. In a region adjoining the first end 222, the outer longitudinal bolt 220 has an outer thread which is formed in a manner corresponding to an inner thread 334 of the outer blind hole 330. The outer longitudinal bolt 220 is screwed in place within the outer blind hole 330.

[0084] The outer fastening cutout 240, in particular a diameter of the fastening cutout 240, is arranged and configured for receiving a counterpart, in particular a nut or an expansion sleeve 242, for connection to the longitudinal bolt 210. The longitudinal bolt 220 has an outer thread adjoining the second end 224. An expansion sleeve 242 is furthermore screwed onto a portion adjoining the second end 224 and abuts with its end facing the blade-fastening element 300 against the transverse bolt 212. The abutment of the expansion sleeve 224 against the transverse bolt 212 and screwing of the expansion sleeve 224 onto the longitudinal bolt 220 and also the screwing of the longitudinal bolt 220 into the outer blind hole 330 give rise to a force in the longitudinal direction L acting on the longitudinal bolt 220. Said force in the longitudinal direction L results in a connection of the fastening region 200 to the blade-fastening element 300.

[0085] Analogously to the outer longitudinal bolt 220, an inner longitudinal bolt 221 extends from the inner blind hole 340 as far as the inner fastening cutout 241 through the inner longitudinal bolt cutout 211. The longitudinal bolt 221 extends from a first end 223 in the region of the blind hole to a second end 225. Analogously to the outer longitudinal bolt 220, the inner longitudinal bolt 221 is fastened by way of an outer thread in an inner thread 344 of the blind hole 340. Furthermore, the longitudinal bolt 221 is secured within the fastening cutout 241 by means of an expansion sleeve 243.

[0086] FIGS. 4 to 7 show a further schematic exemplary embodiment of a rotor blade 400, 400′. The rotor blade 400, 400′ has a wall 405, wherein an outer thickened portion 425 and an inner thickened portion 445 are arranged within a fastening region 410. Furthermore, tapering portions 427, 447 are arranged on the face side-averted sides of the thickened portions 425, 445. Transverse bolt cutouts 450 are arranged within the thickened portions 425, 445 radially with respect to the rotor-blade longitudinal axis. Furthermore, transverse bolts 430 are arranged within the transverse bolt cutout 450. Furthermore, outer longitudinal bolt cutouts 428 and inner longitudinal bolt cutouts 448 are arranged within the outer and inner thickened portion 425, 445 so as to be substantially parallel to the rotor-blade longitudinal axis. An outer longitudinal bolt 420 and an inner longitudinal bolt 440 extend within said cutouts, wherein the longitudinal bolts 420, 440 extend as far as an outer fastening cutout 432 or inner fastening cutout 462. The longitudinal bolts are secured within the outer fastening cutout 432 and inner fastening cutout 462 by means of a nut 426, 446.

[0087] FIGS. 4 and 5 show that the longitudinal bolt cutouts 428, 448 have a diameter which is merely slightly greater than a diameter of the longitudinal bolts 420, 440. FIGS. 6 and 7 show longitudinal bolt cutouts 428′, 448′ which have a diameter which is significantly greater than a diameter of the longitudinal bolts 420, 440.

[0088] FIG. 8 shows a schematic three-dimensional view of an exemplary embodiment of a fastening region. The fastening region 500 is formed by a thickened portion 530, a tapering portion 532 and a wall. Transverse bolt openings 522 in which transverse bolts 520 can be arranged are arranged within the thickened portion 530 radially with respect to the passage direction of the fastening region 500. Furthermore, a longitudinal bolt 510 is arranged in the transverse bolt 520. It can be seen in particular in FIG. 9 that the longitudinal bolt cutouts 502, 504 adjoin the face side 501. Furthermore, it is shown that the longitudinal bolts 510, 512 extend through the longitudinal bolt cutouts 502, 504, project from the face side 501 and are arranged within a transverse bolt 520.

[0089] FIG. 9 furthermore shows a configuration in which an elongate hole 503 is provided in the form of a longitudinal bolt cutout and is arranged to receive both longitudinal bolts 510, 512.

[0090] FIG. 10 shows a schematic three-dimensional view of an exemplary embodiment of a rotor. The fastening region 600 of a rotor blade comprises an inner tapering portion 602 and an inner thickened portion 604, through which an inner longitudinal bolt 614 extends. The longitudinal bolt 614 is secured on the side of the fastening region 600 by means of an inner expansion sleeve 616. The expansion sleeve 616 abuts on the face side against a transverse bolt 620. Analogously to the above-described embodiments, there is arranged radially opposite the inner tapering portion 602 and inner thickened portion 604 an outer tapering portion (not shown) and a thickened portion (not shown), through which there extends an outer longitudinal bolt 610 which is secured by means of an outer expansion sleeve 612 which abuts on the face side against the transverse bolt 620.

[0091] The fastening region 600 serves for the fastening of the rotor blade to the blade-fastening element 630, wherein the blade-fastening element 630 has a U-bearing 632 and a hub element 634, wherein the hub element 634 is mounted in the U-bearing 632 by means of rolling bodies 336, 338. The U-bearing 632 has an outer blind hole 640 and an inner blind hole 642, into which the longitudinal bolts 610, 614 are screwed. Due to the screwing of the longitudinal bolts 610, 612 into the blind holes 640, 642 and the fastening of the longitudinal bolts 610, 614 by means of the expansion sleeves 612, 616, it is possible for the rotor blade to be connected by way of the fastening region 600 to the blade-fastening element 630.

[0092] FIG. 11 shows a schematic three-dimensional view of a further exemplary embodiment of a rotor. The fastening region 700 has an inner thickened portion 702, an inner tapering portion 704, an outer thickened portion 706 and an outer tapering portion 708, wherein a transverse bolt 710 extends through the thickened portions 702 and 706. The rotor blade having the fastening region 700 is secured to a blade-fastening element 720 in such a way that longitudinal bolts, of which only the outer longitudinal bolt 712 is shown here, extend through a longitudinal bolt cutout of the thickened portions 702, 706 and are screwed in place in blind holes of the blade-fastening element 720. Furthermore, the longitudinal bolts are secured on the side of the fastening region by expansion sleeves 714. In the present case, it can be seen that a part of the longitudinal bolt cutout and a part of the fastening cutout are formed as a groove and not as a bore.

REFERENCE SIGNS

[0093] 5, 108, 400, 400′ Rotor blade

[0094] 10, 200, 410, 500, 600, 700 Fastening region

[0095] 12, 450, 522 Transverse bolt cutout

[0096] 14, 212, 430, 520, 620, 710 Transverse bolt

[0097] 16, 220, 420, 510, 610, 712 Outer longitudinal bolt

[0098] 18, 30, 222, 223 First end of longitudinal bolt

[0099] 20, 32, 224, 225 Second end of longitudinal bolt

[0100] 22 Outer rotor blade-side longitudinal bolt cutout

[0101] 24 Outer hub-side longitudinal bolt cutout

[0102] 25, 40, 426, 446 Nut

[0103] 26, 214 Outer transverse bolt opening

[0104] 28, 221, 440, 512, 614 Inner longitudinal bolt

[0105] 34 Inner rotor blade-side longitudinal bolt cutout

[0106] 36 Inner hub-side longitudinal bolt cutout

[0107] 38, 215 Inner transverse bolt opening

[0108] 42, 320, 632 U-bearing

[0109] 44, 46, 321, 322, 636, 638 Rolling body

[0110] 48, 310, 634 Hub element

[0111] 100 Wind turbine

[0112] 102 Tower

[0113] 104 Nacelle

[0114] 106 Rotor

[0115] 108a Rotor blade tip

[0116] 108b, 501 Face side

[0117] 109a, b Rotor blade segment

[0118] 109c Rotor blade parting point

[0119] 109d Fastening side

[0120] 110 Spinner

[0121] 202, 425, 530, 706 Outer thickened portion

[0122] 203, 445, 604, 702 Inner thickened portion

[0123] 204, 427, 532, 708 Outer tapering portion

[0124] 205, 447, 602, 704 Inner tapering portion

[0125] 206, 405 Rotor blade wall

[0126] 210, 428, 428′, 502 Outer longitudinal bolt cutout

[0127] 211, 448, 448′, 504 Inner longitudinal bolt cutout

[0128] 240, 432 Outer fastening cutout

[0129] 241, 462 Inner fastening cutout

[0130] 242, 243, 612, 616, 714 Expansion sleeve

[0131] 300, 630, 720 Blade-fastening element

[0132] 330, 640 Outer blind hole

[0133] 334, 344 Blind hole thread

[0134] 340, 642 Inner blind hole

[0135] 350 Bearing groove

[0136] 503 Elongate hole

[0137] L Rotor blade longitudinal direction