WO2024223500A1

WO2024223500A1 - Device for fastening a rotor blade to a hub body, and multi-part hub assembly for a wind turbine

Info

Publication number: WO2024223500A1
Application number: PCT/EP2024/060969
Authority: WO
Inventors: Daniel Becker; Marco Burtchen; Matthias TÖFKE; Wilfried Spintig
Original assignee: thyssenkrupp rothe erde Germany GmbH; Thyssenkrupp Ag
Priority date: 2023-04-24
Filing date: 2024-04-22
Publication date: 2024-10-31

Abstract

The invention relates to a device (1) for fastening a rotor blade (140) to a hub body (13) of a wind turbine (100), said device comprising a blade-side extender bearing unit (2) having a first bearing ring (3) with a first bolt circle (4) for fastening to the hub body (13), and a second bearing ring (5) for fastening to the rotor blade (140), the second bearing ring (5) being arranged coaxially to the first bearing ring (3) so as to be rotatable about the common bearing axis (A), the first bearing ring (3) being integrally formed with a rotor hub extension (9) which extends on the hub side in the direction of the bearing axis (A) beyond the second bearing ring (5), with the first bolt circle (4) being arranged in the hub-side end region (E) of said rotor hub extension, the device (1) also comprising a hub-side extender bearing unit (10) which is plate-shaped and has a second bolt circle (11), the first bolt circle (4) being aligned with the second bolt circle (11) for joint fastening to the hub body (13). The invention also relates to a multi-part hub assembly (150) which is held together by means of at least one fastening device (1) according to the invention.

Description

Device for fastening a rotor blade to a hub body and multi-part hub arrangement for a wind turbine

State of the art

The invention relates to a device for fastening a rotor blade to a hub body according to the preamble of claim 1, as well as a multi-part hub arrangement for a wind turbine according to the preamble of claim 6.

The rotor blades of wind turbines are attached to the hub using large roller bearings. The large roller bearings enable the angle of attack of the rotor blades to the wind to be adjusted, which is necessary, among other things, to regulate the power of the wind turbine.

Hub bodies are currently usually constructed as one-piece castings. Because the hub body alone is only partially able to meet the ever-increasing demands on the rigidity of the bearing-side connection surfaces as wind turbines grow in size, or would have to be designed to be ever more massive and heavy, it is known that additional, separately manufactured components, such as stiffening elements mounted on the blade connection or hub connection side, can be screwed to the bearing-side attachment parts for targeted, local stiffening of the blade and/or rotor bearing connection surfaces. These stiffening elements can, for example, be designed in a simplified manner as plates with a central hole in the middle to enable access to the components adjacent to the bearing, i.e. the hub or the blade, for assembly and maintenance purposes. The known plates primarily serve to increase the torsional rigidity of the connecting surfaces in order to relieve the connected large roller bearings with regard to the induced structural deformations.

The previous design principle with a one-piece hub is reaching its limits as the power class and size of wind turbines continue to increase. On the one hand, these limits are of a manufacturing nature because, particularly due to the expected hub sizes and weights, it is only possible to cast such large hub bodies in one piece with the required precision and then machine them mechanically with the required high level of detail with great effort. On the other hand, the entire wind turbine manufacturing industry is also predictably reaching its limits. availability limits, because the number of foundries worldwide that are able to manufacture such large hub bodies in one piece is a major obstacle to the expected increase in wind turbines. Finally, there will also be expected to be logistical restrictions due to hub transport, particularly for onshore wind turbines, as hub bodies with dimensions of more than 4 meters can no longer be transported to the site by road without significant additional costs as a result of increased transport and traffic control logistics, due to bridge heights, tunnel diameters, etc. In the onshore area, it can therefore be expected that from a system output of >7 - 8 MW, one-piece hub bodies based on a conventional design of the hub-blade bearing overall system can no longer be transported by road in a cost-effective and therefore practical manner.

Therefore, some concepts are already known from the state of the art according to which the hub body can be divided into several smaller parts.

For example, EP 2 837 820 B1 describes a segmented wind turbine hub, wherein the segments are designed as hollow bodies and each comprise two structurally designed areas with connection surfaces for connecting the segment to two other segments inside the hub. Each area for connecting the segments has a substantially closed surface that rests on the corresponding surface of the adjacent segment and is attached to it with bolts, rivets or by welding. The symmetrical segmentation here takes place specifically between the blade bearing connection surfaces, so that the blade bearing ring does not structurally perform any function in the mechanical fixation of the adjacent hub segments.

US 8449263 B2 also shows a segmented rotor hub, which is designed as a double shell with an inner hub and a hub housing, each of which is segmented and is screwed or riveted together via flanges at the segment joints. The inner hub and hub housing are connected to each other via support struts. The segmentation also takes place here between the blade bearing connection surfaces.

The disadvantage of the two aforementioned patents is that the hub segments and in particular the structural elements for fixing adjacent hub segments are complicated to manufacture and require considerable effort to screw the hub segments together in addition to the assembly of the blade bearings.

From DE 10 2011 052 668 B4 a device for fastening a rotor blade to a hub body according to the preamble of claim 1, as well as a hub arrangement for a wind turbine according to the preamble of claim 5 are known. DE 10 2011 052 668 B4 describes another segmented hub for a wind turbine. The segments have at least one side that rests against the side of an adjacent segment and extends from an outer circumference of the hub to a central region of the hub. The segments are connected to a front plate that is mounted on the side surfaces of the segments that point in a direction away from the nacelle, i.e. against the direction of the wind. Each rotor blade is attached to the hub via an additional component, the so-called connecting hub, which has two concentric, circular arrangements of bolt holes. The outer bolt circle is provided for connection to the hub segments and the inner bolt circle is provided for mounting rotor blade bearings.

The disadvantage is that the connecting hubs must be designed to transfer the load from the blade-side connection diameter to another hub-side connection diameter, and the two bolt circles result in significantly increased manufacturing and assembly costs. Another disadvantage is that the connecting hub only allows the assembly of rotor blade bearings and thus rotor blades that have a smaller diameter than the larger of the two bolt circles. In relation to the hub size, the full potential of the blade bearing and thus the blade root diameter cannot be exploited, which leads to a reduced load-bearing capacity and service life of the blade bearing in relation to the smaller blade bearing diameter. Derived from the smaller blade root diameter, this limits the overall rotor diameter and thus the achievable yield of the wind turbine. With the same hub size, only a comparatively small rotor can be supported by the segmented hub. In the known design, however, such a connecting hub, which causes a radial reduction in the maximum blade root diameter, is necessary because the usual blade bearings require a continuous, i.e. unsegmented, connection surface. In addition, access to the 2 bolt hole circles on the connecting hub - once for fastening the connecting hub on the hub side and once for fastening the connecting hub on the blade side - must be guaranteed for both assembly and maintenance purposes at height. The connecting hub has the function of transferring the normal and thrust forces to the abutting surfaces of adjacent hub segments in order to protect the fixed rings of the blade bearings from additional transmission of additional loads resulting from the hub segmentation.

disclosure of the invention

The object of the invention is therefore to provide a device for fastening a rotor blade to a hub body, as well as a multi-part hub arrangement for a wind turbine, which can be easily manufactured, transported and assembled on site, and which offers greater flexibility in terms of the connection diameter of the blade bearing and rotor blade.

This object is achieved by a device for fastening a rotor blade to a hub body with the features of claim 1 and a multi-part hub arrangement with the features of claim 5.

This creates a device for fastening a rotor blade to a hub body of a wind turbine, which comprises a blade-side extender bearing unit and a hub-side extender bearing unit. The blade-side extender bearing unit comprises a first bearing ring with a first bolt circle for fastening to the hub body, and a second bearing ring for fastening to the rotor blade. The second bearing ring is arranged coaxially to the first bearing ring so as to be rotatable about the common bearing axis. The hub-side extender bearing unit is plate-shaped and has a second bolt circle. According to the invention, it is provided that the first bearing ring is designed with a rotor hub extension which extends on the hub side in the direction of the bearing axis beyond the second bearing ring and in whose hub-side end region the first bolt circle is arranged. The second bolt circle of the hub-side extender bearing unit is aligned with the first bolt circle of the blade-side extender bearing unit for joint fastening to the hub body.

The at least two-part device according to the invention for fastening a rotor blade to a hub body enables the fastening of the rotor blade to a segmented Hub body with screw connections that extend through the first and second bolt circles and thus simultaneously fasten the blade-side and hub-side extender bearing units to the hub body - preferably symmetrically segmented in the blade bearing connection surface. This effectively reduces the number of screws required, which significantly reduces the assembly effort on site and at the same time the costs for the mechanical processing of the individual components.

This simplified assembly is made possible by the separate design of the blade-side and hub-side extender bearing units according to the invention. The hub-side extender bearing unit can also absorb the stresses that occur when hub body segments meet, thus relieving the load on the blade-side extender bearing unit. The rotor hub extension integrated in the blade-side extender bearing unit is also designed in its end area for connection to the hub to absorb the additional stresses that occur as a result of segmentation of the hub body. In this way, deformations of the bearing ring arranged on the blade-side extender bearing unit, which could lead to an impairment of the blade bearing, are specifically avoided.

The hub-side extender bearing unit preferably has a plate thickness that is at least 20% of an axial wall thickness of the rotor hub extension in its hub-side end region. The plate thickness is particularly preferably at least 50% or even at least 70% of the wall thickness of the rotor hub extension in its hub-side end region. Such plate thicknesses go well beyond the extent of plate-like stiffening means for stiffening blade connection surfaces of one-piece rotor hubs, which only have to absorb torsional stresses on the blade connection surfaces. With the aforementioned preferred plate thicknesses, the hub-side extender bearing unit is, however, designed for stresses that are of the same order of magnitude as the stresses introduced into the hub body by the entire rotor blade via the rotor hub extension. Such hub-side extender bearing units are therefore particularly well suited to absorbing the additional thrust forces in the segment joint that occur with a split hub.

In preferred embodiments, the hub-side extender bearing unit has, in addition to the second bolt circle, fastening means for temporary or permanent fixation the hub-side extender bearing unit on the hub body. The additional fastening means allow the device to be assembled step by step on a multi-part hub body. The fastening means can be formed, for example, by fastening holes, form-fitting assembly elements or similar. By fixing the hub-side extender bearing unit to the hub body via the fastening means, for example by fixing elements engaging in the fastening holes, several hub body segments can be positioned easily and accurately in relation to the hub-side extender bearing unit and relative to one another. This simplifies the assembly of the hub segments and the subsequent assembly of the blade-side extender bearing unit on the already assembled hub body and in particular reduces possible errors when carrying out assembly on site.

Preferably, at least one row of rolling elements can be provided which roll between the first and second bearing rings of the blade-side extender bearing unit and which have a rolling element diameter, wherein the rotor hub extension extends in the direction of the bearing axis beyond the second bearing ring by at least 3 times the rolling element diameter of the row of the largest rolling elements. The rolling element diameter of the rolling element row with the largest diameter is a measure of the maximum forces that can be transmitted by the rolling bearing. The tensile and thrust forces occurring at the joint on a multi-part, segmented hub are directly related to the forces introduced by the rotor blades via the blade bearings. It has been found that the raceway system of the blade bearing is particularly well protected against deformation due to the forces at the segment joints of the hub if the rotor hub extension extends in the direction of the bearing axis beyond the second bearing ring by at least 3 times the largest rolling element diameter.

In further preferred embodiments, the hub-side extender bearing unit can comprise at least two parts, each of which contains a circumferential section of the second bolt circle. The multi-part design of the hub-side extender bearing unit further reduces the number of components the size of the blade diameter. In these embodiments, the blade-side extender bearing unit can be the only component whose dimensions reach or exceed the diameter of the rotor blade to be mounted. The object is further achieved by a multi-part hub arrangement for a wind turbine. The hub arrangement comprises a hub body with fastening means for fastening the hub arrangement to a nacelle of the wind turbine and at least one third bolt circle for fastening a rotor blade of the wind turbine. The hub body comprises at least two hub body segments, on each of which a circumferential section of the third bolt circle is formed. The hub body segments are arranged such that the circumferential sections together form the third bolt circle. The hub arrangement further comprises a fastening device according to the invention as described above, wherein the third bolt circle is aligned with the first bolt circle and the second bolt circle of the fastening device. The fastening device is fastened to the hub body with a plurality of screws, each of which extends through the first, second and third bolt circles.

By screwing the hub body segments together with the multi-part fastening device over the first, second and third bolt circles, a frictional connection is created between the hub body segments and the fastening device, which transfers the forces occurring when the hub body segments meet via the fastening device. The aligned arrangement of all three bolt circles allows for simplified assembly with just one row of screws.

The multi-part hub arrangement according to the invention achieves a significant reduction in the transport volume to the construction site of the wind turbine compared to a one-piece hub and at the same time enables simple assembly on site using screw connections. In addition, the hub body segments can be manufactured with less production effort than a one-piece hub, which can mitigate foreseeable bottlenecks in the manufacture of large structural components.

In some preferred embodiments, the third hole circle is designed as through holes that are arranged in a radial flange of the hub body. The radial flange of the hub body simultaneously forms both a stiffening element for the respective hub segment and an enlarged support surface for the frictional engagement with the fastening device. In these embodiments, the hub-side extender bearing unit is particularly preferably arranged on the inside of the hub and the blade-side extender bearing unit is arranged on the outside of the hub. The sandwich-like arrangement and screwing of the radial flanges of adjacent hub segments between the blade-side and hub-side extender bearing units further increases the area effective for the frictional engagement, since both axial surfaces of the flange are made usable for the transmission of thrust and friction forces. Furthermore, in these embodiments, the bending stress on the screw connection that connects both extender bearing units to the hub segments can be reduced.

In other preferred embodiments, the third bolt circle is designed as blind holes in the hub body, with the hub-side extender bearing unit and the blade-side extender bearing unit being arranged on the outside of the hub body. These embodiments are characterized by a particularly simple casting mold for the hub body segments, which are also equipped with only one finely machined support surface for the fastening device.

Furthermore, it is advantageous if the circumferential sections of the second bolt circle formed on the parts of the hub-side extender bearing unit are each arranged to overlap at least two circumferential sections of the third bolt circle formed on the hub body segments. In this way, despite the hub body and the hub-side extender bearing unit being formed in at least two parts, it is possible to transmit the forces occurring at the joint of the hub body segments via the hub-side extender bearing unit.

Finally, it is advantageous if the hub body segments are connected to one another on the windward and/or leeward side with at least one stiffening ring. Stiffening rings, particularly seamless rolled stiffening rings, are designed to absorb particularly high tensile stresses. In comparison to a screwed-on central plate, a stiffening ring also absorbs the tensile forces in the radial direction further out and thus closer to the blade roots, where the loads are introduced into the hub body.

Further advantageous embodiments can be found in the following description and the subclaims. The invention is explained in more detail below with reference to the embodiments shown in the accompanying drawings.

Short description of the drawings

Fig. 1 shows schematically a wind turbine whose rotor blades are mounted on the hub body by means of fastening devices according to the invention,

Fig. 2 shows schematically a hub arrangement according to the invention with a three-part hub body and three fastening devices according to the invention,

Fig. 3 shows schematically in a partially sectioned, perspective view parts of the hub arrangement according to Fig. 2,

Fig. 4 and 5 show schematically in sectional representations the interaction of fastening device and hub body segments according to the embodiment according to Fig. 1 to 3,

Fig. 6 shows schematically in a sectional view the interaction of fastening device and hub body segments according to a second embodiment of the invention, and

Fig. 7 shows schematically the second embodiment according to Fig. 6 in an equipment variant with an electric blade adjustment drive.

embodiments of the invention

In the various figures, identical parts are always provided with the same reference symbols and are therefore usually named or mentioned only once.

In Fig. 1, a wind turbine 100 according to the invention is shown. The wind turbine 100 comprises a tower 110, a nacelle 120 and a rotor 130 rotatably mounted on the nacelle 120. The rotor 130 comprises a multi-part hub arrangement 150 and a plurality of rotor blades 140 rotatably attached to the hub arrangement 150. Typically, the rotor 130 comprises three rotor blades 140 as shown. The rotor blades 140 are rotatably mounted on the hub arrangement 150 in order to enable power control of the wind turbine 100 in fluctuating wind conditions. In addition, a Adjustment of the rotor blades 140 into the vane position, i.e. in the direction of the wind, is possible in order to minimize the power consumption of the rotor blades 140 and to take the wind turbine 100 out of operation.

At least one of the rotor blades 140 is mounted on the hub arrangement 150 by means of a fastening device 1 according to the invention. Preferably, all of the rotor blades 140 are mounted on the hub 150 by means of fastening devices 1 according to the invention.

The hub arrangements 150 according to the invention with the fastening devices 1 used therein for fastening the rotor blades 140 to the hub body are explained in more detail below with reference to Figures 2 to 7.

Figs. 2 to 5 show a first embodiment of a multi-part hub arrangement 150 according to the invention for a wind turbine 100 (see Fig. 1). The hub arrangement 150 comprises a hub body 13 with fastening means 22 for fastening the hub arrangement 150 to the nacelle 120 of the wind turbine 100 and with preferably three third hole circles 14 for fastening a rotor blade 140 of the wind turbine 100.

The hub body 13 preferably comprises three hub body segments 13', 13", 13'", on each of which a circumferential section 14', 14" of two of the three third hole circles 14 is formed. The circumferential sections 14', 14" are arranged such that together they form the third hole circles 14. In other words, the hub body 13 is divided into hub body segments 13', 13", 13'", wherein the joints of the hub body segments 13', 13", ^'" are each located in the blade connection surfaces defined by the third hole circles 14.

The hub arrangement 150 further comprises a fastening device 1 according to the invention for each of the third bolt circles 14, which is explained in more detail below with reference to Figs. 4 and 5.

The fastening device 1 for fastening the rotor blade 140 to the hub body 13 of the wind turbine 100 comprises a blade-side extender bearing unit 2 and a hub-side extender bearing unit 10. The blade-side extender bearing unit 2 has a first bearing ring 3 with a first bolt circle 4 for fastening to the hub body 13 and a second bearing ring 5 for attachment to the rotor blade 140. The second bearing ring 5 is arranged coaxially to the first bearing ring 3 and can rotate about the common bearing axis A.

The first bearing ring 3 is formed with a rotor hub extension 9, which extends on the hub side in the direction of the bearing axis A beyond the second bearing ring 5. The first bolt circle 4 is arranged in a hub-side end region E of the rotor hub extension 9. The hub-side end region E is preferably formed as a radially extending flange.

The rotor hub extension can be essentially cylindrical or conically widening or reducing towards the rotor blade. As a result, rotor blades 140 with different blade root diameters can be mounted on a standardized hub body 13. The fastening device 1 according to the invention therefore functions as an adapter between standardized components of a modular system.

The figures show preferred embodiments with a conical extension of the rotor hub extension 9 towards the rotor blade. Such a conical extension has the advantage that with the same size of the hub body 13, larger blade root diameters and thus also longer rotor blades 140 can be mounted, which enable wind turbines with higher performance.

The hub-side extender bearing unit 10 is plate-shaped and has a second hole circle 11. The plate-shaped hub-side extender bearing unit can have a central opening through which the interior of the rotor blade 140 (see Fig. 1) is accessible from the hub body 13. Plate-shaped in the sense of this disclosure means that the radial extent of the hub-side extender bearing unit 10 is at least three times, preferably at least five times, its plate thickness D.

The plate thickness D of the hub-side extender bearing unit 10 is preferably at least 20% of the axial wall thickness W of the rotor hub extension 9 in its hub-side end region E. In some embodiments, the plate thickness D of the hub-side extender bearing unit 10 can also preferably be at least 50% or even at least 70% of the axial wall thickness W of the rotor hub extension 9 in its hub-side end region E in order to achieve additional stabilization of the segmented hub body.

According to the invention, it is provided that the second bolt circle 11 is aligned with the first bolt circle 4 for joint fastening to the hub body 13. The third bolt circle 14 is also aligned with the first bolt circle 4 and the second bolt circle 11. The fastening device 1 is thus to be fastened to the hub body 13 with a plurality of screws 15, which each extend through the first 4, second 11 and third bolt circle 14.

Also included in the invention are embodiments (not shown) in which at least a second, radially offset set of three bolt circles aligned with one another is provided in the hub-side and blade-side extender bearing units, as well as the hub body. The additional screw row can increase the transfer of loads via the frictional engagement and the area for clamping the adjacent hub body segments between the blade-side and hub-side extender bearing units.

As can be seen in particular in Fig. 5, the hub-side extender bearing unit 10 can have, in addition to the second bolt circle 11, fastening means 12 for temporarily or permanently fixing the hub-side extender bearing unit 10 to the hub body 13. In a first step of assembly, the hub-side extender bearing unit 10 is fastened to the hub body segments 13', 13" via the fastening means 12 so that they are correctly positioned relative to one another. However, the type and number of fastening means 12 are not sufficient to absorb the loads in the segment joint during operation. Rather, they are aids to simplify fail-safe assembly. Centering and/or form-fitting assembly aids for the clear assignment and positioning of the parts can be provided as additional aids for fail-safe assembly. This allows the assembly sequence on site to be optimized and its complexity reduced.

The first bearing ring 3 and the second bearing ring 5 can, for example, be designed as a plain bearing with sliding pads. Preferably, however, in addition to or as an alternative to the sliding pads, at least one row of rolling elements 6, 7, 8 which can roll between the bearing rings 3, 5 and which have a largest rolling element diameter WD is provided. The rolling elements 6, 7, 8 can be balls, cylindrical rollers or tapered rollers, for example. The rotor hub extension 9 extends in the direction of the bearing axis A at least 3 times, more preferably at least 5 times, the largest rolling element diameter WD of the row of the largest rolling elements 7, 8 beyond the second bearing ring 5. Due to the axial extension of the rotor hub extension 9, the rotor hub extension 9 has additional rigidity compared to a conventional blade bearing ring, which allows the forces occurring in the segment joint of the hub body segments to be absorbed and deformations of the raceway system to be limited to a tolerable level.

As shown in Figures 2 to 7, the first and second bearing rings 3, 5 can form, for example, a three-row roller bearing. Alternatively, other bearing designs are also conceivable, such as a double tapered roller bearing or a double-row angular contact ball bearing. The first and/or second bearing rings 3, 5 can be divided in the axial direction to simplify the assembly of the bearing. In the embodiments shown in Figures 2 to 7, the outer ring 3 is divided in the axial direction A. However, embodiments in which the inner ring is divided in the axial direction A or in which there is no division at all in the axial direction A are also conceivable.

As shown in particular in Fig. 3, the hub-side extender bearing unit 10 preferably comprises at least two parts 10', 10", each containing a circumferential section 1T, 11" of the second bolt circle 11. The circumferential sections 1T, 11" of the second bolt circle 11 formed on the parts 10', 10" of the hub-side extender bearing unit 10 are then each arranged to overlap with at least two circumferential sections 14', 14" of the third bolt circle 14 formed on the hub body segments 13', 13".

In addition, the hub body segments 13', 13" can be connected to one another on the windward side and/or the leeward side by means of at least one stiffening ring 17, 18, 19. Preferably, as shown in Fig. 3, two stiffening rings 17, 18 are used at least on the windward side, which sandwich a flange 23 formed on the hub body segments 13', 13" and are penetrated by a row of screw connections. On the leeward side, the fastening means 22 are preferably also designed as a flange with a bolt circle, wherein the stiffening ring 19 is preferably arranged on the inside of the hub body 13. In the assembled state, the flange 22 is then also sandwiched between the stiffening ring 19 and the connection component of the nacelle 120, usually a bearing ring of a rotor bearing or an end flange of a rotor shaft. In this sense, a stiffening ring on the side facing away from the wind can advantageously also be structurally integrated into the rotatable bearing ring of the rotor bearing or the rotor shaft by a correspondingly more solid design of the rotor bearing ring or rotor shaft. The stiffening rings 17, 18, 19 are preferably seamless rolled rings. The stiffening rings 17, 18, 19 can also be designed in segments, wherein the ring segment boundaries each cover the joints of the hub body segments 13', 13".

In the first embodiment shown in Fig. 2 to 5, the third bolt circle 14 is designed as through holes which are arranged in a radial flange 16 of the hub body 13. The hub-side extender bearing unit 10 is arranged on the inside of the hub flange 16 and the blade-side extender bearing unit 2 is arranged on the outside of the hub flange 16.

A second embodiment of the invention is shown in Fig. 6. It differs from the first embodiment shown in Figs. 2 to 5 in that the third bolt circle 14 is designed as blind holes in the hub body 13. Both the hub-side extender bearing unit 10 and the blade-side extender bearing unit 2 are arranged on the outside of the hub body 13.

Furthermore, the statements regarding the first embodiment according to Figs. 2 to 5 apply accordingly to the second embodiment.

Fig. 7 shows an equipment variant of the second embodiment with an electric adjustment drive 20. The adjustment drive 20 is integrated into the blade-side extender bearing unit 2. For this purpose, the adjustment drive 20 is mounted on a stiffening plate 21, which in turn is attached to the second bearing ring 5 of the blade-side extender bearing unit 2. The drive pinion of the adjustment drive 20 is in engagement with a toothing in the hub-side end region E of the rotor hub extension 9. In this way, an adjustment of the pitch angle of the connected rotor blade 140 can be effected. The integration of the The integration of the adjustment drive 20 into the fastening device 1 according to the invention has the advantage that the drive 20 can already be pre-assembled and tested in the factory and assembly in the field is limited to simple screw connections for assembling the hub. A separate supply line for the hub and blade bearing unit including the adjustment drive is also possible. Instead of a single adjustment drive 20, several adjustment drives 20 can be provided distributed over the circumference of the fastening device 1.

The equipment variant with integrated adjustment drive 20 is shown in Fig. 7 as an example for the second embodiment. In the same way, the fastening device according to the first embodiment according to Figs. 2 to 5 can also be equipped with an integrated adjustment drive 20.

list of reference symbols

1 fastening device

2 blade-side extender bearing unit

3 first bearing ring

4 first bolt circle

5 second bearing ring

6, 7, 8 rows of rolling elements

9 Rotor hub extension

10 hub-side extender bearing unit

10', 10" parts of the hub-side extender bearing unit

11 second bolt circle

1 T, 11" circumferential sections of the second bolt circle

12 fasteners

13 hub bodies

13', 13", 13'" hub body segments

14 third bolt circle

14', 14" circumferential sections of the third bolt circle

15 screws

16 flange

17, 18, 19 stiffening ring

20 adjustment drive

21 stiffening plate

22 fasteners

23 flange

100 wind turbines

110 tower

120 gondolas

130 Rotor

140 rotor blades

150 Multi-part hub assembly

A bearing axis

E hub-side end area of the rotor hub extension D Plate thickness of the hub-side extender bearing unit

W Wall thickness of the rotor hub extension

WD rolling element diameter

Claims

PATENT CLAIMS

1. Device for fastening a rotor blade (140) to a hub body (13) of a wind turbine (100), comprising a blade-side extender bearing unit (2) comprising a first bearing ring (3) with a first hole circle (4) for fastening to the hub body (13), and a second bearing ring (5) for fastening to the rotor blade (140), wherein the second bearing ring (5) is arranged coaxially to the first bearing ring (3) so as to be rotatable about the common bearing axis (A), and a hub-side extender bearing unit (10) which is plate-shaped and has a second hole circle (11), characterized in that the first bearing ring (3) is designed with a rotor hub extension (9) which extends on the hub side in the direction of the bearing axis (A) beyond the second bearing ring (5) and in the hub-side end region (E) of which the first hole circle (4) is arranged, wherein the second hole circle (11) is connected to the first hole circle (4) for common fastening aligned with the hub body (13).

2. Device according to claim 1, characterized in that the hub-side extender bearing unit (10) has a plate thickness (D) which is at least 20%, preferably at least 50% and particularly preferably at least 70% of an axial wall thickness (W) of the rotor hub extension (9) in its hub-side end region (E).

3. Device according to claim 1 or 2, characterized in that the hub-side extender bearing unit (10) has, in addition to the second bolt circle (11), fastening means (12) for a temporary or permanent fixation of the hub-side extender bearing unit (10) to the hub body (13).

4. Device according to one of claims 1 to 3, characterized in that at least one row of rolling elements (6, 7, 8) are provided which can roll between the bearing rings (3, 5) and have a rolling element diameter (WD), and the rotor hub extension extends in the direction of the bearing axis (A) by at least 3 times the rolling element diameter (WD) of the row of the largest rolling elements (7, 8) extends beyond the second bearing ring (5).

5. Device according to one of claims 1 to 4, characterized in that the hub-side extender bearing unit (10) comprises at least two parts (10', 10"), each containing a circumferential section (1T, 11") of the second bolt circle (11).

6. Multi-part hub arrangement for a wind turbine (100), comprising a hub body (13) with fastening means (22) for fastening the hub arrangement (150) to a nacelle (120) of the wind turbine (100) and at least one third hole circle (14) for fastening a rotor blade (140) of the wind turbine (100), wherein the hub body (13) comprises at least two hub body segments (13', 13", 13'"), on each of which a peripheral section (14', 14") of the third hole circle (14) is formed and which are arranged such that the peripheral sections (14', 14") together form the third hole circle (14), characterized in that the hub arrangement (150) further comprises a fastening device (1) according to one of claims 1 to 5, wherein the third hole circle (14) is connected to the first hole circle (4) and the second hole circle (11) aligned and the fastening device (1) is fastened to the hub body (13) with a plurality of screws (15) which each extend through the first (4), second (11) and third bolt circle (14).

7. Multi-part hub arrangement according to claim 6, characterized in that the third bolt circle (14) is designed as through holes which are arranged in a radial flange (16) of the hub body (13).

8. Multi-part hub arrangement according to claim 7, characterized in that the hub-side extender bearing unit (10) is arranged on the inside of the hub of the flange (16) and the blade-side extender bearing unit (2) is arranged on the outside of the hub of the flange (16).

9. Multi-part hub arrangement according to claim 6, characterized in that the third bolt circle (14) is designed as blind holes in the hub body (13), wherein the hub-side extender bearing unit (10) and the blade-side extender bearing unit (2) are arranged on the outside of the hub body (13).

10. Multi-part hub arrangement according to one of claims 6 to 9 with a fastening device (1) according to claim 5, characterized in that the circumferential sections (1T, 11") of the second bolt circle (11) formed on the parts (10', 10") of the hub-side extender bearing unit (10) are each arranged to overlap with at least two circumferential sections (14', 14") of the third bolt circle (14) formed on the hub body segments (13', 13").

11. Multi-part hub arrangement according to one of claims 6 to 10, characterized in that the hub body segments (13', 13") on the windward side and/or the windward side are connected to one another by means of at least one stiffening ring (17, 18, 19).