Hub assembly for a wind turbine

Abstract

The invention relates to a hub assembly (1) for a wind turbine, comprising: a hub body (2), with at least one connection surface (3) in which a first hole circle (4) is formed; a blade-side extender bearing unit (5) comprising a first bearing ring (6) with a second hole circle (7) which is aligned to the first hole circle (4) and a second bearing ring (8) for fastening to a rotor blade of the wind turbine, wherein the second bearing ring (8) is arranged coaxially to the first bearing ring (6) so as to be rotatable about the common bearing axis; and a hub-side extender bearing unit (9), wherein the hub body (2) is screwed to the first bearing ring (6) via the first and the second hole circle (4, 7) and wherein the hub-side extender bearing unit (9) comprises at least two tabs (10) which each extend over a circumferential portion of the hole circles (4, 7) and have a corresponding hole circle arc which is aligned to the hole circles (4, 7), wherein the tabs (10) are inserted in the screw connection of the hub body (2) with the first bearing ring (6).

Description

[0001] Hub arrangement for a wind turbine

[0002] State of the art

[0003] The invention relates to a hub arrangement for a wind turbine according to the preamble of claim 1.

[0004] The rotor blades of wind turbines are attached to the hub body using slewing bearings. These slewing bearings enable the adjustment of the rotor blades' angle of attack to the wind, which is necessary, among other things, for controlling the turbine's power. In addition to the bearings, a typically hydraulic or electric adjustment drive is provided for adjusting the rotor blade.

[0005] Hub bodies for wind turbines currently available on the market are generally constructed as one-piece cast molds. If required, separately manufactured stiffening plates can be bolted to the hub body to stiffen the blade and / or rotor bearing connection surfaces. These conventional stiffening plates have a simple, circular disk-shaped geometry and are bolted to the hub body, rotor blade, or blade bearing over a 360° bearing circumference using a bolt circle.

[0006] From WO 2012 / 069062 A1, a hub assembly according to the preamble of claim 1 is known. WO 2012 / 069062 A1 describes a blade adjustment system for rotating a blade of a wind turbine relative to a hub, comprising a bearing with an inner bearing ring for mounting on the hub, and an outer bearing ring for mounting on the blade. A first plate-shaped connecting element is arranged between the hub and the inner bearing ring and covers the opening in the hub at the attachment point for the inner bearing ring, except for an opening that allows access from the hub into the blade.

[0007] A disadvantage is that the plate-shaped connecting element has a high dead weight, which increases the mass of the hub body. In addition, plates with the diameter of the blade connection surface are becoming increasingly difficult to manufacture and transport to the wind turbine site due to technical developments towards ever larger hub bodies. If stiffening plates are to be dispensed with, a conventional solution is to make the wall thickness of the hub body correspondingly stronger, but this has the disadvantage of a particularly high hub weight. Initial considerations for a segmented design of hubs for wind turbines are known, for example, from EP 2 691 646 B1, EP 2 516 845 B1 and DE 102011 052 668 B4. What all of these patents have in common is that the individual hub segments have to be connected to one another using additional screw connections, which is a complex process.To achieve sufficient hub rigidity, the segments are either designed with additional flanges to directly connect them at the joints, or additional connecting plates with multiple bolt circles are required to provide a sufficiently stable connection surface for the blade bearings. In some cases, additional stiffening elements are even required in the hub, which complicates accessibility. All of these measures result in complex manufacturing and assembly of the segmented hubs and a high weight.

[0008] Disclosure of the invention

[0009] The object of the invention is therefore to provide a hub arrangement for a wind turbine which, while maintaining sufficient torsional rigidity of the hub-side blade bearing connection surfaces, has a reduced weight and leads to simplifications in production, transport and assembly.

[0010] This object is achieved by a hub arrangement for a wind turbine having the features of claim 1.

[0011] This creates a hub arrangement for a wind turbine, comprising a hub body, a blade-side extender bearing unit, and a hub-side extender bearing unit. The hub body is equipped with at least one connecting surface in which a first bolt circle is formed. The blade-side extender bearing unit comprises a first bearing ring with a second bolt circle that is aligned with this first bolt circle of the connecting surface. The blade-side extender bearing unit further comprises a second bearing ring for attachment to a rotor blade of the wind turbine. The second bearing ring is arranged coaxially to the first bearing ring and can be rotated about the common bearing axis. The hub body is screwed to the first bearing ring via the first and second bolt circles.According to the invention, the hub-side extender bearing unit comprises at least two tabs, each extending over a circumferential section of the bolt circles and having a corresponding bolt circle arc that is aligned with the bolt circles. The tabs are inserted into the screw connection of the hub body to the first bearing ring. The invention is therefore based on the finding that, in order to stiffen the hub-side blade bearing connection surfaces of the hub body, it is sufficient to provide local reinforcements of the hub body in the form of tab-shaped stiffening elements of a hub-side extender bearing unit, provided that these are inserted into the screw connection of the hub body to the first bearing ring of a blade-side extender bearing unit. By screwing the hub body, hub-side extender bearing unit, and blade-side extender bearing unit together, the contact area in the frictional engagement of the screw connection is locally increased.The resulting increase in the load-bearing capacity of the frictional connection reduces deformation of the hub body in this area. Furthermore, the joint bolting of the hub-side and blade-side extender bearing units makes it possible to utilize the stiffening effect of the blade-side extender bearing unit on the hub-side connection surface to a greater extent. Since the loads on the hub body occur unevenly across the circumference of the connection surface during hub rotation, because they are caused at least in part by the weight of the rotor blades rotating around the hub axis, it has been shown that such local reinforcements ensure sufficient stiffening of the hub-side connection surface, particularly in the circumferential areas subject to the most structural stress.The same applies analogously to the case of segmented hub bodies, where the highly stressed circumferential areas of the hub-side blade bearing connection surfaces – due to the segmentation – arise at the segment joints of the adjacent hub segments. Local stiffening according to the invention also ensures sufficient stiffening of the hub-side blade bearing connection surfaces.

[0012] Furthermore, it is advantageous that the hub assembly according to the invention has a reduced overall weight. The use of tabs for local stiffening allows for weight savings compared to a conventional stiffening plate. Weight savings are also achieved compared to a solution without a stiffening element and a correspondingly thicker hub wall.

[0013] Finally, the joint bolting of the hub body to the hub-side and blade-side extender bearing units in a common bolt circle offers advantages in production due to reduced machining effort for producing connecting flanges and bores, as well as in assembly due to the smaller number of screws required. In preferred embodiments, at least two of the tabs are arranged diametrically opposite each other. Due to the preferred direction of the loads introduced into the connection surface, which is determined by the hub axis—whether due to external loads from the wind turbine or due to hub segmentation—the structurally most stressed areas of the hub-side connection surface typically occur diametrically opposite each other on the circumference of the connection surface.

[0014] Furthermore, it is preferred if at least two of the tabs are connected to each other via a web to radially stiffen the connection surface. Connecting the tabs via a web effectively reduces radial deformation of the connection surface and thus prevents ovalization. Particularly preferably, the tabs are formed integrally with the web.

[0015] Furthermore, it is preferred if the web has at least one rib to increase flexural rigidity. A rib, as defined in this disclosure, is a local increase in the thickness of the web in the direction of the width of the web, which extends in the longitudinal direction of the web. Ribs thus increase the area moment of inertia of the web and stiffen it against deflection in the thickness direction. Furthermore, the assembly consisting of tabs, web, and radial ribbing represents a particularly advantageous solution from the perspective of manufacturing and assembly costs—especially for large hub structures and consequently large diameters of the hub-side blade bearing connecting surfaces.

[0016] In some embodiments, the web has a web width that ranges from 30% to 90% of the maximum width of the circumferential sections covered by the tabs connected by the web. The web width is thus smaller than the width of all circumferential sections covered by the tabs. Since the web primarily serves to absorb tensile and compressive loads, as well as bending loads in the longitudinal direction of the web, the width of the web can be selected within this range to reduce weight.

[0017] Preferably, the hub body is formed with a flange section in the region of the link plates that protrudes radially relative to the first bearing ring, and the flange section is screwed to the link plates via a plurality of fastening bores. In the region of the protruding flange section, there is thus an additional screw connection between the hub body and the hub-side extender bearing unit, which is radially spaced from the first and second bolt circles. The additional connection between the hub body and link plates can further increase the rigidity of the hub body. With a segmented design of the hub body, the additional screw connection can also be advantageously used for pre-assembly of the hub body before connecting the blade-side extender bearing unit.

[0018] Furthermore, embodiments are conceivable in which the hub-side extender bearing unit comprises at least four plates, which are evenly or irregularly distributed around the circumference of the bolt circles. In particular, the four plates can be connected to each other in a star shape via webs. With such a design, it is advantageous that the circular shape of the connection surface is stabilized under loads on the hub body in more than one direction.

[0019] Preferably, the tabs extend over circumferential sections of the bolt circles with a center angle in the range of 20° to 70°, preferably between 30° and 60°. The tabs thus cover only a fraction of the circumference of the bolt circles and accordingly have a locally stiffening effect.

[0020] Furthermore, it is preferred if the center angles of the circumferential sections covered by the tabs total at most 280°, particularly preferably at most 230° and further preferably at most 180°.

[0021] Particular further advantages of the invention arise in embodiments in which the hub body comprises at least two hub body segments, on each of which a section of the first bolt circle is formed, wherein the sections are joined together in such a way that together they form the first bolt circle and the joints are each bridged by a tab. By segmenting the hub body, larger hubs can be transported to the site of the wind turbine in parts. The hub segments are also easier to manufacture because no one-piece hollow body needs to be cast. Handling during machining and assembly are simplified by the lower weight and smaller dimensions of the segments compared to a one-piece hub body. In the hub arrangement according to the invention, the blade-side extender bearing unit is therefore the component with the largest transport diameter to be transported to the site of the wind turbine.The hub assembly according to the invention enables particularly simple assembly, with the blade-side extender bearing unit providing the primary stabilization for the multi-part hub body. At the joints, the hub body is additionally supported by the tabs as local stiffening elements. Thus, direct bolting of the hub segments to one another is not required, nor are any additional structural elements inside the hub required for stabilization.

[0022] The assembly of the hub arrangement according to the invention is advantageously carried out by the joint screwing of the hub body segments with the blade-side and hub-side extender bearing unit.

[0023] Preferably, the connection surface is designed as a connection flange with through holes as a first bolt circle, with the hub-side extender bearing unit being arranged on the inside of the hub of the connection flange and the blade-side extender bearing unit being arranged on the outside of the hub of the connection flange. The sandwich-like arrangement and screw connection of the connection flange between the blade-side and hub-side extender bearing units further increases the area effective for frictional engagement, since both axial surfaces of the flange are utilized for the transmission of thrust and friction forces. Furthermore, with these embodiments, the bending stress on the screw connection connecting both extender bearing units to the one-piece hub body or the hub segments can be reduced.

[0024] In alternative embodiments, the first bolt circle is formed as blind holes in the connection surface, with the hub-side extender bearing unit and the blade-side extender bearing unit being arranged on the outside of the hub body. To ensure uniform support of the blade-side extender bearing unit over its circumference, the connection surface on the hub body and / or the corresponding connection surface of the blade-side extender bearing unit can be provided with recesses for receiving the hub-side extender bearing unit. The recesses for receiving the hub-side extender bearing unit allow the blade-side extender bearing unit to rest directly on the hub body in the remaining circumferential sections. Alternatively, spacer ring elements can be provided between the tabs of the hub-side extender bearing unit for the purpose of uniform support.This design is characterized by only one machined hub-side support surface for fastening the extender bearing units.

[0025] Finally, it is preferred if the first bearing ring is formed with a rotor hub extension which extends beyond the second bearing ring on the hub side in the direction of the bearing axis and in whose hub-side end region the second bolt circle is arranged. The rotor hub extension integrated in the blade-side extender bearing unit increases the rigidity of the blade-side extender bearing unit, which contributes to the stiffening of the hub-side connection surface. This allows, in particular, improved absorption of the additional stresses arising as a result of segmentation of the hub body. Furthermore, the spacing of the connection surface from the first bearing ring arranged on the blade-side extender bearing unit reduces deformations of the bearing ring that could impair the blade bearing.

[0026] Further advantageous embodiments can be found in the following description and the subclaims.

[0027] The invention is explained in more detail below with reference to the embodiments shown in the attached figures.

[0028] Brief description of the drawings

[0029] Fig. 1 shows schematically a wind turbine with a hub arrangement according to the invention,

[0030] Fig. 2 shows schematically a first embodiment of the hub assembly according to the invention in a perspective view,

[0031] Fig. 3 shows schematically the structure of the hub body of the hub assembly according to Fig. 2 in an exploded view,

[0032] Fig. 4 shows schematically in a partially sectioned, perspective view a detailed representation of the fastening of the blade-side and hub-side extender bearing unit to the hub body of the hub arrangement according to Fig. 2,

[0033] Fig. 5 shows schematically in a partially sectioned, perspective view a detailed representation of the connection surface of the hub body of the hub arrangement according to Fig. 2, designed as a connection flange with through holes,

[0034] Fig. 6 shows schematically in a partially sectioned view a second embodiment of the hub arrangement according to the invention, in which the first bolt circle is designed as blind holes in the connection surface,

[0035] Fig. 7 shows schematically a hub-side connection surface of a hub body with a hub-side extender bearing unit designed as two tabs, Fig. 8 shows schematically a hub-side connection surface of a hub body with a hub-side extender bearing unit comprising two tabs connected by a web,

[0036] Fig. 9 shows schematically a hub-side connection surface of a hub body with a hub-side extender bearing unit comprising two tabs connected by a web, which are additionally screwed to a radially projecting flange section of the hub body, and

[0037] Fig. 10A to C schematically show further design variants of the hub-side extender bearing unit.

[0038] Embodiments of the invention

[0039] In the various figures, identical parts are always provided with the same reference symbols and are therefore usually named or mentioned only once.

[0040] Fig. 1 shows a wind turbine 100 with a hub assembly 1 according to the invention. 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 the hub assembly 1 according to the invention and a plurality of rotor blades 140 rotatably mounted on the hub assembly 1. Typically, the rotor 130 comprises three rotor blades 140, as shown.

[0041] The rotor blades 140 are rotatably mounted on the hub assembly 1 to enable power control of the wind turbine 100 in fluctuating wind conditions. Furthermore, the rotor blades 140 can be adjusted to the feathered position, i.e., in the direction of the wind, to minimize the power consumption of the rotor blades 140 and decommission the wind turbine 100.

[0042] For fastening at least one of the rotor blades 140, the hub assembly 1 according to the invention comprises a blade-side extender bearing unit 5 and a hub-side extender bearing unit 9, which are fastened to the hub body 2 (see Figs. 4 and 6). Preferably, all rotor blades 140 are fastened to the hub body 2 in this manner.

[0043] The structure of the hub assembly 1 according to the invention is explained in more detail below with reference to Figures 2 to 10. Figures 2 to 5 show a first exemplary embodiment of the hub assembly 1 according to the invention. Figure 2 shows a perspective external view of the hub assembly 1. To better illustrate the structure of the hub assembly 1, Figure 3 shows an exploded view, and Figures 4 and 5 show detailed illustrations of the hub body 2 and the components connected to it. In the illustration according to Figure 3, a hub body segment and the blade-side extender bearing unit are not shown for the sake of clarity.

[0044] In the first exemplary embodiment illustrated in Figs. 2 to 5, a hub assembly 1 for a wind turbine 100 is shown. The hub assembly 1 comprises a hub body 2, as well as at least one blade-side extender bearing unit 5 and one hub-side extender bearing unit 9. The hub body 2 has at least one connection surface 3 in which a first bolt circle 4 is formed.

[0045] In the illustrated embodiment, the hub body 2 comprises three connection surfaces 3, each of which interacts with a blade-side extender bearing unit 5 and a hub-side extender bearing unit 9 in the manner described below. However, embodiments are also conceivable in which a different number of rotor blades are to be connected to the hub body, or in which only individual rotor blades are attached to the hub assembly via the inventive interaction of the hub body, the hub-side extender bearing unit, and the blade-side extender bearing unit.

[0046] The blade-side extender bearing unit 5 comprises a first bearing ring 6 with a second bolt circle 7, which is aligned with the first bolt circle 4, and a second bearing ring 8 for attachment to a rotor blade 140 of the wind turbine 100. The hub body 2 is screwed to the first bearing ring 6 via the first and second bolt circles 4, 7. The second bearing ring 8 is arranged coaxially to the first bearing ring 6 and is rotatable about the common bearing axis A.

[0047] According to the invention, the hub-side extender bearing unit 9 comprises at least two tabs 10, 11, each extending over a circumferential section 17 of the bolt circles 4, 7 and having a corresponding bolt circle arc 14 aligned with the bolt circles 4, 7. The tabs 10, 11 are inserted into the screw connection of the hub body 2 to the first bearing ring 6 (see Fig. 4). Preferably, at least two of the tabs 10, 11 are arranged diametrically opposite one another.

[0048] Preferably, the first bearing ring 6 of the blade-side extender bearing unit 5 is formed with a rotor hub extension 21, which extends beyond the second bearing ring 8 on the hub side in the direction of the bearing axis A, and in whose hub-side end region E the second bolt circle 7 is arranged. Preferably, the rotor hub extension 21 extends beyond the second bearing ring 8 in the axial direction A by at least half the axial extent of the latter. This achieves an axial spacing of the bearing rings 6, 8 relative to the hub-side connection surface 3, which reduces deformations and the resulting wear stresses on the blade bearing.

[0049] The first bearing ring 6 can be divided into two or more partial rings 6', 6". Depending on the bearing design, the second bearing ring 8 can alternatively or additionally be divided into two or more partial rings (not shown). The division of the bearing rings simplifies the assembly of the bearing. By way of example, the bearing composed of the first bearing ring 6 and the second bearing ring 8 is shown in the exemplary embodiments as a three-row roller bearing assembly. However, the invention also encompasses other bearing designs with any rolling elements (such as balls or rollers) and / or plain bearings.

[0050] As can be seen in particular from Fig. 3, the hub body 2 can preferably comprise at least two hub body segments 2', 2", on each of which a section 4', 4" of the first bolt circle 4 is formed. The sections 4', 4" are then joined together during assembly of the hub body 2 such that they together form the first bolt circle 4. The joining points 20 are each bridged by a tab 10, 11. With such a segmented design of the hub body 2, the hub body segments 2', 2" can preferably additionally be connected to one another by one or more rings 22 on the upwind and / or downwind side of the hub body 2.

[0051] The detailed illustrations in Figs. 4 and 5 show that the connection surface 3 in this first exemplary embodiment is designed as a connection flange with through holes forming the first bolt circle 4. The hub-side extender bearing unit 9 is arranged on the inside of the hub of the connection flange, and the blade-side extender bearing unit 5 is arranged on the outside of the hub of the connection flange. The hub-side and blade-side extender bearing units 9, 5 thus form a sandwich-like arrangement with the connection flange forming the connection surface 3. The top and bottom sides of the connection flange are thus utilized to create a frictional connection in the screw connection.

[0052] 4 and 5 that the hub body 2 can be formed with a flange section 18 projecting radially relative to the first bearing ring 6 in the region of the tabs 10, 11, wherein the flange section 18 is screwed to the tabs 10, 11 via a plurality of fastening bores 19. The fastening of the flange sections 18 to the tabs 10, 11 provides additional stabilization of the hub body 2 that is independent of the screw connection of the first bolt circle 4. In particular, when assembling a multi-part hub body composed of hub body segments 2', 2", 2'", the screw connection of the flange sections 18 to the tabs 10, 11 allows pre-assembly of the hub body 2 before the blade-side extender bearing unit 5 is attached via the first bolt circle 4.

[0053] Fig. 6 schematically shows a hub assembly 1 according to the invention according to a second exemplary embodiment. Since only the difference in the fastening of the blade-side extender bearing unit 5 and the hub-side extender bearing unit 9 compared to the first exemplary embodiment according to Figures 2 to 5 is to be clarified, only one hub body segment 2' of the hub body 2 is shown in the illustration according to Fig. 6 for the sake of clarity.

[0054] In contrast to the first exemplary embodiment, in Fig. 6, the first bolt circle 4 is formed as blind holes in the hub-side connection surface 3. The hub-side extender bearing unit 9 and the blade-side extender bearing unit 5 are both arranged on the outside of the hub body 2. Fastening is achieved by screws 24, which engage through the blade-side extender bearing unit 5 and the hub-side extender bearing unit 9 into the blind holes. This allows for simplified production of the hub body, with only one finely machined support surface 3 for the hub-side extender bearing unit 9.

[0055] In the embodiment according to Fig. 6, it is preferably provided that spacer ring sections 23 are arranged between the tabs 10, 11 on the connecting surface 3, which spacer ring sections provide an additional support surface for the blade-side extender bearing unit 5 between the tabs 10, 11. The spacer ring sections 23 therefore preferably end flush with the tabs 10, 11. Alternatively, according to an embodiment not shown, the connecting surface can have recesses for receiving the tabs, so that the tabs, after being received in the recesses, preferably end flush with the connecting surface.

[0056] With reference to Fig. 7 to 10, various embodiments of the hub-side extender bearing unit 9 are described below. All of the embodiments shown in Fig. 7 to 10 can be combined with both of the previously described embodiments, i.e. each of the hub-side extender bearing units 9 according to Fig. 7 to 10 can be used in the hub assemblies according to the invention according to Fig. 2 to 6. Fig. 7 shows an embodiment in which the hub-side extender bearing unit 9 consists of two tabs 10, 11. The tabs 10, 11 each extend over a circumferential section 17 of the first bolt circle 4 in the connection surface 3. The circumferential extension of the tabs 10, 11 defines a center angle ß1, ß2 assigned to the respective tabs 10, 11.The tabs 10, 11 preferably extend over a circumferential section 17 of the bolt circle 4 with a center angle ß1, ß2 in the range of 20° to 70°, particularly preferably between 30° and 60°. For example, the tab 11 is equipped with fastening holes 19, designed for interaction with a flange section 18 projecting radially inwardly relative to the first bearing ring, while the tab 10 does not have such fastening holes. Likewise, design variants are conceivable in which both tabs have such fastening holes or both tabs are designed without such fastening holes.

[0057] In preferred embodiments, the tabs 10, 11 extend over circumferential sections 17 of the hole circles 4, 7 with a center angle ß1, ß2 in the range of 20° to 70°, preferably between 30° and 60°. The center angles ß1, ß2 of the circumferential sections 17 covered by the tabs 10, 11 preferably total at most 280°, more preferably at most 230°, and particularly preferably at most 180°.

[0058] The embodiment shown in Fig. 8 differs from the previously described embodiment in that, for radial stiffening of the connecting surface 3, the two tabs 10, 11 are connected to each other via a web 15. It is preferred if the tabs 10, 11 are formed integrally with the web 15, as this allows particularly high stiffness to be achieved. Finally, the web 15 can preferably have at least one rib 16 to increase its flexural rigidity. The rib 16 results in a T-profile of the web 15 in the slightly enlarged section AA shown in Fig. 8.

[0059] The web 15 preferably has a web width W1 which is in the range of 30% to 90% of the maximum width W2 of the circumferential sections 17 covered by the tabs 10, 11 connected by the web 15.

[0060] The design variants according to Fig. 9 differ from Fig. 8 in that fastening holes 19 are provided for an additional screw connection of the tabs 10, 11 with the radially projecting flange section 18 of the hub body 2. Otherwise, the statements regarding the previous design variants apply accordingly to Fig. 8 and 9.

[0061] In Fig. 10A to 10C, three further design variants of the hub-side extender bearing unit 9 are shown.

[0062] Fig. 10A shows a variant with two tabs 10, 11 connected by a web. Compared to Figs. 8 and 9, the tabs are designed asymmetrically, with the tab 11 extending over a significantly larger circumferential section with the center angle ß2 than the tab 10.

[0063] Fig. 10B shows a variant of the hub-side extender bearing unit 9 with four plates 10, 11, 12, 13, which are evenly distributed over the circumference of the bolt circles 4, 7. The four plates 10, 11, 12, 13 are connected to each other in a star shape via webs 15, 15'.

[0064] Additionally, spacer ring sections 23 are shown in dashed lines in Fig. 10B, which can be used in an assembly according to the second embodiment (see Fig. 6). Similar spacer ring sections 23 can also be used in all other embodiments when assembled according to Fig. 6.

[0065] The design variant shown in Fig. 10C corresponds to the variant shown in Fig. 10B, with the difference that the tabs 10, 11, 12', 13' are distributed unevenly around the circumference of the bolt circles 4, 7. Due to the uneven distribution, the extender bearing unit 9 can be optimized for uneven load cases.

[0066] All tabs 10, 11, 12, 13, 12', 13' extend over circumferential sections of the bolt circles 4, 7 with a center angle ß1, ß2, ß3, ß4, which are in the range of 20° to 70°, preferably between 30° and 60°. The center angles ß1, ß2, ß3, ß4 of the circumferential sections covered by the tabs 10, 11, 12, 13, 12', 13' preferably total at most 280°, more preferably at most 230°, and particularly preferably at most 180°.

[0067] Otherwise, the statements regarding the previous embodiments apply accordingly to Figs. 10A to 10C.

[0068] 1 hub arrangement

[0069] 2 hub bodies

[0070] 2', 2", 2'" hub body segments

[0071] 3 Connection surface

[0072] 4 first bolt circle

[0073] 4', 4" section of the first bolt circle

[0074] 5 blade-side extender bearing unit

[0075] 6 first bearing ring

[0076] 6', 6" partial rings

[0077] 7 second bolt circle

[0078] 8 second bearing ring

[0079] 9 hub-side extender bearing unit

[0080] 10 to 13, 12', 13' tabs

[0081] 14 bolt circle arches

[0082] 15 jetty

[0083] 16 ribs

[0084] 17 Circumferential section

[0085] 18 Flange section

[0086] 19 mounting holes

[0087] 20 joints

[0088] 21 Rotor hub extension

[0089] 22 rings

[0090] 23 spacer ring sections

[0091] 24 screw

[0092] 100 wind turbines

[0093] 110 Tower

[0094] 120 gondolas

[0095] 130 rotor

[0096] 140 rotor blade

[0097] A bearing axis ß1 , ß2, ß3, ß4 center angle

[0098] E hub-side end area of ​​the rotor hub extension

[0099] W1 web width

[0100] W2 maximum width of the tabs

Claims

PATENT CLAIMS 1 . Hub arrangement for a wind turbine (100), comprising a hub body (2) with at least one connection surface (3) in which a first hole circle (4) is formed, a blade-side extender bearing unit (5) comprising a first bearing ring (6) with a second hole circle (7) which is aligned with the first hole circle (4), and a second bearing ring (8) for fastening to a rotor blade (140) of the wind turbine (100), wherein the second bearing ring (8) is arranged coaxially to the first bearing ring (6) so as to be rotatable about the common bearing axis (A), and a hub-side extender bearing unit (9), wherein the hub body (2) is screwed to the first bearing ring (6) via the first and second hole circles (4, 7), characterized in that the hub-side extender bearing unit (9) comprises at least two tabs (10, 11, 12, 13), which each extend over a circumferential section (17) of the hole circles (4, 7) and have a corresponding hole circle arc (14),which is aligned with the bolt circles (4, 7) and the tabs (10, 11, 12, 13) are inserted into the screw connection of the hub body (2) with the first bearing ring (6).

2. Hub arrangement according to claim 1, characterized in that at least two of the tabs (10, 11; 12, 13) are arranged diametrically opposite one another.

3. Hub arrangement according to claim 1 or 2, characterized in that for radial stiffening of the connecting surface (3) at least two of the tabs (10, 11, 12, 13) are connected to one another via a web (15).

4. Hub arrangement according to claim 3, characterized in that the tabs (10, 11, 12, 13) are formed in one piece with the web (15).

5. Hub arrangement according to claim 3 or 4, characterized in that the web (15) has at least one rib (16) to increase the flexural rigidity.

6. Hub arrangement according to one of claims 1 to 5, characterized in that the web (15) has a web width (W1) which is in the range of 30% to 90% of the maximum width (W2) of the circumferential sections (17) covered by the tabs (10, 11, 12, 13) connected by the web (15).

7. Hub arrangement according to one of claims 1 to 6, characterized in that the hub body (2) in the region of the tabs (10, 11, 12, 13) is formed with a flange section (18) projecting radially relative to the first bearing ring (6) and the flange section (18) is screwed to the tabs (10, 11, 12, 13) via a plurality of fastening bores (19).

8. Hub arrangement according to one of claims 1 to 7, characterized in that the hub-side extender bearing unit (9) comprises at least four tabs (10, 11, 12, 13) which are arranged distributed evenly or unevenly over the circumference of the bolt circles (4, 7).

9. Hub arrangement according to claim 8, characterized in that the four tabs (10, 11, 12, 13) are connected to one another in a star shape via webs (15, 15').

10. Hub arrangement according to one of claims 1 to 9, characterized in that the tabs (10, 11, 12, 13) extend over circumferential sections (17) of the bolt circles (4, 7) with a center angle (ß1, ß2, ß3, ß4) in the range from 20° to 70°, preferably between 30° and 60°.

11. Hub arrangement according to one of claims 1 to 10, characterized in that the center angles (ß1, ß2, ß3, ß4) of the circumferential sections (17) covered by the tabs (10, 11, 12, 13) amount in total to at most 280°, preferably to at most 230° and particularly preferably to at most 180°.

12. Hub arrangement according to one of claims 1 to 11, characterized in that the hub body (2) comprises at least two hub body segments (2', 2"), on each of which a section (4', 4") of the first bolt circle (4) is formed, wherein the sections (4', 4") are joined together in such a way that they jointly form the first bolt circle (4), and the joints (20) are each bridged by a tab (10, 11, 12, 13).

13. Hub arrangement according to one of claims 1 to 12, characterized in that the connecting surface (3) is designed as a connecting flange with through holes as a first bolt circle (4), wherein the hub-side extender bearing unit (9) is arranged on the inside of the hub of the connecting flange and the blade-side extender bearing unit (5) is arranged on the outside of the hub of the connecting flange.

14. Hub arrangement according to one of claims 1 to 12, characterized in that the first bolt circle (4) is designed as blind holes in the connection surface (3), wherein the hub-side extender bearing unit (9) and the blade-side extender bearing unit (5) are arranged on the outside of the hub body (2).

15. Hub arrangement according to one of claims 1 to 14, characterized in that the first bearing ring (6) is formed with a rotor hub extension (21) which extends on the hub side in the direction of the bearing axis (A) beyond the second bearing ring (8) and in whose hub-side end region (E) the second bolt circle (7) is arranged.

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