Rotor hub having slotted holes

Abstract

The invention relates to a rotor hub (109) comprising a first screwed flange (201) for screwing together with an output shaft or output hub (107) of a gearing (101) of a wind turbine, and further comprising a second screwed flange (203) for screwing together with a rotor (111) of a generator (103) of the wind turbine. The one or more screw holes (209) of the second screwed flange (203) are slotted holes.

Description

[0001] Rotor hub with elongated holes

[0002] The invention relates to a rotor hub according to the preamble of claim 1, a method according to the preamble of claim 5, a generator rotor according to the preamble of claim 6 and a method according to the preamble of claim 7.

[0003] EP 3 899 255 B1 discloses a drive train for a wind turbine with a gearbox and a generator. The hub has a first screw flange for screwing to the output shaft and a second screw flange for screwing to the rotor. The screw holes of the first screw flange are designed as elongated holes. This makes it possible to connect the rotor and the output shaft to the hub at any angular position relative to each other.

[0004] The invention is based on the object of advantageously developing the prior art. This object is achieved by a rotor hub according to claim 1, a method according to claim 5, a generator rotor according to claim 6, and a method according to claim 7. Preferred developments emerge from the subclaims as well as the following description and the figures.

[0005] The rotor hub according to the invention comprises a first screw flange and a second screw flange. A screw flange generally refers to a rotationally symmetrical means for screwing to a counterpart. The screw flange preferably has a circular ring-shaped surface provided with screw holes as the contact surface with which it rests against the counterpart. The counterpart can also be a screw flange.

[0006] The first screw flange is used for screwing to an output shaft or hub of a wind turbine gearbox, or for screwing to a screw flange of the output shaft or hub. The first screw flange is therefore screwed or can be screwed to the output shaft or hub, or its screw flange. The second screw flange is designed for screwing to a rotor of a wind turbine generator, or to a flange of the rotor.

[0007] The second screw flange is thus screwed or can be screwed to the rotor or its screw flange. In particular, the second screw flange can be designed for screwing to an armature or magnet wheel of the rotor.

[0008] According to the invention, one or more screw holes, preferably all of the screw holes, of the second screw flange are designed as elongated holes. These preferably extend in the circumferential direction relative to a rotational axis of the rotor hub.

[0009] The invention is based on the finding that while the elongated holes improve assembly, the load-bearing capacity of the respective screw flange deteriorates due to the lack of positive locking within the elongated holes. This could be counteracted by increasing the diameter of the screw flange. By increasing the diameter, a reduction in the forces transmitted in the flange can be achieved while maintaining the same torque load.

[0010] However, the size of the first screw flange is limited by the size of the output shaft or hub. The inventive connection to the rotor, however, allows the diameter of the second screw flange to be significantly increased. This reduces the forces transmitted via the second screw flange. Consequently, the transmittable torque is not reduced by the elongated holes, while the advantage of improved assembly is retained.

[0011] The rotor hub is preferably constructed in one piece.

[0012] Preferably, the rotor hub is further developed with a central part. This can be rotationally symmetrical to a rotational axis of the rotor hub. In particular, it can be rotationally symmetrical in the broader sense. This means that the central part can be mapped onto itself by rotation through a discrete number of angles less than 360°.

[0013] The middle section connects the first screw flange and the second screw flange. The middle section thus extends between the first screw flange and the second screw flange and is connected at its ends to the first screw flange and the second screw flange. In particular, the middle section can be integrally connected to the first screw flange and / or the second screw flange.

[0014] The center section preferably has a spoke structure. The center section consists of several interconnected spokes. The spokes preferably cross each other. This means that each spoke crosses at least one, preferably several, other spokes. At their ends, the spokes are each connected to the first screw flange and the second screw flange.

[0015] Starting from the central part, the first screw flange projects radially inwards and / or the second screw flange projects radially outwards. A radially inward projection of the first screw flange means that the first screw flange extends radially inwards towards the axis of rotation of the rotor hub, starting from the central part or starting from a section of the central part at which the central part is connected to the first screw flange. A radially outwards projection of the second screw flange analogously means that the second screw flange extends radially outwards from the axis of rotation of the rotor hub, starting from the central part or starting from a section of the central part at which the central part is connected to the second screw flange.

[0016] If the first screw flange projects inward and the second screw flange projects outward from the center section, the second screw flange extends radially further outward relative to the first screw flange. In particular, a bolt circle diameter, inner and / or outer diameter of the second screw flange can be larger than a bolt circle diameter, inner and / or outer diameter of the first screw flange. Due to the resulting leverage ratios, the forces to be transmitted to the second screw flange are reduced by the bolt flange's design.

[0017] The rotor hub is preferably further developed with an extension for receiving a brake disc. The extension is preferably integrally connected to the rest of the rotor hub.

[0018] The rotor hub described above can be assembled using a method according to the invention as part of a drive train of a wind turbine, which includes a gearbox and a generator in addition to the rotor hub. The method provides that the first screw flange is screwed to an output shaft or hub of the gearbox, or to a corresponding screw flange of the output shaft or hub. The second screw flange of the rotor hub is screwed to a rotor of the generator, or to a corresponding screw flange of the rotor, according to the method.

[0019] According to the invention, the rotor and the rotor hub are not rotated relative to each other between the two steps. Thus, according to the invention, there is no need to align the rotor relative to the rotor hub after screwing the rotor hub to the output shaft or hub, since the rotor hub according to the invention allows screwing to the rotor in any angular position of the rotor relative to the rotor hub.

[0020] Alternatively, the idea underlying the invention can be realized by a generator rotor with at least one screw flange. The screw flange is used for screwing to an output shaft or hub of a gearbox of a wind turbine or to a rotor hub joined to the output shaft or hub. The screw flange is therefore screwed or can be screwed to the output shaft or hub or to the rotor hub. The rotor hub can be a conventional rotor hub with circular-cylindrical screw holes. According to the invention, one or more screw holes, preferably all of the screw holes of the at least one screw flange of the generator rotor, are designed as elongated holes. These preferably extend in the circumferential direction with respect to a rotational axis of the generator rotor. The elongated holes allow the generator rotor to be screwed to the output shaft or hub or to the rotor hub in any rotational position.

[0021] A corresponding method according to the invention for assembling a drive train of a wind turbine, the drive train of which comprises a gearbox, a generator with a generator rotor according to the invention, and a rotor hub, provides for screwing a first screw flange of the rotor hub to an output shaft or hub of the gearbox or to a corresponding screw flange of the output shaft or hub. Furthermore, it is provided for screwing a second screw flange of the rotor hub to the rotor or to a corresponding screw flange of the rotor.

[0022] According to the invention, the rotor remains in its position relative to the rotor hub between the two steps. Thus, the rotor and the rotor hub are not rotated relative to each other between the two steps.

[0023] A preferred embodiment of the invention is illustrated in the figures. Corresponding reference numerals indicate identical or functionally equivalent features. In detail:

[0024] Fig. 1 shows a section of a drive train of a wind turbine; and

[0025] Fig. 2 a rotor hub.

[0026] The drive train shown in Fig. 1 comprises a transmission 101 and a generator 103. An output shaft 105 of the transmission 101 is connected in a rotationally fixed manner to a hub 107 via a spline. The hub 107 is bolted to a rotor hub 109, which in turn is bolted to a rotor 111 of the generator 111.

[0027] In addition to the rotor 111, the generator also includes a stator 113. The rotor hub 109 has a hollow cylindrical extension 115 for accommodating a brake disk. Further features of the rotor hub 109 can be seen in Fig. 2.

[0028] According to this, the rotor hub 109 is divided into a first screw flange 201, a second screw flange 203, and a central part 205 consisting of several intersecting spokes. The spokes, and thus the central part 205, extend between the first screw flange 201 and the second screw flange 203.

[0029] The first screw flange 201 has screw holes 207. These are designed as bores, i.e., as cylindrical holes.

[0030] The second screw flange also has screw holes 209. However, these are designed as elongated holes.

[0031] Reference symbol

[0032] Gearbox Generator

[0033] Output shaft hub rotor hub rotor

[0034] stator

[0035] appendage

[0036] Screw flange Screw flange Middle part Screw hole

[0037] screw hole

Claims

Patent claims 1. Rotor hub (109) with a first screw flange (201) for screwing to an output shaft or hub (107) of a gearbox (101) of a wind turbine, and with a second screw flange (203) for screwing to a rotor (111) of a generator (103) of the wind turbine; characterized in that one or more screw holes (209) of the second screw flange (203) are designed as elongated holes.

2. Rotor hub (109) according to claim 1; characterized by a central part (205) which connects the first screw flange (201) and the second screw flange (203) to one another; wherein the first screw flange (201) projects radially inward from the central part (205) and / or the second screw flange (203) projects radially outward from the central part (205).

3. Rotor hub (109) according to one of the preceding claims; characterized in that the second screw flange (203) extends radially further outward than the first screw flange (201).

4. Rotor hub (109) according to one of the preceding claims; characterized by an extension (115) for receiving a brake disc.

5. A method for assembling a drive train of a wind turbine with a gearbox (101), a generator (103) and a rotor hub (109) according to one of the preceding claims; with the steps - screwing the first screw flange (201) to an output shaft or hub (107) of the gearbox (101); and - screwing the second screw flange (203) to a rotor (111) of the generator (103); characterized in that between the two steps no rotation of the rotor (111) and the rotor hub (109) relative to each other occurs.

6. Generator rotor (111) with at least one screw flange for screwing to an output shaft or hub (107) of a gearbox (101) of a wind turbine or to a rotor hub (109) joined to the output shaft or hub (107); characterized in that one or more screw holes of the at least one screw flange are designed as elongated holes.

7. A method for assembling a drive train of a wind turbine with a gearbox (101), a generator (103) having a rotor (111) according to the preceding claim, and a rotor hub (109) having a first screw flange (201) and a second screw flange (203); comprising the steps of - screwing the first screw flange (201) to an output shaft or hub (107) of the gearbox (101); and - screwing the second screw flange (203) to the rotor (111); characterized in that between the two steps there is no rotation of the rotor (111) and the rotor hub (109) relative to each other.

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