Rotor hub with elongated holes

Abstract

The invention relates to a 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. The one or more screw holes (209) of the second screw flange (203) are designed as elongated holes.

Description

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.EP 3 899 255 B1 discloses a drive train for a wind turbine having a transmission 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 formed as elongated holes. This makes it possible to connect the rotor and the output shaft to the hub in any angular position relative to one another.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.The rotor hub according to the invention comprises a first screw flange and a second screw flange. A screw flange generally denotes a rotationally symmetrical means for screwing to a counterpart. Preferably as a contact surface with which it abuts the counter piece, the screw flange preferably has an annular surface which is provided with screw holes. The counterpiece can likewise be a screw flange.The first screw flange serves for screwing to an output shaft or hub of a gearbox of a wind turbine or for screwing to a screw flange of the output shaft or hub. The first screw flange is thus screwed or screwable to the output shaft or output shaft hub or the screw flange thereof.The second screw flange is designed for screwing to a rotor of a generator of the wind turbine or to a flange of the rotor. The second screw flange is thus screwed or screwable to the rotor or to its screw flange. In particular, the second screw flange can be designed for screwing to an armature or pole wheel of the rotor.According to the invention, one or more screw holes, preferably all screw holes of the second screw flange, are formed as elongated holes. These preferably extend in the circumferential direction with respect to an axis of rotation of the rotor hub.The invention is based on the finding that although the assembly capability is improved by the slots, the load-bearing capacity of the screw flange in question deteriorates due to the absence of a positive fit within the slots. This could be counteracted by increasing the diameter of the screw flange. By increasing the diameter, a reduction of the forces transmitted in the flange can be achieved with constant torque loading.However, the size of the first threaded flange is limited by the size of the output shaft or hub. By means of the connection according to the invention to the rotor, in contrast, the diameter of the second screw flange can be considerably increased. This reduces the forces transmitted via the second screw flange. The transmittable torque is consequently not reduced by the elongated holes, while the advantage of improved assembly is retained.The rotor hub is preferably embodied in one piece.Preferably, the rotor hub is further developed with a central part. This can be rotationally symmetrical to an axis of rotation 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 which are smaller than 360°.The middle part connects the first screw flange and the second screw flange to each other. The central part 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 central part can be connected integrally to the first screw flange and / or the second screw flange.Preferably, the central part has a spoke structure. The central part consists of several interconnected spokes. Preferably, the spokes run in a crossed manner. This means that each spoke crosses at least one, preferably several other spokes. At their ends, the spokes are connected to the first screw flange and the second screw flange, respectively.Starting from the central part, the first screw flange extends radially inward and / or the second screw flange extends radially outward. A radially inward protrusion of the first screw flange means that the first screw flange extends radially inward toward 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 outward projection of the second screw flange analogously means that the second screw flange extends radially outward 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.If the first screw flange protrudes inward and the second screw flange protrudes outward from the central part, a further development of the second screw flange with respect to the first screw flange results radially further outward. In particular, a pitch circle diameter, inner and / or outer diameter of the second screw flange can be greater than a pitch circle diameter, inner and / or outer diameter of the first screw flange. Due to the development of the screw flanges, the forces to be transmitted into the second screw flange are reduced due to the lever ratios associated therewith.The rotor hub is preferably further developed with an extension for receiving a brake disc. Preferably, the extension is integrally connected to the remaining rotor hub.The rotor hub described above can be mounted in a method according to the invention as part of a drive train of a wind turbine to which, in addition to the rotor hub, a gear mechanism and a generator belong. The method provides that the first screw flange is screwed to an output shaft or hub of the transmission or to a corresponding screw flange of the output shaft or hub. According to the method, 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 invention, the rotor and the rotor hub are not rotated relative to one another between the two steps. According to the invention, it is therefore not necessary to align the rotor relative to the rotor hub after the screwing of the rotor hub to the output shaft or hub, since the rotor hub according to the invention enables a screwing to the rotor in any desired rotational angle position of the rotor relative to the rotor hub.Alternatively, the idea underlying the invention can be realized by a generator rotor having at least one screw flange. The screw flange serves for screwing to an output shaft or output hub of a gearbox of a wind turbine or to a rotor hub joined to the output shaft or output hub. The screw flange is thus screwed or screwable to the output shaft or output 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 screw holes of the at least one screw flange of the generator rotor, are formed as elongated holes. These preferably extend in the circumferential direction with respect to an axis of rotation of the generator rotor. The generator rotor can be screwed to the output shaft or output hub or to the rotor hub in any desired rotational position by means of the slots.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 a first screw flange of the rotor hub to be screwed to an output shaft or output hub of the gearbox or to a corresponding screw flange of the output shaft or output hub. Furthermore, it is provided to screw a second screw flange of the rotor hub to the rotor or to a corresponding screw flange of the rotor.According to the invention, the rotor remains in its position relative to the rotor hub between the two steps. The rotor and the rotor hub are therefore not rotated relative to one another between the two steps.A preferred exemplary embodiment of the invention is illustrated in the figures. Corresponding reference numerals identify identical or functionally identical features. In detail, the following shows: FIG. 1 shows a detail of a drive train of a wind turbine; and FIG. 2 shows a rotor hub.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 screwed to a rotor hub 109 which is in turn screwed to a rotor 111 of the generator 111. In addition to the rotor 111, the generator also includes a stator 113.The rotor hub 109 has a hollow cylindrical extension 115 for receiving a brake disc. Further features of the rotor hub 109 can be seen in FIG. 2.After this, the rotor hub 109 is subdivided into a first screw flange 201, a second screw flange 203 and a middle part 205, which consists of a plurality of mutually intersecting spokes. The spokes and thus the middle part 205 extend between the first screw flange 201 and the second screw flange 203.The first screw flange 201 has screw holes 207. These are designed as bores, i.e. as cylindrical holes.The second screw flange also has screw holes 209. However, these are designed as elongated holes.Reference numerals denote reference numerals101 Transmission 103 Generator 105 Output shaft 107 Hub 109 Rotor hub 111 Rotor 113 Stator 115 Extension 201 Screw flange 203 Screw flange 205 Middle part 207 Screw hole 209 Screw holeReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedEP 3 899 255 B1

[0002]

Claims

Rotor hub (109) having a first screw flange (201) for screwing to an output shaft or hub (107) of a gearbox (101) of a wind turbine, and having 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 slots.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) protrudes radially inward starting from the central part (205) and / or the second screw flange (203) protrudes radially outward starting from the central part (205).Rotor hub (109) according to one of the preceding claims; characterized in that the second screw flange (203) runs radially further outwards than the first screw flange (201).Rotor hub (109) according to one of the preceding claims; characterized bya continuation (115) for receiving a brake disc.Method for mounting a drive train of a wind turbine having a gearbox (101), a generator (103) and a rotor hub (109) according to one of the preceding claims; having 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 a rotor (111) of the generator (103); characterized in that no rotation of the rotor (111) and the rotor hub (109) relative to one another takes place between the two steps.Generator rotor (111) having at least one screw flange for screwing to an output shaft or output hub (107) of a gearbox (101) of a wind turbine or a rotor hub (109) joined to the output shaft or output hub (107); characterized in that one or more screw holes of the at least one screw flange are designed as slots.Method for mounting a drive train of a wind turbine having a gearbox (101), a generator (103) which has a rotor (111) according to the preceding claim, and a rotor hub (109) which has a first screw flange (201) and a second screw flange (203); having 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 no rotation of the rotor (111) and the rotor hub (109) relative to one another takes place between the two steps.

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