Drivetrain

Abstract

The invention relates to a drive train arrangement, preferably for a wind turbine, comprising a rotor shaft (2), a generator (5) and a gear wheel (1), which is indirectly or directly connected to the rotor shaft (2) and the generator (5), wherein the gear wheel (1) is at least partially or completely integrated in the rotor shaft (2).

Description

Technical Field

[0001] The invention relates to a drive train arrangement, preferably for a wind power plant, having a rotor shaft, a generator and a gear wheel which is indirectly or directly connected to the rotor shaft and the generator. Background Art

[0002] To generate electrical energy, the generator in a wind turbine is typically located at the upper end of the tower along with the rotor. The rotor's rotational speed typically ranges from 0 to 12 revolutions per minute. Direct rotor generators suitable for such low rotational speeds are very heavy. With high electrical outputs in the megawatt range, this results in a very heavy rotor and nacelle. For this reason, a gear is often connected between the rotor and generator to enable the use of a fast-running generator, which significantly reduces weight.

[0003] DE 199 17 605 A1 is based on a shaft-mounted gear connected to the rotor shaft of a wind turbine via a press fit, through which wind power is introduced into the gear. The wind turbine discloses a multi-stage planetary gear arrangement and a spur gear stage for output to a generator. Power drive input to the planetary gear arrangement occurs via an internal gear, which drives at least one planetary gear. Another planetary gear is disposed on a shaft fixed to the housing. The planetary gears mesh with a sun gear, from which power is output to the spur gear stage.

[0004] Furthermore, DE 20 2018 100 231 U1 discloses a device in which the mounting of the frame gear simultaneously mounts the rotor to the rotor shaft. This eliminates the need for additional bearings for the rotor with the rotor shaft, thereby further reducing the head weight of a wind turbine with the same power output.

[0005] DE 10 2011 106 535 A1 relates to a drive train for a turbine generator, in particular a wind turbine or ocean current turbine, comprising a rotor hub carrying at least one rotor blade and a gearwheel comprising multiple planetary stages, which amplifies the rotational motion of a rotor shaft connected to the rotor and transmits it to the drive of a downstream generator. The rotor hub, gearwheel, and generator are arranged coaxially with one another. Furthermore, the document discloses a drive train for a turbine generator, wherein a suitable increase in the rotational motion of the rotor shaft can be achieved in a compact manner via a gearwheel embodied as a power splitter gearwheel having three planetary stages, thereby enabling the drive of the downstream generator.

[0006] The above-mentioned gear device is a complicated structure and is very long, because all parts are arranged one after another in sequence. In addition, the assembly and disassembly of the related parts and maintenance are very complicated. Summary of the Invention

[0007] Therefore, the object of the present invention is to provide a drive train arrangement, preferably for a wind turbine, which further reduces the weight of the rotor and the nacelle, simplifies assembly, and is constructed to be more compact in length while maintaining the same system output.

[0008] This object is achieved by the feature combination according to patent claim 1 .

[0009] According to the present invention, a drive train arrangement, preferably for a wind turbine, is provided. The drive train arrangement comprises a rotor shaft, a generator, and a gear connected indirectly or directly to the rotor shaft and the generator. The gear is at least partially or completely integrated into the rotor shaft. This results in a more compact design for the entire drive train and a reduced overall component weight.

[0010] In an advantageous embodiment of the present invention, a fixed machine support is arranged between the generator and the gear, as viewed in the axial direction of the rotor shaft. The generator, as viewed in the axial direction, is directly fastened to the machine support on one side, while the gear is indirectly or directly fastened to the machine support on the opposite side. Advantageously, the fixed machine support absorbs the reaction torques of the gear and the generator.

[0011] The decisive advantage of this drive train arrangement lies in its compact design, allowing the individual components, the generator and gear, to be removed from the drive train simultaneously without having to reinstall the rotor. The machine frame is a key component in making this possible. This gives the drive train a significant advantage over fully integrated drive trains, where the wind turbine rotor must first be disassembled in order to remove the gear.

[0012] Preferably, the drive train arrangement is designed such that the gear is connected to the rotor shaft by means of a torsionally rigid coupling. Advantageous here is a compact design and a backlash-free, angularly true transmission of the torque due to a very high torsional rigidity.

[0013] In an exemplary embodiment of the invention, it is provided that the rotor shaft is mounted on the surrounding structure by means of sliding bearings or rolling bearings attached on the outside. In this way, the gravity and wind loads acting on the rotor shaft are supported on the surrounding structure.

[0014] Furthermore, it is preferred that the generator is connected to a drive shaft which represents the output shaft of the gear. Thus, the entire drive train can be designed to be more compact and lighter.

[0015] In another advantageous variant, the invention provides that the gear is designed as a planetary gear. Planetary gears are characterized by high efficiency and, due to their compact design, allow for a reduced overall length at a high power density.

[0016] In one embodiment variant, the drive train arrangement according to the present invention is designed so that the gearing includes at least two planetary stages, whose internal gears are indirectly fixed to one another via housing components or directly and non-rotatably fixed to one another, resulting in a sequential housing group of at least internal gears. The multiple planetary stages or sequential housing groups further increase the power density of the gearing. Consequently, all internal gears rotate at the drive rotational speed, thereby enabling power distribution across the planetary stages and integrating the gearing into the rotor shaft. Furthermore, the use of internal gears, in particular, reduces the size and mass of the gearing.

[0017] It should be noted that the internal gear and housing assembly are connected to the rotor shaft and therefore rotate at the speed of the rotor.

[0018] It is further advantageous when the gear comprises a planet carrier connected to the machine support by means of a torsionally rigid coupling. In this case, it is advantageous that the support of the reaction torque of the gear on the machine support is carried out by means of the planet carrier.

[0019] In an embodiment of the drive train arrangement, it is further provided that the gear comprises a sun gear, which is coupled to an output shaft of the gear for driving the latter. Advantageously, the generator is driven via the sun gear of a rapidly rotating planetary gear stage, since the powers of the planetary gears in this stage are correspondingly summed.

[0020] Preferably, the drive train arrangement is arranged such that the output shaft of the gear is indirectly or directly connected to the generator by means of a flexible coupling. Advantageously, the flexible coupling transmits high torque with a small size, absorbs shocks and vibrations and suppresses torque peaks.

[0021] In an alternative embodiment of the invention, it is provided that the flexible coupling or the intermediate shaft connected thereto projects through a central opening in the machine frame and is connected to the generator.

[0022] In an advantageous embodiment, a braking device is arranged between the flexible coupling and the generator. The braking device is preferably designed with a brake disk and a brake, wherein the braking device is directly connected to the machine support and indirectly or directly connected to the flexible coupling. The braking device enables emergency shutdown or manual stopping, for example, during maintenance or repair of the wind turbine. A further advantage is that the reaction torque of the braking device is supported on the machine support. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Further advantageous developments of the invention are characterized in the dependent claims or are presented in more detail below together with the description of preferred embodiments of the invention by means of the accompanying drawings. The drawings show:

[0024] Figure 1 It is a cross-sectional view of the transmission system. DETAILED DESCRIPTION

[0025] exist Figure 1 , a cross-sectional view of a drive train for a wind turbine is shown. It includes a rotor shaft 2, a generator 5, and a gear 1. The gear 1 is designed as a planetary gear. Furthermore, the rotor shaft 2 is mounted on the surrounding structure 8 of the wind turbine by means of two rolling bearings 3a, 3b arranged on the outer circumference, and the planetary gear 1 is indirectly connected to the rotor shaft 2 via a torsionally rigid coupling 15. As an alternative to rolling bearings 3a, 3b, plain bearings can also be used. Here, the planetary gear 1 is partially integrated into the rotor shaft 2 and directly connected to the generator 5.

[0026] As seen in the axial direction of the rotor shaft 2, the generator 5 is spaced apart from the end member of the rotor shaft 2 and the planetary gears 1. In this axial direction, a fixed machine support 4 is arranged between the generator 5 and the planetary gears 1. The machine support 4 is fixed to the surrounding structure 8 of the wind turbine. The machine support 4, having a central passage opening in the axial direction, extends in a radial direction that extends orthogonally to the axial direction of the rotor shaft 2.

[0027] Furthermore, the generator 5 is directly fastened to the machine support 4 on a side spaced apart from the rotor shaft 2, while the gear 1 is indirectly fastened to the machine support 4 on a diametrically opposite side. The planetary gear 1 comprises a planet carrier 9, which is connected to the machine support 4 by means of a torsionally rigid coupling 12.

[0028] Planetary gear 1 includes a sun gear 10, which is coupled to the output shaft 6 of planetary gear 1 in order to drive it. Furthermore, a generator 5 is coupled to a drive shaft, which represents the output shaft 6 of planetary gear 1. This output shaft 6 is in turn indirectly connected to the generator 5 via a flexible coupling 11. The generator shaft lies on the same axis of rotation as the output shaft 6 and the rotor shaft 2. The central passage opening of the machine support 4 is arranged in the region of this axis of rotation and is formed so that an intermediate shaft connected to the flexible coupling 11 protrudes through the passage opening and is coupled to the generator 5.

[0029] besides, Figure 1 The planetary gear 1 is shown to comprise three planetary stages, the ring gears 16 of which are indirectly fixed to one another in a rotationally fixed manner via housing parts 7 , as a result of which a successive housing group 17 is formed.

[0030] In addition, a braking device 18 with a brake disc 13 and a brake 14 is arranged between the flexible coupling 11 and the generator 5. The brake 14 is shown connected directly to the machine support 4, and the brake disc 13 is coupled to the intermediate shaft.

[0031] Reference Signs List

[0032] 1 Gear

[0033] 2 Rotor shaft

[0034] 3a, 3b bearings

[0035] 4 Machine bracket

[0036] 5. Generator

[0037] 6 Output shaft

[0038] 7 Housing components

[0039] 8 Surrounding structures

[0040] 9 Planet carrier

[0041] 10 Sun gear

[0042] 11 Flexible connectors

[0043] 12 Torsionally rigid joints

[0044] 13 brake disc

[0045] 14 Brakes

[0046] 15 Torsionally rigid joints

[0047] 16 Internal gear

[0048] 17 Sequential Shell Group

[0049] 18 Braking device.

Claims

1. A drive train arrangement for a wind power plant, comprising a rotor shaft (2), a generator (5), and a gear (1) indirectly or directly connected to the rotor shaft (2) and the generator (5), wherein the gear (1) is at least partially or completely integrated in the rotor shaft (2). in, A machine support (4) is arranged fixed in place between the generator (5) and the gear (1) as viewed in the axial direction of the rotor shaft (2), the generator (5) being directly fixed to the machine support on one side and the gear (1) being indirectly or directly fixed to the machine support on a diametrically opposite side, and the machine support (4) being fixed to a surrounding structure (8); and wherein the gear (1) comprises a planet carrier (9) connected to the machine support (4) by means of a torsionally rigid first coupling (12), The reaction torque of the gear (1) and the generator (5) is supported by means of a fixed machine support (4), so that the gear (1) and the generator (5) can be removed from the drive train device separately without reinstalling the rotor.

2. The powertrain device according to claim 1, wherein: The gear wheel (1) is connected to the rotor shaft (2) by means of a torsionally rigid second coupling (15).

3. The transmission system device according to claim 1 or 2, wherein: The rotor shaft (2) is mounted on the surrounding structure (8) by means of sliding bearings (3a, 3b) or rolling bearings (3a, 3b) mounted on the outside.

4. The transmission system device according to claim 1 or 2, wherein: The generator (5) is connected to a drive shaft, which represents the output shaft (6) of the gear (1).

5. The transmission system device according to claim 1 or 2, wherein: The gear (1) is designed as a planetary gear.

6. The powertrain arrangement according to claim 5, wherein: The gear (1) comprises at least two planetary stages, the internal gears (16) of which are indirectly fixed to one another via housing parts (7) or directly and non-rotatably fixed to one another, resulting in a sequential housing group (17) of at least the internal gears (16).

7. The powertrain arrangement according to claim 6, wherein: The gear (1) comprises a sun gear (10) coupled to an output shaft (6) of the gear (1) for driving the output shaft.

8. The powertrain device according to claim 1 or 2, wherein: The output shaft (6) of the gear (1) is connected to the generator (5) indirectly or directly by means of a flexible coupling (11).

9. The powertrain arrangement according to claim 8, wherein: The flexible coupling (11) or an intermediate shaft connected to the flexible coupling protrudes through a central opening in the machine support (4) and is connected to the generator (5).

10. The powertrain arrangement according to claim 8, wherein: A braking device (18) is arranged between the flexible coupling (11) and the generator (5), wherein the braking device (18) is directly connected to the machine support (4) and indirectly or directly connected to the flexible coupling (11).

11. The drive train device according to claim 10, wherein the brake device is designed to have a brake disc (13) and a brake (14).

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