Shaft-hub connection for wind turbine

Abstract

A shaft-hub connection (10) for a wind turbine (100), in particular for connecting a rotor shaft (118) to a transmission (110), comprising a shaft element (12) and a hub element (14), which are both arranged concentrically with respect to a longitudinal axis AL, wherein the shaft element (12) and the hub element (14) form at least two toothing pairings (18) formed from planar face toothings (16), and the toothing pairings (18) are arranged in two radial regions (20) running separately from each other. The shaft-hub connection uses the power of a planar face toothing (16) which is attached on the planar side, permits a high torque density and can be guided by an axial assembly movement and simply closed.

Description

[0001] FLENDER GMBH Düsseldorf, November 18, 2025

[0002] Our reference number: FD45677 - 2024P04746WO

[0003] Flender GmbH

[0004] Alfred-Flender-Str. 77, 46395 Bocholt, Germany

[0005] Shaft-hub connection for wind turbine

[0006] Description

[0007] The invention relates to a shaft-hub connection for a wind turbine, in particular for connecting a rotor shaft to a gearbox and / or a gearbox to a generator, with a shaft element and a hub element, both of which are arranged concentrically to a longitudinal axis AL, wherein the shaft element and the hub element form at least two gear pairs formed from face teeth.

[0008] Modern wind turbines are being developed with ever-increasing power outputs due to limited installation space and cost pressures. Consequently, transport weights and component dimensions are becoming so large that transporting and handling a drivetrain pre-assembled in a production hall using standard logistics (transport vehicles and lifting equipment) is no longer feasible. The drivetrain components are therefore transported separately to the wind turbine installation site. On-site, the components are then assembled into the drivetrain. Harsh environmental and weather conditions, limited possibilities for precise alignment of the components with construction site equipment, short timeframes due to suitable weather windows, expensive crane rental, and the use of potentially poorly trained personnel necessitate a simple and robust connection method for the drivetrain components. The connection between the main bearing shaft and the gearbox, or...The connection between the gearbox and generator can be expediently achieved through a positive locking mechanism, considering the steadily increasing torque density. Alternatively, a purely friction-based connection can also be used. The disadvantages of this are the relatively large component dimensions, such as the diameter required for transmitting torque and bending forces, as well as sensitive surfaces that are typically specially treated to increase friction and are susceptible to harsh environmental conditions or repeated assembly processes. This applies not only, but also, to the connection between the main bearing shaft and the gearbox, for which a simple and robust connection option does not yet exist. The state of the art in this context includes GB 2509560 A and US 7 936 080 B2. Based on this, there is a constant need to improve the connection between the main bearing shaft and the gearbox through suitable measures, taking into account assembly and the increased power density.

[0009] The object of the invention is to identify measures that improve the connection between the main bearing shaft and the gearbox, as well as between the gearbox and the generator, with regard to assembly and increased power density.

[0010] The problem is solved by a shaft-hub connection with the features of claim 1. Preferred embodiments are specified in the dependent claims and the following description, each of which, individually or in combination, can represent an aspect of the invention. When a feature is presented in combination with another feature, this serves only to simplify the presentation of the invention and is in no way intended to imply that this feature cannot also be a further development of the invention without the other feature.

[0011] One embodiment relates to a shaft-hub connection for a wind turbine, in particular for connecting a rotor shaft to a gearbox and / or a gearbox to a generator, comprising a shaft element and a hub element, both arranged concentrically to a longitudinal axis AL, wherein the shaft element and the hub element form at least two gear pairs consisting of face teeth and the gear pairs are arranged in two separate regions. In particular, these regions may be radial regions.

[0012] A gear pair is characterized by the fact that one set of teeth is located on the shaft element and the other set of teeth is located on the hub element. The longitudinal direction AL defines the axial direction, from which the respective radial directions are derived. The shaft element can be designed as a rotor shaft of a main bearing unit for a wind turbine. In this case, the shaft element can be designed as a hollow shaft. The hub element can be designed as a drive element of a gearbox.

[0013] The proposed shaft-hub connection allows a shaft element, such as a rotor shaft, to be positively connected to a hub element, such as a gearbox planetary carrier, through a simple axial joining motion. This eliminates the need for a press fit achieved through cooling or heating, or for precise alignment of bores for dowel pins or bolts with expanding diameter. The connection centers itself upon axial engagement of the shaft element and hub element and is automatically positioned correctly in the circumferential direction. This connection enables robust and simple assembly and allows for the transmission of forces, torques, and bending moments with high torque density. Furthermore, stress-optimized tooth flanks and a tooth root geometry can be incorporated.

[0014] The proposed shaft-hub connection utilizes the performance of a face-mounted striated toothing, which allows for high torque density and can be easily assembled and closed with a single axial assembly movement. Unlike expensive gear-cutting machines or complex processes, as is typical for well-known Hirth gears, this design employs simple face milling, such as a 5-axis finger milling process. By dividing the striated toothing into two gear pairs in two separate radial sections, critical double notches are avoided through stress relief. The positive locking of the face teeth achieves high torque density and a reduced connection diameter for the shaft-hub connection.

[0015] Preferably, the shaft element and the hub element are connected to each other between gear pairs via a circumferential screw connection. This ensures that the assembly position remains closed even under operating loads. In particular, a preloaded screw connection can be used, which merely secures the position of the components but does not need to prevent slippage of a frictional connection. Furthermore, it is preferred that the screw connection comprises a plurality of circumferentially distributed and axially oriented screw elements. By transmitting the torque via the positive locking ensured by the face teeth, the number of screw elements and thus the axial preload force can be reduced.Furthermore, a tooth flank angle can be designed to be self-locking or non-self-locking, so that an operational torque leads to an axial force that compensates for the screw preload.

[0016] In a preferred embodiment, the shaft element or hub element has a radially outside or radially inside the face gear teeth and an axially oriented centering collar or centering cone. This ensures a positive fit that can be mounted in the axial direction and offers self-centering capability. Additionally, centering chamfers can be provided on the respective inner or outer part to further improve self-centering through a taper.

[0017] In a further preferred embodiment, the radial areas in which the gear pairs are arranged are offset from one another in the direction of the longitudinal axis AL. This axially offset face gearing ensures improved load transmission into the components. It is particularly preferred that the axial offset relative to the hub element is designed such that the outer radial area is set back from the inner radial area in the direction of the longitudinal axis AL.

[0018] In a preferred embodiment, the shaft element and / or the hub element form positioning mandrels that project towards and engage with the other element. Fixed positioning mandrels for precise self-alignment in the circumferential direction are particularly advantageous when so-called head bearings are to be avoided. However, it is also possible for the positioning mandrels to be designed as detachable and removed after assembly of the shaft-hub connection.

[0019] In a preferred embodiment, the face teeth in one of the respective end faces of the shaft element and the hub element are inclined at an angle with respect to the respective radial directions.

[0020] In a preferred embodiment, the respective pitch planes of the shaft element and the hub element, in which the planar pitch teeth are arranged, are conically shaped to complement each other starting from the longitudinal axis AL.

[0021] The problem is further solved by a drive train for a wind turbine for the torque-transmitting connection of a rotor to a generator, comprising a main bearing unit, a main shaft, and a gearbox driven via the main shaft, wherein the gearbox drives the generator at least indirectly, and the connection between the main shaft and gearbox is designed as a shaft-hub connection as described. In particular, it can be provided that the main shaft is designed as a shaft element and a planet carrier of the gearbox as a hub element. Preferably, the face teeth of the gear pairs, i.e., the positive-locking geometries, are machined directly onto the main shaft and the planet carrier. However, adapter discs with face teeth for the rotor shaft and planet carrier can also be provided.These can be manufactured on existing machinery in the production hall with good manufacturing accuracy using positive locking, e.g., a locating bore / dowel pin, and pre-assembled on the rotor shaft and planet carrier, and can be made of high-strength, low-wear or coated material.

[0022] The problem is further solved by a wind turbine comprising a rotor flange with a rotor and a generator, wherein a drive train held on a machine carrier and connecting the rotor flange to the generator is provided, wherein the drive train is designed as described.

[0023] The invention is explained below by way of example with reference to the accompanying drawings and preferred embodiments, wherein the features shown below can represent an aspect of the invention, either individually or in combination. The drawings show:

[0024] Fig. 1: a schematic representation of a drive train of a wind turbine,

[0025] Fig. 2: a perspective sectional view of a shaft-hub connection for a wind turbine according to Figure 1,

[0026] Fig. 3a) and 3b): Details of a shaft-hub connection according to Fig. 2,

[0027] Fig. 4: another embodiment of a shaft-hub connection,

[0028] Figs. 5, 6a) and 6b): further schematic representations of a shaft-hub connection with details and

[0029] Fig. 7: a schematic representation of another embodiment of a shaft-hub connection as a gearbox-generator interface.

[0030] Figure 1 shows a schematic, not-to-scale representation of a wind turbine 100 in one possible embodiment. A side view is shown. The essential element of the wind turbine 100 is a drive train 102, which in this case can structurally comprise a rotor flange 104 with a rotor 106, a rotor bearing 108, a gearbox 110, and a generator 112. At least the rotor bearing 108 and the generator 112 are supported on a ground via a machine carrier 114 and a tower (not shown). The rotor bearing 108 comprises a rotor shaft 118, which is rotatably mounted about a drive train axis AD relative to a rotor bearing housing 120 of the rotor bearing 108, for example, by means of an angled tapered roller bearing. The drive train axis, or longitudinal axis AL, defines an axial direction.

[0031] The rotor flange 104 is mounted at one end of the rotor shaft 118, and the rotor 106 is mounted to the flange. A gearbox 110 is connected to the generator 112 for drive purposes. The rotor shaft 118 is connected to the gearbox 110 via a shaft-hub connection 10. A reaction torque of the gearbox 110—and also of the flanged generator 112—is supported against the machine carrier 114 by a torque arm 116. In a first embodiment, the torque arm 116—as shown in Figure 1—can connect the gearbox component 12 directly to the machine carrier 114. The machine carrier 114, the rotor bearing 108 with rotor shaft 118, the torque arm 116, the gearbox 110, and the generator 112 can be referred to as the drive train 102.

[0032] Figure 2 shows a perspective view of a section of the shaft-hub connection 10. Structurally, the shaft-hub connection 10 comprises a shaft element 12 and a hub element 14. For example, the shaft element 12 is associated with the rotor shaft 118 and the hub element with the gearbox 110. Both the shaft element 12 and the hub element 14 are arranged concentrically with respect to the longitudinal axis AL.

[0033] Figures 3a) and 3b) show the shaft element 12 and the hub element 14 as individual components in a section and in perspective view. Figures 2 to 3b) are initially described together. The shaft element 12 and the hub element 14 each form face teeth 16. On both the shaft element 12 and the hub element 14, the face teeth 16 are arranged in two separate radial sections 20. In an assembly of shaft element 12 and hub element 14, as shown in Figure 2, the face teeth 16 form gear pairs 18 through which a torque can be transmitted in an operating situation. The shaft element 12 and the hub element 14 are connected to each other between the gear pairs 18 via a circumferential screw connection 22, which comprises a plurality of circumferentially distributed and axially directed screw elements 24 in the form of expansion screws.

[0034] In the present case, the shaft element 12 has a radially outside the face gear 16 and axially directed centering collar 26. Alternatively, the hub element 14 can also have the centering collar 26, but this is not shown.

[0035] Figure 4 shows a further embodiment of the shaft-hub connection 10, in which the radial areas 20, in which the gear pairs 18 are arranged, are offset from each other in the direction of the longitudinal axis AL. The axial offset with respect to the hub element 14 is designed such that the outer radial area 20A is set back from the inner radial area 20i in the direction of the longitudinal axis AL.

[0036] Figure 5 schematically shows the shaft-hub connection 10 in a side view. The shaft element 12 forms positioning pins 28 projecting towards and engaging with the hub element 14. The positioning pins 28 may be designed to be detachable.

[0037] Figure 6a) shows an axial view of the hub element 14. The end plane 30 of the hub element 14 is visible, on which the face gear teeth 16 are shown schematically. The face gear teeth 16 are inclined at an angle to their respective radial directions in a face plane 30 of the hub element 14. The face gear teeth 16 on the shaft element 12 exhibit a corresponding or complementary inclination. Figure 6b) schematically shows the shaft-hub connection 10 in a side view. The respective end planes 30 of the shaft element 12 and the hub element 14, in which the face gear teeth 16 are arranged, are funnel-shaped and complementary to each other, extending from the longitudinal axis AL.

[0038] Figure 7 shows a schematic representation of another embodiment of a shaft-hub connection 10. The shaft-hub connection 10 is designed as a gearbox-generator interface. The gearbox 110 and the generator 112 are shown only partially. The gearbox 110 has a gearbox output shaft 126, which is designed here as a shaft element 12. The generator 112 has a generator rotor 128, which is designed here as a hub element 14. The face teeth 16 are machined directly onto the gearbox output shaft 126 and the generator rotor 128, respectively.

[0039] Reference symbol list

[0040] 10 Shaft-hub connection

[0041] 12 wave elements

[0042] 14 hub element

[0043] 16 Planar face gearing

[0044] 18 gear pairing

[0045] 20 Radial area

[0046] 22 Screw connection

[0047] 24 screw element

[0048] 26 Centering collars

[0049] 28 positioning domes

[0050] 30 voting levels

[0051] 100 wind turbines

[0052] 102 Drive string

[0053] 104 Rotor flange

[0054] 106 multi-blade rotor

[0055] 108 Rotor bearing

[0056] 110 gearbox

[0057] 112 Generator

[0058] 114 machine carriers

[0059] 116 Torque support

[0060] 118 Rotor shaft

[0061] 120 rotor bearing housings

[0062] 124 Generator shaft

[0063] 126 Gearbox output shaft

[0064] 128 Generator rotor

Claims

Patent claims 1. Shaft-hub connection (10) for a wind turbine (100), in particular for connecting a rotor shaft (118) with a gearbox (110) and / or a gearbox (110) with a generator (112), with a shaft element (12) and a hub element (14), both of which are arranged concentrically to a longitudinal axis (AL), wherein the shaft element (12) and the hub element (14) form at least two gear pairs (18) formed from planar teeth (16) and the gear pairs (18) are arranged in two separate areas (20).

2. Shaft-hub connection (10) according to claim 1, characterized in that the separately extending areas are radial areas (20).

3. Shaft-hub connection (10) according to claim 1 or 2, characterized in that the shaft element (12) and the hub element (14) are connected to each other between the tooth pairs (18) via a circumferential screw connection (22).

4. Shaft-hub connection (10) according to claim 3, characterized in that the screw connection (22) comprises a plurality of circumferentially distributed and axially directed screw elements (24).

5. Shaft-hub connection (10) according to one of claims 1 to 4, characterized in that the shaft element (12) or the hub element (14) has a radially outside or radially inside the face gear (16) and axially directed, in particular conically tapered, centering collar (26).

6. Shaft-hub connection (10) according to one of claims 1 to 5, characterized in that the radial areas (20) in which the gear pairings (18) are arranged are offset from each other in the direction of the longitudinal axis (AL).

7. Shaft-hub connection (10) according to claim 6, characterized in that the axial offset with respect to the hub element (14) is designed such that the outer radial area (20A) is set back from the inner radial area (20i) in the direction of the longitudinal axis (AL).

8. Shaft-hub connection (10) according to one of claims 1 to 7, characterized in that the shaft element (12) and / or the hub element (14) forms positioning mandrels (28) projecting towards and engaging in the other element, preferably detachably designed.

9. Shaft-hub connection (10) according to one of claims 1 to 8, characterized in that the face teeth (16) are inclined at an angle in one of the respective face planes (30) of the shaft element (12) and the hub element (14) with respect to respective radial directions.

10. Shaft-hub connection (10) according to one of claims 1 to 9, characterized in that the respective end planes (30) of the shaft element (12) and the hub element (14), in which the face teeth (16) are arranged, are conically shaped in a complementary manner to each other starting from the longitudinal axis (AL).

11. Drive train (102) for a wind turbine (100) for the torque-transmitting connection of a rotor (106) with a gearbox (110) and a generator (112), characterized in that at least one connection is provided between the rotor (106) and the gearbox (110) and / or between the gearbox (110) and the generator. (112) is designed as a shaft-hub connection (10) according to one of claims 1 to 10.

12. Drive train (102) according to claim 11, characterized in that the connection between a main shaft (118), in particular designed as a shaft element (12), a main bearing unit (108) and the transmission (110), in particular designed as a planet carrier of the transmission (110), is designed as a shaft-hub connection (10).

13. Drive train (102) according to claim 11, characterized in that a transmission output shaft (126) of the transmission (110) is designed as a hub element (14) and a generator rotor (128) of the generator (112) is designed as a shaft element (12).

14. Drive train (102) according to claim 12 or 13, characterized in that the face teeth (16) of the gear pairings (18) are machined directly onto the main shaft (118) and the planet carrier and / or the transmission output shaft (126) and the generator rotor (128).

15. Wind power plant (100) comprising a rotor flange (104) with a rotor (106) and a generator (112), wherein a drive train (102) is provided which is held on a machine carrier (114) and connects the rotor flange (104) to the generator (112), characterized in that the drive train (102) is designed according to one of claims 11 to 14.

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