Support element for gear system components

Abstract

The invention relates to a planetary gear system 10 for a wind turbine 106 operated via a rotor 106, having at least a first and second planetary stage 141, 142 which circulates about an axis of rotation AD in a gear system housing 12, wherein the two planetary stages 141, 142 are drivingly connected between a sun gear 221 of the first planetary stage 141 and a planet carrier 162 of the second planetary stage 142. The sun gear 221 of the first planetary stage 141 is connected as required to the planet carrier 161 of the first planetary stage 141 via a detachable support element 30. By means of the support element 30 connecting the sun gear 221 of the first planetary stage 141 to the planet carrier 161 of the first planetary stage 141, the planet carrier 161 of the first planetary stage 141 can, in a transport situation and before final installation on or removal from a rotor shaft 118, be used for supporting and centring its own sun gear 221.

Description

[0001] From support element for transmission components

[0002] Description

[0003] The invention relates to a planetary gear for a wind turbine driven by a rotor, with at least one first and second planetary stage rotating in a gear housing about an axis of rotation AD, wherein the two planetary stages are drivingly connected between a sun gear of the first planetary stage and a planet carrier of the second planetary stage.

[0004] In the wind turbine industry, integrated drivetrain systems are increasingly being used due to increasing cost pressure and the demand for increased torque density. In one possible design for an integrated drivetrain bearing, the gearbox housing of the planetary gearbox is rigidly connected to a housing of the main bearing unit, with the rotor shaft being held rotatably relative to the housing via a bearing in the main bearing unit. The planet carrier of the first planetary stage is, on the one hand, connected to the rotor shaft for driving purposes and, on the other hand, not independently mounted in the gearbox housing. The planet carrier of the first planetary stage is thus indirectly mounted in the main bearing unit via the rotor shaft.This means that when the planetary gear set is not mounted on the main bearing unit, the planet carrier of the first planetary stage is not supported by a bearing and is in an off-center position due to gravity. Therefore, for assembly, disassembly, and transport purposes, the planet carrier of the first planetary stage must be fixed in a suitable position and at least roughly centered so that no contact forces or mass acceleration forces act on the gear teeth. If contact forces and mass acceleration forces were to act, the meshing teeth of the first planetary stage could collide due to impacts or vibrations and be damaged, or be pre-damaged by fretting corrosion.

[0005] Until now, the planet carrier was fixed relative to the ring gear - in each case of the first planetary stage - via threaded holes distributed around the outer circumference in the connection flanges of the gearbox housing on the rotor side and / or generator side using threaded bolts. This solution has the disadvantage that both a rotor-side and generator-side flange must be present on the gearbox ring gear of the first planetary stage to enable fixing. Alternatively, if only the generator-side flange were available, an anchoring option, e.g. threaded holes, would have to be incorporated in the planet carrier, thus ensuring targeted positioning of the planet carrier relative to the threaded holes in the connection flange. Only in this way is fixing in all spatial directions possible. DE 10 2019 214094 A1 describes a variant with inserted sliding pieces that press against the planet carrier and hold it in position.US 2018 02 09 512 A1 shows a planetary gear unit for a wind turbine in which a planetary carrier bearing is designed such that it is mounted on the rotor side indirectly via the main shaft. The main shaft or the corresponding shaft flange covers the plane in which the first sun gear and the first planet carrier are located. This plane is not accessible without dismantling the main shaft. Dismantling would not be possible anyway, since the shaft flange, with a circumferential contact shoulder, engages behind the bearing of the first planetary stage held in the housing. DE 10 2014 201 465 A1 shows a generator for a wind turbine whose rotor is modularly coupled to the output side of a planetary gear unit.

[0006] In newer drivetrain concepts, there is no rotor-side housing flange. This is an integral part of the rotor bearing housing and is not available for support during transport or assembly of the gearbox to the main bearing unit. Therefore, there is a need for modern drivetrain concepts to provide support for the planetary carrier of the first planetary stage for transport and assembly purposes.

[0007] The object of the invention is to show measures that enable the planet carrier to be supported for transport and assembly purposes.

[0008] This object is achieved by a planetary gear mechanism having the features of claim 1. Preferred embodiments are specified in the subclaims and the following description, each of which, individually or in combination, may represent an aspect of the invention. If a feature is presented in combination with another feature, this merely serves to simplify the illustration 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.

[0009] One embodiment relates to a planetary gear for a wind turbine driven by a rotor, with at least one first and second planetary stage rotating in a gear housing about a rotational axis AD, wherein the two planetary stages are drivingly connected between a sun gear of the first planetary stage and a planet carrier of the second planetary stage, and a support element connecting the sun gear of the first planetary stage to the planet carrier of the first planetary stage and detachable as required.

[0010] The planetary gear comprises at least two or more planetary stages. The last planetary stage can drive a generator directly or indirectly. In the case of an indirect drive, an intermediate spur gear stage can be provided. The planet carrier can be designed like a basket. The axis of rotation AD, around which the at least one planetary stage rotates during operation, defines the axial direction in this case. Planet gears are held on the respective planet carrier via planetary axes. The planet axes run parallel and offset to the axis of rotation AD. The planet carriers are free from the planet carrier or the side walls in a radially inward direction and a radially outward direction and are in engagement with a ring gear and a sun gear or a sun gear shaft via a respective toothing.

[0011] Due to the support element that connects the sun gear of the first planetary stage to the planet carrier of the first planetary stage, the planet carrier of the first planetary stage uses its own sun gear for support and centering. The support element is preferably arranged concentrically to the axis of rotation AD. The sun gear of the first planetary stage is connected to the planet carrier of the second stage in a bending and rotationally fixed manner. For this purpose, it is preferred that the planet carrier of the second planetary stage is centrally mounted in the gearbox housing via a bearing. This ensures the correct alignment of the planet carrier with respect to the ring gear of the first planetary stage. The term sun gear refers to the functionality of the component. In practical design, the sun gear is designed, for example, as a sun shaft, i.e. with an axial extension that extends beyond a pure toothed section.The support via the support element does not have to be at the center of gravity of the pre-assembled planet carrier, but the remaining tilting moment around the center of gravity of the planet carrier can be supported via the support element using additional axially offset support points.

[0012] With the described design, the presence of a rotor-side connection flange between the ring gear and the rotor bearing can be dispensed with. This makes it possible to provide fixation and centering of the planet carrier for modern integrated drive trains using components already present within the gearbox. A further advantage is that the support element does not interfere with the assembly of the gearbox to the main bearing unit. The support element can remain in place, i.e. mounted, until the positioning and fixation is no longer required. Access to remove the temporarily attached support element remains available through the access through the hollow rotor shaft. This access must be used anyway to establish the connection between the rotor shaft and the planet carrier of the first planetary stage. Even before any necessary disassembly, i.e.When the wind turbine is mounted on the tower, the support element can be attached via the hollow rotor shaft, and the planetary carrier can be supported on the gearbox housing. This eliminates the need to position the rotor in a specific manner relative to the planetary gear. Furthermore, the described arrangement allows the first planetary carrier to be secured even without the presence of a gearbox housing flange on the rotor side.

[0013] In a preferred embodiment, the support element is held against an axial bearing surface of the sun gear of the first planetary stage. This ensures that the support element can be securely mounted on the sun gear. In particular, it is preferred that a screw connection is provided, by means of which the support element is held relative to the sun gear. This screw connection can, for example, comprise a single central screw or a plurality of concentrically arranged screws. In an alternative embodiment, the support element can also be partially inserted into the sun gear and supported against an inner circumferential surface of the sun gear.

[0014] Furthermore, a preferred embodiment is one in which the support element is accommodated radially within a receiving volume of the planet carrier of the first planetary stage. The receiving volume can be cup-shaped or cylindrical. In a further preferred embodiment, the support element is supported against an inner circumferential surface of the receiving volume.

[0015] In a first possible embodiment, the support element can be held relative to the inner circumferential surface by at least one screw connection. Preferably, several screw elements are arranged at equal spacings around the circumference. In an alternative embodiment, the support element can be held relative to the inner circumferential surface by a set of conical clamping elements.

[0016] In an otherwise preferred embodiment, several, preferably at least three, support domes can be provided to support the support element. These support domes are distributed over a circumference of the transmission housing and support the planet carrier of the first planetary stage relative to the housing element. Simple, mechanically adjustable bolts or screws can be used with threads. It is particularly preferred if the support domes comprise electrically or hydraulically operated cylinder elements. The support domes attached to the transmission housing find their counterpart in a generator-side flange of the planet carrier of the first planetary stage.

[0017] The object is also achieved by a drive train for a wind turbine for the torque-transmitting connection of a rotor to a generator, comprising a main bearing unit and a main shaft and a gear driven via the main shaft, characterized in that the gear is designed as a planetary gear as described above.

[0018] Furthermore, the object is achieved by a wind turbine comprising a nacelle to which a multi-blade rotor and a generator are rotatably mounted, wherein the multi-blade rotor is connected to the generator in a torque-transmitting manner via a drive train and the drive train is designed as previously described.

[0019] The invention will be explained below by way of example with reference to the accompanying drawings using preferred embodiments, wherein the features presented below can represent an aspect of the invention both individually and in combination. They show:

[0020] Fig. 1: a non-scale representation of a wind turbine, Fig. 2: a section of an assembly of a planetary gear and a main bearing unit with a support element,

[0021] Fig. 3a), 3b): alternative design of the support element and Fig. 4: an additional possibility for supporting the planet carrier.

[0022] Figure 1 shows a schematic and not-to-scale representation of a wind turbine 100 in one possible embodiment. A key element of the wind turbine 100 is a drive train 102, which in this case structurally comprises a rotor flange 104 with a rotor 106, a main bearing unit 108, a gearbox 10, and a generator 112. At least the main bearing unit 108 and the generator 112 are supported by a tower 116 via a machine support 114 relative to a ground (not shown). The main bearing unit 108 comprises a main shaft 118, which is mounted via an adjusted tapered roller bearing relative to a bearing housing 120 of the main bearing unit 108 for rotation about an axis of rotation AD. The rotor flange 104 is held at one end of the main shaft 118, and the rotor 106 is held thereto.The other end of the main shaft 118 is rigidly connected to the gearbox 10 for driving purposes, in order to transmit a drive torque generated by the rotor 106 to the gearbox 10. The gearbox 10 is designed as a planetary gear with one or more planetary stages. The gearbox 10 is drivingly connected to the generator 112 via a generator shaft 124. The bearing housing 120 is connected to the gearbox 10 via a flange 126. A reaction torque of the gearbox 10 is supported relative to the machine support 114 via the flange 126.

[0023] Figure 2 shows a section of an assembly of a gearbox 10 designed as a planetary gear and the main bearing unit 108, as can be installed, for example, in a wind turbine 100 shown in Figure 1. Shown are two planetary stages 141 and 142 arranged one behind the other, which are arranged in a gearbox housing 12 so as to rotate about a rotational axis AD. A third planetary stage, not shown, can also be provided. Apart from their dimensions, the planetary stages 14i and 142 are constructed accordingly and each have a planet carrier 16i, 162, a ring gear 20i, 202, a sun gear 22i, 222, and a plurality of planet gears 181, 182 rotating with the respective planet carrier 16i, 162 and alternately meshing with the ring gear 20i, 202 and the sun gear 22i, 222. The planet carrier I62 of the second planetary stage M2 is supported on both sides or one side via bearings 24 on support flanges 26 on the housing side.The second planetary carrier is held largely centrally in the gear housing 12 of the planetary gear 10 via the bearings 24. The sun 22i of the first planetary stage 14i is connected in a rotationally fixed and rigid manner to the planetary carrier 162 of the second planetary stage 142. The planetary carrier 161 of the first planetary stage 141 is not separately mounted in the housing 12, but after assembly, is mounted indirectly via the main bearing unit 108 via a rotationally fixed connection to the main shaft 118.

[0024] In the assembled state shown in Figure 2, as described, the planet carrier I61 of the first planetary stage 141 is supported indirectly via the main bearing unit 108, and the planet carrier I62 of the second planetary stage 142 is supported in the transmission housing 12 via the bearings 24. The sun gear 22i of the first planetary stage 141 is positioned indirectly via the second planet carrier I62 by the bearings 24. Consequently, in a state in which the main bearing unit 108 and the planetary gear 10 are not connected to one another, the planet carrier 161 of the first planetary stage 14i assumes an unsupported or undefined position. The first planet carrier 161 then exerts an undefined load on the teeth of the toothed elements due to the inertial forces.

[0025] For such a non-assembled position, a support element 30 is provided in the present case. The support element 30 can be designed as an insert in the first planetary carrier 161. The support element 30 connects the sun gear 22i of the first planetary stage 14i to the planetary carrier 161 of the first planetary stage 141. The support element 30 is designed to be detachable and adjustable as needed, at least from the sun gear 22i or at least from the planetary carrier 161, in each case of the first planetary stage 141. It is preferred if the support element 30 is designed to be detachable as needed, both from the sun gear 22i and from the planetary carrier 161, in each case of the first planetary stage 14i. This offers the possibility that the support element 30 can be removed after assembly of the planetary gear 12 and main bearing unit 108, namely through the hollow main shaft 118. The support element 30 positions the planet carrier 161 concentrically to the rotation axis AD.

[0026] The support element 30 is held against an axial bearing surface 32 of the sun gear 22i of the first planetary stage 14i and is held relative to the sun gear 22i, for example, via at least one screw connection 34, which is only sketched in Figure 2. The support element 30 is received radially within a receiving volume 36 of the planet carrier 161 of the first planetary stage 14i. Preferably, the support element 30 is completely recessed into the receiving volume 36, so that the support element 30 is at least flush with an axial end face 38 of the first planet carrier 161 or—as shown—offset inward relative to the end face 38. With respect to the first planet carrier 16i, the support element 30 is supported relative to an inner circumferential surface 40 of the receiving volume 36. In the variant of the support element 30 shown in Figure 2, this is held relative to the inner circumferential surface 40 by at least one screw connection 42.It is preferred that a plurality of screw connections 42 are distributed over the circumference. As shown in Figure 2, a plurality of screw connections 42 can additionally be provided at an axial distance from one another.

[0027] Figures 3a) and 3b) each show an alternative embodiment of the support element 30 and its seat in the receiving volume 36 of the first planet carrier 161. In the variant shown in Figure 3a), the support element 30 is held relative to the inner circumferential surface 40 of the first planet carrier 16i by a conical clamping element set 44. In the variant shown in Figure 3b), the support element 30 is held, as already described, against the axial contact surface 32 of the sun gear 22i of the first planetary stage 14i and, on the planet carrier 161 side, against an axial contact surface 46 within the receiving volume 36. The support element 30 is held against this axial contact surface 46 by one or more screw connections 48. Figure 4 shows an additional possibility for supporting the first planet carrier 161 relative to the transmission housing 12.For this additional support option, several, preferably at least three, support domes 50 are provided, distributed over a circumference of the transmission housing 12 and supporting the planetary carrier 16i of the first planetary stage 14i relative to the transmission housing 12. The support domes 50 can comprise electrically or hydraulically operated cylinder elements 52.

[0028] List of reference symbols

[0029] 10 Pl anetengetri eb e

[0030] 12 Gearbox housing

[0031] 14 planetary stage

[0032] 16 planet carriers

[0033] 18 planetary gears

[0034] 20 ring gear

[0035] 22 Sun gear

[0036] 24 warehouses

[0037] 26 Support flange

[0038] 30 support element

[0039] 32 axial contact surface

[0040] 34 screw connection

[0041] 36 recording volume

[0042] 38 frontal area

[0043] 40 inner circumferential surface

[0044] 42 screw connection

[0045] 44 clamping element set

[0046] 46 Axial contact surface

[0047] 48 screw connection

[0048] 50 From support mandrel

[0049] 52 cylinder element

[0050] 100 wind turbines

[0051] 102 drive train

[0052] 104 Rotor flange

[0053] 106 multi-blade rotor

[0054] 108 Main bearing unit

[0055] 112 Generator 114 Machine carrier

[0056] 116 Tower

[0057] 118 Main shaft

[0058] 120 Bearing housing 124 Generator shaft

[0059] 126 flange

Claims

Patent claims 1. Planetary gear (10) for a wind turbine (70) driven by a rotor (72), with at least one first and second planetary stage (14i, M2) rotating in a gear housing (12) about an axis of rotation (AD), wherein the two planetary stages (14i, M2) are drivingly connected between a sun gear (22i) of the first planetary stage (14i) and a planet carrier (162) of the second planetary stage (M2), and a support element (30) connecting the sun gear (22i) of the first planetary stage (14i) to the planet carrier (161) of the first planetary stage (14i) and which can be released if necessary.

2. Planetary gear (10) according to claim 1, characterized in that the planet carrier (I62) of the second planetary stage (M2) is mounted as centrally as possible in the gear housing (12) via a bearing (24).

3. Planetary gear (10) according to claim 1 or 2, characterized in that the support element (30) is arranged concentrically to the axis of rotation AD.

4. Planetary gear (10) according to one of claims 1 to 3, characterized in that the support element (30) is held against an axial contact surface (32) and / or a radial contact surface of the sun gear (22i) of the first planetary stage (141).

5. Planetary gear (10) according to claim 4, characterized in that the support element (30) is held relative to the sun gear (22i) by at least one screw connection (34).

6. Planetary gear (10) according to one of claims 1 to 5, characterized in that the support element (30) is received radially within a receiving volume (36) of the planet carrier (16i) of the first planetary stage (14i).

7. Planetary gear (10) according to claim 6, characterized in that the support element (30) is supported relative to an inner circumferential surface (40) of the receiving volume (36).

8. Planetary gear (10) according to claim 7, characterized in that the support element (30) is held relative to the inner peripheral surface (40) by at least one screw connection (42).

9. Planetary gear (10) according to claim 6, characterized in that the support element (30) is held against an axial contact surface (46) within the receiving volume (36) via at least one screw connection (48).

10. Planetary gear (10) according to claim 7, characterized in that the support element (30) is held relative to the inner peripheral surface (40) by a conical clamping element set (44).

11. Planetary gear (10) according to one of claims 1 to 10, characterized in that several, preferably at least three, support mandrels (50) are provided, distributed over a circumference of the gear housing (12) and supporting the planet carrier (16i) of the first planetary stage (141) relative to the gear housing (12).

12. Planetary gear (10) according to claim 11, characterized in that the support domes (50) comprise electrically or hydraulically operated cylinder elements (52).

13. Drive train (102) for a wind turbine (100) for the torque-transmitting connection of a rotor (106) to a generator (112), comprising a main bearing unit (108) and a main shaft (118) and a gear (10) driven via the main shaft (118), characterized in that the gear (10) is designed as a planetary gear according to one of the preceding claims.

14. Wind turbine (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) according to claim 13 is trained.

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