WO2015003706A1

WO2015003706A1 - Bearing arrangement for a planetary gearbox of a wind turbine

Info

Publication number: WO2015003706A1
Application number: PCT/DE2014/200304
Authority: WO
Inventors: Markus Werner
Original assignee: Schaeffler Technologies Gmbh & Co. Kg
Priority date: 2013-07-12
Filing date: 2014-07-07
Publication date: 2015-01-15
Also published as: DE102013213662A1

Abstract

A bearing arrangement for a planetary gearbox (1), in particular of a wind turbine, comprises: - a planetary carrier (5), which is connected fixedly to a hollow shaft (7); - a gearbox housing (2), in which the planetary carrier (5) is arranged; - an inner toothing (3) of the gearbox housing (2); - planetary gears (4), which mesh with the inner toothing (3); - a sun gear (8), which meshes with the planetary gears (4); - and bearings (9, 10), which are arranged on both end faces of the planetary gears (4), for bearing the planetary carrier (5) in the gearbox housing (2), wherein each of the bearings (9, 10) is formed as a cylindrical roller bearing having an inner ring (11), which has two rims (14), and an outer ring (12), which has a rim (15) only on the side facing the planetary gears (4).

Description

Name of the invention

Bearing arrangement for a planetary gearbox of a wind turbine Description

Field of the invention

The invention relates to a for a planetary gear, in particular a wind turbine, provided bearing arrangement according to the preamble of claim 1.

A generic bearing arrangement is known for example from EP 1 431 575 A2. The bearing assembly is part of a planetary gear and serves to support a planet carrier in a transmission housing. The planet carrier is connected via a hollow shaft with the rotor shaft of a wind turbine. Details of the bearings for the rotatable mounting of the hollow shaft and the planet carrier in the gear housing are not specified in EP 1 431 575 A2.

Another bearing arrangement according to the preamble of claim 1 is disclosed in DE 198 57 914 B4. Also in this case, a planetary carrier of a planetary gear is connected to a rotor of a wind turbine. The bearing of the planet carrier in the gear housing is done with two arranged on the front sides of the planet carrier camps. The planetary gear is followed by a spur gear, connected to the output of the generator of the wind turbine.

For the main shaft bearing in wind turbines different storage concepts come into consideration, their selection also depends on the type and presence of a transmission of the wind turbine. A wind turbine with three-point support of the rotor shaft is for example from DE 10 2006 037 890 B4. Here, as a rotor main bearing a winkeleinstellbares floating bearing, namely a Toroidalrollenlager, provided while a fixed bearing is arranged in a planetary gear, in which the rotor shaft feeds power.

A wind turbine with concentric gear / generator arrangement and two-point support of the rotor shaft is known for example from DE 102 42 707 B3. The two-point support is intended here to ensure that aerodynamic loads and mass loads of the rotor are introduced into the tower of the wind turbine without being routed through the gearbox or the generator.

OBJECT OF THE INVENTION The invention is based on the object of specifying a bearing arrangement for a wind turbine with planetary gear, which is characterized both by good mountability and by favorable mechanical stress conditions. Description of the invention

This object is achieved by a bearing assembly with the features of claim 1. The bearing assembly serves to support a planet carrier in a planetary gear of a wind turbine. The planet carrier is rotatably connected to a hollow shaft or integrally formed. The hollow shaft is the main shaft of the wind turbine or a shaft coupled to the main shaft. The main shaft in turn is rotatably connected to the rotor hub, on which the rotor blades of the wind turbine are held. The planetary gear thus represents the only stage or input stage of a single or multi-stage gear arrangement of a wind turbine. The rotating with the rotor speed planet carrier is rotatably mounted in a transmission housing of the wind turbine. Several planet gears are rotatably mounted on the planet carrier and mesh with an internal toothing, which is located on the inside of the gear housing and is formed either by this housing itself or by a fixedly connected to the transmission housing component. The gear housing thus forms the ring gear of the planetary gear. Furthermore, the planetary gear on a likewise meshing with the planet gears sun gear, which is fixedly connected to an output shaft of the planetary gear or formed in one piece. The front side of the planet carrier, on which the hollow shaft is located, is referred to as the drive-side end face. In the opposite end face is the output side end face of the planet carrier.

The bearing of the planet carrier takes place on its two end faces, each with a cylindrical roller bearing. These cylindrical roller bearings absorb radial forces as well as axial forces and tilting moments during operation of the wind turbine. Particularly high forces act on the cylindrical roller bearings when they support at least part of the aerodynamic forces which are conducted via the main shaft. However, even in cases where wind forces and weight forces of the rotor are completely decoupled from the gearbox of the wind turbine, the cylindrical roller bearings of the planetary gearbox have considerable capacity to absorb forces acting in different directions. In this case, a notable tilting moment can be given in particular by means of a gearbox and / or generator arrangement connected on the output side to the planetary gearbox. In addition, there are weight forces of the components of the planetary gear itself.

To control the various forces occurring during operation of the wind turbine with simultaneously ensured mountability and disassembly of the planetary gear and the other, connected to this power transmitting components of the wind turbine bearing the planet carrier cylindrical roller bearings are designed as follows: Each cylindrical roller bearing has an inner ring with two radially outwardly directed rims. Each outer ring, however, has only on its inner, the planet carrier side facing an inboard board, while on the axially outer, ie the planet carrier side facing away from the outer rings no career for the rolling elements, ie cylindrical rollers, limiting board is present. The generator-side, that is output-side cylindrical roller bearing, which in a plant constellation in which wind forces and weight forces of the rotor are completely decoupled from the wind turbine gearbox has to absorb a higher radial load than the drive-side cylindrical roller bearing, according to this design also suitable for receiving during operation occurring axial loads , The two cylindrical roller bearings, that is the first, drive-side cylindrical roller bearings on the one hand and the second, output-side cylindrical roller bearings on the other hand, are not necessarily exposed to the same axial and radial loads.

The drive-side cylindrical roller bearing can be designed to be weaker overall than the output-side cylindrical roller bearing in the said system constellation in which wind forces are decoupled from the cylindrical roller bearing. This design is based on the consideration that for the performance of a cylindrical roller bearing in general, the ratio of axial to radial bearing load is important, with the smallest possible value of this ratio, that is the smallest possible axial force compared to the radial force is sought. In the bearing arrangement according to the invention, that bearing which has to absorb the higher axial forces also has to absorb the higher radial forces. The quotient between axial force and radial force can thus be kept in the same low ranges in both cylindrical roller bearings. Overall, the performance of the bearings is better exploitable compared to the prior art. With a tilting of the planet carrier in the gear housing, moreover, in comparison with conventional solutions, lower loads on the drive side cylindrical roller bearings, since sliding contacts between rolling elements and Borden are reduced.

In a preferred embodiment, the drive-side cylindrical roller bearing has a larger diameter than the generator-side cylindrical roller bearing. In a preferred embodiment, a cylinder described by the central axes of all planetary gears rotating with the rotating planet carrier has a diameter which is smaller than the pitch circle diameter of the drive-side cylindrical roller bearing and greater than the pitch circle diameter of the generator-side cylindrical roller bearing. The pitch circle of a cylindrical roller bearing is always defined as the circle defined by the centers of the respective rolling elements.

The single board of the outer ring of the first drive-side Zylinderrollenla- gers is preferably supported on a fixed to the transmission housing disc. This disc can be arranged on the inside of the gear housing and fastened by means of studs on the gear housing. A plurality of studs held on the disk and aligned in the axial direction of the bearing assembly in this case penetrate the gear housing, wherein each stud bolt is screwed on the outside of the gear housing with a nut. This attachment of a stop for the outer ring of the first cylindrical roller bearing forming disc on the transmission housing is preferably integrated in a bearing cap, which is a component of the transmission housing. Another component of the gear housing is a substantially cylindrical housing shell, which concentrically surrounds the axis of rotation of the bearing assembly and connected to the bearing cap, in particular screwed, is. The housing shell carries on its inside directly or indirectly the internal toothing, in which engage the planetary gears of the planetary gear.

On the output side, the gear housing has a further substantially disk-shaped housing component connected to the housing shell, which has a central opening through which the output shaft of the planetary gear is guided. The axis of rotation of the bearing assembly concentrically surrounding opening of this housing component is bounded by an axially inwardly directed, the planet carrier ring edge of the Gehäusekompo- component. Between this annular edge and the inner ring of the second cylindrical roller bearing or a retaining ring fixing the inner ring an annular gap is formed, which always remains open during operation of the planetary gear. When mounting the planetary gear, however, the inner ring of the second cylindrical roller bearing or this superior retaining ring can be supported on the annular edge of the transmission housing.

In contrast to the drive-side bearing cap of the frontal end of the gear housing on the output side is preferably designed multi-layered. In addition to the housing component having the inner ring edge, there is also an auxiliary housing part which likewise describes a disk shape and which is located on the inner side, that is to say the side facing the planet carrier, of the housing component having the annular rim. Like the housing component provided with the annular rim, the auxiliary housing part which directly adjoins this has a central opening, which, however, is larger than the opening of the first-mentioned housing component. In the comparatively large opening of the auxiliary housing part of the outer ring of the second cylindrical roller bearing is held. The only, inner, ie the planet carrier facing, board of the outer ring is supported in this case on an inwardly directed support flange of the auxiliary housing part. In a region lying radially further outward, said housing component and the auxiliary housing part are preferably screwed together with the housing jacket.

The bearing assembly is particularly suitable for wind turbines, but also for other applications, such as stationary gearboxes in industrial plants or for mobile applications. Short description of the drawing

An embodiment of the invention will be explained in more detail with reference to a drawing. Herein show:

1 is a sectional view of a bearing assembly in a planetary gear of a wind turbine,

Fig. 2 - 5 different steps of mounting the bearing assembly according to

Fig. 1.

Detailed description of the drawing

A planetary gearbox of a wind power plant, designated overall by the reference numeral 1, with respect to its basic function of which reference is made to the cited prior art, in particular EP 1 431 575 A2, has the following components:

A transmission housing 2 forms the ring gear of the planetary gear 1 and has an internal toothing 3 for this purpose. With the internal teeth 3 mesh planet wheels 4, which are mounted on a rotatable planet carrier 5 by means of roller bearings 6. The axis of rotation of the Plantenträg- 5 is designated R and at the same time represents the axis of symmetry of the entire planetary gear 1. On its left in the arrangement of Figure 1 side of the planet carrier 5 is in one piece in a hollow shaft 7. The hollow shaft 7 is fixedly connected to the main shaft of the wind turbine or identical. The planet carrier 5 thus rotates with the rotor of the wind turbine. The aerodynamic forces acting on the rotor can be decoupled from the planetary gear 1 in a manner not shown. The rotor bearing of the wind turbine is designed for this purpose preferably in the form of a two-point support. The side of the planetary gear 1, on which itself the rotor of the wind turbine is - in the arrangement of Figure 1 left - is referred to as the drive side AN.

The output from the planetary gear 1 to a generator, not shown, optionally via another, intermediate gear, is effected by a concentric with the axis of rotation R arranged sun gear 8, which meshes with the planetary gears 4. The sun gear 8 continues in the form of a shaft or is connected to such and protrudes on the output side of the planetary gear 1 out. The corresponding side of the planetary gear 1 is referred to as the output side AB.

The planet carrier 5 is mounted by means of two cylindrical roller bearings 9,10 in the transmission housing 2. The left in the arrangement of Figure 1 cylindrical roller bearing 9 is referred to as drive-side cylindrical roller bearing, the right cylindrical roller bearing 10 as a driven side cylindrical roller bearing. Each cylindrical roller bearing 9, 10 has an inner ring 1 1 held on the planet carrier 5 and an outer ring 12 held in the gearbox housing 2. Between the bearing rings 1 1, 12 roll each cylindrical rollers 13 as rolling elements. An unillustrated cage may be provided for guiding the cylindrical rollers 13. Alternatively, the cylindrical roller bearings can be configured as full complement bearings. Both cylindrical roller bearings 9, 10 are designed as single-row roller bearings.

The inner rings 1 1 of the cylindrical roller bearings 9,10 each have two shelves 14. In contrast, each outer ring 12 only a single board 15. This board 15 is located in each case on the interior of the gear housing 2 facing side of the outer ring 12th

While the inner rings 1 1 of the cylindrical roller bearings 9,10 are fixed on the drive side AN and on the output side AB in a comparable manner by means of a retaining ring 16 on the planet carrier 5, have the fasteners of the outer rings 12 of the first, drive-side cylindrical roller bearing 9 on the one hand and the second, output-side Zylinerrollenlagers 10 on the other hand considerable differences, as will be explained below.

The outer ring 12 of the cylindrical roller bearing 9 on the drive side AN is held by a disc 17 on the gear housing 2, which in the illustrated cross section (Figure 1) has an angular shape. The board 15 of the outer ring 12 abuts against a ring portion 18 of the disc 17. Radially outwardly connects to the ring portion 18 in one piece a flange portion 19 of the disc 17 at. Measured in the axial direction, the flange portion 19 is narrower than the ring portion 18, whereby between the ring portion 18 and the flange portion 19, a step is formed, which is also adapted to the stepped contour of the transmission housing 2 in this area, so that a determination of the disc 17 both in Radial direction is given as well as in an axial direction. The gear housing 2 is formed in the region in which the disc 17 abuts, as a bearing cap 20 having a plurality of concentric steps. The abutting on the inside of the bearing cap 20 flange portion 19 is a plurality of stud bolts 21 attached to the bearing cap 20, which are each held in the flange portion 19 and the bearing cap 20 in the axial direction, that is parallel to the rotation axis R, penetrate. On the outside of the bearing cap 20, each stud bolt 21 is screwed by means of a nut 22. The bearing cap 20 in turn is screwed by means of a screw 23 to a housing shell 24 of the gear housing 2, which has the internal toothing 3. On the bearing cover 20 opposite side of the planet carrier 5, that is on the drive side AB of the planetary gear 1, two parts 25,26 namely a disc shape descriptive housing component 25 and a contacting auxiliary housing part 26 by means of a common screw 27 to the housing shell 24 are connected , The disc-shaped housing component 25 has a central circular opening, the edge of which is formed by an axially inwardly directed, that is to say the interior of the gearbox housing 2 facing annular edge 28, which also as Support nose is called. The annular edge 28 is spaced from the retaining ring 16 by an annular gap, which fixes the inner ring 12 of the cylindrical roller bearing 10 on the planet carrier 5. The associated outer ring 12 of the cylindrical roller bearing 10 is inserted into the auxiliary housing part 26 and is there in the axial direction on the one hand by a radially inwardly directed, formed directly on the auxiliary housing 26 retaining flange 29 and on the other hand prevented by a inserted into the auxiliary housing part 26 securing ring 30 to displacements. During operation of the planetary gear 1, axial forces are mainly inward, that is to say towards the retaining flange 29. The board 15 of the outer ring 12 is located directly on the retaining flange 29.

The assembly of the planetary gear 1 is explained in more detail below with reference to Figures 2 to 5: The planet carrier 5 with the rotatably mounted thereon planet gears 4 is provided as a preassembled unit. Likewise, a preassembled unit is provided which comprises the auxiliary housing part 26 and the driven-side cylindrical roller bearing 10 held therein. With the aid of the output-side retaining ring 16, the last-mentioned unit is subsequently screwed onto the planet carrier 5. On the drive side AN of the planet carrier 5, the disc 17 is first pushed together with inserted stud bolts 21. The displacement is limited in the axial direction by a stop ring 31 of the planet carrier 5. As soon as the disk 17 bears against the stop ring 31, the drive-side cylindrical roller bearing 9 is pushed onto the planet carrier 5. The inner ring 1 1 of the cylindrical roller bearing 9 is then fixed by means of the drive-side retaining ring 16 in its final position. The associated outer ring 12 is still somewhat displaceable in the axial direction, wherein its displaceability is limited on the one hand by the cylindrical rollers 13 of the cylindrical roller bearing 9 and on the other hand by the annular portion 18 of the disc 17.

After both cylindrical roller bearings 9, 10 are provisionally held on the planet carrier 5, this, including the auxiliary housing part 26, is pressed against the housing attached component 25, wherein the auxiliary housing part 26 over a large area with the housing component 25 comes into contact. The sun gear 8 is pushed from the output side AB ago in the planetary gear 1. With the help of the screw 27, a solid bond between the housing component 25, the auxiliary housing part 26, as well as the pushed onto the planet gears 4 housing shell 24 is formed.

As the next assembly step, the bearing cap 20 is placed, the studs 21 penetrate openings in the bearing cap 20. The housing cover 24 bearing bearing cap 20 is connected by the screw 23 with this. Subsequently, the nuts 22 are tightened on the stud 21 and in this case the disc 17 is pulled to the outer ring 12 of the cylindrical roller bearing 9. The bearing assembly of the planetary gear 1 is thus completely assembled.

LIST OF REFERENCE NUMBERS

1 planetary gear

2 gearbox housing

3 internal toothing

4 planetary gear

5 planet carrier

6 roller bearings

7 hollow shaft

8 sun wheel

9 cylindrical roller bearings

10 cylindrical roller bearings

1 1 inner ring

12 outer ring

13 cylindrical rollers

14 shelves

15 board

16 retaining ring

17 disc

18 ring section

19 flange section

20 bearing caps

21 studs

22 mother

23 screw connection

24 housing jacket

25 housing component

26 auxiliary housing part

27 screw connection

28 ring edge

29 retaining flange

30 circlip stop ring

Output side Drive side Rotation axis

Claims

claims

Bearing arrangement for a planetary gear (1), in particular a wind turbine, comprising

a planet carrier (5) fixedly connected to a hollow shaft (7),

- A transmission housing (2), in which the planet carrier (5) is arranged,

- An internal toothing (3) of the transmission housing (2),

- with the internal teeth (3) meshing planet wheels (4),

a sun gear (8) meshing with the planet wheels (4),

- At both ends of the planetary gears (4) arranged bearing (9,10) for supporting the planet carrier (5) in the transmission housing (2), characterized in that each of the bearings (9,10) as a cylindrical roller bearing with a two shelves (14 ) having inner ring (1 1) and one on the planetary gears (4) facing side of a board (15) having outer ring (12) is formed.

Bearing arrangement according to claim 1,

characterized in that the bearing (9), which on the hollow shaft (7) facing side of the planet carrier (5) is arranged, a larger diameter than the hollow shaft (7) facing away from the bearing (10).

Bearing arrangement according to claim 2,

characterized in that the central axis of each planet wheel (4) is arranged radially between the pitch circles of the bearings (9,10).

Bearing arrangement according to one of claims 1 to 3,

characterized in that the board (15) of the outer ring (12) of the hollow shaft (7) facing bearing (9) on a transmission housing (2) attached to the disc (17) is supported. Bearing arrangement according to claim 4,

characterized in that the disc (17) arranged on the inside of the transmission housing (2) and with the transmission housing (2) penetrating, with nuts (22) on the outside of the transmission housing (2) tightened stud bolts (21) on the transmission housing (2) is held.

Bearing arrangement according to claim 5,

characterized in that the studs (21) penetrate a bearing cap (20) of the gear housing (2) which is fixed to a housing shell (24) concentrically surrounding the planetary carrier (5) and having the internal toothing (3).

Bearing arrangement according to one of claims 1 to 6,

characterized in that the transmission housing (2) on its side facing away from the hollow shaft (7) has a housing part descriptive of a housing component (25) which has a central opening which by an axially inwardly directed, the planet carrier (5) facing annular edge ( 28) is limited, which is spaced by an annular gap of the hollow shaft (7) facing away from the bearing (10).

Bearing arrangement according to claim 7,

characterized in that the annular edge (28) having housing component (25) fixedly connected to its on the planet carrier (5) side facing auxiliary housing part (26), in which the outer ring (12) of the bearing (10) is accommodated ,

Bearing arrangement according to claim 8,

characterized in that the annular edge (28) having housing component (25) together with the auxiliary housing part (26) with a further housing part, in particular housing casing (24) is connected.

10. Wind turbine, comprising a planetary gear (1) with a bearing arrangement according to claim 1.