DE102014104862A1 - Rolling bearing assembly and wind turbine - Google Patents

Abstract

It is proposed a rolling bearing assembly for a wind turbine comprising an outer ring and a relative to the outer ring rotatable about an axis inner ring, wherein between the outer ring and the inner ring, a first tapered roller bearing with first rolling elements and a second tapered roller bearing are formed with second rolling elements, wherein the axes of rotation of the first and second rolling elements are each inclined relative to the axis of rotation and wherein the first and the second tapered roller bearings are formed asymmetrically.

Description

State of the art

The present invention is based on a roller bearing assembly according to the preamble of claim 1.

Such rolling bearing arrangements are well known from the prior art and are used for example in the form of so-called large rolling bearings for supporting the rotor shaft of a wind turbine. Wind turbines usually have a tower and a rotatably mounted on the tower and acting as a machine carrier nacelle. The arranged in the nacelle rotor shaft is connected at one end to a rotor hub, which carries the wind-driven rotor blades, while the other end is coupled via a possible transmission directly or indirectly with a generator for generating electricity.

The problem with such wind turbines is that, in particular with changing wind loads in the rotor shaft very high axial forces along the rotor shaft, as well as significant tilting forces occur perpendicular to the rotor shaft, which must be absorbed by the bearings for supporting the rotor shaft.

From the publication DE 10 2007 049 087 A1 It is known to support the rotor shaft by means of double-row tapered roller bearings to accommodate both axial and radial forces. The two tapered roller bearings are symmetrical. Due to the asymmetrical load distribution in a wind turbine and the relatively high tilting forces acting on the rotor shaft of a wind turbine, the two symmetrical tapered roller bearings are disadvantageously loaded unevenly and therefore use unequal. Furthermore, the dimensioning of the tapered roller bearings is always based on the highest expected forces, so that one of the two bearings is unnecessarily oversized.

It is the object of the present invention to provide a roller bearing assembly with an inner ring and an outer ring, in which the disadvantages of the prior art are avoided. In particular, a needs-based dimensioning of the bearings should be made possible in order to optimize the overall costs for the rolling bearing assembly.

This object is achieved according to the invention by a rolling bearing assembly for a wind turbine having an outer ring and a relative to the outer ring rotatable about an axis inner ring, wherein between the outer ring and the inner ring, a first tapered roller bearing with first rolling elements and a second tapered roller bearing are formed with second rolling elements, wherein the Rotary axes of the first and second rolling elements relative to the axis of rotation are each aligned inclined and wherein the first and second tapered roller bearings are formed asymmetrically.

The roller bearing assembly according to the invention has the advantage over the prior art that the two tapered roller bearings are designed differently and thus can be adapted to the uneven loads occurring in wind turbines. In particular, it is conceivable that that tapered roller bearing, which is arranged closer to the rotor blades provided with rotor, dimensioned larger and thus more loadable, as the other tapered roller bearing, which is located closer to the generator. In this way, this other tapered roller bearing can be made smaller, which advantageously reduce the total cost of the rolling bearing assembly. It goes without saying that both the inner ring and the outer ring can be rotatable, i. the outer ring may also be rotatable relative to the inner ring about the axis of rotation.

Advantageous embodiments and modifications of the invention are the dependent claims, as well as the description with reference to the drawings.

According to a preferred embodiment of the present invention, it is provided that the first rolling elements each rotate about a first axis of rotation and have a first tread concentrically arranged about the first axis of rotation and wherein the second rolling elements each rotate about a second axis of rotation and concentrically arranged about the second axis of rotation In each case, the extension of the first tread parallel to the first axis of rotation is greater than the extension of the second tread parallel to the second axis of rotation. Advantageously, the load capacity of the first tapered roller bearing is increased compared to the second tapered roller bearing by the first treads are widened. In this way, the tilting forces typically occurring in a wind turbine can be better absorbed by the first tapered roller bearing. It is conceivable that the extent of the first running surface is 1.1 to 2.0 times, preferably 1.1 to 1.5 times and particularly preferably 1.1 to 1.3 times greater than that Extension of the second tread is.

According to a preferred embodiment of the present invention, it is provided that the nominal diameter of the first rolling elements is greater than the nominal diameter of the second rolling elements. Alternatively or in addition to the enlargement of the first running surfaces, the load capacity of the first tapered roller bearing can also be achieved by increasing the nominal diameter of the first rolling elements in comparison with the second rolling elements. In the context of the present invention, the nominal diameter of a rolling element is, in particular, that diameter which the rolling element has in its geometric center, ie in particular the center of the running surface along its axis of rotation. It is conceivable that the nominal diameter of the first rolling elements between 36 and 180 millimeters, preferably between 80 and 160 millimeters and more preferably between 120 and 140 millimeters, while the nominal diameter of the second rolling elements between 36 and 180 millimeters, preferably between 80 and 160 millimeters and more preferably between 120 and 140 millimeters.

According to a preferred embodiment of the present invention, it is provided that between the rotation axis and the first rolling elements always a first angle is formed and wherein between the rotation axis and the second rolling elements always a second angle is formed, wherein the first angle is smaller than the second angle , The tilting forces occurring in a wind turbine ensure in particular that on the first tapered roller bearing comparatively large radial forces must be absorbed perpendicular to the axis of rotation, while in the region of the second tapered roller bearing increased axial forces along the axis of rotation occur. By a smaller first angle (also referred to as the first support angle) compared to the second angle these features can be taken into account in a particularly efficient manner. The flatter first angle provides greater radial load bearing capacity on the first tapered roller bearing, while the steeper second angle provides better axial force absorption on the second tapered roller bearing. It is conceivable that the first angle is between 30 and 60 degrees, preferably between 30 and 50 degrees and particularly preferably between 30 and 40 degrees, while the second angle is between 40 and 90 degrees, preferably between 50 and 85 degrees and particularly preferably between 60 and 85 degrees.

According to a preferred embodiment of the present invention, it is provided that the outer ring has a first outer raceway, on which the first rolling elements run, and a second outer raceway, on which the second rolling elements run, wherein the outer ring has a circumferential ring segment projecting in a wedge shape in the direction of the axis of rotation having two wedge flanks, wherein on the one wedge flank, the first outer raceway and on the other wedge flank, the second outer raceway is formed. Advantageously, the formation of the first and second outer race on a single one-piece ring segment makes it possible for the rolling element arrangement to be realized in a particularly space-saving and cost-effective manner. In addition, the axial and radial forces are introduced directly into the bilaterally supported ring segment, resulting in a particularly tamper-proof, torsionally rigid and stable storage. The outer ring is for this purpose in particular integrally formed.

According to a preferred embodiment of the present invention, it is provided that the inner ring is formed in several parts from a first inner ring part and a second inner ring part. The inner ring preferably has a first inner race on which the first rolling elements run, and a second inner race on which the second rolling elements run, wherein the first inner race is formed on the first inner ring part and the second inner race is formed on the second inner ring part. The two-part design of the inner ring allows advantageously a simple and quick installation of the rolling element, whereby the manufacturing costs can be further reduced.

According to a preferred embodiment of the present invention, provision is made for a shoulder to be formed on the inner ring between the first inner raceway and the second inner raceway. It has surprisingly been found that the distribution of lubricant between the first and the second inner raceway can be optimized by the heel and thus always a reliable lubrication of the first and second rolling elements is ensured.

According to a preferred embodiment of the present invention, it is provided that the first and second rolling elements are each received in cages and at least one recess is formed on a surface of the inner ring facing the cages, in which an end region of a cage runs. The recess offers the advantage that lubricant collects within the recess and thus always a reliable lubrication between the cage and inner ring is guaranteed. In principle, it would also be conceivable for a corresponding depression to be formed on the outer ring in the area of the cages.

Another object of the present invention is a wind turbine comprising a rotor hub with a plurality of rotor blades, wherein the rotor hub rotatably connected to a rotor shaft and the rotor shaft is coupled directly or indirectly with a generator, wherein the wind turbine has a bearing assembly for supporting the rotor shaft and wherein the bearing assembly comprises the rolling bearing assembly according to the invention. Advantageously, the wind turbine is due the use of the rolling bearing assembly according to the invention comparatively inexpensive feasible.

Further details, features and advantages of the invention will become apparent from the drawings, as well as from the following description of preferred embodiments with reference to the drawings. The drawings illustrate only exemplary embodiments of the invention, which do not limit the essential inventive idea.

Brief description of the drawings

1 shows a schematic sectional view of a rolling bearing assembly according to an exemplary first embodiment of the present invention.

2 shows a schematic sectional view of a rolling bearing assembly according to an exemplary second embodiment of the present invention.

3 shows a schematic sectional view of a rolling bearing assembly according to an exemplary third embodiment of the present invention.

Embodiments of the invention

In 1 is a schematic sectional view of a rolling bearing assembly 1 according to an exemplary embodiment of the present invention.

The rolling bearing arrangement 1 has an outer ring 2 and an inner ring 3 on. The inner ring 3 is about a rotation axis 24 rotatable relative to the outer ring 2 stored. The rolling bearing arrangement 1 is designed for this two-row and has two tapered roller bearings, a first tapered roller bearing 4 and a second tapered roller bearing 6 on.

The first tapered roller bearing 4 includes a plurality of first rolling elements 5 , which in each case about their longitudinal axis, present as the first axes of rotation 12 designated, rotate. Every first rolling element 5 has a circumferential first tread 14 which, as a lateral surface concentric around the first axis of rotation 12 extends. The first rolling element 5 is in each case of frustoconical design, so that its diameter along the first axis of rotation 12 changed. The first rolling elements 5 are between the outer ring 2 and the inner ring 3 arranged and run with their first treads 14 in each case at one on the outer ring 2 trained circumferential first outer raceway 8th and one on the inner ring 3 trained circumferential first inner raceway 16 from. The first axis of rotation 12 is in each case opposite to the axis of rotation 24 at a first angle 10 inclined so that both along the axis of rotation 24 acting axial forces, as well as perpendicular to the axis of rotation 24 acting radial forces of the first tapered roller bearing 4 can be included.

Analogous to the first tapered roller bearing 4 includes the second tapered roller bearing 6 a plurality of second rolling elements 7 , which likewise each about their longitudinal axes, as second axes of rotation 13 designated, rotate. The second rolling elements 7 each have circumferential second treads 15 on, which is a concentric lateral surface around the second axis of rotation 13 extends. Analogous to the first rolling elements 5 are also the second rolling elements 7 formed frusto-conical, so that its diameter along the second axis of rotation 13 changed. The outer ring 2 points next to the first outer raceway 8th Furthermore, a circumferential second outer raceway 9 and the inner ring 3 next to the first inner raceway 16 Furthermore, a circumferential second inner raceway 17 on, between which the second rolling elements 7 are arranged and on which the second rolling elements 7 with their second treads 15 each expire. The second axis of rotation 13 is also opposite the axis of rotation 24 at a second angle 11 inclined so that both along the axis of rotation 24 acting axial forces, as well as perpendicular to the axis of rotation 24 acting radial forces also from the second tapered roller bearing 6 can be included. The first and second rolling elements 5 . 7 are each in cages 25 added.

The present rolling bearing arrangement 1 is intended for mounting a rotor shaft of a wind turbine not shown. The rotor shaft usually extends from the rotor hub provided with the rotor hub to the generator of the wind turbine. The rotor hub is partially freestanding, so that on the rotor shaft due to the wind forces and the gravitational force acts a significant tilting moment. The first and second tapered roller bearings 4 . 6 are thus charged unequally.

To accommodate this unequal load are the first and second tapered roller bearings 4 . 6 asymmetric design, ie the first and second tapered roller bearings 4 . 6 different support angles 10 . 11 , differently dimensioned rolling elements 5 . 7 , as well as different widths have raceways.

When the first tapered roller bearing 4 the one bearing which is closer to the rotor hub, while the second tapered roller bearing 6 The closer to the generator bearing is cause the tilting forces in the area of the first tapered roller bearing 4 a higher radial load compared to the second tapered roller bearing 6 , The first angle 10 is therefore smaller than the second angle 11 around the first tapered roller bearing 4 Increased accumulating radial forces perpendicular to the axis of rotation 24 act to absorb. The first angle 10 for example, is between 30 and 40 degrees, while the second angle 11 for example, could be between 60 and 85 degrees. In addition, the first rolling elements 5 larger than the second rolling elements 7 formed, ie the first rolling elements 5 have compared to the second rolling elements 7 each have both a larger nominal diameter, and a wider tread. It is conceivable, for example, that the nominal diameter of the second rolling elements 7 only between 50 and 90 millimeters, while the nominal diameter of the first rolling elements 5 between 120 and 140 millimeters. It would also be conceivable that the extension of the first tread 14 along the associated first axis of rotation 12 each 1.1 to 1.3 times the extension of the second tread 15 along the associated second axis of rotation 13 is.

In the present rolling bearing assembly 1 is the outer ring 2 designed in such a way that the outer ring 2 one in the direction of the axis of rotation 24 wedge-shaped protruding circumferential ring segment 23 with two wedge flanks 20 . 21 having, on the one wedge flank 20 the first outer career 8th and on the other wedge flank 21 the second outer raceway 9 is trained. The first and second outer career 8th . 9 are thus on the wedge flanks 20 . 21 of the ring segment 23 arranged extremely space-compact, wherein between the first and second outer raceway 8th . 9 only the tip of the wedge-shaped ring segment is arranged.

The inner ring 3 is preferably in two parts of a first inner ring part 18 and a second inner ring part 19 is formed. The first inner raceway 16 is on the first inner ring part 18 trained and the second inner raceway 17 is on the second inner ring part 19 educated.

In the rolling bearing assembly 1 According to the first embodiment is between the first and the second inner raceway 16 . 17 a paragraph 22 educated.

In 2 is a schematic sectional view of a rolling bearing assembly 1 according to an exemplary second embodiment of the present invention, wherein the rolling bearing assembly 1 according to the second embodiment of the rolling bearing assembly 1 according to the in 1 illustrated first embodiment, in contrast, the rolling bearing assembly 1 according to the second embodiment, no paragraph 22 and on the inner ring 3 each wells 26 are formed, in which the contact surfaces of the cages 25 of the first and second rolling elements 5 . 7 to run. The wells 26 ensure that lubricant in the area of cages 25 collect and maintain adequate lubrication between the cages 25 and the inner ring 3 guarantee.

In 3 is a schematic sectional view of a rolling bearing assembly 1 according to an exemplary third embodiment of the present invention, wherein the rolling bearing assembly 1 according to the third embodiment, a mixed form of the rolling bearing assembly 1 according to the in 1 illustrated first embodiment and the rolling bearing assembly according to the in 2 illustrated second embodiment. The rolling bearing arrangement 1 according to the third embodiment therefore has both the paragraph 22 on, as well as depressions 26 on the inner ring 3 in which the contact surfaces of the cages 25 of the first and second rolling elements 5 . 7 to run.

LIST OF REFERENCE NUMBERS

1

 roller bearing assembly

2

 outer ring

3

 inner ring

4

 First tapered roller bearing

5

 First rolling elements

6

 Second tapered roller bearing

7

 Second rolling elements

8th

 First outer career

9

 Second outside career

10

 First angle

11

 Second angle

12

 First axis of rotation

13

 Second axis of rotation

14

 First tread

15

 Second tread

16

 First inner race

17

 Second inner race

18

 First inner ring part

19

 Second inner ring part

20

 wedge edge

21

 wedge edge

22

 paragraph

23

 ring segment

24

 axis of rotation

25

 Cage

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102007049087 A1 [0004]

Claims (15)

Rolling bearing arrangement ( 1 ) for a wind turbine having an outer ring ( 2 ) and a relative to the outer ring ( 2 ) about a rotation axis ( 24 ) rotatable inner ring ( 3 ), between the outer ring ( 2 ) and the inner ring ( 3 ) a first tapered roller bearing ( 4 ) with first rolling elements ( 5 ) and a second tapered roller bearing ( 6 ) with second rolling elements ( 7 ) are formed, wherein the axes of rotation ( 12 . 13 ) of the first and second rolling elements ( 5 . 7 ) with respect to the axis of rotation ( 24 ) are each inclined, characterized in that the first and second tapered roller bearings ( 4 . 6 ) are formed asymmetrically. Rolling bearing arrangement ( 1 ) according to claim 1, wherein the first rolling elements ( 5 ) each about a first axis of rotation ( 12 ) and one around the first axis of rotation ( 12 ) concentrically arranged first tread ( 14 ) and wherein the second rolling elements ( 7 ) each about a second axis of rotation ( 13 ) and one around the second axis of rotation ( 13 ) concentrically arranged second tread ( 15 ), wherein in each case the extent of the first tread ( 14 ) parallel to the first axis of rotation ( 12 ) greater than the extension of the second tread ( 15 ) parallel to the second axis of rotation ( 13 ). Rolling element arrangement ( 2 ) according to claim 2, wherein the extension of the first tread ( 14 ) by 1.1 to 2.0 times, preferably by 1.1 to 1.5 times and more preferably by 1.1 to 1.3 times greater than the extension of the second running surface ( 15 ). Rolling bearing arrangement ( 1 ) according to one of the preceding claims, wherein the nominal diameter of the first rolling elements ( 5 ) greater than the nominal diameter of the second rolling elements ( 7 ). Rolling bearing arrangement ( 1 ) according to claim 4, wherein the nominal diameter of the first rolling elements ( 5 ) is between 36 and 180 millimeters, preferably between 80 and 160 millimeters, and more preferably between 120 and 140 millimeters. Rolling bearing arrangement ( 1 ) according to one of claims 4 or 5, wherein the nominal diameter of the second rolling elements ( 7 ) is between 36 and 180 millimeters, preferably between 80 and 160 millimeters, and more preferably between 120 and 140 millimeters. Rolling bearing arrangement ( 1 ) according to one of the preceding claims, wherein between the axis of rotation ( 24 ) and the first rolling elements ( 5 ) always a first angle ( 10 ) and wherein between the axis of rotation ( 24 ) and the second rolling elements ( 7 ) always a second angle ( 11 ), wherein the first angle ( 10 ) smaller than the second angle ( 11 ). Rolling bearing arrangement ( 1 ) according to claim 7, wherein the first angle ( 10 ) is between 30 and 60 degrees, preferably between 30 and 50 degrees, and more preferably between 30 and 40 degrees. Rolling bearing arrangement ( 1 ) according to one of claims 7 or 8, wherein the second angle ( 10 ) is between 40 and 90 degrees, preferably between 50 and 85 degrees, and more preferably between 60 and 85 degrees. Rolling element arrangement ( 1 ) according to one of the preceding claims, wherein the outer ring ( 2 ) a first outer raceway ( 8th ), on which the first rolling elements ( 5 ), and a second outer raceway ( 9 ) on which the second rolling elements ( 7 ), wherein the outer ring ( 2 ) in the direction of the axis of rotation ( 24 ) wedge-shaped protruding circumferential ring segment ( 23 ) with two wedge flanks ( 20 . 21 ), wherein on the one wedge flank ( 20 ) the first outer raceway ( 8th ) and on the other wedge flank ( 21 ) the second outer raceway ( 9 ) is trained. Rolling element arrangement ( 1 ) according to one of the preceding claims, wherein the inner ring ( 3 ) in several parts from a first inner ring part ( 18 ) and a second inner ring part ( 19 ) is formed. Rolling element arrangement ( 1 ) according to claim 11, wherein inner ring ( 3 ) a first inner raceway ( 16 ), on which the first rolling elements ( 5 ), and a second inner raceway ( 17 ) on which the second rolling elements ( 7 ), wherein on the first inner ring part ( 18 ) the first inner raceway ( 16 ) and on the second inner ring part ( 19 ) the second inner raceway ( 17 ) is trained. Rolling element arrangement ( 1 ) according to claim 12, wherein between the first inner raceway ( 16 ) and the second inner raceway ( 17 ) a paragraph ( 22 ) on the inner ring ( 3 ) is trained. Rolling element arrangement ( 1 ) according to one of the preceding claims, wherein the outer ring ( 2 ) is formed in one piece. Wind turbine having a rotor hub with a plurality of rotor blades, wherein the rotor hub rotatably connected to a rotor shaft and wherein the rotor shaft is coupled directly or indirectly with a generator, wherein the wind turbine has a bearing assembly for supporting the rotor shaft, characterized in that the Bearing arrangement a rolling bearing assembly ( 1 ) according to one of the preceding claims.

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