DE102015112056B4 - Rolling bearing arrangement, in particular large rolling bearing arrangement, and blade bearing for a wind turbine - Google Patents

Abstract

Rolling bearing arrangement, in particular large rolling bearing arrangement, comprising an inner ring (5) and an outer ring (6) which is rotatable relative to the inner ring (5) about a rotation axis (R) and overlaps in the radial direction, wherein two rows of rolling elements (13, 14) offset from one another in the axial direction are arranged between the inner ring (5) and the outer ring (6), wherein the rolling elements (13, 14) each run in raceways (11, 12, 15, 16) formed on the inner ring (5) and on the outer ring (6), wherein the inner ring (5) and the outer ring (6) overlap one another in the axial direction by means of a radial projection (10) formed on the inner ring (5) or on the outer ring (6) and projecting between the two rows of rolling elements (13, 14), wherein the outer ring (6) or the inner ring (5) has a circumferential groove (8) into which the radial projection (10) arranged on the inner ring (5) or on the outer ring (6) projects in the opposite direction to the radial direction, raceways (11, 12, 15, 16) for the rolling elements (13, 14) being formed on the flanks of the radial projection (10), a radial additional bearing (20) being arranged in the axial direction between the two rows of rolling elements (13, 14), characterized in that the rolling elements (13, 14) are designed as toroidal rollers, the radii of the inner contours of the raceways (11, 12, 15, 16) being selected to be larger than the crowning radii of the toroidal rollers (13, 14), the raceways (11, 12, 15, 16) being designed without rims, and in the radial direction laterally of the raceways (11, 12, 15, 16) open spaces are arranged on both sides.

Description

State of the art

The present invention relates to a rolling bearing arrangement having the features of claim 1.

Such rolling bearing arrangements are used, for example, as blade bearings for the rotatable connection of rotor blades in wind turbines in order to enable the power of the wind turbine to be controlled by adjusting the blade angle.

From the EP 2 087 249 B1 A rolling bearing arrangement of this type with two rows of rolling elements offset from one another in the axial direction is known. The rolling elements of this rolling element arrangement are spherical in shape so that forces can be absorbed in both the axial and radial directions. An elliptical contact surface forms between the rolling elements and the raceways, which limits the load-bearing capacity of this rolling bearing arrangement.

Higher load capacities can be achieved with a rolling bearing arrangement that has cylindrical roller-shaped rolling elements, such as those used in the EP 0 413 119 A2 is known. In this rolling bearing arrangement, the cylindrical rollers are in line contact with the raceways, which results in an increased load-bearing capacity. However, load-related deformations of the inner ring and/or the outer ring cannot be partially compensated by the cylindrical rollers. Depending on the connecting structure, such deformations can lead to increased standstill wear (false brinelling) of the rolling bearing arrangement.

In the print EN 10 2012 004 329 A1 An arrangement for supporting parts of an energy plant, in particular a wind turbine, which can be rotated relative to one another is disclosed, in which barrel-shaped rolling elements can be used.

The publication EN 10 2010 053 140 A1 deals with the design of the overall profile of a roller body. The overall profile should be suitable for roller bodies of toroidal bearings, among other things.

Disclosure of the invention

The object of the present invention is to provide a rolling bearing arrangement with increased load capacity which is less susceptible to wear caused by load-related deformations.

In a rolling bearing arrangement of the type mentioned at the outset, the object is achieved in that the rolling elements are designed as toroidal rollers, wherein the radii of the inner contours of the raceways (11, 12, 15, 16) are selected to be larger than the crowning radii of the toroidal rollers (13, 14), wherein the raceways (11, 12, 15, 16) are designed without rims, and wherein free spaces are arranged on both sides of the raceways (11, 12, 15, 16) in the radial direction.

At increased loads, a linear contact zone forms between the toroidal rollers and the raceways, which increases the load-bearing capacity. Due to the geometry of the toroidal rollers, misalignments are permitted even at increased loads, so that load-related deformations can be compensated. Overall, this provides a rolling bearing arrangement with increased load-bearing capacity that can better compensate load-related deformations and therefore wears less quickly.

According to the invention, the raceways are designed without rims, so that the toroidal rollers in the raceway are not guided by rims, but solely by the frictional forces occurring between the toroidal rollers and the raceway. According to the invention, free spaces are arranged on both sides of the raceways in the radial direction, so that a radial displacement of the raceways of the inner ring and the raceways of the outer ring against each other is possible.

The design according to the invention, in which the outer ring or the inner ring has a circumferential groove into which the radial projection arranged on the inner ring or on the outer ring projects counter to the radial direction, so that a compact construction of the rolling bearing arrangement is possible, is structurally advantageous.

Another advantage of the design of the rolling bearing arrangement according to the invention is that raceways for the rolling elements are formed on the flanks of the radial projection. Such a design has the advantage that the rolling elements can be guided in the area between the flanks of the radial projection and an inner side of the groove.

According to the invention, a radial additional bearing is arranged in the axial direction between the two rows of rolling elements. The radial additional bearing can be used to transmit forces acting in the radial direction between the inner ring and the outer ring. The radial additional bearing is arranged on a front side of the radial projection that connects the flanks. This reduces the gap between the flanks. The axial installation space is well utilized and a compact design is achieved in the axial direction. The additional radial bearing can support the rolling elements, which are designed as toroidal rollers, in absorbing forces acting in the radial direction.

Toroidal rollers are relatively long, slightly crowned rollers. The ratio of the length of the toroidal rollers to the nominal diameter of the toroidal rollers can be greater than 1, preferably greater than 1.1, particularly preferably greater than 1.2.

According to an advantageous embodiment, the raceways in which the toroidal rollers run are spherical, which makes it easier to position the toroidal rollers inclined within the raceways. The radius of curvature of the raceways is preferably larger than the crowning radius of the toroidal rollers, so that at low loads there is point contact between the toroidal rollers and the corresponding raceways.

An advantageous embodiment is one in which the toroidal rollers each have a length and a crown radius and the ratio of the crown radius to the length is in the range from 1 to 5, preferably in the range from 3 to 5, particularly preferably in the range from 4 to 5.

It is advantageous if the radial additional bearing has a series of additional rolling elements in the form of cylindrical rollers, wherein the respective axes of rotation of the cylindrical rollers run essentially parallel to the axis of rotation of the rolling bearing.

According to an alternative embodiment, the radial additional bearing has a series of spherical additional rolling elements.

In this context, it has proven to be advantageous if a raceway for the additional rolling elements is formed on one end face of the radial projection and another raceway for the additional rolling elements is formed, in particular centrally, in the circumferential groove. The raceways for the additional rolling elements in the form of cylindrical rollers can be flat and optionally have rims. The raceways for spherical additional rolling elements are preferably spherical, with the radius of curvature of the raceways for the additional rolling elements preferably being larger than the radius of the spherical additional rolling elements.

The rolling bearing arrangement preferably has a diameter in the range of 1 m to 10 m, preferably from 3 m to 7 m, particularly preferably from 4 m to 6 m, so that it can be used in a blade bearing for a wind turbine.

Another object of the invention is a blade bearing for a wind turbine comprising a rolling bearing arrangement as described above.

Further details, features and advantages of the invention emerge from the drawings and from the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not restrict the inventive concept.

Short description of the characters

• The 1 shows an embodiment in a wind turbine according to the invention in a front view.
• The 2 shows an embodiment of a rolling bearing arrangement without additional radial bearing in a sectional view, not covered by the patent claims.
• The 3 shows an embodiment of a rolling bearing arrangement according to the invention in a sectional view.

Embodiments of the invention

In the various figures, identical parts are always provided with the same reference symbols and are therefore usually named or mentioned only once.

In the 1 a wind turbine 1 is shown which has a rotor 3 arranged on a tower. The rotor 3 is mounted so that it can rotate in azimuth relative to the tower via an azimuth bearing. Several rotor blades 2 are provided on the rotor 3, which are mounted so that they can rotate on the rotor 3 via blade bearings 4 in order to adjust the blade angle of the individual rotor blades 2.

The azimuth bearing and the blade bearings 4 each have a large roller bearing arrangement with a diameter in the range of 1 m to 10 m, preferably from 3 m to 7 m, particularly preferably from 4 m to 6 m. A blade bearing 4 which rotatably connects the rotor blades 2 to the rotor 3 will be described below. Alternatively or additionally, it is possible to design an azimuth bearing of the wind turbine 1 as described below.

The rolling bearing arrangements described below each have two rows of rolling elements spaced apart in the axial direction, which are designed as toroidal rollers 13, 14 The toroidal rollers 13, 14 are relatively long, slightly crowned rollers, wherein the ratio of the length of the toroidal rollers 13, 14 to the nominal diameter of the toroidal rollers 13, 14 can be greater than 1, preferably greater than 1.1, particularly preferably greater than 1.2.

The 2 shows an embodiment of a blade bearing 4, which is not covered by the patent claims, because the rolling bearing arrangement according to 2 has no additional radial bearing. The rolling bearing arrangement comprises an inner ring 5 and an outer ring 6 which is arranged so as to be rotatable relative to the inner ring 6 about an axis of rotation R. The average radius of the inner ring 5 is smaller than the average radius of the outer ring 6. Since the outer radius of the inner ring 5 is larger than the inner radius of the outer ring 6, an area is created in which the inner ring 5 and the outer ring 6 overlap along the radial direction. This overlap comes about because the inner surface 7 of the outer ring 6 has a groove 8 and the outer surface 9 of the inner ring 6 has a radial projection 10 which engages in the groove 8. Furthermore, the inner ring 5 and the outer ring 6 overlap in the area of the radial projection 10 in the axial direction, i.e. in a direction which runs parallel to the axis of rotation R of the rolling bearing arrangement 4.

In order to facilitate the insertion of the toroidal rollers 13, 14, the outer ring 6 is designed in two parts. The outer ring has a first ring element 6.1 and a second ring element 6.2, which can be releasably secured to one another, for example via a screw connection.

Two raceways 11, 12 for rolling elements designed as toroidal rollers 13, 14 are arranged on the outer ring 6. The raceways 11, 12 of the outer ring 5 are provided in the area of the groove 8, in particular on the inner sides of the groove 8. The inner ring 5 also has two raceways 15, 16 in which the toroidal rollers 13, 14 are guided. The raceways 15, 16 of the inner ring 5 are formed on the flanks of the radial projection 10. The raceways 11, 12, 15, 16 have a spherical inner contour, i.e. the cross section of the inner contour is circular. The radius of the inner contour of the raceways 11, 12, 15, 16 is essentially identical, whereby the radius is selected to be slightly larger than the crowning radius of the toroidal rollers 13, 14. Alternatively, the radii of the raceways 11, 12, 15, 16, on which a toroidal roller 13, 14 rests, can be different.

Because the radii of the raceways 11, 12, 15, 16 are larger than the crowning radii of the toroidal rollers 13, 14, the toroidal rollers 13, 14 touch the corresponding raceways 11, 12, 15, 15 in an essentially point-like contact area under low load. Under increased load, a circular contact zone forms between the toroidal rollers 13, 14 and the raceways 11, 12, 15, 16, which increases the load-bearing capacity. Due to the crowned geometry of the toroidal rollers 13, 14, misalignments are possible even under increased load, so that load-related deformations can be compensated. Overall, this provides a rolling bearing arrangement with an increased load-bearing capacity that can better compensate load-related deformations and therefore wears less quickly.

The raceways 11, 12, 15, 16 are designed without rims. Furthermore, free spaces are arranged to the side of the raceways 11, 12, 15, 16 in a direction perpendicular to the axis of rotation R. In this respect, it is possible to compensate for load-related deformations as a result of which the inner ring 5 tilts at least in some areas relative to the outer ring.

In the sectional view in 2 a deformation of the rolling bearing arrangement is shown in which the inner ring 5 is inclined relative to the outer ring 6 in the area of the cutting plane as a result of a load-related deformation in such a way that an increased load acts on the lower toroidal roller 14, while the upper toroidal roller 13 arranged in the axial direction above the lower toroidal roller 14 is relieved. The outer surface 9 of the inner ring 5 rests against a lower area of the inner surface 7 of the outer ring 6, while there is a gap between the outer surface 9 of the inner ring 5 and an upper area of the inner surface 7 of the outer ring 6, which is spaced apart in the axial direction. The toroidal rollers 14 of the lower row are in circular contact with the corresponding raceways 12, 16, so that an increased load can be absorbed without there being any fear of damage to the toroidal rollers 14 or the raceways 12, 16.

In the 3 an embodiment of a rolling bearing arrangement according to the invention is shown in a sectional view. In contrast to the embodiment according to 2 is in the embodiment according to 3 a groove 8 is arranged on the outer surface 9 of the inner ring 6. The inner surface 7 of the outer ring 6 has a radial projection 10 engaging in the groove 8. Furthermore, in the embodiment according to 3 In addition, a radial additional bearing 20 is provided, which can absorb forces acting in the radial direction, ie perpendicular to the rotation axis R. The radial additional bearing 20 is arranged in the axial direction between the two rows of rolling elements designed as toroidal rollers 13, 14 As a result, the installation space available in the axial direction between the toroidal rollers 13, 14 is used in a space-saving manner and a compact design of the rolling bearing arrangement in the axial direction is achieved.

The radial additional bearing 20 contains a series of additional rolling elements, which are either designed as cylindrical rollers whose axes of rotation run essentially parallel to the axis of rotation R, or as spherical rolling elements. A raceway is provided on one end face of the radial projection 10, in which the additional rolling elements run. A further raceway for the additional rolling elements is formed centrally in the circumferential groove 8.

The rolling bearing arrangements described above, in particular large rolling bearing arrangements, each have an inner ring 5 and an outer ring 6 which is rotatable relative to the inner ring 5 about an axis of rotation R and overlaps the inner ring in the radial direction, wherein two rows of rolling elements designed as toroidal rollers 13, 14 are arranged between the inner ring 5 and the outer ring 6, offset from one another in the axial direction, wherein the rolling elements designed as toroidal rollers 13, 14 each run in raceways 11, 12, 15, 16 formed on the inner ring 5 and on the outer ring 6, wherein the inner ring 5 and the outer ring 6 overlap one another in the axial direction by means of a radial projection 10 formed on the inner ring 5 or on the outer ring 6 and projecting between the two rows of rolling elements 13, 14. By means of the rolling elements 13, 14 designed as toroidal rollers 13, 14, an increased load-bearing capacity can be achieved with reduced susceptibility to wear caused by load-related deformations.

List of reference symbols

1

Wind turbine

2

Rotor blade

3

rotor

4

Blade bearing

5

Inner ring

6

Outer ring

7

Shell surface

8

Groove

9

Shell surface

10

Radial projection

11

career

12

career

13

Rolling elements

14

Rolling elements

15

career

16

career

20

Additional storage

R

Rotation axis

Claims (8)

Rolling bearing arrangement, in particular large rolling bearing arrangement, comprising an inner ring (5) and an outer ring (6) which is rotatable relative to the inner ring (5) about a rotation axis (R) and overlaps in the radial direction, wherein two rows of rolling elements (13, 14) offset from one another in the axial direction are arranged between the inner ring (5) and the outer ring (6), wherein the rolling elements (13, 14) each run in raceways (11, 12, 15, 16) formed on the inner ring (5) and on the outer ring (6), wherein the inner ring (5) and the outer ring (6) overlap one another in the axial direction by means of a radial projection (10) formed on the inner ring (5) or on the outer ring (6) and projecting between the two rows of rolling elements (13, 14), wherein the outer ring (6) or the inner ring (5) has a circumferential groove (8) into which the radial projection (10) arranged on the inner ring (5) or on the outer ring (6) projects in the opposite direction to the radial direction, raceways (11, 12, 15, 16) for the rolling elements (13, 14) being formed on the flanks of the radial projection (10), a radial additional bearing (20) being arranged in the axial direction between the two rows of rolling elements (13, 14), characterized in that the rolling elements (13, 14) are designed as toroidal rollers, the radii of the inner contours of the raceways (11, 12, 15, 16) being selected to be larger than the crowning radii of the toroidal rollers (13, 14), the raceways (11, 12, 15, 16) being designed without rims, and in the radial direction laterally of the raceways (11, 12, 15, 16) there are free spaces on both sides. Rolling bearing arrangement according to Claim 1 , wherein the ratio of the length of the toroidal rollers to the nominal diameter of the toroidal rollers is greater than 1, preferably greater than 1.1, particularly preferably greater than 1.2. Rolling bearing arrangement according to one of the preceding claims, wherein the raceways (11, 12, 15, 16) in which the toroidal rollers run are spherical. Rolling bearing arrangement according to one of the preceding claims, wherein the toroidal rollers each have a length (L) and a crown radius and the ratio of the crown radius to the length is in the range of 1 to 5, preferably in the range of 3 to 5, particularly preferably in the range of 4 to 5. Rolling bearing arrangement according to one of the preceding claims, wherein the radial additional bearing (20) has a series of additional rolling elements in the form of cylindrical rollers, wherein the respective axes of rotation of the cylindrical rollers run substantially parallel to the axis of rotation (R). Rolling bearing arrangement according to one of the preceding claims, wherein the radial additional bearing (20) has a series of spherical additional rolling elements. Rolling bearing arrangement according to one of the Claims 5 or 6 , wherein a raceway for the additional rolling elements is formed on one end face of the radial projection (10) and wherein another raceway for the additional rolling elements is formed centrally in the circumferential groove (8). Blade bearing for a wind turbine (1) comprising a rolling bearing arrangement according to one of the preceding claims.

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