BEARING ASSEMBLY

Abstract

Disclosed is a bearing assembly, in particular a large bearing assembly, including at least one inner ring and at least one outer ring, between which at least one circumferential seal is disposed that slips on a circumferential slip surface of the inner ring or of the outer ring, wherein guide channels are formed on the slip surface or the circumferential seal.

Claims

1. A large bearing assembly comprising: at least one first bearing ring, at least one second bearing ring having a first slip surface, and at least one circumferential seal having a seal lip, the at least one seal being mounted to the at least one first bearing ring with the seal lip in contact with the first slip surface, wherein the first slip surface or the seal lip includes guide channels.

2. The bearing assembly according to claim 1, wherein the guide channels extend obliquely to an axis of rotation of the bearing assembly.

3. The bearing assembly according to claim 1, wherein the guide channels are configured to generate a pumping effect in a certain direction along the axis of rotation.

4. The bearing assembly according to claim 1, wherein the guide channels are distributed equally circumferentially.

5. The bearing assembly according to claim 1, wherein the guide channels have a pitch of greater than or equal to 4 mm per rotation.

6. The bearing assembly according to claim 5, wherein a circumferential distance between the guide channels is smaller than the pitch.

7. The bearing assembly according to claim 6, wherein the circumferential distance between the guide channels is less than or equal to 0.1 mm.

8. The bearing assembly according to claim 1, wherein the first slip surface has a surface roughness that is less than or equal to 0.1 μm.

9. The bearing assembly according to claim 1, wherein the first slip surface is a radial surface, a planar axial surface, or a conical surface.

10. The bearing assembly according to claim 1, wherein the at least one second bearing ring includes a second slip surface, wherein the at least one circumferential seal includes a first seal having a seal lip in contact with the first slip surface and a second seal having a seal lip in contact with the second slip surface, and wherein the guide channels in the first seal or in the first slip surface are oriented oppositely to the guide channels in the second seal or in the second slip surface.

11. A large bearing assembly comprising: at least one first bearing ring, at least one second bearing ring having a first slip surface, and at least one circumferential seal having a seal lip, the at least one seal being mounted to the at least one first bearing ring with the seal lip in contact with the first slip surface, wherein the first slip surface includes guide channels.

12. The bearing assembly according to claim 11, wherein the guide channels extend obliquely to an axis of rotation of the bearing assembly.

13. The bearing assembly according to claim 11, wherein the guide channels are configured to generate a pumping effect in a certain direction along the axis of rotation.

14. The bearing assembly according to claim 11, wherein the guide channels are distributed equally circumferentially.

15. The bearing assembly according to claim 11, wherein the guide channels have a pitch of greater than or equal to 4 mm per rotation.

16. The bearing assembly according to claim 15, wherein a circumferential distance between the guide channels is smaller than the pitch.

17. The bearing assembly according to claim 16, wherein the circumferential distance between the guide channels is less than or equal to 0.1 mm.

18. The bearing assembly according to claim 11, wherein the first slip surface has a surface roughness that is less than or equal to 0.1 μm.

19. The bearing assembly according to claim 11, wherein the first slip surface is a radial surface, a planar axial surface, or a conical surface.

20. The bearing assembly according to claim 11, wherein the at least one second bearing ring includes a second slip surface, wherein the at least one circumferential seal includes a first seal having a seal lip in contact with the first slip surface and a second seal having a seal lip in contact with the second slip surface, and wherein the guide channels in the first slip surface are oriented oppositely to the guide channels in the second slip surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 is a sectional view of a bearing assembly including a seal.

[0022] FIG. 2 is a plan view of a section of the slip surface for the seal of the bearing assembly of FIG. 1.

[0023] FIG. 3 is an enlarged view of the region X of FIG. 2.

[0024] FIG. 4 is a plan view of a section of the slip surface including a track or path of the seal.

[0025] FIG. 5 is a plan view of a section of a bearing assembly including two slip surfaces.

[0026] FIG. 6 is a plan view of a section of an alternate slip surface of the bearing.

DETAILED DESCRIPTION

[0027] In the following, identical or functionally equivalent elements are designated by the same reference numbers.

[0028] FIG. 1 shows a section of a bearing assembly 1 including at least one inner ring 2 and at least one outer ring 4. Rolling elements 6, in this case rollers, are disposed between the rings 2, 4. The rolling elements 6 can also be balls, spherical rollers, or the like. Alternatively the bearing assembly 1 can also be a plain bearing. The bearing assembly 1 is in particular a large bearing for a wind turbine main shaft or similar, having an outer diameter of more than 2 m.

[0029] In order to seal the bearing assembly 1, a seal 12 is provided that is, for example, attached to a housing 8. The seal 12 includes a seal lip 14 that slips on a slip surface 10 of the inner ring 2. Alternatively the seal 12 can also be attached to the inner ring 4, and in this case the seal lip 14 slips on a slip surface that is provided on the outer ring 2.

[0030] In the example shown in FIG. 1, the slip surface 10 is a cylindrical surface. Alternatively the slip surface 10 can be a planar, annular side surface or a generally conical surface. The seal 12 is respectively disposed so that the seal lip 14 slips on the corresponding slip surface 10.

[0031] The rotating part of the bearing assembly 1 can either be the part that includes the slip surface 10 or the part that holds the seal 12. The seal slip surface 10 can thus be disposed on a rotating outer ring 2 or a rotating inner ring 4 in the bearing assembly 1.

[0032] FIG. 2 shows a plan view of a section of the slip surface 10. The slip surface 10 includes guide channels 18. The guide channels 18 can be provided as recesses in the slip surface 10 or can be provided as the gaps between rib-shaped surface textures 16. The showing of FIG. 2 could also represent the appearance of guide channels in the seal lip.

[0033] As is shown in FIG. 2, the guide channels 18 extend obliquely to the axis of rotation R. The slip surface 10 has a diameter D and a surface area A. The slip surface 10 rotates about the axis of rotation R. Due to the slanted position of the guide channels 18 with respect to the axis of rotation R, a pumping effect can be achieved on the one or the other side of the slip surface 10. Depending on the rotational direction of the bearing assembly 1, the medium to be sealed against is thus pumped into a bearing intermediate space or pumped out of the bearing assembly 1.

[0034] In comparison to previous slip surfaces that usually do not have surface textures, a slip surface 10 is provided here that makes possible guide channels 18 having a high pitch angle for the targeted pumping of media to be sealed against toward the bearing intermediate space or out of the bearing 1. Due to the guide channels 18, a better control of the medium to be sealed against can thus be achieved.

[0035] FIG. 3 shows an enlarged region X of FIG. 2. The rib-shaped structures 16 or the guide channels 18 are uniformly distributed over the circumference of the slip surface 10. A distance A between two ribs 16 is thus constant over the circumference of the slip surface 10. Furthermore, a pitch angle γ, which indicates a slope of the ribs 16 or of the guide channels 18 in the circumferential direction, is also constant over the circumference of the slip surface 10. With reference to FIGS. 2 and 6, the pitch angle γ can be calculated from the pitch P of the guide channels 18 and the seal surface diameter D as:

γ=arctan(P/D).

[0036] The pitch of the ribs 16 is preferably larger than the distance A between the guide channels 18.

[0037] FIG. 4 shows a section of the slip surface 10 including a seal track 20. Here the track of the seal lip 14 of the seal 12, which is deformed during operation, is depicted on the slip surface 10. The seal track 20 is a curved line that is generated by alignment tolerances and mainly by an elastic deformation of the entire application under external mechanical loads and deformations.

[0038] The slope angle γ of the guide channels 18 is chosen such that the slope of the guide channels 18 is larger than the largest normally occurring slopes S of the wave shape 20 of the seal lip 14. It can thus be ensured that the slope S and the slope of the guide channels 18 do not match, and thus the seal lip 14 does not extend in a guide channel 18.

[0039] Despite the curved seal track 20, due to the guide channels 18 and the ribs 16, a pumping effect is always ensured between the slip surface 10 and the seal 12 over the circumference of the slip surface 10.

[0040] As is shown in FIG. 5, slip surfaces 10 can be provided on both axial or radial ends of the bearing assembly 1., The bearing intermediate space 22, located between the two slip surfaces 10, is filled with lubricant.

[0041] Due to the opposing arrangement of the ribs 16 or of the guide channels 18, an inward pumping effect, for example, into the bearing intermediate space 22, is achieved in order to seal the bearing interior against the loss of lubricant. In this way lubricant that is pressed outward by a rotation of the bearing assembly 1 can be pumped back into the bearing intermediate space 22 by the guide channels 18. Alternatively another medium, for example, water, but also superfluous lubricant, can be pumped out of the bearing intermediate space 22 by the guide channels 18. The direction of the pumping effect can be changed by a changing of the rotational direction of the bearing assembly 1.

[0042] In summary, due to the guide channels provided with a controlled, particularly large separation or pitch, an improved seal effect of the bearing assembly is achieved by the bearing assembly proposed here.

[0043] Representative, non-limiting examples of the present invention were described above in detail with reference to the attached drawings. This detailed description is merely intended to teach a person of skill in the art further details for practicing preferred aspects of the present teachings and is not intended to limit the scope of the invention. Furthermore, each of the additional features and teachings disclosed above may be utilized separately or in conjunction with other features and teachings to provide improved bearing assemblies.

[0044] Moreover, combinations of features and steps disclosed in the above detailed description may not be necessary to practice the invention in the broadest sense, and are instead taught merely to particularly describe representative examples of the invention. Furthermore, various features of the above-described representative examples, as well as the various independent and dependent claims below, may be combined in ways that are not specifically and explicitly enumerated in order to provide additional useful embodiments of the present teachings.

[0045] All features disclosed in the description and/or the claims are intended to be disclosed separately and independently from each other for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter, independent of the compositions of the features in the embodiments and/or the claims. In addition, all value ranges or indications of groups of entities are intended to disclose every possible intermediate value or intermediate entity for the purpose of original written disclosure, as well as for the purpose of restricting the claimed subject matter.

REFERENCE NUMBER LIST

[0046] 1 Bearing assembly [0047] 2 Outer ring [0048] 4 Inner ring [0049] 6 Rolling element [0050] 8 Housing [0051] 10 Slip surface [0052] 12 Seal [0053] 14 Seal lip [0054] 16 Rib [0055] 18 Guide channels [0056] 20 Seal track [0057] 22 Bearing intermediate space [0058] A Surface of the slip surface [0059] D Diameter of the slip surface [0060] Δ Distance between ribs [0061] γ Pitch angle of the guide channels [0062] R Axis of rotation [0063] S Pitch of the seal wave shape [0064] X Enlarged region