Roller bearing cage

Abstract

A roller bearing cage, in particular for use with insufficient lubrication, including a plastic base body (2), a modified surface (4) of the base body (2), and a metallic coating (3) on the modified surface (4) of the base body (2).

Claims

1. A roller bearing cage comprising: a base body made from plastic, a modified surface on the base body, and a metallic coating on the modified surface of the base body, wherein the modified surface of the base body has a waviness (Wt) that is at least ten times as large as a roughness (Ra) of the modified surface and greater than a layer thickness of the metallic coating.

2. The roller bearing cage according to claim 1, wherein the modified surface comprises a chemical modification of a surface of the base body.

3. The roller bearing cage according to claim 1, wherein the metallic coating contains wear-protection particles.

4. The roller bearing cage according to claim 1, wherein an additional layer is deposited on the metallic coating.

5. The roller bearing cage according to claim 4, wherein the additional layer comprises a sol-gel layer.

6. The roller bearing cage according to claim 4, wherein the additional layer comprises a carbon layer.

7. The roller bearing cage according to claim 1, wherein the metallic coating includes friction-reducing particles.

8. The roller bearing cage according to claim 1, wherein the metallic coating has a grain size that is less than 500 nm.

9. The roller bearing cage according to claim 1, wherein a thickness of the metallic layer is less than 0.5 mm.

10. The roller bearing cage according to claim 1, wherein the metallic layer includes chromium, copper, nickel, cobalt, and/or iron.

11. The roller bearing cage according to claim 1, wherein the metallic layer is formed as a nanocrystalline coating.

12. A method for producing a roller bearing cage comprising: producing a base body made from plastic, modifying a surface of the base body to form a modified surface, depositing a metallic coating on the modified surface of the base body, wherein the modified surface of the base body has a waviness (Wt) that is at least ten times as large as a roughness (Ra) of the modified surface and greater than a layer thickness of the metallic coating.

13. The method according to claim 12, wherein the surface of the base body is modified by a plasma.

14. The method according to claim 12, further comprising mechanically pre-treating the surface of the base body.

15. The method according to claim 12, further comprising depositing an additional layer on the metallic coating by high velocity oxygen fuel spraying.

16. The method according to claim 12, wherein the metallic coating includes friction-reducing particles.

17. The method according to claim 12, wherein the metallic coating has a grain size that is less than 500 nm.

18. The method according to claim 12, wherein a thickness of the metallic layer is less than 0.5 mm.

19. The method according to claim 12, wherein the metallic layer includes chromium, copper, nickel, cobalt, and/or iron.

20. The method according to claim 12, wherein the metallic layer is formed as a nanocrystalline coating.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Several embodiments of the invention are explained below in more detail with reference to a drawing. Shown herein are, each in schematic representation:

(2) FIG. 1 in a section view, a first embodiment of a roller bearing cage made from metallized plastic,

(3) FIG. 2 in a view analogous to FIG. 1, a second embodiment of a roller bearing cage.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) FIGS. 1 and 2 each show a greatly enlarged, not-to-scale cut-out of a cross section of a roller bearing cage that is designated overall with the reference symbol 1 and with respect to its principle function, reference is made to the prior art cited above.

(5) Each roller bearing cage 1 has a base body 2 made from plastic on which a metallic coating 3 is located. The metallic coating 3 is here deposited on a modified surface 4 of the base body 2. The modification of the surface 4 of the base body 2 is shown in FIGS. 1 and 2 by a clearly recognizable roughness of the surface 4. Deviating from the symbolic representation according to FIGS. 1 and 2, the modification of the surface 4 of the base body 2 can also involve merely a chemical surface modification that has no influence on the measurable roughness. In each case, directly before the metallic coating 3 is deposited, properties of the surface 4 deviate from the surface condition of the base body 2 directly after its production.

(6) In the embodiment according to FIG. 1, different particles 5, 6, namely wear-protection particles 5 and friction-reducing particles 6, are incorporated into the metallic coating 3. The particles 5, 6 have small dimensions such that they have no influence on the impermeability of the metallic coating 3. The metallic coating 3 is a nanocrystalline coating with an average grain size of less than 500 nm.

(7) In the embodiment according to FIG. 2, the metallic coating 3 contains, in contrast to the embodiment according to FIG. 1, no additives. Instead, in this case, an additional layer 7 is deposited on the metallic coating 3. This can be, for example, a carbon layer or a sol-gel layer. In both cases, the sum of the layer thicknesses from the metallic coating 3 and additional layer 7 is no more than 0.5 mm.

(8) Both in the embodiment according to FIG. 1 and also in the embodiment according to FIG. 2, final processing of the metallic coating 3 or the additional layer 7 can be provided by grinding, slide finishing, honing, or electropolishing.

LIST OF REFERENCE NUMBERS

(9) 1 Roller bearing cage 2 Base body 3 Metallic coating 4 Modified surface 5 Wear-protection particle 6 Friction-reducing particle 7 Additional layer