Rolling bearings having an integrated current-removal function

Abstract

A rolling bearing for rotatably supporting a shaft has an inner ring with a first raceway for a rolling body, an outer ring with a second raceway for a rolling body, and rolling bodies which are arranged between the raceways of the bearing rings. At least two plates are fastened to a first of the bearing rings, wherein an electrically conducting element is arranged between the two plates, which electrically conducting element lies against the respective other bearing ring or a component which is connected to the respective other bearing ring.

Claims

1. A rolling bearing for rotatably supporting a shaft, the bearing comprising: an inner ring with a first raceway, an outer ring with a second raceway, rolling bodies arranged between the first and second raceways of the bearing rings, at least two plates fastened to a first of the bearing rings, and an electrically conducting element arranged between the two plates, the electrically conducting element contacting the respective other bearing ring or a component which is electrically connected to the respective other bearing ring.

2. The rolling bearing according to claim 1, wherein the electrically conducting element has an opening through which the shaft rotatably supported by the rolling bearing can be passed.

3. The rolling bearing according to claim 1, wherein the plates are annular.

4. The rolling bearing according to claim 1, wherein the electrically conducting element is designed as a fabric blank or a non-woven disc.

5. The rolling bearing according to claim 4, wherein electrically conducting threads and/or electrically conducting additives are incorporated into the fabric of the fabric blank or into the non-woven disc.

6. The rolling bearing according to claim 1, wherein the electrically conducting element is designed as a disc or a film made of a polymer material, and the disc or the film is provided with electrically conducting additives.

7. The rolling bearing according to claim 1, wherein a sleeve is arranged on the inner ring or on the shaft.

8. The rolling bearing according to claim 7, wherein the sleeve has a first area which runs parallel to the surface of the shaft or the inner ring and a second area which runs at an angle to the first area such that the second area prevents or reduces leakage of lubricant from the area of the rolling bodies, such that a contact point between the electrically conducting element and the inner ring or the shaft is kept essentially free of lubricant.

9. The rolling bearing according to claim 1, wherein the plates have a bend, whereby the electrically conducting element is guided such that it lies at an angle deviating from a right angle on the inner ring, the shaft or the sleeve.

10. A method for producing a rolling bearing having an inner ring with a first raceway for rolling bodies, an outer ring with a second raceway for the rolling bodies, and rolling bodies arranged between the raceways of the bearing rings, that the method comprising: clamping an electrically conducting element between two plates, wherein an opening is made in the electrically conducting element, and fastening the two plates to one of the bearing rings of the rolling bearing.

11. A rolling bearing comprising: first and second rings; rolling bodies arranged between the first and second rings; and two plates fastened to the first ring, an electrically conductive element arranged between the two plates, the electrically conducting element contacting the second ring or a component which is electrically connected to the second bearing ring.

12. The rolling bearing according to claim 11, wherein the electrically conductive element has an opening through which a shaft can be passed.

13. The rolling bearing according to claim 11, wherein the plates are annular.

14. The rolling bearing according to claim 11, wherein the electrically conductive element is a fabric blank or a non-woven disc.

15. The rolling bearing according to claim 14, wherein electrically conductive thread and/or electrically conductive additives are incorporated into the fabric of the fabric blank or into the non-woven disc.

16. The rolling bearing according to claim 11, wherein the electrically conductive element is a disc or a film made of a polymer material, and the disc or the film is provided with electrically conducting additives.

17. The rolling bearing according to claim 11, wherein a sleeve is arranged on the second ring.

18. The rolling bearing according to claim 17, wherein the sleeve has a first area which runs parallel to a surface of the shaft or the second ring and a second area which runs at an angle to the first area such that the second area prevents or reduces leakage of lubricant from the area of the rolling bodies.

19. The rolling bearing according to claim 11, wherein the plates have a bend, whereby the electrically conductive element is guided such that it lies at an angle deviating from a right angle on the second ring, the shaft or the sleeve.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In the following, the bearing is explained in more detail by means of a preferred exemplary embodiment and the corresponding drawings. In the figures:

[0027] FIG. 1 shows an exemplary embodiment of a rolling bearing with an integrated current-removal function via an electrically conducting element held between two discs;

[0028] FIG. 2 shows a further exemplary embodiment for a rolling bearing with an integrated current-removal function;

[0029] FIG. 3 shows a third exemplary embodiment for a rolling bearing with an integrated current-removal function, wherein two electrically conducting elements are provided in this embodiment variant which are each clamped between plates;

[0030] FIG. 4 shows an arrangement of two annular plates, between which an electrically conducting element is clamped;

[0031] FIG. 5 shows an arrangement of the same type after a central opening has been made in the electrically conducting element; and

[0032] FIG. 6 shows an alternative embodiment of such an arrangement, wherein a plurality of contact segments distributed over the circumference are formed on the electrically conducting element.

DETAILED DESCRIPTION

[0033] FIG. 1 shows an exemplary embodiment of a rolling bearing 1 for use on an electric motor, in particular for supporting a shaft 15, in particular the drive shaft of the electric motor, with an integrated current-removal function. The rolling bearing 1 comprises an inner ring 2 and an outer ring 3, which can be rotated relative to one another. For this purpose, raceways 13, 14 are formed on the inner ring 2 and the outer ring 3, in which rolling bodies 4, in particular balls or rollers, are guided. The inner ring 2 is carried by the drive shaft of the electric motor and is non-rotatably connected to this shaft 15. For this purpose, the inner ring 2 can in particular be pressed onto the shaft 15. The outer ring 3 is arranged in a housing of the electric motor and non-rotatably connected to this housing. Two plates 5, 6, between which an electrically conducting element 7 is clamped, are pressed into the outer ring 3 of the rolling bearing 1. The electrically conducting element 7 is preferably designed as a blank 8, in particular as a fabric blank 17, a non-woven disc 18 or a thin disc 19 made of a polymer material. The plates 5, 6 have an angle 21 and a further bend 22 in order to enable both simple clamping on the outer ring 3 and stable accommodation of the electrically conducting element 7. The plates 5, 6 are bent at the bend 22 in such a way that the electrically conducting element 7 is oriented at an angle deviating from a right angle, in particular at an angle between 30° and 60°, to the inner ring 2 or to the shaft 15, whereby the friction compared to a right-angled contact between the inner ring 2 or the shaft 15 and the electrically conducting element 7 can be reduced. In order to minimize the friction or to improve the current-removal function, a preferably coated sleeve 12 can be pressed onto the shaft 15 or the inner ring 2. The sleeve 12 has an angle 27 in order to minimize the leakage of lubricant from the area of the rolling bodies 4. For this purpose, the sleeve 12 forms a labyrinth seal 28 with a sealing element 29. The rolling bearing 1 also has a second sealing element 30 in order to minimize the leakage of lubricant and to prevent dirt from penetrating into the area of the rolling bodies 4.

[0034] FIG. 2 shows a further exemplary embodiment of a rolling bearing 1. With essentially the same structure as in FIG. 1, the plates 5, 6 in this exemplary embodiment are installed rotated by 180° in comparison with the embodiment shown in FIG. 1. As a result, the bent angle 21 of the plates 5, 6 can serve as an insertion bevel, whereby assembly is simplified. In addition, this installation position improves the labyrinth effect of the labyrinth seal 28, such that the area of the rolling bodies 4 is better protected against dirt and the leakage of lubricant from this area is minimized. The electrically conducting element 7 again rests against the sleeve 12 at an angle of approximately 45°.

[0035] In FIG. 3 a third embodiment of a rolling bearing 1 is shown with a current-removal function. With essentially the same structure as in FIGS. 1 and 2, three plates 5, 6, 23 are provided in this exemplary embodiment, between which two electrically conducting elements 7 are arranged, which are separated from one another by the central plate 6. The electrically conducting elements 7 are preferably formed as fabric blanks 8, 17, 24, wherein electrically conducting threads are woven into the fabric of the fabric blanks 8, 17, 24 in order to increase the electrical conductivity of the fabric. The electrically conducting elements 7 rest on the sleeve 12, which is arranged on a shaft 15. Alternatively, the sleeve 12 can also be pressed onto the inner ring 2 of the rolling bearing 1.

[0036] FIG. 4 shows an assembly which comprises a first plate 5 and a second plate 6 as well as an electrically conducting element 7 clamped between the two plates 5 and 6. The plates 5, 6 have a press-in section 25 with which the plates 5, 6 are pressed into the outer ring 3 of the rolling bearing 1 and a clamping section 26 in which the electrically conducting element 7 is clamped with a press fit 9 between the two plates 5, 6. The electrically conducting element 7 is designed in the form of a flexible blank 8, in particular a fabric blank 17, a non-woven disc 18 or a disc 19 or film made of a polymer material. The blank 8 is provided with conductive elements 20, for example electrically conducting threads or electrically conducting additives such as carbon black, graphite, carbon, nanotubes or the like, in order to increase the electrical conductivity of the blank.

[0037] A central opening 10 is made in the electrically conducting element 7, wherein the cutting or punching of the opening 10 is simplified by clamping the electrically con-ducting element 7 between the two plates 5, 6. An assembly with two plates 5, 6 and an electrically conducting element 7, into which a central opening 10 has been made, is shown in FIG. 5.

[0038] FIG. 6 shows a further representation of such an assembly, wherein in this embodiment the electrically conducting element 7, in addition to the opening 10, is divided into a plurality of contact segments 11, preferably evenly distributed over the circumference. By dividing it into a plurality of contact segments 11, the friction between the electrically conducting element 7 and the inner ring 2 or the shaft 15 can be further reduced. The contact segments 11 lie as sliding elements 16 on the shaft 15 or the inner ring 2, wherein a current path between the inner ring 2 and the outer ring 3 is closed by the sliding contact on the sliding elements 16, such that an electrical potential difference between the inner ring 2 and the outer ring 3 is possible.

LIST OF REFERENCE SYMBOLS

[0039] 1 Rolling bearing [0040] 2 Inner ring [0041] 3 Outer ring [0042] 4 Rolling body [0043] 5 First plate [0044] 6 Second plate [0045] 7 Electrically conducting element [0046] 8 Blank [0047] 9 Press fit [0048] 10 Opening [0049] 11 Contact segment [0050] 12 Sleeve [0051] 13 Raceway [0052] 14 Raceway [0053] 15 Shaft [0054] 16 Sliding element [0055] 17 Fabric blank [0056] 18 Non-woven disc [0057] 19 Disc [0058] 20 Guiding elements [0059] 21 Angle [0060] 22 Bend [0061] 23 Third plate [0062] 24 Second blank [0063] 25 Press-in section (of the plate) [0064] 26 Clamping section (of the plate) [0065] 27 Angle (of the sleeve) [0066] 28 Labyrinth [0067] 29 First sealing element [0068] 30 Second sealing element