DE102019110734A1 - Sealing element and sealing arrangement with this - Google Patents

Abstract

The invention relates to a sealing element (06) for sealing between machine elements (01, 02). The sealing element comprises an elastomeric, disk-shaped sealing body (07) and a reinforcement (08) which is at least partially surrounded by the sealing body (07). An electrically conductive material (09) is arranged in and / or on the reinforcement (08) and is located in the installed state extends at least to one of the machine elements, so that an electrical current path is formed along the reinforcement (08) and parallel to the sealing element (06). The invention also relates to a sealing arrangement with such a sealing element.

Description

The present invention relates to a sealing element for sealing between machine elements, the sealing element fulfilling a current discharge function in addition to the sealing function. The invention also relates to a sealing arrangement with this sealing element.

Electrical bearing currents, for example in the case of magnetic asymmetry, can occur especially in rapidly rotating bearings. These bearing currents cause electrical erosion on the machine elements or the roller bearing components through the passage of current on roller bearing components. For example, corrugation or bearing profiling occurs on rolling elements. Damage to the rolling element raceways can also occur, which can lead to premature bearing failure. Another type of damage in bearings due to the passage of current are so-called “white etching cracks” (WEC), in which a structural change in the material occurs.

Seals are known which are electrically conductive in order to ground two mutually movable components or to enable potential equalization between machine elements. Possibilities to divert bearing currents are, for example, the use of earthing brushes. To avoid bearing currents, for example, electrically insulating ceramic coatings or ceramic rolling elements are used. When using electrically conductive foils applied to the seals, the foils can be torn due to mechanical influences. Current dissipation via seals with electrically conductive elastomers has also generally been considered. However, due to the material composition selected in each case, these have only a low electrical conductivity, are less elastic or wear out quickly. The electrical conductivity of elastic seals depends on the type of filler and the filler content of the elastomer.

From the DE 33 40 458 C1 a grounding ring for a tubular transducer is known which also has a sealing function. The grounding ring comprises a sealing ring with a graphite foil and a metal foil arranged on the graphite foil. The grounding ring further comprises a grounding conductor which is connected to the sealing ring.

In the US 2013/0005158 A1 a power control brush assembly is described. An axial button and a radial shaft grounding ring have electrically conductive filaments through which electrical currents can be diverted.

The US 2015/0256054 A1 shows a grounding ring on which brushes made of an electrically conductive material are arranged. The electrically conductive brushes can contact a shaft, whereby currents can be diverted.

Based on the prior art mentioned, the object of the present invention is to provide an improved sealing element which avoids ball bearing damage due to current passages in the bearing, the bearing currents being safely and permanently diverted via an electrically conductive path. However, the sealing element should not be impaired in its properties essential for the sealing function by the current discharge function. In addition, an increase in installation space should be avoided. Furthermore, a sealing arrangement with such a sealing element is to be provided.

According to the invention, the object is achieved by a sealing element according to the attached claim 1 and by a sealing arrangement according to the attached independent claim 4.

The sealing element according to the invention is used to seal a space between machine elements, particularly preferably to seal a roller bearing space which extends between an outer bearing ring and an inner bearing ring that can be rotated about an axis. The sealing element has a disk-shaped sealing body which is formed from an elastomer. With regard to its material properties (rigidity, thermal conductivity, surface roughness, etc.), the elastomer can be optimally adapted to the respective sealing task. The sealing element also includes a reinforcement. The reinforcement is at least partially surrounded by the sealing body. In and / or on the reinforcement, an electrically conductive material is arranged, which extends between the two machine elements. The material arranged in and / or on the reinforcement forms a current path in the sealing element for diverting electrical currents.

The current is preferably carried along the reinforcement, the reinforcement itself being formed from an electrically conductive material and further comprising electrically conductive material at its radial ends, via which electrical current can be diverted to the adjacent machine elements.

Alternatively, the reinforcement itself can preferably have an electrically non-conductive material, the current conduction continuing along the reinforcement takes place via an electrically conductive material additionally applied to the reinforcement.

Again, as an alternative, the reinforcement can preferably comprise an electrically non-conductive material and furthermore comprise an electrically conductive material which is introduced into the non-conductive material and forms a current path.

The electrically conductive material is preferably an electrically conductive fleece which is arranged in and / or on the reinforcement. Alternatively, the electrically conductive material is preferably designed as carbon fibers which are arranged in and / or on the reinforcement. The electrically conductive material can also consist of metallic fibers.

Particularly preferably, the reinforcement has electrically conductive material at its ends, which is designed in the form of brushes and serves to make contact with an adjacent machine element or another component, which can be part of a current path.

The reinforcement is preferably completely surrounded by the elastomeric sealing body. Alternatively, the reinforcement is preferably arranged on an axial side of the sealing body. Alternatively, the reinforcement can be surrounded in sections by the sealing body.

The sealing arrangement according to the invention comprises an outer bearing ring, an inner bearing ring and a sealing element located between the two bearing rings. The sealing element corresponds to the sealing element described above with all its embodiments. The sealing element extends radially between the two bearing rings, the sealing element having a non-rotatable sealing seat radially on the outside on an inner surface of the outer bearing ring and bearing sealingly on an outer surface of the inner bearing ring radially on the inside. With its reinforcement, the sealing element forms a current path between the two bearing rings, via which electrical bearing currents are diverted, which advantageously prevents rolling bearing damage caused by the passage of current. Electrically conductive material in the form of electrically conductive fleece, carbon fibers, metal fibers or the like, which is arranged in and / or on the reinforcement, rests on the bearing rings so that the current path contacts them and an electric current flows through the bearing rings and the sealing element can be derived.

The sealing element is preferably designed as a sealing washer, has a sealing bead on one radial end, which serves as a sealing seat, and has a sealing lip on the other radial end. By means of the sealing bead, the sealing element is seated non-rotatably on the outer bearing ring. The sealing element rests against the inner bearing ring by means of the sealing lip. Between the outer bearing ring and the inner bearing ring there is a current path along the sealing element to divert harmful bearing currents.

• 1 eine Schnittansicht einer ersten Ausführungsform einer erfindungsgemäßen Dichtungsanordnung;
• 2 eine Schnittansicht einer zweiten Ausführungsform der Dichtungsanordnung;
• 3 eine Schnittansicht einer dritten Ausführungsform der Dichtungsanordnung;
• 4 eine Schnittansicht einer vierten Ausführungsform der Dichtungsanordnung.

Further advantages and details of the present invention emerge from the following description of preferred embodiments with reference to the drawing. Show it:

• 1 a sectional view of a first embodiment of a sealing arrangement according to the invention;
• 2 a sectional view of a second embodiment of the sealing arrangement;
• 3 a sectional view of a third embodiment of the sealing arrangement;
• 4th a sectional view of a fourth embodiment of the sealing arrangement.

1 shows a sectional view of a first embodiment of the sealing arrangement according to the invention. The seal arrangement includes an outer bearing ring 01 , one to the outer bearing ring 01 rotatable and coaxially arranged inner bearing ring 02 as well as between the bearing rings 01 , 02 arranged rolling elements (not shown), which by a rolling element cage 03 being held. Both bearing rings 01 , 02 have at least one groove 04 on their opposite faces. Radially between the bearing rings 01 , 02 is a disc-shaped, elastomeric sealing element 06 arranged, which in the groove 04 of the outer bearing ring 01 Is rotatably arranged and in the groove 04 of the inner bearing ring 02 is applied. The sealing element 06 consists of a sealing body 07 and a reinforcement 08 which at least in the central area completely from the sealing body 07 is surrounded. Furthermore, the sealing element comprises 07 an electrically conductive material 09 , preferably in the form of numerous elongated carbon fibers or in the form of an electrically conductive fleece. The electrically conductive material 09 can also be the material of the reinforcement itself. Furthermore, the material is electrically conductive 09 arranged so that it is at the two radial ends of the reinforcement 08 escapes through the seal body 07 runs out and on the two bearing rings 01 , 02 is applied so that a continuous current path is formed between the bearing rings. The electrically conductive material is thus arranged so that a current path between the bearing rings 01 , 02 along the reinforcement 08 of the sealing element 06 arises. Damaging bearing currents can advantageously be diverted via the current path so that damage to the rolling elements and their rolling surfaces (not shown) is prevented. The seal body 07 includes a sealing bead 11 the one in the groove 04 of the outer bearing ring 01 is arranged and a tight fit of the sealing element 06 ensures. The sealing body also includes 07 a sealing lip 12 , which on the inner bearing ring 02 comes to the point.

2 Figure 11 shows a sectional view of a second embodiment of the sealing arrangement. In the 2 The seal arrangement shown initially resembles that in 1 sealing arrangement shown. Deviating from 1 has the sealing element 06 in 2 a changed shape. The seal body 07 surrounds the reinforcement 08 only partially. The reinforcement 08 is axially angled at its ends in the direction of the rolling elements. The in 2 Reinforcement shown 08 not from the electrically conductive material. Rather, the in 2 Reinforcement shown 08 made of another, also electrically conductive material and has the electrically conductive material at its ends 09 on. The electrically conductive material 09 is due to the bearing rings 01 , 02 so that there is electricity through the reinforcement 08 through the seal body 07 leads. Thus, in the in 2 embodiment shown a continuous current path between the bearing rings made.

3 FIG. 13 shows a sectional view of a third embodiment of the sealing arrangement, which initially corresponds to that in FIG 1 The seal arrangement shown is the same. Deviating from 1 is the electrically conductive material 09 in the reinforcement of the 3 embedded. The current path is in turn formed continuously between the bearing rings.

4th FIG. 13 shows a sectional view of a fourth embodiment of the sealing arrangement, which initially corresponds to that in FIG 2 The seal arrangement shown is the same. Deviating from 2 indicates the in 4th Reinforcement shown 08 the electrically conductive material 09 only at its radially inner end, so that the electrically conductive material 09 only the bottom bracket ring 02 contacted. The current path leads from the inner bearing ring 02 via the electrically conductive material 09 , over the electrically conductive armoring 08 to the outer bearing ring 01 . The reinforcement 08 lies directly on the outer bearing ring 01 in its groove 04 on. The seal body 07 is in the radially inner area of the reinforcement 08 arranged and has two sealing lips 12 on.

List of reference symbols

01

Outer bearing ring

02

Inner bearing ring

03

Rolling element cage

04

Groove

05

-

06

Sealing element

07

Seal body

08

Reinforcement

09

electrically conductive material

10

-

11

Sealing bead

12

Sealing lip

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• DE 3340458 C1 [0004]
• US 2013/0005158 A1 [0005]
• US 2015/0256054 A1 [0006]

Claims (4)

Sealing element (06) for sealing between machine elements (01, 02), comprising an elastomeric, disk-shaped sealing body (07) and a reinforcement (08) at least partially surrounded by the sealing body (07), wherein in and / or on the reinforcement (08) an electrically conductive material (09) is arranged, which in the installed state extends at least as far as one of the machine elements, so that an electrical current path is formed along the reinforcement (08) and parallel to the sealing element (06). Sealing element (06) after Claim 1 , characterized in that the electrically conductive material (09) on and / or in the reinforcement (08) is designed as an electrically conductive fleece which forms the current path. Sealing element (06) after Claim 1 , characterized in that the electrically conductive material (09) on and / or in the reinforcement (08) are designed as carbon fibers or metallic fibers which form the current path. Sealing arrangement for sealing a space between an outer bearing ring (01) and an inner bearing ring (02) rotatable about a common axis, comprising the outer bearing ring (01), the inner bearing ring (02) and a sealing element (06) according to one of the Claims 1 to 3 , which extends radially between the two bearing rings (01, 02) and forms a current path between them, the sealing element (06) having a rotationally fixed seal seat radially on the outside on an inner surface of the outer bearing ring (01) and radially on the inside on an outer surface of the inner bearing ring ( 02) fits tightly.

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