DE102018104753A1 - sealing arrangement - Google Patents

Abstract

The invention relates to a sealing arrangement (1), in particular for a roller bearing, with which a space between two components (2, 3) arranged movably relative to one another can be sealed, wherein the sealing arrangement (1) has a sealing body (4) which is in or is fastened to one of the components (2) and has at least one sealing lip (5) which frictionally abuts against the other component (3), means (6) being present to allow a passage of current between the two components (2, 3) to induce.
In order to ensure an effective current transfer with low frictional torque without the need for readjustment in the event of wear, the invention provides that the means (6) are formed to cause a current transition through a preferably annular or disc-shaped body, the at least partially electrically conductive is, which is connected to the sealing body (4) and which extends in the assembled state of the seal assembly over the entire area between the two components (2, 3), wherein the sealing body (4) has a portion (7) mounted in the Condition presses an end portion (8) of the preferably annular or disc-shaped body (6) against the one component (3).

Description

Field of the invention

The invention relates to a sealing arrangement, in particular for a rolling bearing, with which a space between two relatively movably arranged components can be sealed, wherein the sealing arrangement comprises a sealing body which is fixed in or on one of the components, and at least one sealing lip which rubbing against the other component, wherein means are provided to cause a current transfer between the two components.

Background of the invention

For example, in the bearings of asynchronous machines electrical voltages are induced by rapid rotation of the rotor, which must be derived through the bearing. The derivation of the stress on the bearing rings and the rolling elements can cause damage to the raceways; In particular, it can come to a scoring on the raceways. Furthermore, as a result of induced currents in the case of electric drives, induced voltages can occur which, in certain frequency ranges, can lead to disturbances in the vehicle electrical system as well as in radio devices. In order to reduce this problem, sealing arrangements of the type mentioned are known, which are used in the bearings.

A seal arrangement of this kind is known from DE 10 2014 010 269 A1 known. The ballast seal disclosed herein has a disc made of an electrically conductive material, which is manufactured separately and which is connected to a support body. As a result of the electrically conductive disk, a passage of current between the two parts that are movable relative to one another can be accomplished.

A similar solution shows the DE 10 2016 010 926 A1 , Here, a grounding ring is described, which serves for the derivation of induced voltages from a first to a second machine part.

In general, therefore, sealing arrangements are known with a device for targeted power line, which are used to protect the bearings in the case of induced electrical voltages. This concept can be realized as a so-called Aegis® ring, which is screwed in front of a bearing and derives the electrical voltages by means of carbon fiber brushes, which are distributed around its circumference. A disadvantage of this solution is the risk of contamination of the carbon fiber brushes and thus a restriction of the functionality of the conductivity of the element used. Furthermore, the radially overlying brushes have no active adjusting function, so that it is not possible to compensate for wear.

Furthermore, electrically conductive nonwovens are known which can be arranged or glued to radial shaft sealing rings and which allow a passage of current through the bearing. The disadvantage here is a relatively large space requirement and a very limited possibility for adjustment of the electrically conductive components, so that even in this case problems occur when wear has occurred.

The previously known solutions are therefore still in need of improvement, as that a permanent and reliable flow passage between the bearing rings or the housing in connection in particular in the application of radial shaft sealing rings is required, which also in the case of wear does not limit the functionality.

This is intended to achieve improved protection of the bearing or to ensure good grounding between rotating or relatively displaceable machine parts.

Object of the invention

The present invention is therefore an object of the invention to provide a generic seal assembly that ensures an effective current transfer with low friction torque without the need for adjustment in case of wear. Accordingly, the electric current to a path of low resistance on the seal to be created, which should cause a corresponding relief of the bearing and other components.

Description of the invention

The solution of this object by the invention is characterized in that the means for causing a current transition are formed by a preferably annular or disk-shaped body, which is at least partially electrically conductive, which is connected to the sealing body and in the mounted state of the seal assembly extends over the entire area between the two components, wherein the sealing body has a portion which presses in the assembled state, an end portion of the preferably annular or disc-shaped body against the one component.

The seal assembly is preferably designed as a radial shaft seal.

The preferably annular or disk-shaped body preferably consists at least partially of polytetrafluoroethylene (PTFE) or a derivative of the polytetrafluoroethylene. This material may be one which has been made electrically conductive, in particular by appropriate incorporation of electrically conductive particles (graphite). Alternatively, the disk-shaped body can also have a layer of metal, in particular of silver, in order to be electrically conductive.

The annular or disk-shaped body is preferably arranged on one side of the sealing body.

The preferably ring-shaped or disk-shaped body preferably has, in the not yet mounted state, a dimension which projects radially beyond the sealing body, at least in one direction.

The preferably ring-shaped or disk-shaped body is preferably fastened cohesively to the sealing body. The cohesive attachment is preferably a bond or a compound by a vulcanization process.

The bearing can be arranged a rolling or sliding bearing and the seal assembly between the two bearing rings of the bearing effectively.

The bearing may also be a rolling or sliding bearing and the sealing arrangement between a housing and a shaft which is supported by the bearing, be arranged effectively.

The proposed concept primarily relates to a seal for a bearing (which may be a rolling bearing or a plain bearing, but also a linear bearing), providing effective additional functionality for conducting an electrical current.

For this purpose, in particular a conductive seal made of PTFE or an elastomer composite is provided. The preferred application is that of a radial shaft sealing ring.

According to a preferred embodiment of the invention, a flexible disk or film of PTFE is thus connected to a sealing body of a radial shaft sealing ring (in particular glued or vulcanized) to the electrical contact between the shaft and housing or between a bearing inner and outer ring in a rolling - or plain bearings or to produce a linear guide.

The PTFE disc or the PTFE ring is preferably connected to the elastomeric material of the sealing body and is in the initial state on the outer contour of the sealing ring radially over. During assembly, the current-conducting element, so the PTFE disc, then attaches to the housing and ensures a reliable electrical contact.

In an advantageous manner, in particular, a radial shaft seal is thus created which prevents contamination from the bearing interior or significantly reduces such. This can be dispensed with in the proposed embodiment to additional dust and oil-repellent components or on non-woven discs, which not only offers cost advantages, but also keeps the friction between the components rotating relative to each other low.

In the case of a radial shaft sealing ring, the spring of the same can be used with appropriate geometric design of the seal body to ensure a permanent contact of the current-conducting PTFE disc.

This results in an effective current-conducting function with simultaneous good sealing in a component, with only a small frictional torque is present. Pollution can be avoided or reduced.

In the case of wear, a readjustment takes place virtually automatically, so that always a good electrical contact of the PTFE disc is ensured. Thus, extensive maintenance is given.

Finally, it is advantageous that only a small space is required in order to be able to accommodate the proposed solution.

A special application of the proposed solution are asynchronous machines or applications in electrically powered vehicles.

list of figures

• 1 im Radialschnitt eine Dichtungsanordnung im noch nicht montierten Zustand und
• 2 im Radialschnitt die Dichtungsanordnung gemäß 1 im montierten Zustand in einem Wälzlager.

A preferred embodiment of the inventively embodied sealing arrangement will be explained in more detail with reference to the accompanying drawings. Showing:

• 1 in radial section, a sealing arrangement in the not yet assembled state and
• 2 in radial section, the seal arrangement according to 1 in the assembled state in a rolling bearing.

Detailed description of the drawings

In the figures is a seal arrangement 1 to see, which is formed in the embodiment as a radial shaft seal. It becomes here between a first component 2 in the form of a bearing outer ring and a second component 3 used in the form of a bearing inner ring, so that the two components 2 and 3 relative to each other about an axis A can turn (s. 2 ).

The seal arrangement 1 includes a sealing body 4 , in a conventional manner, a reinforcement 9 is integrated. The seal body 4 is in the component 3 assembled. At its radially inner end region, the sealing body 4 a sealing lip 5 on, rubbing on the component 3 is applied. It is likewise provided a spring element 10 which is the sealing lip 5 to the surface of the component 3 presses and thus ensures tightness.

Next available are funds 6 to cause a current transfer between the two components 2 and 3 ,

These funds 6 are formed here as a ring-shaped or disc-shaped body, which is at least partially electrically conductive. This may preferably be a PTFE ring which is electrically conductive or which has been provided with a coating of a metal in order to render it conductive.

The ring-shaped or disc-shaped body 6 is with the seal body 4 connected, for which purpose, for example, a gluing process or a vulcanization process can be used.

As from the installed situation according to 2 can be seen extends in the mounted state of the seal assembly of the ring 6 in the radial direction r over the entire area between the two components 2 and 3 in order to establish electrical conductivity between the components in this way.

As can be seen further from the figures, the seal body 4 a section 7 on, in the assembled state (see 2 ) has a radially inner end region 8th of the annular or disc-shaped body 6 against the component 3 suppressed.

For this purpose, the design shown in the figures in radial section of the seal body 4 intended. Starting from the sealing lip 5 extends in radial section of the seal body 4 at a shallow angle α (approximately between 10 ° and 45 °) to the axis A in the area where the radially inner end of the reinforcement 9 is arranged. At about half the axial distance between the sealing lip 5 and the position of the radially inner end of the reinforcement 9 is the section 7 of the seal body 4 provided on which the ring 6 and especially its end area 8th is arranged.

The radially inner end region 8th of the ring 6 is through the section 7 of the seal body 4 thus to the component 3 pressed.

If wear occurs, this is caused by the spring element 10 balanced, the ring 6 and in particular its end area 8th However, this will continue against the component 3 pressed.

Permanent contact of the ring 6 at the radially outer end and thus at the component 2 is by a supernatant a in the radial direction r given in the not yet assembled state (see 1 ) is present.

Thus, a Stromleitpfad S established in 2 is indicated and is also given and maintained when wear in the seal assembly 1 occurs.

The electrically conductive, elastic disc 6 may be made of electrically conductive PTFE or coated with a metal for the purpose of producing electrical conductivity. The ring 6 can also be designed as a film, so very thin. It is also possible, the disc 6 completely in the final contour of the seal body 4 to integrate, ie to connect to this.

Thus it is achieved that by the sealing effect to that through the seal assembly 1 sealed space both a dirt entry and a contamination with oil or grease from the interior can be almost completely avoided. Further protection by appropriate windows, felts or fleeces is not required, whereby the friction torque can be kept low.

Due to the illustrated geometry and the direct connection of the disc 6 to the seal body 4 Ensures that the conductive disk 6 an integral part of the seal body 4 represents and always electrical contact with the two components 2 and 3 which, as I said, may be either bearing rings or a housing and a shaft. In this regard, the said Stromleitpfad S pointed.

In case of wear, an automatic adjustment is performed by the spring element 10 is guaranteed. The disc 6 then always has contact with the component 3 , A long life of the seal assembly 1 is thus guaranteed.

LIST OF REFERENCE NUMBERS

1

sealing arrangement

2

Component (bearing outer ring)

3

Component (bearing inner ring)

4

seal body

5

sealing lip

6

Means for causing a current transfer (ring / disc, in particular of PTFE)

7

Section of the seal body

8th

End region of the disc-shaped body

9

Reinforcement (reinforcing ring)

10

Spring element (worm spring)

a

Got over

r

radial direction

S

Current conducting path

A

axis

α

corner

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 102014010269 A1 [0003]
• DE 102016010926 A1 [0004]

Claims (10)

Sealing arrangement (1), in particular for a rolling bearing, with which a space between two relatively movably arranged components (2, 3) can be sealed, wherein the sealing arrangement (1) has a sealing body (4), in or on one of the components (2) is fixed, and at least one sealing lip (5) rubbing against the other component (3), wherein means (6) are provided to cause a current transfer between the two components (2, 3), characterized in that the means (6) for causing a current transition are formed by a preferably annular or disk-shaped body which is at least partially electrically conductive, which is connected to the sealing body (4) and which in the assembled state of the sealing arrangement over the entire Area between the two components (2, 3), wherein the sealing body (4) has a portion (7) which in the mounted state a Endberei Ch (8) of the preferably annular or disc-shaped body (6) against which a component (3) presses. Seal arrangement according to Claim 1 , characterized in that it is designed as a radial shaft seal. Seal arrangement according to Claim 1 or 2 , characterized in that the preferably annular or disc-shaped body (6) consists at least partially of polytetrafluoroethylene (PTFE) or a derivative of the polytetrafluoroethylene. Sealing arrangement according to one of Claims 1 to 3 , characterized in that the preferably annular or disk-shaped body (6) has a layer of metal, in particular of silver. Sealing arrangement according to one of Claims 1 to 4 , characterized in that the annular or disc-shaped body (6) on one side of the sealing body (4) is arranged. Sealing arrangement according to one of Claims 1 to 5 , characterized in that the preferably annular or disc-shaped body (6) in the unassembled state has a dimension that the sealing body (4) at least in one direction, preferably radially (r) surmounted (a). Sealing arrangement according to one of Claims 1 to 6 , characterized in that the preferably annular or disc-shaped body (6) is fastened to the sealing body (4) in a material-locking manner. Seal arrangement according to Claim 7 , characterized in that the cohesive fastening is produced by an adhesive process or a vulcanization process. Sealing arrangement according to one of Claims 1 to 8th , characterized in that the bearing is a rolling or sliding bearing and the seal assembly between the two bearing rings of the bearing is arranged effectively. Sealing arrangement according to one of Claims 1 to 8th , characterized in that the bearing is a rolling or sliding bearing and the sealing arrangement between a housing and a shaft which is mounted with the bearing, is arranged effectively.

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