DE102009019396A1 - Seal arrangement for roller bearing utilized for supporting cardan shaft of rear-wheel driven vehicle, has bracket that forms gap together with outer fixed element, where gap runs in axial direction and radial direction - Google Patents

Abstract

The arrangement has a main seal (1) sealing an interior (8) between an outer fixed element (2) and an internal rotatable element (3). A plastic pre-sealing (10) provided upstream of the seal is firmly connected to the rotatable element. The pre-sealing has a bracket (11) extending towards the fixed element and projecting into a recess (12) in the fixed element in a radial direction. The bracket forms a gap (13) together with the fixed element, where the gap runs in an axial direction and the radial direction. The elements form inner and outer rings of a roller bearing.

Description

Field of the invention

The The invention relates to a sealing arrangement, in particular for a rolling bearing comprising a main seal which for sealing an interior space between an outer, fixed element and an inner, rotatable element placed is and has a static seal with the outside Element communicates while having a contact between the main seal and the inner element over at least a sealing lip is realized, wherein the main seal is a pre-seal is connected upstream, which is firmly connected to the inner element and over at least one, towards the outside Elements extending leg features.

Background of the invention

sealing arrangements of the aforementioned type find in particular in the field of rotating elements, as waves, or in rolling bearings application, in which an entry of liquids and dirt particles into one Interior space must be prevented. For example, in motor vehicles Wheel bearings or bearings from under the vehicle floor running Cardan shafts exposed to direct environmental influences, something when particles of particles enter the area of the rolling bodies to a failure of the camp and in extreme cases to a lie down of the vehicle can lead. Significant impairment Moisture and particles in particular occur here Off-road vehicles on.

Next A reliable seal is used in modern sealing arrangements but also a low internal friction required to the resulting Minimize losses and minimize wear.

State of the art

From the DE 196 00 125 A1 a seal arrangement for a roller bearing is known, in which between an outer, stationary element in the form of an outer ring and an inner, rotatable element, which forms the inner ring of the rolling bearing, an angle element is placed, which is fixedly connected to the outer element. Furthermore, a pre-seal is provided on the inner member, which is fixedly connected to the inner member and has a leg which extends in the direction of the outer member. This leg engages over the outer element at its end and shields this. In addition, on a, the rolling elements of the rolling bearing facing side of the leg, a sealing lip extends in the direction of the angle element and occurs in the radial direction with this in contact. In this case, the sealing lip with the angle element forms a main seal, which prevents the penetration of liquid and dirt particles into the interior of the rolling bearing. Upon rotation of the inner member also impinging impurities are deflected radially outward on the leg of the pre-seal due to a centrifugal force and thus greatly reduces the risk of ingress between the inner and the outer member.

disadvantageous on such a sealing arrangement, however, is that liquids and particles that are still in the space between pre-seal and the outer element, for example at a Standstill of rolling bearing, have arrived, due to the overlap of the thigh only extremely bad again can be transported. This leads long term to a strong dirt accumulation in front of the main seal.

Furthermore, the DE 691 07 890 T2 a seal assembly for a hub bearing of a motor vehicle, wherein between a outer, fixed member and a rotatable inner member, a main seal is provided. This main seal has a support ring partially surrounded by a sealing material, the main seal communicating with the outer member via this sealing material. In addition, a sealing lip is provided, which is in contact with the inner element and forms a dynamic seal. In addition, a pre-seal is placed in front of the main seal, which is fixedly connected to the inner element and has a leg extending in the direction of the outer element which, as a result of a centrifugal force caused thereby, rotates the inner element to repel liquids and dirt particles provides.

Indeed is in the radial direction between the outer Element and the leg of the pre-seal a gap formed over which impurities impinge in this area, directly in the space between the inner and the outer Element can get. Thus, the effect of the pre-seal reduced.

Object of the invention

It is therefore an object of the present invention to provide a seal assembly whose pre-seal as effectively as possible prevents entry of impurities, but at the same time allows the outbound already penetrated liquids and particles as unhindered. This should also caused by this seal arrangement the lowest possible friction the.

These The object is based on the preamble of claim 1 in conjunction solved with its characterizing features. The on it the following, dependent claims respectively advantageous developments of the invention again.

The Invention includes the technical teaching that the leg of the pre-seal in one, in the radial direction on the outer element pronounced recess protrudes and this together with the outer element one, in axial and radial gap extending forms. By means of this gap will between the leg and the outer element a course similar to a labyrinth formed, due to the thus formed, high flow resistance the Entry of impurities greatly reduced. Because of that Leg does not overlap the outer element, can still penetrate fluids and Particles, especially at standstill of the inner element, almost get out of the way unhindered. Furthermore, by a Such design of the pre-seal no additional Generates friction.

Corresponding an embodiment of the invention has the outer Element in the region of the recess and in the axial direction in front of the Pre-seal a radially inwardly directed, circumferential edge on. This can be achieved that on the outside Element draining liquid already before reaching between the leg and the outer element dripped formed cleft. Accordingly, the entry be reduced by liquids in the gap.

In Development of the invention has the main seal over one, in the direction of the pre-seal and radially outward extending catch lip. This has the advantage of being liquid, which despite the pre-seal between the inner and the outer Element has arrived, collects at this point and especially at Standstill of the system again flow over the pre-seal can.

According to one advantageous embodiment of the invention is on the Thighs formed a gutter that extends in the direction of Main seal and extends radially outward. hereby can also in the pre-seal a collection option are formed for penetrated impurities.

advantageously, is the gutter on the pre-seal also in the radial direction placed above the collecting lip of the main seal. This can an infiltrated liquid after the gutter also be caught by the collecting lip, for example when a larger amount gets into the space is that can no longer be absorbed by the gutter alone.

It is a further advantageous embodiment of the invention that on the side facing the outer element the gutter a porous material is provided which carries a liquid-repellent lubricant. This has the advantage that by a continuous delivery of this Lubricant the ingress of liquid over the gap is much more difficult.

In Further development of the invention has the pre-seal over one, lying in the axial direction between the leg and the main seal Centrifugal disc extending radially in the direction of the outer Elements extends. This will create a second barrier against invading Contaminants are formed, which due to the also in this area produced by the sputtering effect further reduces the contamination, at the same time not increasing the friction of the System contributes.

Corresponding a further advantageous embodiment of the invention the leg and / or the slinger have over Swirl ribs. As a result, the Abschleuderwirkung the leg or the centrifugal disc can be increased. advantageously, are also surfaces of the leg and / or the centrifugal disc provided with a liquid-repellent coating, what the Abschleuderwirkung further improved.

A further embodiment of the seal arrangement according to the invention provides that the pre-seal of several individual elements composed. Accordingly, it is possible even complex Shape the geometry of the pre-seal.

According to one advantageous embodiment of the invention is the Pre-seal made of plastic. By this measure, the Production costs for the pre-seal considerably reduced and also to save weight.

Corresponding a further variant of the sealing arrangement is between the Pre-seal and the main seal provided a grease lubrication. By means of this grease lubrication can liquids and particles only very difficult in front of the at least one sealing lip get the main seal.

Further, The measures improving the invention will be described below together with the description of preferred embodiments of the invention with reference to the figures shown in more detail.

Brief description of the drawings

It shows:

1 a sectional view of the seal assembly according to the invention according to a first embodiment;

2 a sectional view of the seal assembly according to the invention according to a second embodiment;

3 a sectional view of the seal assembly according to the invention according to a third embodiment; and

4 a sectional view of the seal assembly according to the invention according to a fourth embodiment.

Detailed description the drawings

In 1 is a sectional view of a first embodiment of the seal assembly according to the invention to see, which is a main seal 1 comprising, between an outer, stationary element 2 and an inner, rotatable element 3 is placed. In this case, form the outer element 2 and the inner element 3 the outer and the inner ring of a rolling bearing. A rotation of the inner element 3 is about a wave 4 caused, which is for example a propeller shaft of a rear-wheel drive motor vehicle. The main seal 1 has a support ring 5 which is partially surrounded by a sealing material, preferably an elastomer. On the side of the outer element 2 the sealing material forms a static seal 6 out, over which the main seal 1 in a circumferential groove 7 of the outer element 2 is positioned and the an entry of impurities in an interior 8th effectively prevented over this range. At the opposite end of the main seal 1 is also a sealing lip 9 provided, which to the inner element 3 presses and thus ensures a dynamic seal against this rotatable part. The main seal 1 is also a pre-seal 10 upstream, via an interference fit on its radially inner side with the inner element 3 is firmly connected and over, towards the outer element 2 extending thighs 11 features. This thigh 11 protrudes with its outer radial end in a recess 12 of the outer element 2 into it, forming together with the outer element 2 a, extending in the axial and radial direction gap 13 out.

With a rotation of the shaft 4 and thus also the inner element 3 Become from the outside impinging liquids and particles through the leg 11 the pre-seal 10 due to a, centrifugal force generated by the rotation thrown radially outward. This is an intrusion of contaminants between the leg 11 and the outer element 2 through the labyrinth-like course of the gap 13 and obstructed due to the associated high flow resistance. In the area of the recess 12 is also a circumferential edge 14 on the outer element 2 provided, which at, on the outer element 2 flowing liquids already before reaching the gap 13 ensures a dripping. The Abschleuderwirkung the thigh 11 can be further improved by coating with a liquid-repellent material. The still between pre-seal 10 and main seal 1 Liquids and particles get through the static seal 6 and the sealing lip 9 at the entrance to the interior 8th prevented and can due to the design of the gap 13 , especially at a standstill of the system, again almost unhindered before the pre-seal 10 reach.

In 2 the seal assembly according to the invention is shown according to a second embodiment. In contrast to the previously described variant is the pre-seal 10 ' from two single elements 15a and 15b formed jointly the course of the thigh 11 in the direction of the outer element 2 ' define. These individual elements 15a and 15b can be designed here as plastic parts, as well as sheet metal angle rings from a reinforcing sheet. On the part of the main seal 1' form the individual elements 15a and 15b Furthermore, together a gutter 16 on the thigh 11 in which over the gap 13 Into contaminants can be collected immediately. It also has the main seal 1' over one in the direction of the pre-seal 10 ' oriented collecting lip 17 , which in the radial direction below the gutter 16 is placed. By means of this collecting lip 17 The liquids and particles can not pass through the gutter 16 intercepted, at a further advance towards the interior 8th be prevented. This is due to the relative positioning of the gutter 16 to the catching lip 17 promoted. In addition, between the pre-seal 10 ' and the main seal 1' another grease lubrication 18 provided, which impedes the penetration of impurities in this area and thus a total sealing effect further improved.

Out 3 Furthermore, a third embodiment of the sealing arrangement according to the invention emerges. In this case, the pre-seal continues 10 '' from a thigh 11 ' , as well as one, between thighs 11 ' and main seal 1 lying slinger 19 together. Also the slinger 19 extends towards the outside Elements 2 ' and is stuck with the inner element 3 connected. Consequently, by the slinger 19 another barrier in front of the main seal 1 formed during rotation of the inner element 3 also causes a Abschleuderwirkung and thus the discharge of between legs 11 ' and slinger 19 got contaminated. To further improve this discharge, the thigh has 11 ' on his, the slinger 19 facing side via swirl ribs 20 , which increase the Abschleuderwirkung.

Finally, in 4 to see a fourth embodiment of the seal assembly according to the invention, in which, in contrast to the variants described above on the, the outer element 2 ' facing side of the gutter 16 a porous material 21 is provided, which carries a liquid-repellent lubricant. It is characterized by the porous material 21 the lubricant is continuously discharged and thus an entry of liquids through the gap 13 between thighs 11 the pre-seal 10 ''' and the outer element 2 ' further diminished.

By the sealing arrangement according to the invention can be an entry of impurities in the interior 8th effectively be prevented, with a friction here in principle only by the sealing lip 9 the main seal 1 or 1' is caused. Additionally, you can still choose between pre-seal 10 . 10 ' . 10 '' respectively. 10 ''' and main seal 1 respectively. 1' impurities are transported back almost unhindered. Here, the structural details of the individual embodiments can also be combined with each other.

1, 1'

main seal

2, 2 '

outer element

3

inner element

4

wave

5

support ring

6

static seal

7

groove

8th

inner space

9

sealing lip

10 10 ', 10' ', 10' ''

pre-seal

11 11 '

leg

12

recess

13

gap

14

edge

15a, 15b

individual elements

16

collecting channel

17

capture lip

18

grease lubrication

19

slinger

20

swirl ribs

21

porous material

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - DE 19600125 A1 [0004]
• - DE 69107890 T2 [0006]

Claims (13)

Sealing arrangement, in particular for a rolling bearing, comprising a main seal ( 1 ; 1' ), which for sealing an interior ( 8th ) between an outer, fixed element ( 2 ; 2 ' ) and an inner, rotatable element ( 3 ) and via a static seal ( 6 ) with the outer element ( 2 ; 2 ' ), while contact between the main seal ( 1 ; 1' ) and the inner element ( 3 ) via at least one sealing lip ( 9 ) is realized, wherein the main seal ( 1 ; 1' ) a pre-seal ( 10 ; 10 '; 10 ''; 10 ''' ) which is fixed to the inner element ( 3 ) and at least one, in the direction of the outer element ( 2 ; 2 ' ) extending legs ( 11 ; 11 ' ), characterized in that the at least one limb ( 11 ; 11 ' ) in one, in the radial direction on the outer element ( 2 ; 2 ' ) pronounced recess ( 12 protrudes and together with the outer element ( 2 ; 2 ' ) a, in the axial and radial direction extending gap ( 13 ) trains. Sealing arrangement according to claim 1, characterized in that the outer element ( 2 ) in the region of the recess ( 12 ) and in the axial direction before the pre-seal ( 10 ) a radially inwardly directed, circumferential edge ( 14 ) having. Sealing arrangement according to claim 1 or 2, characterized in that the main seal ( 1' ) over one, in the direction of the pre-seal ( 10 '; 10 ''' ) and radially outwardly extending collecting lip ( 17 ). Sealing arrangement according to one of claims 1-3, characterized in that on the at least one leg ( 11 ) a gutter ( 16 ) is formed, which in the direction of the main seal ( 1' ) and extends radially outward. Sealing arrangement according to claim 3 and 4, characterized in that the gutter ( 16 ) in the radial direction above the collecting lip ( 17 ) is placed. Sealing arrangement according to claim 4 or 5, characterized in that on the, the outer element ( 2 ' ) facing side of the gutter ( 16 ) a porous material ( 21 ) is provided, which carries a liquid-repellent lubricant. Sealing arrangement according to one of the preceding claims, characterized in that the pre-seal ( 10 '' ) over one, in the axial direction between legs ( 11 ' ) and main seal ( 1 ) lying slinger ( 19 ) which extends radially in the direction of the outer element ( 2 ' ). Sealing arrangement according to one of the preceding claims, characterized in that the at least one limb ( 11 ' ) and / or the centrifugal disc ( 19 ) via swirl ribs ( 20 ) feature. Sealing arrangement according to one of the preceding claims, characterized in that surfaces of the at least one leg ( 11 ; 11 ' ) and / or the centrifugal disc ( 19 ) are provided with a liquid-repellent coating. Sealing arrangement according to one of the preceding claims, characterized in that the pre-seal ( 10 '; 10 ''' ) consists of several individual elements ( 15a . 15b ). Sealing arrangement according to one of the preceding claims, characterized in that the pre-seal ( 10 ; 10 '; 10 ''; 10 ''' ) consists of plastic. Sealing arrangement according to one of the preceding claims, characterized in that between the pre-seal ( 10 ' ) and the main seal ( 1' ) grease lubrication ( 18 ) is provided. Rolling bearing with an inner ring and an outer ring, comprising at least one sealing arrangement according to one of the claims 1-12.