Seal assembly for a wheel bearing, comprising a diagonal contact surface, and wheel bearing

Abstract

The invention relates to a seal assembly (1) for sealing a bearing with an inner bearing ring (2) and an outer bearing ring (3). The seal assembly (1) has an inner support element (4) which is connected to the inner bearing ring (2) and an outer support element (5) which is connected to the outer bearing ring (3). A first seal element (6) with at least one seal lip (7) is formed on the outer support element (5), said seal lip sealingly lying against a contract surface (8) of the inner support element (4). The contact surface (8) of the inner support element (4) is configured at an angle between 0° and 90 degrees, with respect to a horizontal, in the direction of the outer bearing ring (3) when the seal assembly (1) is installed. The invention also relates to a wheel bearing for a motor vehicle, comprising a seal assembly (1) according to the invention.

Description

[0001] Sealing arrangement for a wheel bearing, with an inclined contact surface, and wheel bearing

[0002] The present invention relates to a sealing arrangement for sealing a (rolling) bearing, wherein the sealing arrangement comprises a sealing element with at least one sealing lip which sealingly bears against an associated contact surface, as claimed in claim 1, and a wheel bearing as claimed in claim 10.

[0003] Rolling and plain bearings are used to support a rotating component, such as a shaft. The rolling elements in such bearings are susceptible to contamination in the form of foreign particles or liquids. The interior of these bearings must therefore be tightly sealed to prevent the ingress of dirt or liquids. Such a sealing effect, particularly in the wheel bearings of a motor vehicle, is typically achieved through contact between several dynamic sealing lips of a first sealing element and a rotating counter-running surface.

[0004] From JP 2015 - 152 030 A and KR 10 - 2013 0 087 875, for example, sealing arrangements for sealing a rolling bearing between a first and a second bearing part are known. The sealing arrangements have a stationary sealing disc with at least one sealing lip, which is in axial sealing contact with a contact surface of a second rotating sealing disc, as well as a radial gap seal. The design of the overlap of the sealing lip or the seal with the rotating contact surface depends on the (axial) position of a flinger, which is subject to tolerances. In particular, the effect of the axially aligned sealing lip is sensitive to the mutual positioning of the stationary sealing disc and the rotating sealing disc. This means that the position tolerances of the flinger have a direct effect on the overlap of the axial sealing lips.To cushion / mitigate the positioning tolerances, a nominal sealing lip overlap must be defined. A minimum overlap between a sealing lip and the contact or counter-surface is required to ensure adequate sealing performance, whereas a maximum overlap should not be exceeded to keep friction between the two components as low as possible.

[0005] DE 10 2917 110 115 A1 discloses another sealing arrangement that achieves a sealing effect by means of a sealing lip that is in radial contact with an opposing contact surface. However, such a radial alignment of the sealing lip impedes the axial flow or drainage of water that accumulates at the sealing lip.

[0006] The object of the present invention is to avoid or at least mitigate the disadvantages of the prior art and, in particular, to further develop a sealing arrangement for a wheel bearing in which the influence of an (axial) positioning of the flinger disc on the resulting overlap between a sealing lip and the opposing contact surface is reduced.

[0007] This object is achieved by a sealing arrangement for sealing a bearing with an inner and an outer bearing ring, with the features of patent claim 1, namely that a contact surface / counter-running surface or contact surface of a rotating carrier element, against which a sealing lip bears in a sealing manner, is formed at an angle between 0° and 90°, relative to a horizontal, in the direction of the outer bearing ring. This makes it possible to provide a sealing arrangement in which a tolerance-dependent positioning of a flinger disc has a lesser influence / effect on the sealing lip overlap between a sealing lip and an opposing contact surface, i.e. the theoretical overlap of the sealing lip and the contact surface. The invention accordingly relates to a sealing arrangement for sealing a bearing, in particular a wheel bearing, with an inner rotatable bearing ring and an outer stationary bearing ring.The sealing arrangement comprises an inner support element / sealing disc connected to the inner bearing ring and an outer support element / sealing disc connected to the outer bearing ring. A first sealing element with at least one sealing lip is formed on the outer support element, which sealingly abuts a contact surface / running surface / counter-running surface of the inner support element. Furthermore, the contact surface of the inner support element, in the assembled state of the sealing arrangement, is formed at an angle between 0° and 90°, relative to a horizontal, toward the outer bearing ring.

[0008] In other words, the sealing arrangement according to the invention has two support elements, each of which is connected to an inner and outer (with respect to the axis of the rotatably mounted component) bearing ring. The support element arranged on the outer, stationary bearing ring has a sealing element, which in turn has at least one radially or axially projecting / aligned sealing lip. The inner support element has an obliquely formed contact surface with which the at least one sealing lip can be brought into sealing contact. The oblique orientation of the contact surface of the outer support element occurs in the direction of the outer bearing ring, specifically at an angle between 0° and 90° to a horizontal. A theoretical angle of 0° describes an orientation of the contact surface in which the contact surface corresponds to the horizontal.Since the contact surface of the rotating sealing disc is angled, the overlap of the sealing lip is also angled or oblique.

[0009] This angled arrangement of the contact surface for the sealing lip reduces the tolerance- and position-related influence of the flinger and thus of the rotating support element of the sealing arrangement. A (tolerance-related) axial positional shift of the flinger thus has a lesser impact on the resulting engagement / overlap between the sealing lip and the corresponding contact surface of the rotating support element. This angled contact surface and the resulting angled sealing lip engagement can also be used to reduce the nominal sealing lip engagement, thus keeping friction losses low while maintaining a sufficiently effective sealing effect. Thus, the sealing lip engagement described above is optimized with regard to sealing capability and friction. This occurs as independently as possible from the tolerances of the flinger.

[0010] Advantageous embodiments are the subject of the subclaims and are explained in more detail below.

[0011] According to an advantageous embodiment, the sealing lip rests on the contact surface of the inner carrier element in the radial direction.

[0012] In other words, the sealing lip, which can be brought into contact with the oblique / angled contact surface of the inner support element, is radially formed. This means that the sealing lip is slotted in the radial direction.

[0013] A radial design of the sealing lip in combination with the associated, inclined contact surface of the counter-rotating support element ensures that no dirty water accumulates in the area of ​​the sealing lip overlap. Dirty water at the contact point of the sealing lip above the rotational axis and also below the rotational axis of the rotating component is able to drain away directly. Thus, no dirty water reservoir forms at the sealing contact, in contrast to an axial design of the sealing lip. In a further preferred aspect of the invention, the angle between the contact surface of the inner support element and the horizontal is approximately 30°.

[0014] Arranging the contact surface of the inner support element at an angle of approximately 30° between the contact surface of the inner support element and a horizontal line, in the direction of the outer bearing ring, means that an axial position change (of the flinger or the rotating support element) is only approximately half translated into a change in the sealing lip overlap. Thus, the influence of a (tolerance-related) axial displacement of the flinger is reduced by approximately half compared to axial contact between the sealing lip and the contact surface (i.e., at an angle of 90° between the contact surface and a horizontal line), thereby reducing the chance of insufficient sealing effectiveness or excessive frictional torque.

[0015] According to a further advantageous embodiment of the invention, the first sealing element has at least one collecting chamber which is designed and provided to collect dirt and / or liquid.

[0016] In other words, the first sealing element forms a notch-shaped trap chamber that extends along the entire circumference of the sealing element and is designed to trap contaminants. In particular, this prevents splash water and contaminants such as dust or other foreign particles from entering the interior of the bearing. This counteracts any impairment of the bearing's function.

[0017] According to a further advantageous embodiment of the invention, the two support elements of the sealing arrangement are each frictionally connected to the two associated bearing rings. In other words, the outer support element, which has the first sealing element, is frictionally connected to the outer bearing of the rolling bearing or wheel bearing. At the same time, the inner support element is frictionally connected to the inner bearing. Such a frictional connection is achieved, for example, by a press fit. This ensures a secure and relatively firm connection between the components while keeping manufacturing costs low.

[0018] In a further preferred aspect of the invention, the inner support element of the sealing arrangement has a second sealing element. The additional sealing element on the inner support element allows the sealing space between the two (opposing) support elements to be geometrically influenced and additionally protects the inner support element from external influences.

[0019] In a further advantageous aspect of the invention, the two carrier elements are arranged axially such that a sealing gap is formed between the first and the second sealing element.

[0020] Preferably, this sealing gap between the two support elements extends largely axially, thereby increasing the axial path for contaminants / dirt particles into the interior of the bearing. Furthermore, this effect can be increased by a stepped sealing gap in the radial direction.

[0021] According to a further advantageous embodiment of the invention, at least the second sealing element has at least one trapezoidal sealing projection, and at least the first sealing element has at least one trough-shaped recess associated with it. In other words, at least one trapezoidal or rectangular sealing projection is formed integrally on at least the second sealing element and is aligned horizontally. In this embodiment, at least the first sealing element has at least one trough-shaped recess that is formed opposite the sealing projection of the second sealing element and is associated with it. In the assembled state of the sealing arrangement according to the invention, the trough-shaped recess engages around / encloses the associated sealing projection, while maintaining a sufficiently wide sealing gap between the two support elements to ensure unhindered rotational movement.

[0022] In a further preferred aspect of the invention, the sealing gap is designed in the form of a labyrinth structure comprising a plurality of trapezoidal sealing projections arranged one behind the other and the respective associated trough-shaped depressions.

[0023] In other words, a sealing gap is created between the two support elements by a series arrangement of several sealing projections and the associated recesses, particularly in the radial or axial direction. This sealing gap has a labyrinth-like / serpentine shape. This series arrangement occurs in the axial or radial direction of the (assembled) sealing arrangement.

[0024] Such a design of the sealing gap between the two support elements further increases the distance / path / length of the sealing gap into the bearing interior, thereby making it more difficult for (dirt) particles to penetrate. The invention further relates to a wheel bearing for a motor vehicle with the sealing arrangement according to the invention, as claimed, for example, in claim 10.

[0025] The invention and the technical environment are explained in more detail below with reference to the figures. It should be noted that the invention is not intended to be limited by the exemplary embodiments shown. In particular, unless explicitly stated otherwise, it is also possible to extract partial aspects of the facts explained in the figures and combine them with other components and findings from the present description and / or figures. In particular, it should be noted that the figures and in particular the proportionalities shown are only schematic. Identical features are referenced with the same reference numerals. Furthermore, it should be noted that the features of the individual embodiments can be interchanged and occur in a specific combination.

[0026] Fig. 1 is a (side) cross-sectional view through the sealing arrangement according to a first advantageous embodiment.

[0027] Fig. 2 is an isometric cross-sectional view through the transmission side of a wheel bearing with the mounted seal assembly according to the embodiment shown in Fig. 1.

[0028] Fig. 3 is an enlarged (side) cross-sectional view through the sealing lip overlap of the sealing arrangement according to the first advantageous embodiment.

[0029] Fig. 4 is an enlarged (side) cross-sectional view through the sealing contact of the sealing lip above a rotational axis of the sealing arrangement according to the first embodiment. Fig. 5 is an enlarged (side) cross-sectional view through the sealing contact of the sealing lip below a rotational axis of the sealing arrangement according to the first embodiment.

[0030] Fig. 6 is a diagram showing the relationship between a change in sealing lip coverage and an angle of the contact surface for different axial position changes for the sealing arrangement according to the invention.

[0031] Fig. 7 is a (side) cross-sectional view through the sealing arrangement according to a second advantageous embodiment.

[0032] Fig. 8 is a (side) cross-sectional view through the wheel side of a partially shown wheel bearing with a mounted sealing arrangement according to a third advantageous embodiment.

[0033] The present invention and the advantageous embodiments are described below with reference to the figures.

[0034] Figure 1 shows a (side) cross-sectional view through the sealing arrangement 1 according to the invention according to a first advantageous embodiment. In this view, the sealing arrangement 1 is arranged above a rotational axis and has an outer support element 5 (relative to the rotational axis), which is connected to an outer bearing ring 3 of a rolling or wheel bearing. In addition, the sealing arrangement 1 has an inner support element 4, which is connected to an inner bearing ring 2. In this cross-sectional view, the outer support element 5 has an L-shaped profile and the inner support element 4 has an almost C-shaped profile. Both support elements 4, 5 are arranged relative to one another in such a way that they form a sealing chamber between them. The outer support element 5 further has, on the side facing the sealing chamber, a first sealing element 6 with a sealing lip 7, a radial end piece 14, and a collecting chamber 9.The sealing lip 7 is aligned radially in the direction of the outer bearing ring 3 and is in sealing contact with an obliquely angled contact surface 8 of the inner support element 4. In the illustrated embodiment of the sealing arrangement 1, the contact surface 8 for the sealing lip 7 is formed at an angle of approximately 30° to a horizontal, in the direction of the outer bearing ring. Accordingly, the sealing lip 7 bears against this oblique contact surface 8 of the inner support element 4. The radial end piece 14 of the first sealing element is formed on the side facing the inner bearing ring 2 and extends in the axial direction towards the inner support element 4, thereby creating an axial gap seal. Furthermore, a second sealing element is formed on the side of the inner support element 4 facing away from the sealing chamber.Both sealing elements 6, 10 are arranged relative to one another in such a way that they form a sealing gap 11 between them, which runs in a step-like manner.

[0035] Figure 2 shows an isometric cross-sectional view through the transmission side of a wheel bearing with the mounted sealing arrangement 1 according to the embodiment shown in Fig. 1. The wheel bearing shown consists of the outer bearing ring 3, which in this embodiment is designed as an axle body, and a rotatable inner bearing ring 2, which is connected to a wheel flange 15. A first and second row of rolling elements 16, 17 are arranged between the inner bearing ring 2 and the outer bearing ring 3. The first row of rolling elements 16 faces the transmission side in this illustration, and the sealing arrangement 1 according to the advantageous first embodiment from Fig. 1, with a first sealing element 6 and a second (transmission-side) sealing element 10, is arranged next to this first row of rolling elements 16.

[0036] Figure 3 shows an enlarged (side) cross-sectional view through the sealing lip overlap of the sealing arrangement 1 according to the first advantageous embodiment. In particular, the oblique profile of the contact surface 8 of the inner support element 4 with the second sealing element 10 can be seen, against which the sealing lip 7 of the first sealing element 6 bears or rests in a sealing manner. Furthermore, the collecting chamber 9, which in this view is arranged below the sealing lip 7, is shown for collecting dirt or liquids. For illustration purposes, a plurality of dashed lines are drawn in this illustration. The two oblique lines running parallel to one another illustrate an overlap of the sealing lip 7 and the oblique contact surface 8. Only a theoretical sealing lip overlap is shown, which differs from the actual shape of the sealing lip 7 in the assembled state.Another horizontal dashed line illustrates the oblique course of the contact surface 8, which runs at an angle a relative to the horizontal.

[0037] Figures 4 and 5 each show an enlarged (side) cross-sectional view through the sealing contact of the sealing lip 7 of the sealing arrangement 1 according to the first embodiment, with the inner support element 4 and the two sealing elements 6, 10. The radially aligned sealing lip 7 is in contact with the obliquely formed contact surface 8 of the inner support element 4. Figure 4 shows the sealing contact of the sealing lip 7 with the oblique contact surface 8 above a rotational axis of a rolling / wheel bearing, whereas Figure 5 shows a view of the sealing contact below the same rotational axis. Furthermore, in both views, a drainage direction of dirty water within the sealing arrangement 1 is shown by an arrow.Due to the inclined contact surface 8, no dirty water collects at the contact between the sealing lip 7 and the contact surface 8, but instead flows into the collecting chamber 9 upon contact above the axis of rotation, or along the contact surface 8 toward the sealing gap 11 between the two sealing elements 6 and 10 upon contact below the axis of rotation. This ensures direct axial drainage of dirty water accumulating on the sealing lip. Figure 6 shows a diagram illustrating the relationship between a change in the sealing lip overlap and an angle of the inclined contact surface 8 of the inner support element 4 for different axial position changes for the sealing arrangement 1 according to the invention.The angle α between 0° and 90° on the contact surface 8 relative to a horizontal is plotted on the x-axis of the diagram, and each of the seven curves in the illustrated set of curves represents an axial change in position of the flinger disc or the inner support element 4 in relation to the outer support element 5 of the sealing arrangement 1. The individual curves each represent an axial change in position between 0 mm (lowest horizontal curve) and 0.3 mm (top curve). A predetermined angle α for a predetermined axial change in position is assigned to a change in the sealing lip overlap (in mm), which is plotted on the y-axis of the diagram. For an angle of the contact surface 8 of 90°, for example, i.e. a perpendicular contact surface 8, an axial change in position of 0.3 mm between the rotating and stationary components results in a change in the sealing lip overlap of 0.3 mm.Thus, an axial position change translates 100% into a change in the sealing lip's overlap. An oblique or angled orientation of the contact surface 8 relative to the horizontal, however, leads to a smaller impact of the axial position change. For example, an axial position change of 0.3 mm with a contact surface 8 aligned at an angle of 30° relative to the horizontal only results in a change in the sealing lip's overlap of 0.15 mm. The influence of the axial position change is thus halved compared to the case of a vertical contact surface 8.

[0038] Figure 7 shows a (side) cross-sectional view through the sealing arrangement 1 according to a second advantageous embodiment. The arrangement / configuration of the two support elements 4, 5, the sealing lip 7 and the inclined contact surface 8 corresponds to their arrangement from the first embodiment (see Fig. 1). In this second embodiment of the sealing arrangement 1, the first sealing element 6 has two trough-like depressions 13, into each of which a rectangular sealing projection 12 of the second sealing element engages. Between the two sealing projections 12 of the second sealing element, a further depression 13 is formed, which in turn engages around a further sealing projection 12 on the side of the first sealing element 6. The arrangement of the sealing projections 12 or the depressions 13 takes place alternately in the axial direction.Due to these geometries, the sealing gap 11 between the two sealing elements 6, 10 extends in a labyrinthine / serpentine manner through the sealing arrangement 1 and ends in the collecting chamber 9. Furthermore, in this embodiment, the inner carrier element 4 has, outside the sealing contour, a (magnetic) encoder 19, which is provided in particular for an ABS signal of the wheel bearing.

[0039] Figure 8 shows a (side) cross-sectional view through the wheel side of the partially illustrated wheel bearing from Figure 2, with a mounted sealing arrangement 1 according to a third advantageous embodiment. In this view, the sealing arrangement 1 is arranged between a (stationary) outer bearing ring 3, in particular in the form of an axle body, and a (rotating) wheel flange 15 as the inner bearing ring. Furthermore, the second rolling element region 17 from Figure 2 can be seen between the outer bearing ring 3 and the wheel flange. The outer carrier element 5 of the sealing arrangement 1 is connected to the outer bearing ring 3, and the inner carrier element 4 is connected to the wheel flange 15. The inner carrier element 4 of the sealing arrangement 1 according to the third embodiment does not have an additional second sealing element or rubber coating and also has a different contour.In this embodiment, the inner support element 4 extends above the inclined contact surface 8 in the direction of the outer bearing ring 3 and ends in an outer end piece which is bent and points opposite to the sealing chamber.

[0040] List of reference symbols

[0041] Seal arrangement inner bearing ring outer bearing inner support element outer support element first sealing element sealing lip contact surface catch chamber second sealing element sealing gap sealing projection recess radial end piece wheel flange first row of rolling elements second row of rolling elements outer end piece

[0042] Encoder

Claims

Claims 1. Sealing arrangement (1) for sealing a bearing with an inner bearing ring (2) and an outer bearing ring (3), wherein the sealing arrangement (1) has an inner support element (4) connected to the inner bearing ring (2) and an outer support element (5) connected to the outer bearing ring (3), wherein a first sealing element (6) with at least one sealing lip (7) is formed on the outer support element (5), which abuts a sealing surface (8) of the inner support element (4), characterized in that the contact surface (8) of the inner support element (4) is formed in the assembled state of the sealing arrangement (1) at an angle between 0° and 90°, with respect to a horizontal, in the direction of the outer bearing ring (3).

2. Sealing arrangement (1 ) according to claim 1 , characterized in that the sealing lip (7) abuts the contact surface in a sealing direction in the radial direction.

3. Sealing arrangement (1 ) according to claim 1 or 2, characterized in that the angle between the contact surface (8) of the inner support element (4) and the horizontal is approximately 30°.

4. Sealing arrangement (1) according to one of the preceding claims, characterized in that the first sealing element (6) has at least one collection chamber (9) which is designed and provided to collect dirt and / or liquid.

5. Sealing arrangement (1 ) according to one of the preceding claims, characterized in that the two support elements (4, 5) are each positively connected to the bearing rings (2, 3) belonging to them.

6. Sealing arrangement (1 ) according to one of the preceding claims, characterized in that the inner support element (4) has a second sealing element (10).

7. Sealing arrangement (1 ) according to claim 6, characterized in that the two support elements (4, 5) are arranged axially such that a sealing gap (11 ) is formed between the first sealing element (6) and the second sealing element (10).

8. Sealing arrangement (1 ) according to claim 6 or 7, characterized in that at least the second sealing element (10) has at least one trapezoidal or rectangular sealing projection (12) and at least the first sealing element has at least one trough-shaped recess (13) associated with the sealing projection (12).

9. Sealing arrangement (1 ) according to claim 8, characterized in that the sealing gap (11 ) is formed in the form of a labyrinth structure consisting of several trapezoidal sealing projections (12) connected in series and the respective associated trough-shaped recesses (13).

10. Wheel bearing for a motor vehicle, characterized by a sealing arrangement (1 ) according to one of claims 1 to 9.

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