Seal assembly for sealing a wheel bearing

Abstract

The invention relates to a seal assembly for sealing a wheel bearing (1) of a vehicle, comprising: a seal unit (2) rigidly connected to an outer ring (5) of the wheel bearing (1); and a centrifugal disk (3) rigidly connected to an inner ring (4) or a wheel hub of the wheel bearing, wherein the centrifugal disk (3) has an axial part (3a) and a radial part (3b) adjacent to the axial part; the seal unit (2) has a seal carrier (2a) and a seal element (2b); the centrifugal disk (3) has, on at least an outer end face of the radial part (3b), an encoder (6) designed to provide magnetic fields; the inner ring (4) has a cylindrical seat (4a) for the centrifugal disk (3) and a step (4b) adjacent to said seat; the encoder (6) has a radial extension (6a) which protrudes, at least in parts, into the step (4b) of the inner ring (4); and the radial extension (6a) has a recess (7).

Description

[0001]Sealing arrangement for sealing a wheel bearing The invention relates to a sealing arrangement for sealing a wheel bearing of a vehicle and to a wheel bearing unit for a vehicle. Seals for sealing a wheel bearing are sufficiently known in the prior art. In the prior art, so-called cassette seals are used to seal wheel bearings. These are provided between the outer ring and inner ring and are intended to prevent dirt and water from penetrating the bearing. In particular, in the area of ​​the spur gearing between the wheel bearing and the joint bell, a further seal, the so-called interface seal, can be provided. This is intended to protect the gearing. In the prior art, the interface seal is usually fastened in the area of ​​the inner ring of the wheel hub. It is also known that an encoder is provided on the cassette seal, which transmits signals, in particular.in the form of magnetic fields, which are detected by a sensor and forwarded to a control unit for evaluation. The geometry of the encoder is usually matched to the sensor position. One such known seal is shown, for example, in the document DE 102018118880 A1. Depending on the interfering contour of the sensor / speed sensor, it may be necessary to push the interface seal further into the interior of the bearing. This can prevent a collision and increase the bearing service life. The object of the invention is therefore to create a wheel bearing unit and a sealing arrangement that has a long service life. Furthermore, it should be ensured that the interfering contour of the sensor does not collide with the interface seal. The object is achieved according to the invention by a wheel bearing unit with the features of claim 1.Preferred embodiments of the invention emerge from the subclaims and the following description, which may each individually or in combination represent an aspect of the invention.The sealing arrangement according to the invention for sealing a wheel bearing of a vehicle has a sealing unit which is connected in a rotationally fixed manner to an outer ring of the wheel bearing, and a flinger which is connected in a rotationally fixed manner to an inner ring or a wheel hub of the wheel bearing, wherein the flinger has an axial part and an adjoining radial part, wherein the sealing unit has a seal carrier and a sealing element, and wherein the flinger has an encoder on at least one outer end face of the radial part, which encoder is designed to provide magnetic fields, wherein the inner ring has a cylindrical seat for the flinger and a step axially adjoining thereto, wherein the encoder has a radial extension which projects at least partially into the step of the inner ring, characterized in that the radial extension has a recess.The radial extension of the encoder refers to the area that projects into the step of the inner ring. The recess in the area of ​​the radial extension makes it possible to push an interface seal, which is provided for sealing a spur gear between the wheel hub and the ball joint, further into the interior of the bearing. This separates the interfering contour of the speed sensor from the interface seal. According to a preferred embodiment, the recess on the encoder is formed over the entire circumference. This means that the recess, e.g. in the form of a groove, extends continuously over the entire circumference. The recess is preferably provided radially at the end of the radial extension of the encoder. The interface seal is seated in this area and preferably has a leg formed correspondingly to the recess. The radial extension of the encoder particularly preferably rests against the inner ring.For this purpose, an additional axial sealing lip can preferably be provided on the extension. The tight fit in this area can prevent corrosion on the inner ring. Alternatively, it would be conceivable for the encoder to form a gap in the area between the radial extension and the inner ring. In a preferred embodiment of the invention, the encoder extends over the entire outer end face of the flinger disc and has an axial extension that extends in the direction of the sealing unit. The axial extension of the encoder is preferably directly connected to the radial part of the flinger disc. By providing the axial extension, the ingress of dirt and water into the seal can be better prevented.The invention further relates to a wheel bearing unit for a vehicle, comprising a rotatable inner ring and a stationary outer ring, wherein a plurality of rolling elements are arranged between the inner ring and the outer ring, wherein a sealing arrangement as defined above is provided for sealing a wheel bearing. Preferably, the encoder interacts with an interface seal, in particular in the region of the radial extension. The interface seal preferably has a radial leg running in the direction of the encoder, which interacts with the recess of the encoder. Preferably, the radial leg of the interface seal bears sealingly against the recess of the radial extension of the encoder. In this way, corrosion of the inner ring can be avoided.The invention is explained below by way of example with reference to the attached drawings using preferred exemplary embodiments, wherein the features presented below can represent an aspect of the invention both individually and in combination. They show: Fig. 1 a schematic representation of part of a wheel bearing according to the prior art Fig. 2 a schematic representation of part of a wheel bearing according to the invention Figure 1 shows a schematic representation of part of a wheel bearing 1 according to the prior art. To seal the wheel bearing, a sealing arrangement is provided which comprises a sealing unit 2 and a flinger disc 3. The sealing unit 2 consists of a seal carrier 2a and a sealing element 2b connected to the latter. The sealing unit 2 is connected in a rotationally fixed manner to an outer ring 5 of the wheel bearing. As can be seen in Figure 1, the flinger disc 3 is pressed onto an inner ring 4.For this purpose, the inner ring has a cylindrical press fit 4a. The inner ring 4 also has a step 4b. The step 4b is axially adjacent to the cylindrical press fit 4a. The step 4b here is to be understood as a reduction in the diameter of the inner ring 4, as can also be seen in Figure 1. An interface seal 9 is fastened in the step. For this purpose, the interface seal 9 has a cylindrical region 9b which is pressed at least partially onto the inner ring, in particular onto the step 4b. The interface seal 9 seals an area of ​​a spur gear (not shown in detail). For this purpose, the interface seal 9 has a sealing lip 9d on the axial end, which comes into sealing contact with a joint bell (likewise not shown).It can be seen in the prior art that the radial leg 9a rests against the radial extension on the encoder and is thus arranged axially outside the outer ring end face. In Fig. 1, the radial extension on the encoder also has a sealing projection that comes into contact with the radial leg 9a of the interface seal 9. In both cases, the interface seal thus comes into contact with the speed sensor, which can lead to a collision and thus damage to the speed sensor or the interface seal. This impairs the bearing function and the speed detection. Figure 2 shows an embodiment according to the invention in which the problem described above is to be prevented. The basic structure of the wheel bearing unit including the sealing arrangement is very similar to the structure in Figure 1.A sealing unit 2 is attached to the outer ring 5 and essentially consists of a seal carrier 2a and the sealing element 2b connected to it. The flinger is pressed onto the inner ring 4 via the axial part 3a. The inner ring 4 has a step 4b axially adjoining the press fit 4a. The step 4b is essentially realized by a reduction in diameter compared to the press fit 4a. The encoder 6 is provided on the outer end face of the flinger. The encoder 6 extends into the step 4b of the inner ring. For this purpose, the encoder 6 has a radial extension 6a which is integrally connected to the encoder. A recess 7 is provided in the area of ​​the radial extension 6a. The recess 7 is preferably provided in the end area of ​​the encoder and essentially consists of a reduction in the width or wall thickness.The wall thickness of the encoder in the area of ​​the recess 7 is preferably less than half the wall thickness of the encoder in the area of ​​the flinger disc 3. The wall thickness of the encoder in the area of ​​the flinger disc 3 is assumed to be average. The recess 7 thus reduces the wall thickness of the encoder by approximately half. The wall thickness in the area of ​​the recess 7 is preferably less than 0.5 mm. The recess 7 makes it possible for a radial leg 9a of the interface seal, which corresponds to the recess 7, to come into contact with the encoder in a sealing manner (thereby preventing corrosion) and, on the other hand, to move the interface seal 9 further into the bearing interior (and thus does not represent a collision with the sensor). The radial leg 9a of the interface seal is particularly preferably flush with the outer surface of the encoder 6.Preferably, a gap S can be provided axially between the radial extension 6a of the encoder 6 and the inner ring 4. However, it would also be conceivable for the radial leg 9a of the interface seal 9 to press against the radial extension 6a on the encoder 6 in such a way that the radial extension 9a bears sealingly against the end face of the inner ring. Particularly preferably, the recess 7 is implemented in the form of a groove that extends over the circumference of the encoder. Furthermore, the recess 7 can also extend radially over the area of ​​the radial extension 6a of the encoder 6.List of reference symbols 1 Wheel bearing 2 Sealing unit 2a Seal carrier 2b Sealing element 3 Flinger disc 3a Axial part 3b Radial part 4 Inner ring 4a Cylindrical seat 4b Step 5 Outer ring 6 Encoder 6a Radial extension 6b Axial extension 7 Recess 8 Rolling element 9 Interface seal 9a Radial leg 9b Cylindrical area 9c End area 9d Additional sealing element S Gap A Axial direction R Radial direction.

Claims

Patent claims 1. Sealing arrangement for sealing a wheel bearing (1) of a vehicle, comprising a sealing unit (2) which is connected in a rotationally fixed manner to an outer ring (5) of the wheel bearing (1), and a centrifugal disc (3) which is connected in a rotationally fixed manner to an inner ring (4) or a wheel hub of the wheel bearing, wherein the centrifugal disc (3) has an axial part (3a) and an adjoining radial part (3b), wherein the sealing unit (2) has a seal carrier (2a) and a sealing element (2b), and wherein the centrifugal disc (3) has an encoder (6) on at least one outer end face of the radial part (3b), which encoder is designed to provide magnetic fields, wherein the inner ring (4) has a cylindrical seat (4a) for the centrifugal disc (3) and a step (4b) axially adjoining thereto, wherein the encoder (6) has a radial extension (6a),which projects at least partially into the step (4b) of the inner ring (4), characterized in that the radial extension (6a) has a recess (7).

2. Sealing arrangement according to claim 1, characterized in that the recess (7) is formed over the entire circumference.

3. Sealing arrangement according to claim 1 or 2, characterized in that the recess (7) is provided radially at the end of the radial extension (6a).

4. Sealing arrangement according to one of the preceding claims, characterized in that the radial extension (6a) bears sealingly against the inner ring (4).

5. Sealing arrangement according to one of claims 1 to 3, characterized in that the encoder (6) forms a gap (S) in the region between the radial extension (6a) and the inner ring (4).

6. Sealing arrangement according to one of the preceding claims, characterized inthat the encoder (6) extends over the entire outer end face of the centrifugal disc (3) and has an axial extension (6b) which extends in the direction of the sealing unit (2).

7. A wheel bearing unit for a vehicle, comprising a rotatable inner ring (4) and a stationary outer ring (5), wherein a plurality of rolling elements (8) are arranged between the inner ring (4) and the outer ring (5), wherein a sealing arrangement is provided for sealing a wheel bearing, wherein the sealing arrangement is designed according to one of claims 1 to 6.

8. A wheel bearing unit according to claim 7, characterized in that the encoder (6) interacts with an interface seal (9), particularly in the region of the radial extension (6a).

9. A wheel bearing unit according to claim 8, characterized in that the interface seal (9) interacts with the recess (7) of the encoder (6) by means of a radial leg (9a) extending in the direction of the encoder (6). 10.Wheel bearing unit according to claim 9, characterized in that the radial leg (9a) of the interface seal (9) bears sealingly against the recess (7) of the radial extension (6a) of the encoder (6).

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