Sealing arrangement of a wheel bearing

Abstract

Sealing arrangement of a wheel bearing (3) for sealing an interface between a wheel bearing (3) and a joint bell (4), comprising at least one carrier element (5) which has a first end (6) and a second end (7), wherein the first end (6) is connected in a rotationally fixed manner to a sealing seat (2, 16, 17) formed by an inner bearing ring (8) of the wheel bearing (3) and wherein the second end (7) comes into contact with the joint bell (4), wherein an air duct (14) is provided between the first end and the sealing seat (2, 16, 17) and a connection between the bearing interior and the exterior is made possible by means of the axially extending air duct (14), whereby pressure equalization or pressure relief from the interior relative to the environment can be achieved in all operating states of the wheel bearing unit.

Description

Field of the invention

[0001] The invention relates to a sealing arrangement of a wheel bearing, in particular for motor vehicles. Background of the invention

[0002] Sealing a wheel bearing against environmental influences is necessary in many applications to ensure a sufficient service life. For example, in automotive wheel bearings, it is essential to protect the rolling bearings located in the wheel mounts from splash water and other contaminants during daily use. Contact seals are typically used for this purpose, for example, in the form of cassette seals, which can be installed in the rolling bearings as a seal set.

[0003] With sealed wheel bearings there is a risk that temperature differences will lead to overpressure or underpressure developing inside the wheel bearing. This is caused, among other things, by different thermal expansions of air and lubricant as well as the steel of the bearing rings. Temperature increases, e.g. during driving, lead to overpressure in the bearing interior, some of which can escape via the sealing system. When the wheel bearing is stationary, the temperature inside the bearing adapts to the temperature of the outside environment. However, air cannot be supplied to the bearing, so the lost air volume creates a vacuum inside the wheel bearing. Pressure differences have a negative effect on the sealing effect of the sealing arrangements in wheel bearings, resulting in greater wear and higher friction on the sealing lips.

[0004] The sealing lips of the sealing arrangements are typically designed so that excess pressure can escape on at least one sealing side by lifting the sealing lips. However, negative pressure cannot be relieved due to the geometry of the sealing lips.

[0005] The primary purpose of the sealing arrangement is to protect the interior against external influences such as the ingress of dirt and water. The sealing arrangement also has the task of preventing lubricant from escaping from the rolling bearing. A negative pressure inside the wheel bearing presses the sealing lips more firmly against the sealing surface. Likewise, greater external pressure increases the contact pressure of the sealing lips. In both cases, the sealing effect is increased, but this prevents pressure equalization. The additional force of the sealing lips on their running surfaces due to the pressure difference increases the friction between the sealing lips and sealing surfaces, which further leads to undesirable increased wear, greater friction and higher operating temperatures. Ventilation devices such as a membrane or vent openings or defects in the contact area of ​​the sealing lip are known for pressure equalization in wheel bearings.

[0006] DE 10 2006 032 159 A1 discloses a bearing arrangement for a motor vehicle wheel hub driven by a rotary joint. The wheel hub, connected to a wheel flange, and the rotary joint, connected to a drive shaft, are connected to one another in a rotationally fixed manner by means of a toothing. Furthermore, a double-row rolling bearing with at least one separate, axially outwardly arranged bearing inner ring directed toward the rotary joint is mounted on the wheel hub. The bearing inner ring is arranged with an axially outer end face in the region of one end of an axle stub of the wheel hub and is axially preloaded by a radial surface of the wheel hub acting on the end face of the separate bearing inner ring. The outer ring and the bearing inner ring are provided with a seal, which has at least one sealing ring connected to the bearing inner ring and made of sheet metal, each having a radial leg and an axial leg in cross-section.The axial leg is non-rotatably connected to the bearing inner ring and is directed axially inward. Furthermore, the axial leg of the sealing ring of the bearing inner ring is bent radially inward and axially outward, with a free end of the axial leg projecting axially outward beyond the end face of the bearing inner ring. This design achieves an additional sealing function for axial gearing or radial gearing in driven wheel bearings through a simple axial extension of the inner sheet metal leg of the seal.

[0007] EP 2 815 891 B1 discloses a wheel bearing unit in which a sealing device seals between an inner ring and an outer ring. The sealing device has an interface seal that at least partially forms a gap with the inner ring. Summary of the invention

[0008] The object of the present invention is to further develop a sealing arrangement for sealing an interface between a wheel bearing and a joint bell, which is suitable for realizing pressure equalization in the interior of the wheel bearing unit and which is simple in design and can be produced cost-effectively.

[0009] According to the invention, this object is achieved by a sealing arrangement of a wheel bearing for sealing an interface between a wheel bearing and a joint bell, comprising at least one carrier element which has a first end and a second end, wherein the first end is connected in a rotationally fixed manner to a sealing seat formed by an inner bearing ring of the wheel bearing and wherein the second end comes into contact with the joint bell, wherein an air duct is provided between the first end and the sealing seat and by means of the axially extending air duct a connection between the bearing interior and the exterior is made possible, whereby pressure equalization or pressure relief from the interior relative to the environment can be realized in all operating states of the wheel bearing unit.

[0010] The air duct designed according to the invention effectively prevents adverse pressure differences between the interior and the surroundings of the wheel bearing unit. During operation of the wheel bearing unit, any pressure differences that occur are compensated for by the action of the air duct according to the invention, so that no increased contact pressure of the seals or sealing lips of the sealing arrangement occurs. This advantageously results in lower friction in the sealing arrangement, reducing CO2 emissions and also having a positive effect on wear and thus the service life of the sealing lips. The invention thus also meets the requirements of today's vehicle manufacturers, who increasingly demand reduced friction in rolling bearings, especially wheel bearings, combined with a longer service life.

[0011] According to a preferred embodiment of the invention, the air duct is formed by at least one axially extending recess on the seal seat and / or by at least one axially extending recess on the first end of the support element. The axially extending air duct enables a connection between the bearing interior and the exterior, whereby pressure equalization or pressure relief from the interior to the environment can be achieved in all operating states of the wheel bearing unit. The recesses can advantageously be designed as grooves, notches, or in a similar linear or thread-shaped form. Advantageously, the ventilation duct is easy to manufacture and can be combined, for example, with existing concepts to achieve a sealing arrangement whose overall design is characterized by improved functional reliability.

[0012] In an alternative embodiment of the invention, the second end is bent radially inward to form a rim which rests on the joint bell.

[0013] Preferably, the second end of the support element has a sealing profile which bears against at least the joint bell.

[0014] Preferably, an elastomer is provided at the second end, which comes into contact with the joint bell. Short description of the drawing

[0015] Below, three embodiments of the invention are illustrated with reference to three figures. They show: Fig. 1 is a schematic sectional view illustrating the structure of a sealing arrangement according to the invention, which is arranged between a wheel bearing and a joint bell according to a first embodiment, Fig. 2 a schematic sectional view to illustrate the structure of a sealing arrangement according to the invention, which is arranged between a wheel bearing and a joint bell according to a second embodiment, and Fig. 3 a schematic sectional view to illustrate the structure of a sealing arrangement according to the invention, which is arranged between a wheel bearing and a joint bell according to a third embodiment. Detailed description of the drawing

[0016] According to Fig. 1, a sealing arrangement 1 according to the invention is provided for sealing an interface between a wheel bearing 3 and a joint bell 4. The sealing arrangement 1 comprises at least one carrier element 5 which has a first end 6 and a second end 7, wherein the first end 6 is connected in a rotationally fixed manner to a sealing seat 2 formed by an inner bearing ring 8 of the wheel bearing 3, and wherein the second end 7 comes into contact with the joint bell 4. This seals the interface.

[0017] Furthermore, a cassette seal 10 is arranged radially between the bearing inner ring 8 and an outer ring 9 for sealing the wheel bearing 3, in particular for protecting two rows of rolling elements 11 arranged radially between the outer and inner rings, only one of which is partially shown. Furthermore, it can be seen that the first end 6 of the carrier element is angled radially outward and simultaneously forms the flinger plate 12 of the cassette seal 10, against which the sealing lips of the cassette seal 10 abut, and on which an encoder 13 is provided.

[0018] Furthermore, an air duct 14 is provided between the first end 6 and the seal seat 2. The air duct 14 designed according to the invention effectively prevents adverse pressure differences between an interior space A and the surroundings of the wheel bearing unit. The air duct is formed by at least one recess (not shown in detail) running in the axial direction on the seal seat 2 and / or by at least one recess (not shown in detail) running in the axial direction on the first end 6 of the carrier element 5. The axially extending air duct 14 enables a connection between the bearing interior space A and the exterior space, whereby pressure equalization or pressure relief from the interior space A relative to the surroundings can be achieved in all operating states of the wheel bearing unit. The recesses can advantageously be designed as grooves, notches, or in a similar form, linear or thread-shaped.

[0019] The following are based on the Fig. 2 to 3 further embodiments of the invention are described. The same components are identified by the same reference numerals as in the previous Fig. 1. The description of the Fig. 2 to Fig. 3 is therefore limited to the different components. Fig. Figure 2 shows a second embodiment of the invention. The difference from the previous figure lies in the design of the carrier element 5. The first end 6 of the carrier element 5 is also angled radially outward and simultaneously forms the flinger plate 12 of the cassette seal 10. However, the carrier element 5 has an L-shape and a double-flanged area 15, which forms an additional sealing seat 16 on the bearing inner ring 8.

[0020] Fig.Figure 3 shows a third embodiment of the invention. The difference from the previous figure lies in the design of the carrier element 5. The first end 6 of the carrier element 5 is also angled radially outward and simultaneously forms the flinger plate 12 of the cassette seal 10. In this embodiment, the carrier plate is also L-shaped and thereby forms an additional seal seat 17 on the bearing inner ring 8. Furthermore, the carrier element 5 is double-flanged in the area of ​​the encoder 13. List of reference symbols 1 Sealing arrangement 2 Seal seat 3 wheel bearings 4 joint bell 5 support element 6 First End 7 Second Ending 8 Bearing inner ring 9 Outer ring 10 cassette seal 11 rolling element row 12 centrifugal plate 13 encoders 14 Air duct 15 Flanged area 16 Seal seat 17 Seal seat

Claims

[1] Sealing arrangement of a wheel bearing (3) for sealing an interface between a wheel bearing (3) and a joint bell (4), comprising at least one carrier element (5) which has a first end (6) and a second end (7), wherein the first end (6) is connected in a rotationally fixed manner to a sealing seat (2, 16, 17) formed by an inner bearing ring (8) of the wheel bearing (3) and wherein the second end (7) comes into contact with the joint bell (4), wherein an air duct (14) is provided between the first end and the sealing seat (2, 16, 17) and a connection between the bearing interior and the exterior is made possible by means of the axially extending air duct (14), whereby pressure equalization or pressure relief from the interior relative to the environment can be achieved in all operating states of the wheel bearing unit. [2] Sealing arrangement according to claim 1, wherein the air channel is formed by means of at least one recess extending in the axial direction on the sealing seat (2, 16, 17). [3] Sealing arrangement according to claim 1, wherein the air channel is formed by means of at least one recess extending in the axial direction at the first end of the carrier element (5). [4] Sealing arrangement according to one of the preceding claims, wherein the second end (7) of the carrier element (5) is bent radially inward to form a rim which bears against the joint bell (4). [5] Sealing arrangement according to one of the preceding claims, wherein the second end (7) of the carrier element (5) has a sealing profile which bears at least against the joint bell (4).

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