Wheel bearing comprising a signal generating device as part of a sealing arrangement

Abstract

The invention relates to a wheel bearing (1) for a motor vehicle, the wheel bearing comprising an inner ring (2), an outer ring (3) which is mounted on rolling elements relative to the inner ring (2), a sealing arrangement (6) which is inserted between the two rings (2, 3) and seals off a plurality of rolling elements (4) on at least one side (5), and a signal generating device (7) for determining a rotational speed and / or rotational position of one of the rings (2, 3), wherein the signal generating device (7) is integrated in a ring element (8) of the sealing arrangement (6), which ring element is connected to one of the rings (2, 3) for conjoint rotation therewith. The invention also relates to a wheel bearing unit (20) comprising said wheel bearing (1).

Description

[0001] P240753

[0002] - 1 -

[0003] Wheel loader with signaling device as part of a sealing arrangement

[0004] The invention relates to a wheel bearing for a motor vehicle with an inner ring, an outer ring which is mounted in a rolling bearing relative to the inner ring, a sealing arrangement inserted between the two rings which seals several rolling elements to at least one side and a signal transmitter device which serves to determine a rotational speed and / or rotational position of one of the rings.

[0005] Wheel bearings of this type are already well known from the prior art. For example, DE 10 2007 001 963 A1 discloses a wheel bearing with an additional sensor component.

[0006] Furthermore, EP 2 557 325 B1 is known as prior art, showing a groove in the outer ring. Other wheel bearings are known from DE 102024 106 309 A1, JP 2012 - 56 453 A, JP 2006 - 300 800 A and US 2014 / 0 321 784 A1. A generic wheel bearing is described in US 2002 / 0 131 659 A1.

[0007] It is therefore generally known to attach sensor-detectable components to a rotating ring of a wheel bearing, allowing for simple monitoring of the rotational position and / or speed of this ring and the associated component (shaft) during operation. However, it has become apparent that the sensors and signal transmitters used to date result in a relatively complex design and assembly of the wheel bearing.

[0008] The object of the present invention is therefore to provide a wheel bearing with integrated sensing capability, which has a further simplified design and enables low friction. P240753

[0009] - 2 -

[0010] This is solved according to the invention by integrating the signal transmitter device in a ring element of the sealing arrangement which is rotatably connected to one of the rings.

[0011] This integration of the signal transmitter allows the wheel bearing to be mounted in the usual way, without having to attach separate components in separate assembly steps. The wheel bearing can also be designed to be as compact as possible. Furthermore, because the signal transmitter forms a labyrinth seal, multiple sealing lip overlaps between different components, such as the outer ring and the bearing housing, are not required. This allows for greater tolerances in manufacturing and assembly, and also enables a reduction in the required clamping force.

[0012] Further advantageous embodiments are claimed in the dependent claims and are explained in more detail below.

[0013] Therefore, it remains advantageous if the ring element is connected to one of the two rings by a force-fit and / or form-fit connection. This allows for its simple attachment using standard assembly methods.

[0014] It is also advantageous if the ring element is pressed onto a radially outward-facing outer surface of one of the two rings. This further simplifies the assembly process.

[0015] Furthermore, it is advantageous if the ring element is attached to the inner ring. This allows the ring element to be integrated compactly into the wheel bearing.

[0016] Furthermore, it is advantageous if the signaling device has a plastic part mounted / attached to a metal carrier of the ring element. This keeps the design of the signaling device as simple as possible.

[0017] In this regard, it is advantageous if the plastic part has a structure detectable by a speed and / or rotational position sensor. The P240753

[0018] - 3 -

[0019] The structure is preferably designed as a tooth structure / gearing. More preferably, the structure is designed as a magnetized structure, for example by means of a magnet / magnetizable body or by means of several magnets / magnetizable bodies distributed in the circumferential direction / direction of rotation of the ring element.

[0020] The complexity of the wheel bearing is further reduced if the ring element directly forms a sealing surface that is contacted by another seal of the sealing assembly. This additional seal is then preferably connected to the other ring, unlike the ring connected to the ring element.

[0021] Furthermore, it is advantageous if the plastic part forms a sealing contour which interacts with another seal / counter contour of the further sealing ring of the sealing arrangement under (dust-tight) sealing of an intermediate space accommodating the rolling elements.

[0022] Because the plastic part forms a labyrinthine sealing gap with the further seal of the sealing arrangement, the signal transmitter device is used directly as a sealing element, which further simplifies the design.

[0023] The ring element features a joint bell seal for sealing against a joint bell. The joint bell seal is an extension extending axially beyond an end face of the inner ring and / or the outer ring, with this extension prepared for sealing contact with the joint bell. This expands the function of the wheel bearing without necessarily increasing the number of components. In particular, the toothing / face teeth are protected against corrosion.

[0024] Furthermore, it is advantageous if the wheel bearing is equipped with a toothed gear, such as a face gear.

[0025] It is also advantageous if a groove-like opening is present in the outer ring to accommodate the speed and / or rotational position sensor. This allows the P240753

[0026] - 4 -

[0027] The signal transmitter device is designed as a radial encoder. This extends essentially axially, so that a sufficiently long channel can be formed as part of the labyrinth seal.

[0028] In one embodiment of the invention, the ring element has a sheet metal carrier. The encoder can be injection-molded onto this carrier. On the hinge side, the metal carrier can be rubberized or have a sealing lip. Preferably, the metal carrier has a double layer with which it is supported against the inner ring. This allows for a large contact width on the inner ring. Alternatively, it can have a sheet metal projection designed as an axial recess. This axial recess can connect radially inwards to a radial section, with the signal transmitter located at the radially outer end of this section. In a third embodiment, the metal carrier has an LI shape.

[0029] Preferably, the signal transmitter is unencapsulated, at least in the direction of the sensor. This allows it to be positioned particularly close to the sensor that is to receive the signals, resulting in a high signal strength. The signal transmitter, also called an encoder, thus directly limits the gap of the labyrinth seal.

[0030] In one embodiment of the invention, the inner ring is not in direct contact with the seal via a radial sealing lip. This reduces friction and, by eliminating the radial sealing lip, allows the edge of the inner ring to be raised, thus extending the bearing life. In this case, sealing can be achieved by at least one axially oriented sealing lip.

[0031] The invention also relates to a wheel bearing unit for a motor vehicle, comprising a wheel bearing according to the invention in at least one of the embodiments described above and a wheel flange connected to an inner ring of the wheel bearing in a rotationally fixed manner.

[0032] The invention will now be explained in more detail below with reference to figures, in which context various embodiments are also indicated. P240753

[0033] - 5 -

[0034] They show:

[0035] Fig. 1 shows a longitudinal section view of a wheel bearing according to a first embodiment according to the invention, wherein a ring element forming a signal transmitter device with a sealing arrangement with an inner ring (axial and radial) is pressed onto a block,

[0036] Fig. 2 shows a longitudinal section view of a wheel bearing according to a second embodiment of the invention, wherein the ring element is now equipped with a step in its mounting area,

[0037] Fig. 3 shows a longitudinal section view of a wheel bearing according to a third embodiment, wherein the ring element, in comparison to the embodiments of Figs. 1 and 2, is only pressed onto the inner ring from the radial outside.

[0038] Fig. 4 shows a longitudinal section view of a wheel bearing according to a fourth embodiment, wherein the ring element, in comparison to the embodiment of Fig. 3, forms a receiving space open towards the rolling elements for a sealing lip of the sealing ring,

[0039] Fig. 5 shows a longitudinal section view of a wheel bearing according to the invention in a fifth embodiment, which, compared to the embodiment of Fig. 4, has a further enlarged receiving space.

[0040] Fig. 6 shows a longitudinal section view of a wheel bearing according to a sixth embodiment, wherein the inserted ring element forms a labyrinth seal on its radial inner side in comparison to the embodiment of Fig. 2.

[0041] Fig. 7 shows a longitudinal section view of a wheel bearing according to the invention in a seventh embodiment, in comparison to the P240753

[0042] - 6 -

[0043] In the embodiment of Fig. 6, the labyrinth seal is also formed on an axial side of the ring element, as well as

[0044] Fig. 8 shows a longitudinal section view of a wheel bearing according to an eighth embodiment, wherein, in comparison to the embodiment of Fig. 6, the labyrinth seal is only formed on the axial side of the ring element.

[0045] The figures are purely schematic and serve solely to illustrate the invention. The same elements are identified by the same reference symbols.

[0046] Figure 1 illustrates a wheel bearing 1 according to the invention. As also indicated in this figure, the wheel bearing 1 is preferably used as a wheel bearing and thus, in operation, preferably forms part of a wheel bearing unit 20 of a motor vehicle. For the sake of clarity, the wheel bearing unit 20 is shown here only in sections, in which a wheel flange 19 connected to an inner ring 2 of the wheel bearing 1 is particularly visible. The wheel flange 19 is connected to another shaft in the usual way by means of a toothed connection 23. The wheel flange 19 preferably has, in addition to the toothed connection 23 (face teeth), a rolling rivet collar, wherein this toothed connection 23 then further engages with the corresponding counterpart of a ball joint.

[0047] An outer ring 3 of the wheel bearing 1 can therefore, for example, be designed directly as a bearing flange.

[0048] In any case, the wheel bearing 1 typically comprises, in addition to the inner ring 2 and the outer ring 3 arranged radially outside the inner ring 2, several rolling elements 4 distributed circumferentially. Here, the rolling elements 4 are implemented as balls, and thus the wheel bearing 1 is designed as a ball bearing, specifically an angular contact ball bearing. However, it is also possible in principle to design the wheel bearing 1 in a different form, for example, as a double-row ball bearing. P240753

[0049] - 7 -

[0050] A sealing arrangement 6 serves to seal the space 24, the rolling chamber 5, between the inner ring 2 and the outer ring 3 on one (axial) side. The sealing arrangement 6 is located mostly radially between the two rings 2, 3.

[0051] The sealing assembly 6 comprises a seal 15 fixed / attached / fastened to the outer ring 3. The seal 15 has a base carrier 25 (made of sheet metal). The base carrier 25 is attached to the outer ring 3 on its radial outer side (radially inward). A (second) sealing lip 26 is attached to the base carrier 25 on its radial inner side (by injection molding). This (second) sealing lip 26, in turn, rests against the inner ring 2 in a radial direction (from the outside).

[0052] Furthermore, a (first) sealing lip 22 is present, which rests against a ring element 8 of the sealing arrangement 6. The ring element 8 is also firmly connected to / fixed to / attached to / fastened to the inner ring 2.

[0053] The ring element 8 in turn has a metal support 10, which is attached to the inner ring 2. The metal support 10 is also made of a metal sheet. In this configuration, the metal support 10 is pressed onto the inner ring 2. This means that the metal support 10 is pressed onto a radial outer surface 9 of the inner ring 2 with one section and is further supported by another section in the axial direction. This results in a positive-locking and force-locking connection between the ring element 8 and the inner ring 2.

[0054] On its radial outer side, the metal carrier 10 is provided with a sleeve area 27 on which the plastic part 11, described in more detail below, is mounted. Towards its radial inner side, an axially extending extension area is formed on the metal carrier 10 as a hinged bell seal 17. The hinged bell seal 17 projects axially away from the rolling elements 4 and is equipped at its free end with a further (third) sealing lip 28. P240753

[0055] - 8 -

[0056] This (third) sealing lip 28 preferably rests against another component during operation, for example, another shaft that is rotationally connected to the wheel flange 19. In particular, the toothing 23, which is implemented as a face tooth, is thus protected against corrosion in order to ensure the transmission of the drive torque over the vehicle's service life.

[0057] According to the invention, the plastic part 11 is designed as a component of a signal transmitter 7 or is directly and completely implemented as this signal transmitter 7. The plastic part 11 therefore preferably has a structure 13, not shown here for clarity, preferably in the form of at least one or more magnets / magnetizable bodies, magnetized alternately as magnetic north and south poles, or alternatively in the form of a tooth structure / gearing, which is designed such that it is detectable by a speed and / or rotational position sensor 12. In other words, the structure 13 is designed such that, by detecting it with the sensor 12, a rotational speed and / or rotational position of the plastic part 11, and thus also of the inner ring 2, can be detected.

[0058] Preferably, the speed and / or rotational position sensor 12 is inserted in a groove-like opening 32 of the outer ring 3 at a specific circumferential position. This opening 32 extends axially (from the end face 16b of the outer ring 3) to the dashed line shown in Fig. 1. The sensor 12 is positioned in this opening 32 / recess.

[0059] Thus, the sensor 12 is preferably arranged radially outside the plastic part 11 and preferably in the axial direction at least partially at the same level / overlapping with the plastic part 11 / the structure 13.

[0060] Preferably, the signal transmitter 7 is integrated into the wheel bearing 1 / the plastic part 11 in such a way that it is shielded radially inwards by the sleeve area 27. P240753

[0061] - 9 -

[0062] It has proven particularly advantageous for measurement accuracy if the sleeve area 27 is made of a diamagnetic material that is permeable to magnetic fields.

[0063] The plastic part 11 can in principle be made of different plastics, such as thermoplastics or elastomers, and is preferably injection-molded onto the metal carrier 10 as a plastic coating.

[0064] Furthermore, it can be seen that, in order to achieve the most axially compact design possible, the plastic part 11 is inserted, at least partially, axially into the essentially U-shaped base support 25 of the seal 15. In this configuration, the plastic part 11 is also entirely arranged / inserted axially within two end faces 16a, 16b of the two rings 2, 3. The plastic part 11 is thus located axially entirely within the space 24.

[0065] In other words, a radial encoder in the form of the signal transmitter 7 is present, which is integrated into an interface seal (sealing arrangement 6). The interface seal is thus formed as a single unit with the encoder.

[0066] Figures 2 to 8 illustrate further embodiments, all of which, however, are based on the first embodiment shown in Figure 1. For the sake of brevity, only the essential differences between the further embodiments shown in Figures 2 to 8 and the first embodiment will be described.

[0067] In the embodiment shown in Figure 2, the metal support 10 of the ring element 8 is shaped differently. The metal support 10 now has a step 29 between the sleeve area 27 and the joint bell seal 17, which serves directly for attachment to the inner ring 2. An exclusively axially extending area of ​​this step 29 is in turn radially separated from P240753

[0068] - 10 - pressed onto the outside of the inner ring 2, while an exclusively radially extending area of ​​this stage 29 serves as an axial stop on the inner ring 2.

[0069] Furthermore, it can be seen that, in principle, the second sealing lip 26 can also be omitted. This makes the sealing arrangement 6 more compact in the radial direction; the inner ring 2 can also be dimensioned higher, resulting in a larger contact area with the rolling elements 4.

[0070] In the embodiment shown in Figure 3, the metal carrier 10 is also implemented differently. In this embodiment, the metal carrier 10 is essentially U-shaped in cross-section. The sleeve area 27 and the extension area of ​​the joint bell seal 17 both point in the same axial direction, namely away from the rolling element 4. Furthermore, in this embodiment, the metal carrier 10 is pressed onto the inner ring 2 exclusively in the radial direction.

[0071] In the embodiment shown in Figures 4 and 5, the metal supports 10 are again implemented in a similar manner to those in Figures 1 and 2, but have an additional folded section 30 to increase the area in press fit with the inner ring 2. This folded section 30 runs parallel to the sleeve section 27 in certain segments. In Figure 4, this folded section 30 is essentially V-shaped; in Figure 5, it is implemented as a double-walled sandwich structure.

[0072] Furthermore, the metal carrier 10 forms a receiving chamber 21 open towards the rolling elements 4, in which the (first) sealing lip 22 of the sealing ring 15 is received / inserted. This receiving chamber is partially completed in Figures 1 and 2 by the outer surface 9 of the inner ring 2.

[0073] Figures 6 to 8 illustrate that the plastic part 11 can perform additional functions. In these embodiments, the plastic part 11 is a component of a labyrinth seal. This means that the plastic part 11, together with another component, in particular the overmolding 31 forming at least one sealing lip 22, forms a labyrinthine sealing gap 18, which contributes to a further improvement of the sealing effect. P240753

[0074] - 11 -

[0075] In Figure 6, the plastic part 11 is also shown on a radial inner side of the

[0076] The sleeve area 27 is formed and, in turn, has a labyrinthine sealing gap 18 extending radially inwards (in conjunction with the overmolding 31 of the sealing ring 15). The further formation of the metal carrier 10 corresponds in the

[0077] Essentially the execution of Figure 2.

[0078] In Figure 7, in comparison to Figure 6, the labyrinthine sealing gap 18 is also formed by an axial side / end face of the plastic part 11, namely the one that faces the rolling elements 4.

[0079] In Figure 8, building on the embodiment of Figure 3, the labyrinthine sealing gap 18 is also formed exclusively by an axial end face (which faces the rolling elements 4) of the plastic part 11.

[0080] P240753 DE

[0081] - 12 -

[0082] List of reference signs

[0083] 1 wheel bearing

[0084] 2 inner ring

[0085] 3 Outer ring

[0086] 4 rolling elements

[0087] 5 rolling chamber

[0088] 6 Sealing arrangement

[0089] 7 Signal transmitter device

[0090] 8 ring element

[0091] 9 Outside

[0092] 10 metal beams

[0093] 11 plastic part

[0094] 12 Speed ​​and / or rotational position detection sensor / sensor

[0095] 13 Structure

[0096] 14 Sealing contour

[0097] 15 sealing ring

[0098] 16a Front face of the inner ring

[0099] 16b Front face of the outer ring

[0100] 17 Joint bell seal

[0101] 18 Sealing gap

[0102] 19 Wheel flange

[0103] 20 wheel bearing unit

[0104] 21 Recording Room

[0105] 22 first sealing lip

[0106] 23. Toothing as axial toothing or face toothing

[0107] 24 spaces

[0108] 25 basic supports

[0109] 26 second sealing lip

[0110] 27 Sleeve area

[0111] 28 third sealing lip

[0112] 29th level

[0113] 30 relocated area

[0114] 31. Overmolding

[0115] 32 Opening

Claims

P240753 DE - 13 - Patent claims 1. Wheel bearing (1) for a motor vehicle with - an inner ring (2), - an outer ring (3) which is supported relative to the inner ring (2) by rolling elements (4) arranged in a rolling chamber (5), - a seal (6) that seals the rolling chamber (5) and has a sealing ring (15) that contacts the outer ring (3), - a signaling device (7), - a joint bell seal (17) which forms a ring element (8) in one piece with the signal transmitter device (7), characterized in that the signal transmitter device (7) forms a labyrinth seal with the sealing ring (15).

2. Wheel bearing (1 ) according to claim 1 , characterized in that the signal generator device (7) is designed as a radial encoder and a sensor (12) for detecting the signals of the signal generator device (7) is arranged radially offset to the signal generator device (7).

3. Wheel bearing (1 ) according to claim 1 or 2, characterized in that the ring element (8) has a metal support (10) made of sheet metal.

4. Wheel bearing (1 ) according to claim 3, characterized in that the metal carrier (10) is supported by a doubling on the inner ring 82).

5. Wheel bearing (1) according to claim 3, characterized in that the metal carrier (10) has an axially directed sleeve area (27) to which the signal transmitter device (7) is attached, a radial section adjoining thereto, and an axial recess adjoining the radial section radially inside.

6. Wheel bearing (1 ) according to one of claims 1 to 5, characterized in that the signal transmitter device (7) is unencapsulated. P240753 DE - 14 - 7. Wheel bearing (1 ) according to one of claims 1 to 6, characterized in that the inner ring (2) is free from a sealing lip contact.

8. Wheel bearing (1 ) according to one of claims 1 to 7, characterized in that the wheel bearing (1 ) has a face toothing.

9. Wheel bearing (1 ) according to one of claims 1 to 8, characterized in that a groove-like opening is provided in the outer ring (3) for receiving the speed and / or rotation position detection sensor (12).

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