Abstract
The present invention relates to a wheel-bearing device (10), comprising: an outer-ring element (30), a wheel-hub element (20), and a sealing device (40), which seals a gap between the outer-ring element (30) and the wheel-hub element (20), wherein the wheel-hub element (20) comprises an inner axial wheel-hub end face (22) and a cylindrical wheel-hub portion (24), the outer-ring element (30) comprises a radial outer-ring inner face (32), the sealing device (40) comprises a wheel-hub sealing element (50) and an outer-ring sealing element (70), the wheel-hub sealing element (50) comprises a substantially rigid slinger-ring element (51) and an elastomeric wheel-hub sealing structure (60) arranged thereon, the outer-ring sealing element (70) comprises a substantially rigid insertion element (71) and an elastomeric outer-ring sealing structure (80) arranged thereon, the slinger-ring element (51) comprises a cylindrical wheel-hub fastening portion (54) and a radial wheel-hub sealing portion (56), the insertion element (71) comprises a cylindrical outer-ring fastening portion (72) and a radial outer-ring sealing portion (74), the elastomeric outer-ring sealing structure (80) comprises an axial outer-ring sealing lip (81), which extends between the radial outer-ring sealing portion (74) and the radial wheel-hub sealing portion (56) substantially in an axial direction and contacts the radial wheel-hub sealing portion (56), the radial wheel-hub sealing portion (56) is arranged so as to be axially spaced from the inner axial wheel-hub end face (22), and the elastomeric wheel-hub sealing structure (60) comprises an axial wheel-hub sealing lip (62), which extends between the radial wheel-hub sealing portion (56) and the inner axial wheel-hub end face (22) substantially in an axial direction and contacts the inner axial wheel-hub end face (22).
Claims
1. Wheel-bearing device (10), comprising: an outer-ring element (30) for connection to a vehicle body, a wheel-hub element (20) for connection to a wheel, and a sealing device (40), which seals a gap between the outer-ring element (30) and the wheel-hub element (20), wherein the wheel-hub element (20) comprises an inner axial wheel-hub end face (22), which faces the outer-ring element (30), and a cylindrical wheel-hub portion (24), which is arranged in the radial interior of the outer-ring element (30) at least in part, the outer-ring element (30) comprises a radial outer-ring inner face (32), which faces the cylindrical wheel-hub portion (24), the sealing device (40) comprises a wheel-hub sealing element (50), which is mounted on the wheel-hub element (20), and an outer-ring sealing element (70), which is mounted on the outer-ring element (30), the wheel-hub sealing element (50) comprises a substantially rigid slinger-ring element (51) and an elastomeric wheel-hub sealing structure (60) arranged thereon, the outer-ring sealing element (70) comprises a substantially rigid insertion element (71) and an elastomeric outer-ring sealing structure (80) arranged thereon, the slinger-ring element (51) comprises a cylindrical wheel-hub fastening portion (54), which is connected to the cylindrical wheel-hub portion (24), and a radial wheel-hub sealing portion (56), which extends outwards from the wheel-hub element (20) substantially in a radial plane, the insertion element (71) comprises a cylindrical outer-ring fastening portion (72), which is connected to the radial outer-ring inner face (32), and a radial outer-ring sealing portion (74), which extends inwards from the outer-ring element (30) substantially in a radial plane, the elastomeric outer-ring sealing structure (80) comprises an axial outer-ring sealing lip (81), which extends between the radial outer-ring sealing portion (74) and the radial wheel-hub sealing portion (56) substantially in an axial direction and contacts the radial wheel-hub sealing portion (56), the radial wheel-hub sealing portion (56) is arranged so as to be axially spaced from the inner axial wheel-hub end face (22), and the elastomeric wheel-hub sealing structure (60) comprises an axial wheel-hub sealing lip (62), which extends between the radial wheel-hub sealing portion (56) and the inner axial wheel-hub end face (22) substantially in an axial direction and contacts the inner axial wheel-hub end face (22).
2. Wheel-bearing device (10) according to claim 1, wherein the elastomeric wheel-hub sealing structure (60) comprises a radial wheel-hub sealing lip (64), which extends between the radial wheel-hub sealing portion (56) and the wheel-hub element (20) substantially in a radial direction and contacts the wheel-hub element (20).
3. Wheel-bearing device (10) according to claim 2, wherein the elastomeric wheel-hub sealing structure (60) only comprises the axial wheel-hub sealing lip (62) and the radial wheel-hub sealing lip (64) for contacting the wheel-hub element (20).
4. Wheel-bearing device (10) according to either of claims 2 or 3, wherein a thickness ratio of the axial wheel-hub sealing lip (62) to the radial wheel-hub sealing lip (64) is in the range of from approximately 1.5 to approximately 4.0; preferably in the range of from approximately 1.7 to approximately 2.5; and particularly preferably in the range of from approximately 1.9 to approximately 2.1.
5. Wheel-bearing device (10) according to any of claims 1 to 4, wherein the elastomeric outer-ring sealing structure (80) comprises a radial outer-ring sealing lip (82), which extends between the radial outer-ring sealing portion (74) and the cylindrical wheel-hub fastening portion (54) substantially in a radial direction and in particular contacts the cylindrical wheel-hub fastening portion (54).
6. Wheel-bearing device (10) according to claim 5, wherein the elastomeric outer-ring sealing structure (80) only comprises the axial outer-ring sealing lip (81) and the radial outer-ring sealing lip (82) for contacting the slinger-ring element (51).
7. Wheel-bearing device (10) according to either of claims 5 or 6, wherein a thickness ratio of the axial outer-ring sealing lip (81) to the radial outer-ring sealing lip (82) is in the range of from approximately 1.5 to approximately 4.0; preferably in the range of from approximately 1.7 to approximately 2.5; and particularly preferably in the range of from approximately 1.9 to approximately 2.1.
8. Wheel-bearing device (10) according to any of claims 1 to 7, wherein the outer-ring sealing element (70) comprises a collecting-lip structure (84), which extends between an axially outer end of the outer-ring element (30) and the wheel-hub end face (22), on the axially outer end of the outer-ring element (30), wherein a collecting lip (86), which extends so as to be inclined radially outwards, is arranged on the collecting-lip structure (84), wherein an axial outlet gap (d) is configured between the collecting lip (86) and the wheel-hub end face (22).
9. Wheel-bearing device (10) according to claim 8, wherein the collecting-lip structure (84) comprises a substantially radially outwardly extending blocking lip (88), which extends radially beyond a radial outer-ring outer face (36).
10. Wheel-bearing device (10) according to any of claims 1 to 9, wherein the slinger-ring element (51) comprises a wheel-hub labyrinth portion (58), which is arranged radially outside the cylindrical wheel-hub fastening portion (54) and extends from the radial wheel-hub sealing portion (56) substantially axially towards the radial outer-ring sealing portion (74).
11. Wheel-bearing device (10) according to claim 10, wherein the radial outer-ring sealing portion (74) is configured in portions, wherein a first radial outer-ring sealing segment (76) extends axially further inwards than a second radial outer-ring sealing segment (78), the first radial outer-ring sealing segment (76) is arranged radially outside the second radial outer-ring sealing segment (78), the first radial outer-ring sealing segment (76) is connected to the second radial outer-ring sealing segment (78) by a transition portion (77), such that the outer-ring element (30) comprises an axially inwardly recessed peripheral cavity, and the wheel-hub labyrinth portion (58) extends towards the cavity and preferably extends into the cavity.
12. Wheel-bearing device (10) according to any of claims 1 to 11, comprising: an axial inlet gap (c), which is defined as an axial distance between the wheel-hub end face (22) and the outer-ring sealing element (70); an axial collecting gap (e), which is defined as an axial distance between the wheel-hub end face (22) and a radially outer end of the elastomeric wheel-hub sealing structure (60); a radial collecting height (b), which is defined as a radial distance between a radially outer face of the axial wheel-hub sealing lip (62) and the radially outer end of the elastomeric wheel-hub sealing structure (60); wherein the radial collecting height (b) is greater than the axial collecting gap (e); and/or the axial inlet gap (c) is smaller than or equal to the axial collecting gap (e).
Description
[0085] In the drawings:
[0086] FIG. 1 is a sectional view of a wheel-bearing device;
[0087] FIG. 2 is a sectional view of a sealing device of a wheel-bearing device;
[0088] FIG. 3 is another sectional view of a sealing device of a wheel-bearing device;
[0089] FIG. 4 is another sectional view of a sealing device of a wheel-bearing device;
[0090] FIG. 5 is another sectional view of a sealing device of a wheel-bearing device;
[0091] FIG. 6 is another sectional view of a sealing device of a wheel-bearing device;
[0092] FIG. 7 is another sectional view of a sealing device of a wheel-bearing device; and
[0093] FIG. 8 is another sectional view of a sealing device of a wheel-bearing device.
[0094] FIG. 1 is a sectional view of a wheel-bearing device 10 on the basis of a cross section along an axis a of the wheel-bearing device 10. In this figure, the wheel-bearing device 10 comprises an outer-ring element 30 for attachment to a vehicle body, for example by means of an outer-ring fastening portion 38, and a wheel-hub element 20 for connection to a wheel, for example by means of one or more wheel-fastening portions 28. By way of example, the wheel-hub element 20 is rotatably mounted in the outer-ring element 30 by a rolling bearing 90, with the rolling bearing 90, as shown in FIG. 1 by way of example, being able to be arranged on an inner peripheral side of the outer-ring element 30 and also being able to be arranged on at least one portion of an outer peripheral side of the wheel-hub element 20. A sealing device 40 is arranged in a gap between the outer-ring element 30 and the wheel-hub element 20, with a magnification region V being marked on FIG. 1, which includes the sealing device 40 and is described in greater detail in the remaining figures, FIG. 2 to 7, by way of example.
[0095] Furthermore, FIG. 1 shows an axis a of the wheel-bearing device 10 or an axial direction a of the wheel-bearing device 10, which extends from right to left in FIG. 1. Since the wheel of a vehicle can be mounted on the wheel-hub element 20, in particular on the wheel-hub fastening portion 28, the axial direction a corresponds to a width direction of the vehicle from the center of the vehicle towards the outside of the vehicle. In particular, FIG. 1 shows the axial direction inwards or the direction axially inwards by a.sub.inwards, and shows the axial direction outwards or the direction axially outwards by a.sub.outwards. The radial direction r extends substantially radially, i.e. substantially perpendicularly or normally to the axial direction a. Here, “radially outwards” describes a direction proceeding from the axial direction or axis a, i.e. with an increasing radius. By contrast, “radially inwards” describes a direction towards the axial direction or axis a, i.e. with a decreasing radius.
[0096] The orientation in the remaining figures, FIG. 2 to 7, corresponds to the orientation in FIG. 1, and therefore the axial direction a in FIG. 2 to 7 likewise extends from right to left and the direction axially inwards a.sub.inwards extends from left to right.
[0097] FIG. 2 shows an exemplary embodiment of a wheel-bearing device 10 according to the invention, in particular a sealing device 40 for a wheel-bearing device 10, which reproduces various features which can be combined with one another in any way.
[0098] Therefore, by way of example, FIG. 2 shows a wheel-hub sealing element 50, which comprises a substantially rigid slinger-ring element 51, in particular a metal slinger-ring element 51, and comprises an elastomeric wheel-hub sealing structure 60 arranged on the slinger-ring element 51. The slinger-ring element 51 comprises a cylindrical wheel-hub fastening portion 54, which is configured to be connected to a cylindrical wheel-hub portion 24, with it being possible for the connection of the cylindrical wheel-hub fastening portion 54 to the cylindrical wheel-hub portion 24 to be produced by being pressed on, screwed on, or other methods. The wheel-hub sealing element 50 further comprises a radial wheel-hub sealing portion 56, which extends substantially radially, with it being possible for the radial wheel-hub sealing portion 56 to optionally extend directly from the cylindrical wheel-hub fastening portion 54 or to be connected to the cylindrical wheel-hub fastening portion 54 via an inclined inner wheel-hub sealing transition portion 57. As shown by way of example in FIG. 2, an inclined inner wheel-hub sealing transition portion 57 may extend axially outwards from the cylindrical wheel-hub fastening portion 54 with an increasing radius.
[0099] The elastomeric wheel-hub sealing structure 60, as shown in FIG. 2, may be arranged on the wheel-hub sealing element 50 or on the slinger-ring element 51 in any way and may cover or extend over any faces of the slinger-ring element 51. In preferred embodiments, as shown in FIG. 2, the radially inner face of the cylindrical wheel-hub fastening portion may be free of the elastomeric wheel-hub sealing structure 60, in order to allow a secure and rigid arrangement of the wheel-hub sealing element 50 on the wheel hub 20.
[0100] As shown in FIG. 2, the elastomeric wheel-hub sealing structure 60 comprises an axial wheel-hub sealing lip 62, which extends substantially axially outwards and contacts an inner axial wheel-hub end face 22 of the wheel-hub element 20. The inner axial wheel-hub end face 22 describes a face of the wheel-hub element 20 that is arranged axially on the inside and delimits a gap between the wheel-hub element 20 and the outer-ring element 30 axially outwards. In other words, the axial wheel-hub end face 22 faces the outer-ring element 30. The axial wheel-hub end face 22 may extend or lead into a cylindrical portion of the wheel-hub element 20, in particular the cylindrical wheel-hub portion 24, in a contoured manner or so as to follow a curvature.
[0101] Since the axial wheel-hub sealing lip 62 is arranged on the slinger-ring element 51 of the wheel-hub sealing element 50, wherein the slinger-ring element 51 the cylindrical wheel-hub fastening portion 54, which is connected to the cylindrical wheel-hub portion 24, the radial wheel-hub sealing lip 62 can rotate at the same speed as the wheel-hub element 20 while a vehicle is being driven. As a result, the contact of the axial wheel-hub sealing lip 62 on the inner axial wheel-hub end face 22 can be static contact or static sealing, with there being no friction caused by driving. Furthermore, by the wheel-hub sealing lip 62 rotating, dirt, water and other particles that reach the axial wheel-hub sealing lip 62 can be expelled therefrom by centrifugal action, i.e. can be expelled radially outwards through an outlet gap d (see also FIG. 3) in the sealing device 40. By expelling dirt, water and other particles by the axial wheel-hub sealing lip 62 rotating during driving, the sealing device 40 can effectively and advantageously protect the wheel-bearing device 10 against dirt, water and other particles getting in, in particular getting to the rolling bearing 90.
[0102] As shown by way of example in FIG. 2, the slinger-ring element 51 may comprise a wheel-hub labyrinth portion 58, which extends substantially axially inwards from the radial wheel-hub sealing portion 56. The wheel-hub labyrinth portion 58 elongates the path of dirt, water and other particles to one or more sealing lips, as provided by the outer-ring sealing element 70, and therefore makes it difficult for dirt, water and other particles to reach one or more sealing lips, as provided by the outer-ring sealing element 70, such that a wheel-hub labyrinth portion 58 can improve the sealing function of the sealing device 40. Furthermore, the wheel-hub labyrinth portion 58 may advantageously make it difficult for grease to get out of the rolling bearing.
[0103] Since the sealing function of the sealing device 40 can be improved by means of the wheel-hub labyrinth portion 58, the sealing device 40 can also be configured to have a reduced number of sealing lips, in particular on axial and radial outer-ring sealing lips 81, 82, as provided by the outer-ring sealing element 70, for example, meaning that frictional losses that occur in the wheel-bearing device 10 during driving can be reduced.
[0104] Furthermore, by way of example, FIG. 2 shows an outer-ring sealing element 70, which comprises a substantially rigid insertion element 71, optionally in particular a metal insertion element 71, and comprises an outer-ring sealing structure 80 arranged on the insertion element 71. The insertion element 71 comprises a cylindrical outer-ring fastening portion 72, which is configured to be connected to a radial outer-ring inner face 32, with it being possible for the connection of the cylindrical outer-ring fastening portion 72 to the radial outer-ring inner face 32 to be produced by being pressed in, screwed in, or other methods or processes. The outer-ring sealing element 70, in particular the insertion element 71, further comprises a radial outer-ring sealing portion 74, which extends substantially radially inwards from the cylindrical outer-ring fastening portion 72. The elastomeric outer-ring sealing structure 80, which is arranged on the insertion element 71, comprises at least one outer-ring sealing lip 81, which extends substantially axially outwards from the radial outer-ring sealing portion 74 to the radial wheel-hub sealing portion 56.
[0105] If the outer-ring element 30 is mounted on the vehicle body in a rotationally fixed manner and the wheel-hub element 20 is rotatably mounted and rotates with the wheel of a vehicle when it is being driven, there is a relative movement, rotating about the wheel-bearing-device axis a, between the wheel-hub sealing element 50 and the outer-ring sealing element 70 during driving. By arranging the radial wheel-hub sealing portion 56 on the wheel-hub sealing element 50 and arranging the at least one axial outer-ring sealing lip 81 on the outer-ring sealing element 70, there is likewise a rotating relative movement about the axis a of the wheel-bearing device 10 between the radial wheel-hub sealing portion 56 and the at least one axial outer-ring sealing lip 81 during driving. FIG. 2 shows an axial outer-ring sealing lip 81 by way of example and also shows said outer-ring sealing lip projecting into the radial wheel-hub sealing portion 56. This view is schematic and is intended to show that at least one axial outer-ring sealing lip 81 contacts the radial wheel-hub sealing portion 56, in particular contacts the wheel-hub sealing portion 56 by specifically pressing on an elastomeric portion. By means of the rotating relative movement between the radial wheel-hub sealing portion 56 and the at least one outer-ring sealing lip 81, the contact surface of the at least one outer-ring sealing lip 81 is configured as an abrasive surface or frictional surface. The contact between the radial wheel-hub sealing portion 56 and the at least one outer-ring sealing lip 81 is also referred to as dynamic contact or dynamic sealing owing to the rotating relative movement.
[0106] As shown in FIG. 2, the axial outer-ring sealing lip 81 may in particular extend from a region of a radially inner end of the radial outer-ring sealing portion 74.
[0107] As also indicated in FIG. 2, the axial outer-ring sealing lip 81 may extend substantially axially outwards, substantially in parallel with an inclined inner wheel-hub sealing transition portion 57 of the wheel-hub sealing element 50, or axially outwards with an increasing radius. In preferred embodiments, the at least one axial outer-ring sealing lip 81 may contact the radial wheel-hub sealing portion 56 and may extend further radially outwards so as to follow the extension of the radial wheel-hub sealing portion 56 after contacting the radial wheel-hub sealing portion 56, and in particular may abut the radial wheel-hub sealing portion 56 when extending further radially outwards.
[0108] As shown in FIG. 2, the radial outer-ring sealing portion 74 may be configured in portions, with the portions extending substantially radially but at different axial heights of the axis a of the wheel-bearing device 10. For example, the radial outer-ring sealing portion 74 may comprise a first radial outer-ring sealing segment 76 and a second radial outer-ring sealing segment 78. In alternative embodiments, the radial outer-ring sealing portion 74 may comprise three radial outer-ring sealing segments, which extend substantially radially but at different axial heights of the axis a of the wheel-bearing device 10. In other alternative embodiments, the radial outer-ring sealing portion 74 may comprise more than three, in other words any number of, for example four, five or six radial outer-ring sealing segments, which extend substantially radially in succession in the radial direction at different axial heights of the axis a of the wheel-bearing device 10. By configuring the radial outer-ring sealing portion 74 in portions, a wheel-bearing device 10 or a sealing device 40 may be configured to have a sealing labyrinth, which makes it difficult for dirt, water and other particles to reach the sealing lips, in particular the at least one axial outer-ring sealing lip 81, which means that particularly advantageous and reliable sealing is provided.
[0109] FIG. 2 shows, by way of example, that a first radial outer-ring sealing segment 76 and a second radial outer-ring sealing segment 78 can extend substantially radially, with the first radial outer-ring sealing segment 76 extending axially further inwards than the second radial outer-ring sealing segment 78. The first radial outer-ring sealing segment 76 and the second radial outer-ring sealing segment 78 may be interconnected by a transition portion 77, which optionally extends in an inclined manner or in a substantially axial direction.
[0110] By means of the above-described configuration in portions of the radial outer-ring sealing portion 74 as a first radial outer-ring sealing segment 76 and a second radial outer-ring sealing segment 78, with the first radial outer-ring sealing segment 76 extending axially further inwards than the second radial outer-ring sealing segment 78, the outer-ring element 30 is configured to have a peripheral cavity which is recessed axially inwards. In other words, the outer-ring element 30 may comprise an axially inwardly recessed peripheral cavity. The axially inwardly recessed peripheral cavity may preferably be produced by the configuration in portions of the radial outer-ring sealing portion 74 as a first radial outer-ring sealing segment 76 and a second radial outer-ring sealing segment 78, which each extend in a substantially radial direction, with the first radial outer-ring sealing segment 76 extending axially further inwards than the second radial outer-ring sealing segment 78, and with the first radial outer-ring sealing segment 76 being arranged radially outside the second radial outer-ring sealing segment 78, by way of example.
[0111] Furthermore, FIG. 2 shows that the wheel-hub sealing element 50 or the slinger-ring element 51 may comprise a wheel-hub labyrinth portion 58, which extends substantially axially inwards from the radial wheel-hub sealing portion 56.
[0112] Preferably, and as shown in FIG. 2, a wheel-hub labyrinth portion 58 may extend towards the axially inwardly recessed peripheral cavity, and particularly preferably extends into the cavity at least in part. By the wheel-hub labyrinth portion 58 extending towards the cavity or into the cavity in part, the wheel-bearing device 10 or the sealing device 40 can be configured to have a particularly preferred sealing labyrinth which provides reliable sealing or a reliable sealing function, since it is made difficult for dirt, water and other particles to get in.
[0113] Furthermore, FIG. 2 shows, by way of example, that the elastomeric outer-ring sealing structure 80 may comprise a radial outer-ring sealing lip 82, with the radial outer-ring sealing lip 82 being able to be configured to optionally contact, in particular dynamically contact, the cylindrical wheel-hub fastening portion 54.
[0114] Embodiments of the wheel-bearing device 10 which comprise a radial outer-ring sealing lip 82 that contacts the cylindrical wheel-hub fastening portion 54 allow for particularly reliable sealing in order to protect against dirt getting into the rolling bearing 90 or to protect against grease getting out of the rolling bearing 90.
[0115] In exemplary embodiments, and as shown in FIG. 2, the radial outer-ring sealing lip 82 may extend axially inwards with a decreasing radius from an end portion of the radial outer-ring sealing element 74 in an inclined manner, as a result of which the radial outer-ring sealing lip 82 can subsequently abut the cylindrical wheel-hub fastening portion 54 axially inwards, meaning that advantageous sealing against grease getting out of the rolling bearing can be provided, since it is difficult for the radial outer-ring sealing lip 82 to be pushed open axially outwards.
[0116] FIG. 2 also shows that the elastomeric outer-ring sealing structure 80 may comprise a collecting-lip structure 84 on an axially outer end of the outer-ring element 30, which structure extends between the axially outer end 34 of the outer-ring element 30 and the axial wheel-hub end face 22, preferably extends along the axially outer end 34 of the outer-ring element. By way of example, the collecting-lip structure 84 may comprise a collecting lip 86, which optionally extends substantially axially outwards or so as to be inclined radially outwards, i.e. axially outwards with an increasing radius. Preferably, an axial outlet gap d is configured between the collecting lip 86 and the axial wheel-hub end face 22 (as also shown in FIG. 3), as a result of which it is possible for dirt, water and other particles to get out of the gap between the wheel-hub element 20 and the outer-ring element 30 in the radial direction, for example by centrifugal action. For example, the collecting lip 86 may be arranged on a radially outer end portion of the collecting-lip structure 84. Alternatively, the collecting lip 86 may be arranged on a central portion of the collecting-lip structure 84 or a radially inner portion of the collecting-lip structure 84. The collecting lip 86 may advantageously prevent water, dirt and other particles from getting into or being let into the gap between the wheel-hub element 20 and the outer-ring element 30, and thus improves the sealing function of the wheel-bearing device 10 or the sealing device 40. Furthermore, a preferred extension of the collecting lip 86, namely an inclined or axially outward extension with an increasing radius having an axial outlet gap d to the axial wheel-hub end face 22, encourages the escape of dirt, water and other particles which reach the axial wheel-hub sealing lip 62 and are radially outwardly expelled by centrifugal action during driving.
[0117] Furthermore, FIG. 2 shows that the elastomeric outer-ring sealing structure 80 may comprise a blocking lip 88, which extends substantially radially outwards and preferably extends beyond a radial outer-ring outer face 36. The blocking lip 88 advantageously prevents large particles from directly reaching the collecting lip 86, meaning that the service life and functionality of the collecting lip 86 is extended, and therefore reliable sealing of the wheel-bearing device 10 can also be ensured.
[0118] The exemplary embodiment as shown in FIG. 2 therefore has various features for providing a wheel-bearing device 10 or a sealing device 40 for a wheel-bearing device 10 that is reliable and at the same time has low frictional losses. The above-described features, as explained on the basis of FIG. 2, can be combined and/or omitted as desired in the context of the accompanying claims.
[0119] FIG. 3 shows the same exemplary embodiment of a wheel-bearing device 10, in particular a sealing device 40 for a wheel-bearing device 10, as FIG. 2, and further configurations will be explained on the basis of FIG. 3.
[0120] FIG. 3 thus in particular shows gap dimensions and distances b, c, d and e, as well as thicknesses t of the exemplary sealing lips 62, 81, 82.
[0121] As already described with reference to FIG. 2, the collecting lip 86 is preferably configured to have an axial outlet gap d to the axial wheel-hub end face 22, which ensures that dirt, water and other particles that reach the axial wheel-hub sealing lip 62 are expelled where necessary.
[0122] Furthermore, the wheel-bearing device 10, as shown in FIG. 3, preferably has an axial inlet gap c, which is defined as an axial distance between the axial wheel-hub end face 22 and the elastomeric outer-ring sealing element 80. The axial inlet gap c may in particular be defined as the smallest possible axial distance between the axial wheel-hub end face 22 and the outer-ring sealing element 80, with a collecting lip 86 that may be arranged there not being taken into consideration for the definition of the axial inlet gap c. In other words, the axial inlet gap c may in particular be defined as an axial distance, in particular as the smallest possible axial distance, between the axial wheel-hub end face 22 and an axially outer extension of the elastomeric outer-ring sealing element 80, which is arranged on an axially outer end of the cylindrical outer-ring fastening portion 72 of the outer-ring sealing element 70.
[0123] Furthermore, the wheel-bearing device 10, as shown in FIG. 3, preferably has an axial collecting gap e, which is defined as an axial distance between the axial wheel-hub end face 22 and a radially outer end of the elastomeric wheel-hub sealing structure 60. The axial collecting gap e may in particular be defined as the smallest possible axial distance between the axial wheel-hub end face 22 and the radially outer end of the elastomeric wheel-hub sealing structure 60, with an axial wheel-hub sealing lip 62 arranged there not being taken into consideration for the definition of the axial collecting gap e. In other words, the axial collecting gape may be defined as an axial distance, in particular as the smallest possible axial distance, between the axial wheel-hub end face 22 and an axially outer extension of the elastomeric wheel-hub sealing structure 60, which is arranged on a radially outer end of the radial wheel-hub sealing portion 56.
[0124] Furthermore, the wheel-bearing device 10, as shown in FIG. 3, preferably has a radial collecting height b, which is defined as a radial distance between a radially outer face of the axial wheel-hub sealing lip 62 and the radially outer end of the elastomeric wheel-hub sealing structure 60. The radial collecting height b may in particular be defined as the smallest possible radial distance between a radially outer face of the axial wheel-hub sealing lip 62 and the radially outer end of the elastomeric wheel-hub sealing structure 60, with a possible extension of the wheel-hub sealing lip 62 along the axial wheel-hub end face not being taken into consideration for the definition of the radial collecting height b. In other words, the axial collecting height b may be defined as a radial distance, in particular as the smallest possible radial distance, between a radially outer face of the axial wheel-hub sealing lip 62 and the radially outer end of the elastomeric wheel-hub sealing structure 60, which is arranged on a radially outer end of the radial wheel-hub sealing portion 56.
[0125] In preferred embodiments and as shown in FIG. 3, the axial inlet gap c may be smaller than or equal to the axial collecting gap e, which ensures that dirt, water and other particles are not directly let into the sealing labyrinth, i.e. into the region between the radial wheel-hub sealing portion 56 and the radial outer-ring sealing portion 74.
[0126] In other words, the elastomeric outer-ring sealing element 80, which is arranged on an axially outer end of the cylindrical outer-ring fastening portion 72 of the outer-ring sealing element 70, protrudes over the elastomeric wheel-hub sealing structure 60, which is arranged on a radially outer end of the radial wheel-hub sealing portion 56, which ensures that dirt, water and other particles are not directly let into the sealing labyrinth, i.e. into the region between the radial wheel-hub sealing portion 56 and the radial outer-ring sealing portion 74.
[0127] In other preferred embodiments and as shown in FIG. 3, the radial collecting height b may be greater than or equal to the axial collecting gap e, which ensures that dirt, water and other particles are not passively let into the sealing labyrinth, i.e. into the region between the radial wheel-hub sealing portion 56 and the radial outer-ring sealing portion 74, since the radial collecting height b together with the axial collecting gap e provides a buffering volume for any penetrating dirt, water or other particles.
[0128] In other words, the radial collecting height b may also be defined as a radial distance, in particular the smallest radial distance, along the elastomeric wheel-hub sealing structure 60, by way of example also along the radial wheel-hub sealing portion 56, between a radially outer face of the attachment of the axial wheel-hub sealing lip 62 on the elastomeric wheel-hub sealing structure 60 and the radially outer end of the slinger-ring element 51.
[0129] Furthermore, in FIG. 3, the sealing lips are provided with thickness references, and, in particular, the axial wheel-hub sealing lip 62 is provided with the thickness t.sub.621, the axial outer-ring sealing lip 81 is provided with the thickness t.sub.81, and the radial outer-ring sealing lip 82 is provided with the thickness t.sub.82.
[0130] By means of the wheel-bearing device 10 or the sealing device 40, which is preferably configured to have a sealing labyrinth, as shown on the basis of FIGS. 2 and 3 by way of example, the number of sealing lips can be reduced, and in particular the number of dynamically contacting sealing lips, i.e. abrasive sealing lips such as the at least one axial outer-ring sealing lip 81 and the radial outer-ring sealing lip 82, can be reduced, which means that frictional losses or frictional torques during driving can be reduced by the wheel-bearing device 10 according to the invention.
[0131] Furthermore, by means of the wheel-bearing device 10 or the sealing device 40, which is preferably configured to have a sealing labyrinth, as shown on the basis of FIGS. 2 and 3 by way of example, the thicknesses of the sealing lips t.sub.81, t.sub.82 can be reduced, and in particular the thicknesses of the dynamically contacting sealing lips, i.e. abrasive sealing lips such as the at least one axial outer-ring sealing lip 81 and the radial outer-ring sealing lip 82, can be reduced, which means that the contact pressure of the sealing lips on the sealing surfaces or frictional surfaces can be reduced, and in turn frictional losses or frictional torques during driving can be reduced.
[0132] In preferred embodiments of the wheel-bearing device 10 or sealing device 40 for the wheel-bearing device 10, the thickness ratios of the thicknesses t.sub.81, t.sub.82 between the axial outer-ring sealing lip 81 and the radial outer-ring sealing lip 82 can be selected such that, on one hand, reliable sealing is provided by two dynamically contacting sealing lips 81, 82 and, on the other hand, only a small amount of material needs to be used to produce the axial and radial outer-ring sealing lip 81, 82. Furthermore, by providing a radial outer-ring sealing lip 82 which is configured to be dynamically contacting, the axial outer-ring sealing lip 81 can be configured to be thinner, according to preferred thickness ratios, which means that frictional losses of the wheel-bearing device 10 can be reduced.
[0133] Preferred ratios of the thickness t.sub.81 of the axial outer-ring sealing lip 81 to the thickness t.sub.82 of the radial outer-ring sealing lip 82 are in the range of from approximately 1.5 to approximately 4.0, preferably in the range of from approximately 1.7 to approximately 2.5, and particularly preferably in the range of from approximately 1.9 to approximately 2.1.
[0134] FIG. 4 is a sectional view of another exemplary embodiment of a wheel-bearing device 10 or sealing device 40 for a wheel-bearing device 10 in an axial direction a of the wheel-bearing device 10.
[0135] As shown in FIG. 4, the elastomeric wheel-hub sealing structure 60 may comprise a radial wheel-hub sealing lip 64 having a thickness t.sub.64, with the radial wheel-hub sealing lip 64 contacting, in particular statically contacting, the wheel-hub element 20. By additionally arranging the radial wheel-hub sealing lip 64 in addition to the axial wheel-hub sealing lip 62, particularly reliable sealing against dirt, water and other particles getting into the axial gap between the axial wheel-hub end face 22 and the slinger-ring element 51 is provided, which prevents the slinger-ring element 51 from being pushed axially inwards or towards the center of the vehicle in the width direction of the vehicle over the service life of the wheel-bearing device 10. By preventing the slinger-ring element 51 from being pushed axially inwards over the service life of the wheel-bearing device 10, a sealing surface or frictional surface for the at least one axial outer-ring sealing lip 81 and optionally for the radial outer-ring sealing lip 82 can be kept constant over the service life of the wheel-bearing device 10, which means that the sealing function can advantageously be prevented from deteriorating and frictional losses can advantageously be prevented from increasing.
[0136] Furthermore, a radial wheel-hub sealing lip 64, which extends between the radial wheel-hub sealing portion 56 and the wheel-hub element 20 substantially in a radial direction and statically contacts the wheel-hub element 20, advantageously makes it possible for dirt, water or other particles that get into the axial gap between the slinger-ring element 51 and the wheel-hub element 30 or the axial wheel-hub end face 22 past the axial wheel-hub sealing lip 62 to still be reliably caught. Furthermore, dirt, water and other particles that have penetrated into the axial gap and have been caught by the radial wheel-hub sealing lip 64 can be thrown radially outwards by centrifugal action while the vehicle is being driven due to the rotation of the wheel-hub element 20 and the resulting rotation of the elastomeric wheel-hub sealing structure 60. Dirt, water and other particles that have penetrated into the axial gap past the axial wheel-hub sealing lip 62 can be expelled past the axial wheel-hub sealing lip 62. For example, the axial wheel-hub sealing lip 62 may be configured to elastically deform radially outwards or axially inwards when dirt, water and other particles that have got into the axial gap past the axial wheel-hub sealing lip 62 are expelled by centrifugal action on dirt, water and other particles that have penetrated. By the axial wheel-hub sealing lip 62 elastically deforming axially inwards or radially outwards, dirt, water and other particles that have penetrated can get out of the axial gap again, even after passing the axial wheel-hub sealing lip 62 into the axial gap. Therefore, a particularly preferred sealing device 40 that provides reliable sealing, and also a self-cleaning seal, can therefore be provided in an axial gap between the wheel-hub element 20 and the slinger-ring element 51.
[0137] The above-described effect, made possible by a preferred embodiment of the elastomeric wheel-hub sealing structure 60 comprising an axial wheel-hub sealing lip 62 and a radial wheel-hub sealing lip 64, can be further enhanced. To do this, in exemplary embodiments, the axial wheel-hub sealing lip 62 may be configured to taper towards the axial wheel-hub end face 22 in its axial extension in order to be slightly radially outwardly or axially inwardly elastically deformable in the region of the static contact of the axial wheel-hub sealing lip 62. Furthermore, the axial wheel-hub sealing lip 62 may for example be configured to extend substantially axially, with an increasing radius, towards the axial wheel-hub end face 22, as a result of which the axial wheel-hub sealing lip 62 has a radially outwardly directed curvature in its substantially axial extension in order to be slightly radially outwardly or axially inwardly elastically deformable. The above-mentioned exemplary configurations of the axial wheel-hub sealing lip 62 can be used both individually and together, and also so as to be over either the entire periphery or portions of the periphery.
[0138] Furthermore, the preferred embodiment of the elastomeric wheel-hub sealing structure 60 comprising an axial wheel-hub sealing lip 62 and a radial wheel-hub sealing lip 64 makes it possible, by arranging a radial wheel-hub sealing lip 64, for the axial wheel-hub sealing lip 62 having a thickness t.sub.622 to be thinner than in an embodiment having a thickness t.sub.621, the elastomeric wheel-hub sealing structure 60 not comprising a radial wheel-hub sealing lip 64. By means of a comparatively thinner configuration of the axial wheel-hub sealing lip 62 having a thickness t.sub.622 (cf. FIG. 4), which is thinner than a thickness t.sub.621 (cf. FIG. 3), any possible expulsion past the axial wheel-hub sealing lip 62 is made even easier and manufacturing costs are also reduced, while a sealing device 40 for a wheel-bearing device 10 which is particularly reliable and has a long service life is provided. In addition, a comparatively thinner axial wheel-hub sealing lip 62 having a thickness t.sub.622 advantageously makes it possible for deformation of the wheel-hub flange or the inner axial wheel-hub end face 22 towards the slinger-ring element 51 to also be advantageously mitigated under load, i.e. during driving, which advantageously prevents the slinger-ring element 51 from being displaced towards the center of the vehicle over the service life of the wheel-bearing device 10. Therefore, the service life of the wheel-bearing device 10 is advantageously increased and the radial expulsion of dirt, water and other particles outwards past the axial wheel-hub sealing lip is simplified.
[0139] Furthermore, since a radial wheel-hub sealing lip 64 extends radially towards the wheel-hub element 20, it advantageously prevents thermally expanded air from escaping, i.e., in other words, it withstands an overpressure in the bearing 90 which develops due to heating during use, i.e. during driving.
[0140] In exemplary embodiments and as indicated by FIG. 5, the radial wheel-hub sealing lip 64 extends axially so as to be directed towards the center of the vehicle with an inclination, meaning that thermally expanded air can be particularly advantageously prevented from escaping by the radial wheel-hub sealing lip 64 being advantageously supported by the wheel-hub element 20 by means of an axially outwardly directed overpressure in the bearing 90 in the event of deformation. In other words, the radial wheel-hub sealing lip 64, which extends axially towards the center of the vehicle with an inclination, can particularly advantageously withstand an overpressure in the bearing 90. Preventing thermally expanded air from escaping from the bearing 90 therefore prevents a negative pressure from developing when the bearing 90 cools, i.e. after driving, meaning that dirt and water can be prevented from being drawn in after driving and a particularly reliable sealing function can be provided by the sealing device 40.
[0141] FIG. 5 is a sectional view of another exemplary embodiment of a wheel-bearing device 10 or sealing device 40 for a wheel-bearing device 10 in an axial direction a of the wheel-bearing device 10.
[0142] FIG. 5 in particular shows that a radial outer-ring sealing lip 82 can be configured to have a radial distance from the cylindrical wheel-hub fastening portion 54. In other words, the radial outer-ring sealing lip 82 can be configured not to touch or contact the cylindrical wheel-hub fastening portion 54. A radial outer-ring sealing lip 82 as shown in FIG. 5 makes it possible to advantageously reduce the frictional losses of the wheel-bearing device 10 during driving.
[0143] FIG. 6 is a sectional view of another exemplary embodiment of a wheel-bearing device 10 or sealing device 40 for a wheel-bearing device 10 in an axial direction a of the wheel-bearing device 10.
[0144] FIG. 6 in particular shows that an elastomeric outer-ring sealing structure 80 can comprise a first axial outer-ring sealing lip 81a and a second axial outer-ring sealing lip 81b in order to provide particularly reliable sealing against dirt, water and other particles getting in. In this case, the first axial outer-ring sealing lip 81a has a thickness t.sub.81a and the second axial outer-ring sealing lip 81b has a thickness t.sub.81b. The thicknesses t.sub.81a and t.sub.81b may be different from one another or may be the same. By means of the particularly reliable sealing, as provided by the first and the second axial outer-ring sealing lip 81a, 81b, the thicknesses t.sub.81a, t.sub.81b of the first and the second outer-ring sealing lip 81a, 81b can be less than the thickness t.sub.81 of a single outer-ring sealing lip.
[0145] While arranging a plurality of axial outer-ring sealing lips 81a, 81b in principle means that frictional losses of the wheel-bearing device 10 are increased, the improved sealing by the plurality of axial outer-ring sealing lips 81a, 81b makes it possible for the thicknesses t.sub.81a, t.sub.81b of the plurality of axial outer-ring sealing lips 81a, 81b to be configured to be thinner, and therefore improved sealing is associated with only slightly higher frictional losses of the wheel-bearing device 10.
[0146] FIG. 7 is a sectional view of another exemplary embodiment of a wheel-bearing device 10 or sealing device 40 for a wheel-bearing device 10 in an axial direction a of the wheel-bearing device 10.
[0147] By way of example, FIG. 7 shows an embodiment in which two outer-ring sealing lips 81a, 81b are provided by the elastomeric outer-ring sealing structure 80, and furthermore a radial outer-ring sealing lip 82 is arranged on the elastomeric outer-ring sealing structure 80 which contacts the cylindrical wheel-hub fastening portion 54, which therefore provides a wheel-bearing device 10 comprising a sealing device 40 that provides particularly reliable sealing.
[0148] FIG. 8 shows an exemplary embodiment similar to FIG. 7, in which the slinger-ring element 51 does not comprise a wheel-hub labyrinth portion, which therefore provides a wheel-bearing device 10 comprising a sealing device 40 that provides reliable sealing while the production of a slinger-ring element 51 is simplified.
LIST OF REFERENCE CHARACTERS
[0149] 10 wheel-bearing device [0150] 20 wheel-hub element [0151] 22 axial wheel-hub end face [0152] 24 cylindrical wheel-hub portion [0153] 28 wheel fastening portion [0154] 30 outer-ring element [0155] 32 radial outer-ring inner face [0156] 34 axially outer end (of the outer-ring element) [0157] 36 radial outer-ring outer face [0158] 38 outer-ring fastening portion [0159] 40 sealing device [0160] 50 wheel-hub sealing element [0161] 51 (metal) slinger-ring element [0162] 54 cylindrical wheel-hub fastening portion [0163] 56 radial wheel-hub sealing portion [0164] 57 inclined inner wheel-hub sealing transition portion [0165] 58 wheel-hub labyrinth portion [0166] 60 elastomeric wheel-hub sealing structure [0167] 62 axial wheel-hub sealing lip [0168] 64 radial wheel-hub sealing lip [0169] 70 outer-ring sealing element [0170] 71 (metal) insertion element [0171] 72 cylindrical outer-ring fastening portion [0172] 74 radial outer-ring sealing portion [0173] 76 first radial outer-ring sealing segment [0174] 77 outer-ring sealing transition portion [0175] 78 second radial outer-ring sealing segment [0176] 80 elastomeric outer-ring sealing structure [0177] 81 axial outer-ring sealing lip [0178] 81a first axial outer-ring sealing lip [0179] 81b second axial outer-ring sealing lip [0180] 82 radial outer-ring sealing lip [0181] 84 collecting-lip structure [0182] 86 collecting lip [0183] 88 blocking lip [0184] 90 rolling bearing [0185] a axial direction or axis of the wheel-bearing device [0186] a.sub.outwards axial direction outwards or direction axially outwards [0187] a.sub.inwards axial direction inwards or direction axially inwards [0188] r radial direction [0189] b radial collecting height [0190] c axial inlet gap [0191] d axial outlet gap [0192] d axial collecting gap [0193] t thickness of the relevant element [0194] V magnification region
