Bearing housing equipped with a sealing device

Abstract

The invention relates to a rolling bearing comprising two members (1, 2) rotating relative about an axis, at least one side of the bearing space having an annular chamber (5) communicating with the outside through an opening (6), and being equipped with a sealing device comprising two rigid supports (10, 11) respectively fixed to a member (1, 2). The first support (10) is provided with an internal sealing element (12) comprising a lip (12a, 12b) in sealing interference with a medial bearing surface (13) of the second support (11). Said medial bearing surface is arranged radially between two bearing surfaces (15, 16) of said second support. The outer bearing surface (16) has an axial surface (17) fitted onto a complementary axial surface (18) of the second member (2). The inner bearing surface (15) is axially fixed on a radial sill (19) formed on said second member (2). organ. Figure 1a

Description

Title of the invention: Rolling bearing equipped with a sealing device

[0001] The invention relates to a rolling bearing comprising two members, respectively inner and outer, as well as rolling bodies arranged in a rolling space formed between said members to allow their relative rotation around an axis.

[0002] In particular, the invention applies to rolling bearings of motor vehicles, in particular to wheel bearings. Advantageously, a bearing according to the invention allows the mounting of a driving or non-driving wheel of a motor vehicle, the inner member being rotating and comprising means for fixing the wheel while the outer member is fixed and comprises means for fixing to a suspension element of the vehicle.

[0003] To prevent on the one hand leakage of lubricant present in the bearing space and on the other hand contamination of said space with external pollutants, at least one side of the bearing space is equipped with a sealing device.

[0004] In particular, the sealing device may comprise two rigid frames secured respectively to a member, a first frame being provided with an internal sealing element which comprises at least one lip in sealing interference with a medial bearing surface of the second frame.

[0005] Bearings are known in which the second armature is associated with the member by fitting an inner bearing surface of said armature onto an inner axial surface of said member, an outer bearing surface of said second armature being extended axially and / or radially to form a deflector limiting the entry of external pollutants into the bearing space.

[0006] This internal fitting solution is not entirely satisfactory, in that it does not make it possible to avoid the risks of migration of the second reinforcement along the internal axial surface, which can compromise the seal provided by the interference between the sealing element and the medial surface.

[0007] Furthermore, this solution limits the radial dimension of the medial bearing, to the detriment of the space available to form the interference with the sealing element, and requires a fitting length and therefore an axial dimension of the member which are detrimental to the weight of the bearing.

[0008] The invention aims to improve the prior art by proposing in particular a rolling bearing equipped with a sealing device whose reliability is improved, in particular with regard to the risks of migration during rotation, while optimizing the space available to achieve said sealing without compromising the weight of the bearing.

[0009] To this end, the invention proposes a rolling bearing comprising two members and rolling bodies arranged in a rolling space formed between said members to allow their relative rotation about an axis, at least one side of the rolling space having an annular chamber in communication with the outside by an opening, said chamber being equipped with a sealing device comprising a first and a second rigid frame secured respectively to a first and a second of said members, the first frame being provided with an internal sealing element comprising at least one lip which is in sealing interference with a medial bearing surface of the second frame, said medial bearing surface being arranged radially between two respectively outer and inner bearing surfaces of said second frame,the outer bearing surface having an axial surface which is fitted onto a complementary axial surface of the second member, the inner bearing surface being axially immobilized on a radial threshold formed on said second member.

[0010] Other objects and advantages of the invention will appear in the following description, given with reference to the appended figures,

[0011] [Fig. 1] and

[0012] [Fig. la] which partially represent and in longitudinal section a bearing at bearing equipped with a sealing device according to an embodiment of the invention ([Fig.l]), and an enlargement of [Fig.l] centered on the sealing device ([Fig.la]).

[0013] In relation to these figures, a rolling bearing is described below, in particular for mounting a drive or non-drive wheel of a motor vehicle.

[0014] The bearing comprises two members, namely in the figures a first member 1 arranged externally while being fixed and a second member 2 arranged internally while being rotating. In the application considered, the wheel is intended to be associated with the internal member 2, which has for this purpose an axial barrel 2a and a radial flange 2b provided with orifices 3 for fixing to the wheel rim (not shown). Similarly, the external member 1 may have means for fixing the bearing to a suspension element of the motor vehicle.

[0015] Between these two members 1, 2, a rolling space is formed to allow the relative rotation of said members around an axis A. In this description, the terms of positioning in space are taken with reference to the axis A of rotation of the bearing (horizontal in the figures). In particular: - the terms “interior” and “exterior” relate to an arrangement respectively close to and at a distance from this axis A; - the terms "axial" and "radial" relate to a disposition respectively following this axis A and moving away from or approaching it.

[0016] To allow rotation, each member 1, 2 may have at least one rolling track 1c, 2c spaced axially so as to form in the rolling space a rolling path in which a row of rolling bodies 4 is arranged, said rolling bodies being for example in the form of balls which are held in their row by means of a retention cage.

[0017] However, the invention is not limited to one embodiment of the bearing, in particular with respect to the geometry of the rolling bodies 4, to the geometry and / or to the relative arrangement of the fixed 1 and rotating 2 members.

[0018] The figures represent one side of the rolling space which has an annular chamber 5 in communication with the exterior via an annular opening 6 formed between the members 1, 2.

[0019] In this embodiment, the first member 1 has an annular protrusion 7 delimiting a first edge of the opening 6. In particular, the protrusion 7 is in the form of a ring of substantially rectangular section delimited by a radial end wall 7a and two axial walls, respectively inner 7b and outer 7c, the end wall 7a delimiting a first lateral edge of the opening 6.

[0020] Similarly, the second member 2 has an outer lateral wall 8 which extends substantially radially opposite the axial projection 7, delimiting a second lateral edge of the opening 6, said opening thus being delimited laterally between the outer lateral wall 8 and the end wall 7a of said projection.

[0021] The second member 2 also has an inner side wall 9 delimiting an edge which extends radially from the annular chamber 5 and axially opposite the rolling space, so as to laterally delimit one side of said chamber between the opening 6 and the rolling space.

[0022] To prevent on the one hand leaks of lubricant present in the bearing space and on the other hand contamination of said space with external pollutants, in particular based on water and / or sludge, the chamber 5 is equipped with a sealing device.

[0023] The sealing device comprises a first 10 and a second 11 rigid frame secured respectively to a first 1 and a second 2 member, said frames being able to be made of metallic material, in particular by stamping a sheet metal.

[0024] The first frame 10 is provided with an internal sealing element 12 comprising at least one lip 12a, 12b which is in sealing interference with a medial bearing surface 13 of the second frame 11.

[0025] In the embodiment shown, the first frame 10 is secured to the fixed external member 1, in particular by being fixed to the protrusion 7. To do this, the first frame 10 has an external structure 10a in the shape of an inverted L, which comprises an axial outer wall 14a and a radial inner wall 14b, the protrusion 7 having an outer wall 7c on which the axial outer wall 14a is fitted and an end wall 7a against which the radial inner wall 14b is in axial abutment.

[0026] In the description, the terms "internal" and "external" are defined with respect to an arrangement respectively in the sealing chamber 5 and in the external opening 6 of said chamber.

[0027] The first frame 10 further has an internal structure 10b which carries the internal sealing element 12, said internal structure comprising: - an inner wall 14c which extends substantially radially between the rolling space and the medial wall 13, and on which at least one sealing lip 12a, 12b is formed; - a substantially axial outer wall 14d connecting the inner walls 14c, 14b, and whose dimension is sufficiently large to separate the inner wall 14c from the rolling bodies 4.

[0028] The internal sealing element 12 comprises in particular at least one lip 12a in rubbing contact with the medial surface 13 and / or at least one lip 12b forming a reduced sealing clearance with said medial surface.

[0029] In relation to [Fig.1a], the internal sealing element 12 comprises an inner sealing lip 12a which is in frictional contact with the medial bearing surface 13, as well as an outer sealing lip 12b which forms a reduced sealing clearance with said medial bearing surface.

[0030] The medial bearing surface 13 is arranged radially between two bearing surfaces, respectively inner 15 and outer 16, of the second frame 11, said bearing surfaces being arranged to allow the fixing and immobilization of said second frame on the rotating member 2.

[0031] To do this, the outer bearing surface 16 has an axial surface 17 which is fitted onto a complementary axial surface 18 formed on the second member 2.

[0032] Advantageously, the complementary fitting surface 18 is formed outside the sealing chamber 5, and in particular in the opening 6. Thus, the second frame 11 can be produced with a medial sealing surface 13 of larger radial dimension, which makes it possible to have more sealing lips 12a, 12b in the chamber 5, and therefore to increase the sealing interferences in said chamber.

[0033] In the figures, the medial bearing surface 13 is arranged opposite the inner lateral wall 9, said lateral wall being delimited externally by an exgrowth inner surface 20 which extends into the chamber 5 and has the complementary surface 18 for fitting the outer bearing surface 16. Furthermore, the axial fitting surface 17 is formed on the inside of the outer bearing surface 16, in order to allow the fitting of said outer bearing surface around the protrusion 20.

[0034] This arrangement also makes it possible to prevent the infiltration of external pollutants at the interface between the second sealing reinforcement 11 and the side wall 9 of the second member 2, and thus to improve the static sealing at the level of the fitting of said second reinforcement on said second member. In particular, to improve this static sealing, a sealing element can be added to the external surface 16, for example by overmolding a suitable elastomer material, or in the form of a sealing paste, an O-ring and / or a silicone bead.

[0035] The inner side wall 9 has a convex profile to limit the axial size of the rolling bearing while retaining sufficient dimensions to form a sealing chamber 5 between the two members 1, 2.

[0036] The medial bearing surface 13 has a convex profile while being axially spaced from the lateral wall 9, so as to limit the impact on the second frame 11 of the mechanical stresses due to the rotation of the member 2.

[0037] The inner bearing surface 15 is axially immobilized on a radial threshold 19 formed on the second member 2, so as to ensure the axial retention of the second armature 11 on said second member while avoiding as much as possible the need for rectification on the side wall 9.

[0038] Thus, by dissociating the fixing of the second armature 11 by its outer bearing surface 16 surrounding the medial sealing surface 13, from its axial immobilization by means of abutting its inner bearing surface 15 on the radial threshold 19, the reliability of the sealing is improved, in particular with respect to the risks of migration of said second armature during rotation, while optimizing the space available to achieve said sealing without compromising the weight of the bearing.

[0039] In particular, the external fitting of the second armature 11 over a large diameter makes it possible to free up space for its internal abutment on the member, without prejudice to the axial dimension necessary for integrating the sealing device into the bearing.

[0040] The radial threshold 19 and / or the inner bearing surface 15 may extend continuously over their entire circumference, or be formed of discrete sectors equally distributed circumferentially. In particular, in this second case, the inner bearing surface 15 may have tabs equally distributed circumferentially and each intended to come into axial support against respectively a discrete radial rim formed in the member 2.

[0041] In the figures, the inner side wall 9 is bordered internally by a wall inner 21 extending axially, and on which the radial threshold 19 is formed.

[0042] Advantageously, the inner wall 21 connects the side wall 9 to the rolling space, which makes it possible to reduce the total axial size of the bearing. Furthermore, the internal sealing element 12 comprises an additional lip 12c arranged at the interface between the chamber 5 and the rolling space to prevent lubricant leaks into said chamber, this lip 12c coming into rubbing contact with the inner wall 21 of the member 2, and not with the armature 11, in order to axially bring said lip as close as possible to the rolling space.

[0043] In the embodiment shown, the threshold 19 is formed as a radial projection on the internal edge of the groove forming the side wall 9 on the second member 2.

[0044] To limit the entry of external pollutants into the chamber 5, the sealing device comprises an external sealing structure comprising a first 23 and a second 24 section secured to the first 10 and the second 11 frame respectively, said sections forming between them a sealing interface at the opening 6.

[0045] In the figures, the sections 23, 24 form a sealing baffle at their interface, in order to form a barrier to the entry of external pollutants into the chamber 5, and in particular to allow the evacuation of any external pollutants retained in said baffle under the effect of the centrifugal force generated by the rotation of the member 2.

[0046] In relation to [Fig.1a], the outer section 10a of the first frame 10 carries an external sealing element 22 which has a cavity 23 forming the first section, the second section 24 being arranged in said cavity.

[0047] In particular, the external sealing element 22 has an outer ring 22a and an inner bead 22b which both extend substantially axially, and between which the cavity 23 is formed.

[0048] Advantageously, the protrusion 7 has a reduced axial dimension to limit the weight of the external member 1, as well as an increased radial dimension, in order to benefit from a sufficiently large radial space to be able to increase the sealing baffle in the opening 6, and thus limit the penetration of external pollutants through said opening.

[0049] The crown 22a and the bead 22b are each formed on the radial inner wall 14b and the inner wall 14d of the frame 10 respectively, and are connected to each other by a sealing veil made of material which extends over said walls, which makes it possible to modulate the dimensions of the cavity 23 to limit the penetration of external pollutants into the chamber 5 via said cavity.

[0050] In particular, the crown 22a partially surrounds the outer fitting surface 16 of the second armature 11, and has a free end which is folded inwardly towards said outer surface, in order to reduce the play between them, and limit the penetration by said baffle of external pollutants into the cavity 23. Alternatively, the crown 22a may be cylindrical or inclined radially outwards to allow complete flow of water.

[0051] The external sealing element 22 further has a sealing ring 22c which is attached to an external face of the external wall 14a, in order to form a static seal at the level of the fitting of said external wall, and therefore of the first reinforcement 10, on the external member 1. In the figures, the static sealing ring 22c is integral with the crown 22a and the bead 22b, and extends over an axial dimension which is greater than the total axial dimension of the axial fitting wall 14a.

[0052] Advantageously, the external sealing element 22 is formed in a single piece with the internal sealing element 12, which makes it easier to manufacture the first frame 10.

[0053] The sealing elements 12, 22 may be associated by overmolding with the frame 10, and may be made from a single piece of flexible material, for example elastomer, in particular based on butadiene nitrile copolymer (NBR), possibly mechanically reinforced by fillers such as carbon black, hydrogenated NBR (HNBR), fluoropolymer or polyacrylate.

[0054] The second sealing section is formed by a fold 24 of the second frame 11, said fold projecting into the opening 6, in particular by being arranged in the cavity 23, in order to form a baffle at the interface with said cavity.

[0055] In particular, the outer bearing surface 16 of the second armature 11 extends in the axial extension of the fold 24 opposite the cavity 23, which makes it possible to reinforce the rigidity of said outer bearing surface, and thus of the outer fitting of the armature 11 on the rotating member 2.

Claims

Claims

1. Rolling bearing comprising two members (1, 2) and rolling bodies (4) arranged in a rolling space formed between said members to allow their relative rotation about an axis (A), at least one side of the rolling space having an annular chamber (5) in communication with the outside via an opening (6), said chamber being equipped with a sealing device comprising a first and a second rigid frame (10, 11) secured respectively to a first (1) and a second (2) of said members, the first frame (10) being provided with an internal sealing element (12) comprising at least one lip (12a, 12b) which is in sealing interference with a medial bearing surface (13) of the second frame (11), said medial bearing surface being arranged radially between two respectively outer (16) and inner (15) bearing surfaces of said second frame,the outer bearing surface (16) having an axial surface (17) which is fitted onto a complementary axial surface (18) of the second member (2), the inner bearing surface (15) being axially immobilized on a radial threshold (19) formed on said second member, said bearing being characterized in that the first armature (10) is secured to the fixed outer member (1), in particular by being fixed to said protrusion.,

2. Rolling bearing according to claim 1, characterized in that the internal sealing element (12) comprises at least one lip (12a) which is in rubbing contact with the medial bearing surface (13).

3. Rolling bearing according to one of claims 1 or 2, characterized in that the internal sealing element (12) comprises at least one lip (12b) which forms a reduced sealing clearance with the medial bearing surface (13).

4. Rolling bearing according to any one of claims 1 to 3, characterized in that the second member (2) has a side wall (9) delimiting an edge extending radially from the annular chamber (5), said wall being bordered externally by an external protrusion (20) extending into said chamber, said protrusion having the complementary axial fitting surface (18).

5. Rolling bearing according to any one of claims 1 to 4, characterized in that the second member (2) has a side wall (9) delimiting an edge extending radially from the annular chamber (5), said wall being bordered internally by an internal wall (21) extending axially and on which the threshold (19) is formed.

6. Rolling bearing according to claim 5, characterized in that the sealing element (12) comprises an ancillary lip (12c) which is in rubbing contact with the inner wall (21).

7. Rolling bearing according to any one of claims 1 to 6, characterized in that the axial fitting surface (17) is formed on the inside of the outer bearing surface (16).

8. Rolling bearing according to any one of claims 1 to 7, characterized in that the threshold (19) is formed as a radial projection on the internal edge of a groove formed on the second member (2).

9. Rolling bearing according to any one of claims 1 to 8, characterized in that the sealing device comprises an external sealing structure comprising a first (23) and a second (24) section integral with the first (10) and the second frame (11) respectively, said sections forming between them a sealing interface at the opening (6).

10. Rolling bearing according to claim 9, characterized in that the second section (24) is formed by a fold of the second frame (11), said fold projecting into the opening (6).

11. Rolling bearing according to claim 10, characterized in that the outer bearing surface (16) of the second armature (11) extends in the outer extension of the fold.

12. Rolling bearing according to any one of claims 9 to 11, characterized in that the first frame (10) carries an external sealing element (22) which has a cavity forming the first section (23), the second section (24) being arranged in said cavity.

13. Rolling bearing according to claim 12, characterized in that the external sealing element (22) has an outer ring (22a) which partially surrounds the outer bearing surface (16).

14. Rolling bearing according to one of claims 12 or 13, characterized in that the external sealing element (22) is formed in one piece with the internal sealing element (12).

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