FR3042005A1 - BEARING BEARING - Google Patents

Abstract

The invention relates to a rolling bearing comprising a fixed member (1), a rotating member (2) and rolling bodies (4) arranged in a running space (3), at least one side of which has an annular opening (6). which is equipped with a sealing device comprising two rigid armatures (9, 10) integral respectively with a member (1, 2) forming an annular sealing chamber (11), said armatures respectively having an upstream ring ( 13) and a downstream ring (14) which extend axially and are radially disposed in the opening (6) to form the sealing chamber (11), at least one ring (14) being provided with a dynamic sealing element (12) having at least one lip (21) disposed in said chamber in rubbing contact with the other ring gear (13), at least one armature (10) having an inner bearing (18) which is associated with a complementary bearing (19) formed in the opening (6), said inner surface being surrounded by the crown (13) of said armature.

Description

The invention relates to a rolling bearing comprising a fixed member, a rotating member and rolling bodies arranged in a running space formed between said members to allow their relative rotation about an axis.

In particular, the invention applies to rolling bearings of a motor vehicle, in particular wheel bearings. Advantageously, a bearing according to the invention allows the mounting of a drive wheel or non-driving motor vehicle, the inner member being rotatable and comprising means for fixing the wheel while the outer member is fixed and comprises fastening means on an element of the vehicle.

To prevent, on the one hand, the leakage of lubricant present in the running space and, on the other hand, the contamination of said space with external pollutants, at least one side of the running space can be equipped with a device seal.

In particular, the sealing device may comprise two rigid armatures which are secured respectively to a member by forming an annular sealing chamber in which a dynamic sealing element is arranged, said element being integral with an armature and having at least one lip disposed in said chamber being in rubbing contact on the other armature.

To meet increasingly stringent specifications relating to tightness, especially for the validation of wheel bearings by car manufacturers, this solution leads to a high friction torque which, in addition to the negative impact on energy necessary for rotation of the bearing, causes a high operating temperature level and thus premature wear of the friction lip. In addition, this wear is even faster than pollutants can enter the sealing chamber at the friction zone and remain there during rotation.

In an attempt to solve this problem, it can be proposed to add deflectors to form an inlet baffle in the sealing chamber, thus limiting the exchanges between said chamber and the outside, especially at the level of the friction zone. However, this solution, in addition to the additional cost of the deflector and its mounting in the bearing, has a size that can negatively impact the mechanical performance of the bearing by requiring a structural change thereof.

Document FR-3,007,806 proposes a rolling bearing in which at least one side of the running space has an annular opening equipped with such a sealing device, said opening being surrounded on both sides by two outer walls which extend axially respectively on a member, each armature of the sealing device having an axial outer surface which is associated with one of said outer walls, and an axial inner surface which is disposed in said annular opening, the bearings internal being disposed radially facing to form between them the sealing chamber.

However, this solution requires to have sufficient space on the outer walls of the bearing members to be able to fit properly the frames, and thus ensure a good fixing of the sealing device, which may not be the case on the organs intended for mounting a wheel. The invention aims to improve the prior art by providing a rolling bearing equipped with a sealing device whose sealing performance is optimized with respect to the induced friction torque, while limiting the constraints of its integration into the geometry of said bearing. To this end, the invention proposes a rolling bearing comprising a fixed member, a rotating member and rolling bodies arranged in a running space formed between said members to allow their relative rotation about an axis, at least one side of the bearing space having an annular opening which is equipped with a sealing device comprising two rigid armatures integral respectively with a member forming an annular sealing chamber, said reinforcements respectively having an upstream ring and a downstream ring which extend axially by being disposed radially in the opening to form the sealing chamber, at least one of said rings being equipped with a dynamic sealing element which has at least one lip disposed in said sealing chamber by being in rubbing contact on the other of said crowns, at least one of the reinforcements sensing an internal bearing that is associated with a complementary bearing formed in the opening, said inner surface being surrounded by the crown of said armature. Other objects and advantages of the invention will become apparent from the description which follows, made with reference to the appended figures which each partially and in longitudinal section show a rolling bearing equipped with a sealing device according to an embodiment of the invention. the invention.

In connection with these figures, a rolling bearing is described below, in particular for mounting a driving or non-driving wheel of a motor vehicle.

The bearing comprises an outer member 1 and an inner member 2, at least one of said members may comprise fixing means to respectively a fixed structure or a rotating assembly. In one embodiment, the outer member 1 is fixed, for example having means for fixing the bearing on a suspension element of the motor vehicle, the wheel being associated with the inner member 2 which is then rotating.

Between these two members 1, 2, a running space 3 is formed to allow relative rotation of said members about an axis. In this description, the terms of positioning in space are taken with reference to the axis of rotation of the bearing. In particular, the term "inside" relates to a disposition close to this axis and the term "outside" relates to a remote layout of this axis.

To enable rotation, each member 1, 2 may have two axially spaced rolling tracks so as to form between said members two raceways in which are respectively arranged a row of rolling bodies 4, said rolling bodies being for example under the form of balls which are held in a row by means of a retention cage 5.

However, the invention is not limited to an 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 and rotating members 2. 3 opens out through at least one annular opening 6 which is formed between the members 1, 2. In relation to the figures, the annular opening 6 is delimited by two radial edges 7, 8 which are formed on a member 1, 2, respectively, said edges being disposed axially to form between them said opening.

To prevent, on the one hand, the leakage of lubricant present in the running space 3 and, on the other hand, the contamination of said space with external pollutants, in particular based on sludge, the annular opening 6 is equipped with a sealing.

The sealing device comprises two rigid armatures 9, 10 respectively integral with a member 1, 2 forming an annular sealing chamber 11 in which a dynamic sealing element 12 is disposed. In particular, the frames 9, 10 may be made of metal material, in particular stamped sheet metal.

The plates 9, 10 respectively have an upstream ring 13 and a downstream ring 14 which extend axially and are disposed radially in the opening 6 to form the sealing chamber 11. In the description, the terms "upstream" and "downstream" are defined with respect to the direction of introduction of the pollutants into the annular opening 6, the upstream crown 13 shown being disposed externally by surrounding the downstream ring 14.

In the embodiments shown, one of the reinforcements 9 has an axial outer surface 15 which is associated, in particular by axial fitting, on a complementary surface 16 which is formed on the corresponding member 1 by extending axially on one side of the opening 6, said outer surface surrounding the ring 14 of said armature. The armature 9 has an intermediate wall 17 which connects the crown 14 and the outer association surface 15, said intermediate wall being disposed against the corresponding radial edge 7. In particular, the intermediate wall 17 then extends radially along the edge 7 while being in axial abutment on said edge, forming in particular end stop of fitting of the armature 9 on the member 1.

Furthermore, the other armature 10 has an inner bearing 18 which is associated with a complementary bearing 19 formed in the opening 6, said inner bearing being surrounded by the ring 13 of said armature. This arrangement makes it possible to prevent fitting of the armature 10 on the outer wall of the corresponding member 2, and thus to limit the bulk of said outer wall.

In the embodiments shown, the inner association surface 18 extends axially and is associated, in particular by axial fitting, on a complementary surface 19 which extends axially on the corresponding member 2 while being surrounded by the radial edge. 8. The armature 10 has an intermediate wall 20 which connects the crown 13 and the internal association surface 18, said wall being disposed opposite the radial edge 8. In particular, the wall 20 has a radial outer portion 20a which is surrounded by the ring 13, and an inclined inner portion 20b which is arranged to axially distance the inner association surface 18 of the radial edge 8, in particular to avoid the bending of the armature 10 and therefore its deformations during the rotation of the bearing.

In addition, the inclined inner portion 20b is arranged to transmit the force of the axial bearing of the radial edge 8 against the outer portion 20a towards the interference between the inner bearing surface 18 and the complementary bearing surface 19, in order to improve the holding of the fitting of said inner bearing.

At least one of the rings 14 is equipped with the dynamic sealing element 12 which has at least one lip 21 disposed in the sealing chamber 11 while being in frictional contact with the other ring 13. Thus, the axial bulk the sealing device is limited by providing an axial overlap between the rings 13, 14 between which the seal is made, in order to limit the geometric constraints of integration of said device in the bearing.

In addition, the inner bearing surface 18 is also in axial overlap of the rings 13, 14, in particular being arranged concentrically inside said rings. Thus, the axial size of the sealing device is further reduced, in particular by providing that the rings 13, 14 and the bearing surface 18 are disposed entirely inside the opening 6.

In particular, in the case of a rolling bearing comprising two raceways, the axial compactness of the sealing device makes it possible to avoid having to reduce the spacing between the bearing tracks, which would have the consequence of limiting the capacity load of said bearing and / or the dimension of the span 16, 19 association of frames 9, 10, which would be against the reliability of the desired seal.

Advantageously, the lip 21 extends essentially radially in the sealing chamber 11 to be in radial frictional contact with the ring 13.

In addition, the seal is improved by providing that the dynamic sealing element 12 has two lips 21 which are axially spaced each being in rubbing contact on the ring 13. In addition, the figures show a dynamic sealing element 12 having an auxiliary lip 22 which is in frictional contact with the intermediate wall 20 of the armature 10.

The armatures 9, 10 form between them a communication passage 23 between the sealing chamber 11 and the outside, the geometry of said passage being arranged to limit the introduction of pollutants into said chamber, without inducing additional torque, contribute to the reliability of the imperviousness conferred, in particular at the level of the friction zone of the lips 21. In particular, the dimension of the passage 23 can be reduced and / or its curved section to form an inlet baffle in the chamber sealing 11.

In the embodiments shown, the passage 23 is formed between an armature 9 and the free end 24 of the upstream crown 13 belonging to the other armature 10. Thus, the zone of friction of the lips 21 is not arranged in radial view of the passage 23 which, by avoiding that the pollutants can not fall directly at this area, limits the wear of said lips. In particular, it is then possible to better control the interference between the lips 21 and the ring 13 on which they rub, in particular to be able to optimize the friction torque necessary for reliability in time of the seal.

In relation with the figures, the dynamic sealing element 12 is integral with the downstream ring 14, the rubbing contact being produced by external radial support on the inside of the upstream ring 13.

In particular, the armature 9 having the downstream ring 14 is secured to the fixed member 1, the upstream ring 13 being associated with the inner member 2 to rotate around the sealing element 12.

As a variant, the sealing support may be radially inward, providing that the dynamic sealing element 12 is integral with the upstream ring 13 so as to rub on the outside of the downstream ring 14.

In the embodiments shown, the dynamic sealing element 12 comprises an annular support 25 from which the sealing lip 21 extends, said support extending radially in the sealing chamber 11 and having a free edge 25a which is folded axially.

In Figure 1, the support 25 is integral with the downstream ring 14, in particular by being formed by radial folding of the free edge of said downstream ring. In FIG. 2, the support 25 is formed of a part distinct from the downstream ring 14, and has an axial portion 25b which is associated with said downstream ring, as well as a radial portion 25c connecting said axial association portion with free edge 25a.

Furthermore, the bearing may comprise at least one static sealing element which is mounted between an armature 9, 10 and the member 1, 2 on which it is associated, in order to prevent the introduction of pollutants between the armature and said organ.

In the embodiments shown, the rotating armature 10 comprises a first static sealing element 26 which extends at least partially between the outer portion 20a and the radial edge 8, in order to prevent the introduction of pollutants between said frame and said radial edge.

In particular, the static sealing element 26 has at least one lip 27 which extends from the outer portion 20a to be arranged in sealing engagement on the radial edge 8, in order to seal the axial clearance at the interface between said outer portion and said radial edge. The static sealing element 26 also has an extension 28 which extends from the lip 27 by covering the outside of the upstream ring 13 and a web 29 which extends radially under said lip to be interposed between the outer portion 20a and the radial edge 8.

In addition, the fixed armature 9 comprises a second static sealing element 30 which extends at least on the outer surface 15 to be interposed in the fitting between said outer surface and the complementary surface 16 of the fixed member 1 , in order to form the static seal of the fitting of the armature 9 on said fixed member.

In FIG. 1, the dynamic sealing element 12 and the second static sealing element 30 are made of material, and are in particular connected by a web 31 which extends from the outside of the downstream ring 14 until outside the association scope 15.

In FIG. 2, the dynamic sealing element 12 and the second static sealing element 30 are formed of two distinct parts. In particular, the dynamic sealing element 12 has an extension 32 which extends on the support 25 to be interposed between the axial portion 25b and the downstream ring 14, to ensure static sealing at the level of the association between said support and said downstream ring.

According to an advantageous embodiment, the dynamic sealing element 12 and / or the static sealing element 26, 30 is associated by overmolding with the reinforcement 9, 10. In particular, the sealing element 12, 26 , 30 may be made of flexible material, for example elastomer, especially based on nitrile butadiene copolymer (NBR), optionally mechanically reinforced with fillers such as carbon black, hydrogenated NBR (HNBR), fluoropolymer or polyacrylate .

Claims (15)

1. Rolling bearing comprising a fixed member (1), a rotating member (2) and rolling bodies (4) arranged in a rolling space (3) formed between said members to allow their relative rotation about an axis, at least one side of the running space (3) having an annular opening (6) which is equipped with a sealing device comprising two rigid armatures (9, 10) integral respectively with a member (1, 2). forming an annular sealing chamber (11), said reinforcements respectively having an upstream ring (13) and a downstream ring (14) which extend axially and are arranged radially opposite the opening (6) to form the sealing chamber (11), at least one of said rings being equipped with a dynamic sealing element (12) which has at least one lip (21) disposed in said sealing chamber in frictional contact with the other said court said bearing being characterized in that at least one of the reinforcements (10) has an inner bearing (18) which is associated with a complementary bearing (19) formed in the opening (6), said inner bearing being surrounded by the crown (13) of said frame. 2. Rolling bearing according to claim 1, characterized in that the inner bearing surface (18) of association of the armature (10) and the complementary bearing surface (19) of the member (2) extend axially. 3. rolling bearing according to one of claims 1 or 2, characterized in that the inner bearing surface (18) of association is connected to the ring (13) by a wall (20) of the armature (10). 4. rolling bearing according to claim 3, characterized in that the opening (6) is delimited by a radial edge (8) formed on the member (2) axially facing which the wall (20) of the armature (10) is disposed, said radial edge surrounding the complementary bearing (19). Roller bearing according to Claim 4, characterized in that the wall (20) of the armature (10) has a radial outer portion (20a) which is surrounded by the crown (13), and an inclined inner portion ( 20b) which is arranged to axially distance the inner association surface (18) from the radial edge (8). Rolling bearing according to any one of Claims 1 to 5, characterized in that one of the plates (10) has the internal bearing surface (18) associated with an element (2), the other reinforcement ( 9) having an outer bearing surface (15) associated with a complementary bearing surface (16) formed on the other member (1), said outer bearing surface surrounding the ring (14) of said other armature. 7. rolling bearing according to claim 6, characterized in that the outer bearing surface (15) of association of the other armature (9) extends axially, the complementary bearing (16) of the member (1) s extending axially on one side of the opening (6). 8. rolling bearing according to one of claims 6 or 7, characterized in that the armature (10) has the upstream ring (13), the other armature (9) having the downstream ring (14). 9. rolling bearing according to any one of claims 1 to 8, characterized in that the lip (21) extends substantially radially in the sealing chamber (11) to be in radial frictional contact on the ring (13). ). 10. Rolling bearing according to any one of claims 1 to 9, characterized in that the dynamic sealing element (12) is integral with the downstream ring (14). Bearing according to one of Claims 1 to 10, characterized in that the dynamic sealing element (12) comprises an annular support (25) from which the sealing lip (21) extends . Roller bearing according to Claim 11, characterized in that the support (25) extends radially in the sealing chamber (11). 13. Rolling bearing according to claim 12, characterized in that the support (25) has a free edge (25a) which is folded axially. 14. Rolling bearing according to any one of claims 11 to 13, characterized in that the support (25) is integral with the ring (14) of the armature (9). 15. Rolling bearing according to any one of claims 11 to 13, characterized in that the support (25) is associated with the ring (14) of the armature (9).