FR3072742A1 - BEARING BEARING - Google Patents

Abstract

The invention relates to a bearing in which the row of inner rolling bodies (6i) - respectively external (6e) - is in contact on the inner raceway (4i) - respectively external (4e) - along a line of internal force (Li) - respectively external (Le) - forming with the axis of rotation (X) of the bearing an internal contact angle αci - respectively external αce, the shaft (3) having a recess (14) of revolution around the axis of rotation (X), said recess comprising an inner conical portion (14i) and an outer conical portion (14e) which are interconnected by their base at a central portion (14c), the generator (Gi) of the internal conical portion (14i) - respectively the generatrix (Ge) of the outer conical portion (14e) - forming an internal cone angle αi - respectively external αe - with the axis of rotation (X), said angles being such that : αi = 90 - αce +/- 3 ° and αe = αci +/- 3 °.

Description

The invention relates to a rolling bearing comprising a hub and an external member disposed around said hub for mounting in relative rotation of two elements.

The invention applies more particularly to the mounting of a rolling assembly of a vehicle, in particular a motor vehicle, on a suspension element of said vehicle, said rolling assembly comprising in particular a wheel and a brake disc.

For the mounting of such a rolling assembly, bearings are known in which the external member and the hub each carry at least one raceway which are arranged radially facing to produce at least one raceway in which a row of rolling body is arranged to allow relative rotation of the hub and the external member.

According to one embodiment, the hub comprises a barrel around which the external member is rotatably mounted, the external periphery of said barrel being provided with two respectively internal and external rolling tracks.

Furthermore, the bearing comprises a flange which extends radially around the barrel by presenting conduits distributed angularly to allow the association of an element with the hub. Thus, by associating the external member with a suspension element of the vehicle, the rolling assembly can be rotated by fixing it to the flange.

By integrating the different functions and the resulting mechanical stresses, the rolling bearings are relatively massive, which poses problems of weight, size and costs.

The object of the invention is to improve the prior art by proposing in particular a rolling bearing whose compromise between mass and mechanical strength is optimized for the application considered, in particular with regard to the service life, the rigidity and the fatigue strength of said bearing.

To this end, the invention provides a rolling bearing comprising a hub having a barrel whose external periphery is provided with two respectively internal and external raceways, and an external member disposed around said drum by providing a respectively internal raceway. and external in each of which a row of respectively internal and external rolling bodies is arranged in order to allow the relative rotation of the hub and of the external member about an axis, the row of internal respectively external rolling bodies - being in contact on the internal respectively external raceway - along an internal force line - respectively external - forming with the axis of rotation of the bearing an internal contact angle ad

- respectively external ace, the barrel having a recess of revolution around the axis of rotation, said recess comprising an internal conical part and an external conical part which are connected together by their base at a central part, the generator of the internal conical part - respectively the generatrix of the external conical part - forming an internal cone angle œ

- respectively external oe - with the axis of rotation, said angles being such that:

ai = 90 - "ce ± 3 ° and ae = a _C i ± 3 °.

Other objects and advantages of the invention will appear in the description which follows, made with reference to the appended figure which represents in longitudinal section a rolling bearing according to an embodiment of the invention.

In relation to this figure, a rolling bearing is described below for mounting in relative rotation of two elements, said bearing comprising a hub 1 and an external member 2 disposed around said hub. In the description, the terms “exterior” and “interior” are defined with respect to the axis X of rotation of the bearing, respectively for a location distant and close to said axis.

In the embodiment shown, the bearing is intended for mounting a rolling assembly of a vehicle, in particular a motor vehicle, on a suspension element of said vehicle, said rolling assembly comprising in particular a wheel and a brake disc.

To do this, the hub 1 comprises a barrel 3 rotatably mounted in the external member 2, said external member having means of association with a suspension element of the vehicle. However, the invention is not limited to such an application and can be applied to an assembly in which the external member 2 is rotating and the hub 1 is fixed.

The outer periphery of barrel 3 is provided with two rolling tracks 4i respectively internal and external _e 4 which each extend in a circular manner being axially spaced from each other. In the description, the terms "external" and "internal" are defined with respect to the mounting of the bearing on the vehicle, respectively on the left and on the right in the figure.

The outer member 2 is arranged around the shank 3 by providing a raceway 5i respectively internal and external _e 5 in each of which a row of rolling 6i respectively internal and external body 6 is arranged to allow relative rotation of the hub 1 and of the external member 2 around the axis X.

In the embodiment shown, the barrel 3 has an external raceway 4 _e and an internal race 7 intended to receive a ring 8 on which an internal race track 4 is formed, the free edge 9 of said range being folded back to form an axial preload collar of said ring on the periphery of the barrel 3.

Furthermore, the external member 2 also has an internal raceway 10i and an external raceway 10 _e which are each arranged radially opposite the race track 4i, corresponding 4 _th of the barrel 3, a row of spherical balls 6i, 6 _e being in oblique contact in the raceways 5i, 5 _e thus formed.

However, the invention is not limited to a particular embodiment of the rotation function of the rolling bearing, in particular relative to the geometry of the rolling bodies 6i, 6e and of the different rolling tracks 4i, 4 _e ; 10i, 10th on the barrel 3 and / or the external member 2.

To allow the association of a rolling assembly to the hub 1, the barrel 3 is equipped with a flange 11 which is formed around the external side of said barrel, said flange extending radially by presenting association conduits 12 distributed angularly .

In particular, the flange 11 has an annular extension 13 which extends axially from an external side of the barrel 3, the rolling assembly having a bore which is arranged around said annular extension while ensuring perfect concentricity of the mounting of said rolling assembly on said flange before being fixed in the conduits 12.

The hub 1 is made in one piece and can be optimized, especially in terms of the material constituting it, relative to the mechanical forces which it must withstand. According to one embodiment, the hub 1 can be produced, in particular by forging, in a metallic material, in particular in C56 type rolling steel, to allow the barrel 3 to withstand the rolling contact pressures and the flange 11 to withstand the stresses mechanical from the rolling assembly. According to another embodiment, the hub 1 can be obtained by additive manufacturing, in particular by laser sintering of a steel powder with a high carbon content, for example of the 100Cr6 type.

As shown in the figure, the row of internal rolling bodies 6i respectively external 6e - is in contact on the internal raceway 5irespectively external 5e - along an internal force line Li- respectively external Le - forming with the axis of rotation X of the bearing an internal contact angle "ci - respectively external otce. In particular, the force line Li, Le is considered at the level of the rolling body 6i, 6th most loaded on each of the internal and external sides respectively.

The barrel 3 has a recess 14 of revolution about the axis of rotation X, said recess comprising an internal conical part 14i and an external conical part 14 _e which are connected together by their base at a central part 14 _c .

To optimize the bearing weight without compromising its mechanical strength, the generator Gide the internal conical part 14i- respectively the generator G _e of the external conical part 14 _e - forming an internal cone angle œ - respectively external ae - with l axis of rotation X, said angles being such that:

ai = 90 - "ce ± 3 ° and ae = a _C i ± 3 °.

In other words, as shown in the figure, the generator Gi of the internal conical part 14i is essentially perpendicular to the external force line Le, the generator Ge of the external conical part 14 _e being essentially parallel to the line d 'internal effort Li.

In a numerical example, the external contact angle ace is 58.3 ° and the internal contact angle a _C i is 48 °, the external cone angles a _e and internal œ being 48 ° and 31 respectively , 7 °.

The size of the recess 14 and therefore the weight gain can be increased while retaining enough material for the mechanical strength by providing that the central part 14 _c of the recess 14 has a maximum diameter D _c which is less than 90 % of the diameter D _e of the bottom of the external raceway 4 _e .

Thus, in particular when the central part 14 _c of the recess 14 is disposed inside the external raceway 4 _e , a sufficient thickness of material is disposed between said track and said recess, in particular relative to the stiffness vis- vis-à-vis the pressure exerted by the rolling bodies 6 _e on said track.

Similarly, the recess 14 may have an axial length I, that is to say measured between its internal and external edges along the axis X, which is between 50% and 70% of the axial length L of the barrel 3 taken between its internal edges 3i and external _3e , in order to leave a sufficient length of material between the recess 14 and said edges.

On the external side of the hub 1, it is advantageous for the external edge of the recess to be disposed inside a cone whose generator is the external force line Le. More specifically, the outer edge of the recess 14 can be arranged on the inner side of the inner lateral plane P of the flange 11.

With a view to saving weight, the barrel 3 may have an external edge 3 _e in which a conical cavity of revolution 15 is formed. In particular, and as shown in the figure in relation to an improvement in the mechanical strength of the bearing, the cavity 15 forms a solid angle which is essentially equal to that formed by revolution of the external force line Le.

More specifically, the conical cavity 15 opens into the cylindrical cavity formed by the annular extension 13 of the flange 11, the wall of the conical cavity being substantially tangent to the line of external force Le.

For manufacturing reasons, in particular in additive manufacturing but also to eliminate a possible insert having served to form the recess 14, the external edge of the recess 14 can be connected to the external edge 3 _e of the barrel 3 by a conduit, by axial example.

On the internal side of hub 3, always to optimize the mass compromise! mechanical strength, the internal edge of the recess 14 can be separated from the internal edge 3idu barrel 3 by a distance d which is at least equal to 25% of the diameter Di of the bottom of the internal raceway 4i.

In addition, a cavity of revolution 16 can be formed in the internal edge 3idu barrel, especially inside the flange 9 of association of the ring 8, said cavity may have a substantially spherical bottom in which said edge is formed.

Claims (12)

1. Rolling bearing comprising a hub (1) having a barrel (3) whose outer periphery is provided with two respectively internal (4i) and external (4 _e ) tracks, and an external member (2) disposed around said barrel by performing a rolling respectively internal path (5i) and outer (5e) in each of which a row of respectively inner rolling elements (6i) and outer (6 _th) is arranged to allow relative rotation of the hub (1) and of the external member (2) around an axis (X), the row of internal rolling bodies (6i) - respectively external (6e) - being in contact on the internal raceway (4i) - respectively external (4 _e ) - along an internal force line (Li) respectively external (Le) - forming with the axis of rotation (X) of the bearing an internal contact angle α "- respectively external" ce, said bearing being characterized in that the barrel (3) has a recess (14) of revolution around the axis of rotation (X), said recess comprising an internal conical part (14i) and an external conical part (14 _e ) which are connected together by their base at a central part (14 _c ), the generator (Gi) of the internal conical part (14i) - respectively the generator (Ge) of the external conical part (14e) - forming an internal cone angle œ - respectively external to _e - with the axis of rotation (X), said angles being such as : "I = 90 -" ce ± 3 ° and OCe = "ci ± 3 °. 2. Rolling bearing according to claim 1, characterized in that the recess (14) has an external edge which is disposed inside a cone whose generator is the external force line (Le). 3. Rolling bearing according to one of claims 1 or 2, characterized in that the central part (14 _c ) of the recess (14) has a maximum diameter (De) which is less than 90% of the diameter (De ) from the bottom of the external raceway (4 _e ). 4. Rolling bearing according to any one of claims 1 to 3, characterized in that the central part (14 _c ) of the recess (14) is disposed inside the external raceway (4 _e ) . 5. Rolling bearing according to any one of claims 1 to 4, characterized in that the recess (14) has an internal edge which is separated from the internal edge (3i) of the barrel by a distance at least equal to 25 % of the diameter (Di) of the bottom of the internal raceway (4i). 6. Rolling bearing according to any one of claims 1 to 5, characterized in that the recess (14) has an axial length (I) which is between 50% and 70% of the axial length (L) of the bole (3) taken between its internal (3i) and external (3 _e ) edges. 7. Rolling bearing according to any one of claims 1 to 6, characterized in that the barrel (3) has an outer edge (3 _e ) in which a conical cavity of revolution (15) is formed. 8. Rolling bearing according to claim 7, characterized in that the conical cavity (15) forms a solid angle which is essentially equal to that formed by revolution of the external force line (Le). 9. Rolling bearing according to any one of claims 1 to 8, characterized in that it comprises a flange (11) which is formed around the external side of the barrel (3). 10. Rolling bearing according to claim 9, characterized in that the recess (14) has an outer edge which is disposed on the inner side of an inner lateral plane (P) of the flange (11). 11. Rolling bearing according to any one of claims 1 to 10, characterized in that the recess (14) has an outer edge which is connected to the outer edge (3 _e ) of the barrel (3) by a conduit. 12. Rolling bearing according to any one of claims 1 to 11, characterized in that the barrel (3) has an internal edge (3i) in which a cavity of revolution (16) is formed.