FR3103018A1 - Automotive vehicle suspension stopper - Google Patents

Abstract

The invention relates to a suspension stop for a motor vehicle, comprising at least one annular chamber (6) which is delimited laterally by two walls (1a, 2a), as well as an internal sealing element (8i) which is integral with 'a first wall (1a) having an outer baffle (9b) disposed in an outer section (6e) of said chamber, said stopper comprising an outer sealing element (8e) which has two sealing surfaces (11a, 11b ) and is movably mounted in the outer section (6e) between a stable position in which said sealing surfaces are arranged at a distance from complementary surfaces (12a, 12b) of respectively the second wall (2a) and the external deflector (9b) and a constrained position by pressing on said external sealing element in which said sealing surfaces are pressed against respectively one of said complementary surfaces to ensure the sealing of the external section (6e). Figure 3a

Description

Motor vehicle suspension bearing

The invention relates to a motor vehicle suspension thrust bearing, in particular intended to be integrated into a telescopic suspension strut of a motor vehicle steering wheel.

The invention applies to a suspension bearing comprising a fixed upper cup intended to be associated with the body of the vehicle, a rotating lower cup comprising a direct or indirect support for the suspension spring, and rolling bodies arranged between said cups to allow their relative rotation. As a variant, the cups can be mounted in relative rotation in a smooth manner, with or without the interposition of a friction washer between them.

In particular, the invention applies to such a suspension bearing, in which the cups are arranged to form between them at least one annular chamber in which a sealing element is arranged, and this to prevent on the one hand the leakage of the lubricant present in the space between the cups, and on the other hand the contamination of said space with external pollutants.

To do this, it is known to provide sealing elements in particular in the form of annular crowns which are mounted in annular grooves formed for this purpose in the sealing chamber.

Furthermore, to prevent the entry of external pollutants into the chamber, the sealing element can be equipped with an external deflector which is arranged close to an external opening of said chamber, in particular by being arranged in a section external of said chamber.

However, the suspension bearing may be subjected to projections of external pollutants, for example jets of water and/or mud, in particular when the vehicle is used in bad weather on muddy ground and/or covered with puddles of water, or when it is cleaned using a device projecting jets of water at more or less high pressure.

In this case, pollutants can be projected at high speed against the external deflector, which can then prove insufficient to prevent the entry of said pollutants into the sealing chamber.

Such projections are notably simulated during the bearing test phases, by introducing a jet of pressurized liquid into the opening of the sealing chamber.

The invention aims to improve the prior art by proposing in particular a suspension bearing in which the sealing is improved, in particular by protecting the chamber against the introduction of such jets of pollutants.

To this end, the invention proposes a motor vehicle suspension thrust bearing, said thrust bearing comprising an upper cup and a lower cup which are mounted in relative rotation about an axis, said cups being arranged to form between them at least one chamber annular ring which is delimited laterally by two walls coming from respectively one of said cups, said abutment comprising an internal sealing element which is integral with a first wall, said internal sealing element having an external deflector which is arranged in an external section of said chamber, said abutment comprising an external sealing element which has two sealing surfaces, said external sealing element being movably mounted in the external section between a stable position in which said sealing surfaces are arranged at a distance of complementary bearing surfaces respectively of the second wall and of the external deflector and a constrained position by pressing on said external sealing element in which said sealing surfaces are pressed against respectively one of said complementary surfaces to ensure the sealing of the section at their interface external.

Other particularities and advantages of the invention will appear in the following description, made with reference to the attached figures, in which:

shows in axial section a suspension bearing according to one embodiment of the invention;

shows in exploded perspective the external and internal sealing elements of FIG. 1;

,

, And

are enlarged partial views of Figure 1 centered on the right side of the sealing chamber, the outer sealing element being respectively in a stable position (Figure 3a), in movement towards its constrained position (Figure 3b) and in constrained position (FIG. 3c);

is an enlarged partial view of Figure 3a centered on the outer section of the sealing chamber.

In this description, the terms of positioning in space are taken in reference to the axis of rotation A of the suspension bearing (vertical in figure 1). In particular, the term "inner" is relative to a disposition close to this axis A and the term "exterior" is relative to a disposition at a distance from this axis A. On the other hand, the terms "upper" and "lower" are relative to the arrangement of the abutment as shown in the figures, and the terms "internal" and "external" are relative to an arrangement relative to the interior of the abutment.

A wheel of a motor vehicle, in particular a steering wheel, is mounted on the chassis by means of a strut which allows the suspension of the body relative to the ground. To this end, the strut conventionally comprises a shock absorber, a suspension spring, as well as a suspension stop on which the spring bears directly or indirectly.

In relation to the figures, a suspension bearing is described below which comprises a fixed upper cup 1 intended to be associated with the body of the vehicle in particular via a filter block, and a rotating lower cup 2 comprising a support 3 for the spring suspension, said cups being mounted in relative rotation around an axis A. Thus, when the spring is stressed in compression and in relaxation, the winding of the turns of the latter on themselves is modified, which causes the rotation of the lower cup 2. In addition, the steering of the wheels also induces a rotation of the lower cup 2.

In known manner, a suspension bearing may comprise rolling bodies which are arranged between the cups to allow their relative rotation around the axis A. To do this, the upper 1 and lower 2 cups may each comprise a washer, in particular made in stamped sheet metal, which is provided with a lower and upper raceway respectively for the rolling bodies. As a variant, the cups 1, 2 can be mounted in relative rotation in a smooth manner, with or without the interposition of a friction washer between them.

The abutment further comprises two covering parts, in particular made by molding a rigid thermoplastic material, for example of the polyamide 6.6 type. These parts are respectively a cover 4 associated with the upper washer to be interposed between the chassis and said upper washer, and a support 5 associated under the lower washer, said support comprising the spring support 3. These covering parts 4, 5 allow in particular a recovery of the forces of the spring and possibly those of the impact stop.

The cups 1, 2 are arranged to form between them at least one annular chamber 6 which is delimited laterally by two walls 1a, 2a originating from one of said cups respectively.

In the embodiment shown, the cover 4 comprises an outer annular skirt 7 over which extends a first axial wall 1a, the support 5 having a second axial wall 2a delimiting an annular sealing chamber 6 with the axial wall 1a of said skirt.

In particular, the annular chamber 6 has a radial clearance so as to allow the rotation of the lower cup 2 with respect to the upper cup 1 without interference between them.

To prevent on the one hand the leaks of the lubricant present in the space between the cups 1, 2, and on the other hand the contamination of said space with external pollutants, at least one sealing element 8i, 8e is arranged in the annular chamber 6.

According to one embodiment, the chamber 6 can contain a viscous substance to improve the tightness conferred by the sealing element 8i, 8e. In particular, the substance can also have a lubricating function relative to the movements of the sealing element 8i, 8e in the chamber 6.

In the figures, the chamber 6 has an internal section 6i equipped with an internal sealing element 8i which is arranged between the walls 1a, 2a of the cups 1, 2, being integral with the first wall 1a.

Advantageously, the internal sealing element 8i has:

• an upper internal baffle 9a which is arranged in the upper opening of the internal section 6i, in order to prevent the penetration of lubricant into the sealing chamber 6; And
• a lower external deflector 9b which is arranged in a sixth external section of said chamber, in order to prevent the penetration of external pollutants therein.

When the vehicle is used in bad weather on muddy terrain and / or covered with puddles of water, jets of water and / or mud can be projected at high speed against the outer deflector 9b, the arrangement of which can s prove insufficient to prevent the entry of such pollutants into the chamber 6. The same applies when using a cleaning device projecting jets of water at more or less high pressure.

To protect the sealing chamber 6 against such projections, the abutment further comprises an 8th outer sealing element which is arranged in the 6th outer section of said chamber.

In the embodiment shown, the sealing elements 8i, 8e both have an annular geometry. Furthermore, the sealing elements 8i, 8e are in particular made of rigid thermoplastic material, for example polyoxymethylene, polyethylene, polypropylene, polyamide 6, 6.6, 11 or 12.

The 8th outer sealing element has a sealing surface 10 on which are formed two sealing surfaces 11a, 11b, and is mounted movably in the 6th outer section between:

• a stable position (FIGS. 3a, 4), in which the sealing surfaces 11a, 11b are arranged at a distance from complementary surfaces 12a, 12b formed respectively on the second wall 2a and the external deflector 9b; And
• a constrained position by pressing on the external sealing element 8e (FIG. 3c), in particular induced by a jet of external pollutants, in which the sealing surfaces 11a, 11b are pressed against respectively one of the complementary surfaces 12a, 12b for ensure the tightness of the 6th outer section at their interface.

Thus, as shown in the figures, in the absence of projections of external pollutants, the 8th external sealing element is only in contact with one of the cups 1, 2, so as not to induce a torque of additional friction for the stopper. In addition, the 8th sealing element in a stable position forms an additional sealing baffle in the chamber 6, which improves the sealing of said chamber accordingly.

When a projection of external pollutant comes into contact against the external sealing element 8e, said element is moved into the constrained position to achieve at least partially sealed contact and form a barrier to said projection of external pollutant.

Furthermore, after the projection of pollutant, the 8th element is no longer constrained and therefore returns to a stable position, which makes it possible to break the sealed contact between the sealing surfaces 11a, 11b and the complementary surfaces 12a, 12b, and thus not to induce friction torque between two projections.

In addition, in the event of passage of pollutants beyond the outer section 6e, the return of said element to a stable position allows the flow of these possible pollutants out of the chamber 6. In particular, the outer deflector 9b and the element external sealing 8e are arranged so that, in a stable position, said external sealing element is disposed at a distance from the second wall 2a.

In the embodiment shown, the 6th outer section is oriented downwards, the 8th sealing element being raised in the constrained position. Thus, the return of the 8th sealing element to a stable position is done by gravity.

The complementary bearing surface 12b of the external deflector 9b is bordered by an annular hook 13 which extends at least radially in the direction of the complementary bearing surface 12a of the second wall 2a, in order to form an additional barrier against the entry of external pollutants.

The hook 13 is arranged so that, in a stable position, the external sealing element 8e is placed at a distance from the second wall 2a, in order to allow the evacuation by gravity of any pollutants contained in the chamber 6.

In particular, the hook 13 has a radial annular bearing surface 14 on which, in a stable position, one end of the external sealing element 8e is in peripheral support, which makes it possible to maintain said external sealing element at a distance from the lower cup 2.

Furthermore, the complementary bearing surface 12a of the wall 2a is bordered by a housing 15 in which the external sealing element 8e is arranged in a stable position in order to limit its movements. In the figures, the housing 15 is formed on the axial wall 2a so as to extend under the complementary bearing surface 12a.

In relation to FIG. 4, the complementary bearing surfaces 12a, 12b are inclined with respect to the axis of rotation A by an angle θ ₁ and θ ₂ respectively. Advantageously, the angles θ ₁ and θ ₂ are substantially such that θ ₁ = - θ ₂ , which makes it possible to ensure symmetry between the respective supports of the sealing surfaces 11a, 11b on each of the complementary surfaces 12a, 12b .

One of the sealing surfaces 11a, 11b and the complementary surfaces 12a, 12b are substantially flat, the other of the sealing surfaces 11a, 11b and the complementary surfaces 12a, 12b being curved. Thus, when the 8th element is in the constrained position, sealing is ensured by pressing a toroidal surface against a frustoconical surface. In particular, the 8th element can be slightly deformable to allow movement at the level of the plating between the sealing surfaces 11a, 11b and the complementary surfaces 12a, 12b.

In the figures, the complementary bearing surfaces 12a, 12b are substantially flat, the sealing surfaces 11a, 11b being curved. In particular, the sealing surface 10 has a convex geometry on which one sealing surface 11a is formed, and a fold 16 on which the other sealing surface 11b is formed.

As shown in Figures 3a and 4, the fold 16 is in peripheral support on the hook 13 in a stable position.

The sixth outer section has an opening 17 which is formed between two walls 1b, 2b of a cup 1, 2 respectively. forming a dam intended to reduce the speed and/or the power of a projection of pollutant entering through said opening.

Advantageously, the external deflector 9b is arranged facing the opening 17, in order to further limit the risk of entry of external pollutants into the sealing chamber 6. In particular, the hook 13 extends to the inside the opening 17 in the direction of the external sealing element 8e.

The wall 2b formed on the lower cup 2 extends substantially radially to form, with the lower end 1b of the first axial wall 1a, an opening 17 oriented radially which surrounds the external sealing element 8e.

In addition, the external sealing element 8e has a bearing surface 19 opposite the sealing surface 10 and opposite which the opening 17 opens internally. Preferably, the opening 17 is located axially below the external sealing element 8e.

Thus, when a projection of external pollutant enters through the opening 17, the arrangement of the gap 18 makes it possible to direct said projection on the support surface 19, in order to concentrate the pressure on said surface, and thus allow a setting in correct place of the 8th element in its constrained position.

Advantageously, as shown in the figures, the support surface 19 has a concave geometry, which makes it possible to improve the guidance on it of the projections of pollutants.

In particular, the bearing surface 19 has a peripheral rim formed on the fold 16, which makes it possible to guide external pollutants out of the 6th outer section when the 8th outer sealing element is in the constrained position.

To allow the assembly of the sealing elements 8i, 8e, the internal sealing element 8i has at least two independent segments 20 which each extend over an angular portion, in order to form an internal sealing element 8i of annular geometry.

Advantageously, the segments 20 are identical, which makes it possible to facilitate their manufacture, in particular by means of a single mold, and therefore the manufacture of the internal sealing element 8i.

The segments 20 have ends 20a, 20b of complementary shapes, in order to allow them to be arranged in a substantially continuous annular geometry.

According to an advantageous embodiment to limit the entry of pollutants at the interface between the ends 20a, 20b of the segments 20, at least one of said ends has at least one surface inclined with respect to the axis A. In relation to the FIG. 2, the segments have a V-shaped end with double inclined surfaces, respectively raised 20a and recessed 20b.

Furthermore, the internal sealing element 8i represented in FIG. 2 comprises two segments 20 each with an angular dimension of the order of 180°. In a variant not shown, the internal sealing element 8i can comprise more than two segments 20, in particular three segments each with an angular dimension of the order of 120°.

The second wall 2a has at least one annular groove 21 disposed in the internal section 6i, the internal sealing element 8i having at least one crown 22 which is disposed in said groove so as to form a sealing baffle in said section internal.

In the embodiment shown, the second wall 2a has a set of at least two annular grooves 21 which are separated axially by a crown 23, each extending along a radial depth, the internal sealing element 8i having a set of at least two crowns 22 which are separated axially by a groove 24, each extending along a radial length.

Thus, the internal sealing element 8i forms at least a double sealing baffle in the annular chamber 6, which makes it possible to prevent in a particularly effective manner the passage into said chamber of lubricant and/or external pollutants.

In the figures, the suspension bearing has an internal sealing element 8i provided with a set of three crowns 22, the axial wall 2a being provided with three annular grooves 21.

The internal sealing element 8i comprises an annular body 25 provided with a first axial wall 25a on which the set of crowns 22 extends, said first wall being intended to be arranged facing the axial wall 2a provided with the set of grooves 21 during assembly of the abutment.

The crowns 22 can be made in one piece with the annular body 25, for example by molding, which makes it possible to facilitate the manufacture of the internal sealing element 8i. To do this, each segment 20 may comprise in a single piece an annular body portion and annular crown portions, the annular body 25 and the crowns 22 being formed respectively by the body portions and the corresponding crown portions during the thrust bearing assembly.

In a variant not shown, at least one crown 22 can be formed from a part separate from the internal sealing element 8i, in particular by being mounted in a groove formed for this purpose on said internal sealing element.

At least one crown 22 forms an axial and/or radial clearance 26 with the corresponding groove 21, in order to allow free movement of said crown in said groove. To do this, the crown 22 may in particular have a geometry complementary to that of the groove 21 with a reduced radial and/or axial dimension.

In the embodiment shown, each crown 22 forms with the opposite groove 21 a clearance 26 which extends in a U at the interface between said crown and said groove, thus forming a baffle having a head-to-tail axial superposition of at least two U's.

According to another embodiment, at least one crown 22 can be in frictional contact in the corresponding groove 21, in order to improve the sealing function of the internal element 8i.

Advantageously, the grooves 21 of the lower cup 2 and the crowns 22 of the internal sealing element 8i extend along relatively large depths and radial lengths, which makes it possible to improve the efficiency of the baffle. sealing, but also to maintain said sealing element on the axial wall 2a of said lower cup by nesting of said crowns and grooves.

To assemble the stopper, the external sealing element 8e is placed in the housing 15 of the lower cup 2, then each segment 20 of the internal sealing element 8i is placed on an angular portion of the axial wall 2a respectively. , on the one hand by nesting the crowns 22, 23 in the grooves 21, 24, and on the other hand by arranging the free end of the fold 16 in peripheral support against each hook portion 13 of said segments.

Then, the upper cup 1 is placed on the lower cup 2 – sealing elements 8i, 8e assembly, in order to arrange the said sealing elements between the said cups.

To ensure the cohesion of the stop before it is mounted on the motor vehicle, the internal sealing element 8i and the upper cup 1 have reciprocal means for retaining said upper cup on said internal sealing element.

To do this, in the embodiment shown, the axial wall 1a of the upper cup 1 has such retaining means. In addition, the annular body 25 is provided with a second axial wall 25b, radially opposed to the first wall 25a bearing the crowns 22, on which the retaining means are formed.

The reciprocal retaining means may comprise a geometry in relief arranged to come into axial interference on an abutment. The reciprocal retaining means can also be arranged to snap into place.

In the embodiment shown, the axial wall 1a of the upper cup 1 has a radial projection 27 which is engaged in a groove 28 formed on the second wall 25b to ensure the retention of the internal sealing element 8i on said wall. .

Furthermore, the groove 28 is surmounted by a radial bead 29 which is engaged in a housing 30 formed in the wall 1a, said housing comprising an upper radial bearing surface 31 intended to come into axial abutment on an upper radial bearing surface 32 of said bead when of the assembly of the upper cup 1 on the sealing element 8i.

Claims (15)

Motor vehicle suspension thrust bearing, said thrust bearing comprising an upper cup (1) and a lower cup (2) which are mounted in relative rotation about an axis (A), said cups being arranged to form between them at least one annular ring (6) which is delimited laterally by two walls (1a, 2a) originating respectively from one of said cups, said abutment comprising an internal sealing element (8i) which is integral with a first wall (1a), said element of internal sealing having an external deflector (9b) which is arranged in an external section (6e) of said chamber, said abutment being characterized in that it comprises an external sealing element (8e) which has two sealing surfaces (11a, 11b), said external sealing element being movably mounted in the external section (6e) between a stable position in which said sealing surfaces are arranged at a distance from complementary surfaces (12a, 12b) of respectively the second wall (2a) and of the external deflector (9b) and a constrained position by pressing on said external sealing element in which said sealing surfaces are pressed against respectively one of said complementary surfaces to ensure the sealing of the external section at their interface (6th). Suspension thrust bearing according to Claim 1, characterized in that the external deflector (9b) and the external sealing element (8e) are arranged so that, in a stable position, the said external sealing element is arranged at a distance from the second wall (2a). Suspension thrust bearing according to one of Claims 1 or 2, characterized in that the complementary bearing surface (12b) of the external deflector (9b) is bordered by an annular hook (13) which extends at least radially in the direction of the complementary (12a) to the second wall (2a), said hook having a radial annular bearing surface (14) on which, in a stable position, one end of the external sealing element (8e) rests peripherally. Suspension thrust bearing according to any one of Claims 1 to 3, characterized in that the complementary bearing surfaces (12a, 12b) are inclined with respect to the axis (A) of rotation by an angle respectively (θ ₁ ) and ( _θ2 ). Suspension thrust bearing according to Claim 4, characterized in that the angles (θ ₁ ) and (θ ₂ ) are substantially such that: θ ₁ = - θ ₂ . Suspension thrust bearing according to any one of Claims 1 to 5, characterized in that one of the sealing surfaces (11a, 11b) and the complementary surfaces (12a, 12b) are substantially planar, the other of the sealing surfaces (11a, 11b) and the complementary surfaces (12a, 12b) being curved. Suspension thrust bearing according to any one of Claims 1 to 6, characterized in that the external sealing element (8e) has a sealing surface (10) having a convex geometry on which a sealing surface (11a ) is formed, and a fold (16) on which the other sealing surface (11b) is formed. Suspension stopper according to Claim 7 when dependent on Claim 3, characterized in that the fold (16), in the stable position, rests peripherally on the hook (13). Suspension thrust bearing according to one of Claims 7 or 8, characterized in that the external sealing element (8e) has a bearing surface (19) of concave geometry, the said bearing surface having a peripheral rim formed on the fold (16). Suspension thrust bearing according to any one of Claims 1 to 9, characterized in that the external section (6e) has an opening (17) which is formed between two walls (1b, 2b) of respectively a cup (1, 2) , the outer deflector (9b) being arranged facing said opening. Suspension thrust bearing according to any one of Claims 1 to 10, characterized in that the internal sealing element (8i) has at least two independent segments (20) which each extend over an angular portion to form an element sealing (8i) of annular geometry. Suspension thrust bearing according to any one of Claims 1 to 11, characterized in that the annular chamber (6) has an internal section (6i) in which the second wall (2a) has at least one annular groove (21), the internal sealing element (8i) having at least one crown (22) which is arranged in the groove (21) so as to form a sealing baffle in said internal section. Suspension thrust bearing according to Claim 12, characterized in that the second wall (2a) has a set of at least two annular grooves (21) which are separated axially by a ring (23) each extending along a radial depth , the internal sealing element (8i) having a set of at least two crowns (22) which are axially separated by a groove (24) each extending along a radial length, said internal sealing element being placed in the internal section (6i) by nesting the crowns (22, 23) in the grooves (21, 24). Suspension thrust bearing according to any one of Claims 1 to 13, characterized in that the first wall (1a) has a radial projection (27) which is engaged in a groove (28) of the internal sealing element (8i ) to ensure its retention on said wall. Suspension thrust bearing according to Claim 14, characterized in that the groove (28) is surmounted by a radial bead (29) which is engaged in a housing (30) formed in the first wall (1a).