FR3117939A1 - Sealed suspension stopper device - Google Patents

Abstract

The device comprises a lower support cover 16, an upper support cover 14, and at least one bearing 18 disposed between said covers, the support cover comprising an outer skirt 14c radially surrounding at least partly the support cover 16 The device further comprises at least one outer seal 19 arranged radially between the outer skirt 14c of the support cover and the support cover 16. The seal 19 is mounted on one of the covers, leaving a radial mounting clearance with said cowl, the seal being axially integral with said cowl. The seal 19 is provided with an annular centering portion 19a comprising a free end resting against said cover and with at least one annular sealing lip 19b extending in the direction of the other cover which delimits at least in part an annular chamber 40 open axially downwards. Reference: Figure 1

Description

Sealed suspension stopper device

Technical field of the invention

The present invention relates to the field of suspension thrust bearing devices used in particular for motor vehicles in the suspension struts of the steered wheels.

State of the prior art

A suspension thrust bearing device generally comprises a bearing forming an axial thrust bearing and upper and lower covers forming a housing for the rings of the bearing and making it possible to provide the interface between said rings and the neighboring elements.

The suspension thrust bearing device is arranged in the upper part of the suspension strut between a suspension spring and the vehicle body. The suspension spring is mounted around a shock absorber piston rod, the end of which is linked to the vehicle body. The suspension spring, of the helical spring type, bears axially directly or indirectly on the lower cover of the suspension thrust bearing device.

The suspension thrust bearing device makes it possible to transmit axial and radial forces between the suspension spring and the body of the vehicle while allowing a relative rotational movement between the lower cover and the upper cover resulting from a turning of the steering wheels of the vehicle and/or compression of the suspension spring.

Generally, the upper cover of the suspension thrust bearing device is provided with a plurality of hooks arranged on an outer skirt and adapted to interfere diametrically with a plurality of hooks of the lower cover. The hooks of each cover are spaced from each other in the circumferential direction.

The hooks form retaining means making it possible to axially retain the upper and lower cowls relative to each other. These hooks also form narrow passages in order to limit the intrusion of polluting particles radially between the outer skirt of the upper cowl and the lower cowl.

However, a bump stop device is generally exposed to various types of pollution.

With such a device, polluting particles can easily infiltrate between the outer skirt of the upper cover and the lower cover, then be directed towards the bearing and be introduced inside the latter.

The present invention aims to remedy this drawback.

The invention relates to a suspension thrust bearing device comprising a lower support cover, an upper support cover, and at least one bearing arranged between said covers. The upper support cover comprises an outer skirt radially surrounding at least partially the lower support cover.

According to a general characteristic, the device further comprises at least one outer seal arranged radially between the outer skirt of the upper support cover and the lower support cover.

The external seal is mounted on one of the lower support and upper support covers, leaving a radial mounting clearance with said cover. The outer seal is axially integral with said cover.

By “axially secured to said cover”, it is meant that the external seal is fixed with respect to said cover in the axial direction.

The external seal is provided with an annular centering portion comprising a free end resting against said cover and with at least one annular sealing lip extending in the direction of the other cover. The centering portion and said sealing lip delimit at least in part an annular chamber which is open axially downwards.

The external seal limits the intrusion of dust, water and other types of polluting particles inside the bearing. In addition, the chamber delimited by the seal makes it possible to obtain a recirculation of the water initially directed upwards towards the bearing which is returned downwards by the sealing lip.

In a particular embodiment, the radial assembly play extends axially over the entire axial height of the centering portion of the seal with the exception of the bearing zone of the free end of the portion of centering with said cover. Alternatively, the radial mounting clearance may extend axially over the entire axial height of the centering portion of the seal.

In one embodiment, the centering portion and said sealing lip of the outer seal radially delimit the chamber. In another embodiment, the centering portion of the outer seal and said other cover radially delimit the chamber.

In one embodiment, the external seal may comprise an annular heel from which extend the centering portion and said sealing lip, and axially delimiting the chamber.

The centering portion of the outer seal can be held axially between an abutment surface and a bearing surface of said cowl. Retention of the seal is ensured by axial locking against said cover. It is not necessary to use an additional specific element to secure the seal to said cover.

In one embodiment, the bearing surface of said cowl is radial, and the abutment surface is also radial.

In another embodiment, the free end of the centering portion bears against a bearing surface of said cover which is frustoconical or toroidal and the centering portion bears axially against a radial abutment surface, the surface support of said cover having an outer diameter which decreases on the side of the radial abutment surface.

The contact between the free end of the centering portion of the seal and the bearing surface of said cover generates an axial force directed towards the radial abutment surface of the cover which tends to maintain permanent axial contact between this surface of abutment and the centering portion of the gasket. This favors the axial blocking of the seal and the maintenance of a good seal between the seal and said cover.

In one embodiment, the outer seal is elastically deformable.

By "elastically deformable seal" is meant a seal capable, by the material used and/or its size, of deforming under the action of a stress exerted thereon, and of stretching to resume by elasticity its initial shape in the unassembled free state.

In this case, at least the free end of the centering portion can be deformed radially in the direction of the other cowl by pressing against the bearing surface of said cowl. This further increases the axial blocking of the seal and the maintenance of a good seal between the seal and said cover. Indeed, by elasticity, the centering portion of the seal tends to return to its initial shape in the free state.

According to a particular design, said cover may comprise at least one hook extending radially in the direction of said other cover and delimiting said abutment surface.

In one embodiment, the lower free end of the centering portion of the seal bears against said cover. Alternatively, the upper free end of the centering portion of the seal can bear against said cover.

According to a first design, the external seal is mounted radially around the lower support cover.

According to a second alternative design, the external seal is mounted in the bore of the external skirt of the upper support cover.

The invention also relates to a suspension thrust bearing device comprising a lower support cover, an upper support cover, and at least one bearing arranged between said covers. The upper support cover includes an internal skirt extending at least partially into the bore of the lower support cover.

According to a general characteristic, the device further comprises at least one internal seal arranged radially between the internal skirt of the upper support cover and the lower support cover.

The internal seal is mounted on one of the lower support and upper support covers, leaving a radial mounting clearance with said cover. The internal seal is axially integral with said cover.

The internal seal is provided with an annular centering portion comprising a free end resting against said cover and with at least one annular sealing lip extending in the direction of the other cover. The centering portion and said sealing lip delimit at least in part an annular chamber which is open axially downwards.

Brief description of figures

The present invention will be better understood on studying the detailed description of the embodiments, taken by way of non-limiting examples and illustrated by the appended drawings in which:

is a sectional view of a suspension thrust bearing device according to a first embodiment of the invention,

is a detail view of the ,

is a detail view of a suspension thrust bearing device according to a second embodiment of the invention,

is a detail view of a suspension thrust bearing device according to a third embodiment of the invention,

is a sectional view of a suspension thrust bearing device according to a fourth embodiment of the invention, and

is a sectional view of a suspension thrust bearing device according to a fifth embodiment of the invention.

Detailed description of the invention

The suspension thrust bearing device 10 represented on the is adapted to be installed between a cup or upper support seat coming into contact against an element of the fixed frame of a motor vehicle, and a suspension spring of the helical type. On the , the device 10 is shown in an assumed vertical position.

The device 10, with axis 12, comprises an upper support cover 14, a lower support cover 16, and a rolling bearing 18 interposed axially between said covers. In the example illustrated, the covers 14, 16 are mounted in direct contact with the bearing 18 without the interposition of an intermediate element. Alternatively, the covers 14, 16 can be mounted in indirect contact with the bearing 18 with the interposition of an intermediate element.

As will be described in more detail below, the device 10 further comprises an external seal 19 to prevent the intrusion of pollutants towards the bearing 18. In the example illustrated, the seal 19 is fixed on the lower support cover 16.

The upper support cover 14 may be made of a single piece, for example of plastic material, for example such as a polyamide PA 6.6, which may or may not be reinforced with glass fibers.

The support cover 14, with axis 12, comprises a radial portion 14a, an annular axial inner skirt 14b, and an annular axial outer skirt 14c radially surrounding the inner skirt. The radial portion 14a has an upper surface 15 intended to come opposite the upper bearing seat, and an opposite lower surface 17 in contact with the bearing 18. The upper and lower surfaces 15, 17 define the thickness of the radial portion 14a. In the example illustrated, the radial portion 14a has a stepped shape.

The outer skirt 14c of the support cover radially partially surrounds the lower support cover 16. The outer skirt 14c extends axially. The outer skirt 14c extends axially from the radial portion 14a. In the example shown, the outer skirt 14c extends a large diameter edge of the radial portion 14a.

The inner skirt 14b of the support cover extends inside the bore of the lower support cover 16. The inner and outer skirts 14b, 14c extend axially downward from the radial portion 14a. The inner skirt 14b extends a small diameter edge of the radial portion 14a.

The upper support cover 14 further comprises a plurality of internal hooks 14d arranged on the inner skirt 14b and extending radially outwards in the direction of the lower support cover 16. In the example shown, the hooks 14d are spaced from each other in the circumferential direction. Alternatively, it might be possible to provide a ring hook.

The bearing 18 is located entirely radially between the skirts 14b, 14c of the upper support cover 14. The bearing 18 comprises an upper ring 20 in contact with the upper support cover 14, a lower ring 22 in contact with the lower support cover 16, and a row of rolling elements 24, here balls, arranged between the tracks bearings formed on the rings. In the example shown, the bearing 18 is of the angular contact type. The upper ring 20 is in contact with the lower surface 17 of the radial portion 14a of the upper support cover. The lower ring 22 is in contact with an upper surface of the lower support cover 16.

The lower support cover 16 may consist of a single piece, for example of plastic material, for example such as a polyamide PA 6.6, which may or may not be reinforced with glass fibers.

The support cover 16, with axis 12, comprises an annular radial portion 28 in the form of a plate, and an annular axial skirt 30 which extends an edge of small diameter of the radial portion 28. The skirt 30 extends axially at the opposite the upper support cover 14 and the bearing 18. The skirt 30 allows the centering of the suspension spring. The radial portion 28 has a lower annular radial surface 28a delimiting a bearing surface for the suspension spring, and an upper surface 28b in contact with the lower ring 22 of the bearing and of complementary shape.

The lower support cover 16 further comprises a plurality of internal hooks 32 made in the bore of the radial portion 28 and extending radially inwards towards the inner skirt 14b of the upper bearing cover. The hooks 32 are spaced apart from each other in the circumferential direction, preferably regularly. Alternatively, the support cover 16 may comprise an annular inner hook.

The hooks 32 are arranged axially above the hooks 14d of the internal skirt 14b of the upper support cover. The hooks 14d have an outer diameter greater than the inner diameter of the hooks 32 so as to be able to interfere diametrically with the hooks 32 in the event of relative axial displacement of the support cover 14 and the support cover 16. The hooks 14d of the cover upper support form axial retaining means cooperating with complementary axial retaining means of the support cover 16 formed by the hooks 32.

Furthermore, the hooks 14d, 32 form narrow passages in order to limit the intrusion of foreign bodies radially between the internal skirt 14b of the upper support cover and the skirt 30 of the lower support cover.

The support cover 16 also includes an annular outer hook 34 extending radially outwards in the direction of the outer skirt 14c of the upper support cover. The hook 34 extends here at the upper free end of the radial portion 28 of the support cover. Alternatively, the support cover 16 could comprise a plurality of outer hooks spaced from each other in the circumferential direction.

As indicated above, the external seal 19 is fixed to the lower support cover 16. The seal 19 is integral with the support cover 16. The seal 19 is annular. Seal 19 radially surrounds support cover 16. Seal 19 is mounted radially around the outer surface of support cover 16. Seal 19 is mounted radially around radial portion 28 of the support cover.

The seal 19 closes the radial space existing between the lower support cover 16 and the outer skirt 14c of the bearing cover.

As is illustrated more visibly in , a radial assembly clearance 35 remains between the seal 19 and the support cover 16. The radial clearance 35 is defined between the bore of the seal 19 and the cylindrical outer surface of the support cover 16 around which the gasket is fitted. In the free state, the internal diameter of the seal 19 is greater than the external diameter of this cylindrical external surface of the support cap. In other words, there is no radial interference between the seal 19 and this cylindrical outer surface of the support cover.

The seal 19 is mounted axially between the lower radial surface 34a of the hook 34 and a frustoconical surface 36 made on the outer surface of the support cover. The frustoconical surface 36 has an outer diameter which decreases on the side of the lower surface 34a. The tapered surface 36 is provided on the radial portion 28 of the support cover.

The seal 19 is held axially between the frustoconical surface 36 and the lower surface 34a of the hook. The frustoconical surface 36 forms a lower bearing surface for the seal 19 and the lower surface 34a of the hook forms an upper abutment surface.

The seal 19 is provided with an annular centering portion 19a mounted radially around the support cover 16. The centering portion 19a is mounted radially around the radial portion 28 of the support cover. The centering portion 19a extends axially. The centering portion 19a delimits the bore of the seal 19.

The centering portion 19a rests against the tapered surface 36 of the support cover. The lower free end of the centering portion 19a bears against the frustoconical surface 36. The centering portion 19a is in static sealing contact with the frustoconical surface 36 of the support cover over 360°.

Axially on the opposite side, the centering portion 19a of the seal is axially in abutment against the lower surface 34a of the hook of the support cover. The upper end of the centering portion 19a abuts axially against the lower surface 34a. In the illustrated embodiment, the centering portion 19a is in static sealing contact with the lower surface 34a of the hook of the support cover over 360° given the annular shape of the hook 34.

The seal 19 is also provided with an annular sealing lip 19b which radially surrounds the centering portion 19a. The lip 19b extends in the direction of the outer skirt 14c of the support cover. The lip 19b extends obliquely downward. In the illustrated embodiment, the lip 19b extends in the direction of the outer skirt 14c of the support cover while remaining radially at a short distance from the latter. The lip 19b forms a labyrinth lip. The lip 19b cooperates with the outer skirt 14c of the support cover to form a labyrinth type seal. Alternatively, the lip 19b could cooperate with the outer skirt 14c of the support cover by friction.

The seal 19 is also provided with an annular heel 19c from which the centering portion 19a and the lip 19b project. In other words, the heel 19c connects the centering portion 19a and the lip 19b. Centering portion 19a extends radially inward from heel 19c and axially downward. The lip 19b extends obliquely downwards from the heel 19c in the direction of the outer skirt 14c of the bearing cap. Centering portion 19a and lip 19b protrude downward from a bottom surface of heel 19c.

The hook 34 of the support cover has an outside diameter greater than the inside diameter of the seal 19, in this case the diameter of the bore of the seal. The hook 34 ensures the axial retention of the seal 19.

The seal 19 is mounted on the support cover 16 by axial thrust from top to bottom. So as to facilitate this assembly, the upper surface of the hook 34 is of frustoconical shape.

As can be seen in FIGS. 1 and 2, after assembly, the lower free end of the centering portion 19a of the seal is deformed radially outwards by contact against the frustoconical surface 36 of the support cover.

This deformation combined with the contact of the lower free end of the centering portion 19a of the seal against the frustoconical surface 36 of the support cover generates an axial force directed upwards which tends to maintain the axial contact between the portion of centering 19a of the seal and the lower surface 34a of the hook of the support cover. This favors the axial blocking of the seal 19 and the maintenance of a good seal between the seal and the support cover 14. The centering portion 19a of the seal is prestressed axially between the frustoconical surface 36 of the support and the lower surface 34a of the hook.

The support between the lower free end of the centering portion 19a of the seal and the support cover 16 is the only contact having a component in the radial direction which exists between the seal and the cover. In other words, there is no radial interference between the seal 19 and the support cover 16 outside this bearing zone.

The radial assembly clearance 35 extends axially over the entire axial height of the centering portion 19a of the seal, with the exception of the bearing zone of the lower free end of the centering portion with the cover. support. The radial assembly clearance 35 extends axially at least over the entire axial height of the undeformed part of the centering portion 19a of the seal.

The seal 19 is preferably elastically deformable. The seal 19 can for example be made of elastically deformable material, for example nitrile or elastomer. The seal 19 can also be made of a more rigid material, for example polyoxymethylene (POM). The seal 19 is advantageously made in one piece, for example by molding.

The centering portion 19a and the lip 19b of the seal radially delimit an outer annular chamber 40. The chamber 40 is open axially downwards, i.e. axially on the side of the support cover. The chamber 40 is oriented axially downward. The chamber 40 is delimited axially by the heel 19c.

The chamber 40 delimited by the seal 19 makes it possible to limit the intrusion of polluting particles between the support 16 and support 14 caps likely to be directed towards the bearing 18. In addition, the chamber 40 makes it possible to obtain a recirculation of the water directed upwards in the direction of the bearing 18 which is returned downwards by the lip 19b.

As indicated above, in this embodiment, the seal 19 is mounted axially between the lower radial surface 34a of the hook 34 and the tapered surface 36 of the support cover.

Alternatively, it is possible to provide on the support cover 16 another type of surface for cooperation with the seal 19. For example, as illustrated in , on which the identical elements bear the same references, the outer surface of the support cover may comprise a toroidal surface 42 having in cross section a convex profile in the form of an arc of a circle and against which the lower free end of the portion of the centering 19a of the seal. The outer diameter of the toroidal surface 42 decreases on the side of the radial lower surface 34a of the hook 34 of the support cover.

In another variant illustrated in , on which the identical elements bear the same references, the outer surface of the support cover may comprise a toroidal surface 44 having in cross section a concave profile in the form of an arc of circle and against which the lower free end of the portion of the centering 19a of the seal. The outer diameter of the toroidal surface 44 decreases towards the radial lower surface 34a of the hook 34 of the support cover.

The embodiment illustrated in , on which the identical elements bear the same references, differs from the first embodiment by the orientation of the lip 19b of the seal.

In this example, the lip 19b of the seal extends radially in the direction of the outer skirt 14c of the support cover. The lip 19b also remains here at a distance from the outer skirt 14c. Alternatively, the lip 19b could be of the rubbing type. In this example, the lip 19b extends radially from the centering portion 19a. Lip 19b extends from the outer surface of centering portion 19a. The seal 19 is here devoid of heel. Alternatively, it would be possible to provide a seal 19 equipped with a heel.

In this embodiment, the centering portion 19a of the seal and the outer skirt 14c of the support cover radially delimit the chamber 40. The chamber 40 is delimited axially by the lip 19b of the seal. The chamber 40 is open axially downwards. The chamber 40 is oriented axially downward.

The embodiment illustrated in , on which the identical elements bear the same references, differs from the first embodiment in that the upper surface 15 of the support cover is oriented perpendicularly with respect to an axis 46 forming a non-zero angle α with the axis 12 of the device.

In the embodiments illustrated, the seal 19 comprises a single sealing lip extending in the direction of the support cover 14 to cooperate with the latter and obtain a seal. Alternatively, the seal 19 may comprise at least two sealing lips extending in the direction of the bearing cap 14 to form a labyrinth type and/or friction seal.

In the embodiments illustrated, the seal 19 is mounted on the support cover 16. Alternatively, the seal could be mounted on the support cover 14. In this case, the seal is axially integral with the support cover 14, via the centering portion, and leaves a radial mounting clearance with the outer skirt 14c of the support cover. In the free state, the outside diameter of the seal is greater than the inside diameter of the cylindrical part of the bore of the bearing cover 14. The sealing lip(s) of the seal extend in the direction of the cover support 16.

In the embodiments illustrated, the device comprises a single external seal located radially between the support cover 16 and the outer skirt 14c of the support cover. Alternatively or in combination, the device may comprise an internal seal located radially between the support cover 16 and the internal skirt 14c of the support cover. This internal seal can be of a similar design to the external seal or of a different design.

In the embodiments illustrated, the device comprises an angular contact rolling bearing provided with a row of balls. The device may include other types of rolling bearings, for example a bearing with four contact points and/or with at least two rows of balls. The rolling bearing may include other types of rolling elements, for example rollers. In another variant, the bearing of the device may comprise a sliding bearing devoid of rolling elements and provided with one or more rings.

Claims (10)

Suspension thrust bearing device comprising a lower support cover (16), an upper support cover (14), and at least one bearing (18) disposed between said covers, the upper support cover (14) comprising a skirt (14c) radially surrounding at least partly the lower support cover (16), characterized in that it further comprises at least one external seal (19) disposed radially between the outer skirt (14c) of the cover upper support and the lower support cover (16), the outer seal (19) being mounted on one of the lower support and upper support covers, leaving a radial assembly clearance (35) with said cover, the outer seal (19) being axially integral with said cover, the outer seal (19) being provided with an annular centering portion (19a) comprising a free end resting against said cover and at least one annular sealing lip (19b) extending in the direction of the a ur cover, the centering portion (19a) and said sealing lip (19b) delimiting at least in part an annular chamber (40) which is open axially downwards. Device according to Claim 1, in which the radial assembly clearance (35) extends axially over the entire axial height of the centering portion (19a) of the seal, with the exception of the interference zone of the free end of the centering portion with said cover. Device according to Claim 1 or 2, in which the centering portion (19a) and the said sealing lip (19b) of the outer seal radially delimit the chamber (40). Device according to Claim 1 or 2, in which the centering portion (19a) of the external seal and the said other cover radially delimit the chamber (40). Device according to any one of the preceding claims, in which the external seal (19) is provided with an annular heel (19c) from which extend the centering portion (19a) and the said sealing lip (19b), and axially delimiting the chamber (40). Device according to any one of the preceding claims, in which the centering portion (19a) of the external seal (19) is held axially between an abutment surface (34a) and a bearing surface (36; 42; 44) of said cover. Device according to any one of the preceding claims, in which the free end of the centering portion (19a) bears against a bearing surface (36; 42; 44) of the said cover which is frustoconical or toroidal, the portion (19a) bearing axially against a radial abutment surface (34a), the bearing surface (36; 42; 44) of said cover having an outer diameter which decreases on the side of the radial abutment surface (34a) . Device according to Claim 7, in which the external seal (19) is elastically deformable and at least the free end of the centering portion (19a) is deformed radially in the direction of the other cover by the bearing against the bearing surface (36; 42; 44) of said cover. Device according to any one of Claims 6 to 8, in which the said cover comprises at least one hook (34) extending radially in the direction of the said other cover and delimiting the abutment surface (34a). Device according to any one of the preceding claims, in which the external seal (19) is mounted radially around the lower support cover (16).