Suspension stop device with sealing gasket

Abstract

[Suspension bump stop device with sealing gasket] This suspension bump stop device (2) comprises a lower support cover (6), an upper support cover (4), at least one bearing (8) disposed between said covers (4, 6), and at least one sealing gasket (10) disposed radially at least partially between a skirt (14, 16) of the upper support cover (4) and the bearing (8), said sealing gasket (10) being integral with one of the lower support cover (4) and upper support cover (6) and having a sealing portion (40) extending towards said other cover (4, 6), at least one cavity (42, 52, 54) being formed on the sealing portion (40) of said sealing gasket (10) and being open towards said other cover (4, 6), said cavity (42, 52, 54) being filled with lubricant (44) to form a seal with said other hood (4, 6).

Description

Title of the invention: Suspension stop device with sealing gasket Technical field of the invention

[0001] The present invention relates to the field of suspension stop devices used in particular for motor vehicles in the suspension struts of the steering wheels. Prior art

[0002] A suspension stop device generally comprises a bearing forming an axial stop and upper and lower covers forming a housing for the bearing rings and ensuring the interface between said rings and the surrounding elements.

[0003] The suspension bump stop device is located in the upper part of the suspension strut between a suspension spring and the vehicle body. The suspension spring is mounted around a damper piston rod, the end of which is connected to the vehicle body. The suspension spring, of the helical type, bears axially, either directly or indirectly, against the lower end of the suspension bump stop device.

[0004] The suspension stop device allows axial and radial forces to be transmitted between the suspension spring and the vehicle body while allowing a relative rotational movement between the lower hood and the upper hood resulting from a steering of the vehicle's steering wheels and / or the compression of the suspension spring.

[0005] Generally, the upper cover of the suspension stop device is provided with a plurality of hooks arranged on an external skirt and adapted to interfere diametrically with a plurality of hooks on the lower cover. The hooks on each cover are spaced from each other in the circumferential direction.

[0006] The hooks form retaining means for axially retaining the upper and lower covers relative to each other. These hooks also form narrow passages to limit the intrusion of polluting particles radially between the outer skirt of the upper cover and the lower cover.

[0007] However, such a suspension stop device is generally exposed to various types of pollution.

[0008] Indeed, 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.

[0009] To remedy this drawback, it is known from patent application DE-Al-10 2020 201 404 (SKF) to provide an external sealing gasket fixed by pinching between the bearing and the lower cover of the suspension stop device and provided with at least one sealing lip cooperating with the upper cover.

[0010] The present invention aims to further improve the sealing of suspension stop devices. Summary of the invention

[0011] The invention relates to a suspension stop device comprising a lower support cover, an upper support cover, at least one bearing disposed between said covers, and at least one sealing gasket disposed radially at least in part between a skirt of the upper support cover and the bearing.

[0012] Said sealing gasket is integral with one of the lower support and upper support covers.

[0013] Said sealing joint is provided with a sealing portion extending towards said other hood.

[0014] According to a general characteristic, at least one cavity is formed on the sealing portion of said sealing joint and is open towards said other hood, said cavity being filled with lubricant to form a seal with said other hood.

[0015] The lubricant-filled cavity in the sealing portion ensures a seal between the sealing portion of said seal and said other cover by forming a barrier that stops polluting particles from reaching the bearing. Furthermore, the lubricant reduces friction between the sealing portion of said seal and said other cover, thereby reducing wear on the seal and the friction torque of the thrust bearing.

[0016] By "sealing gasket integral with one of the lower support and upper support covers," it is understood that said sealing gasket is fixed relative to said cover. Said sealing gasket may be an added part fixed to said cover, or alternatively said sealing gasket may be made in one piece with said cover by molding or overmolding onto said cover.

[0017] According to a first conception, the sealing portion of said sealing gasket remains at a distance from said other cover. In this case, only the lubricant comes into contact with said other cover.

[0018] According to a second alternative design, the sealing portion of said sealing joint can bear against said other cover.

[0019] Advantageously, the cavity of the sealing portion of the sealing joint is annular. This further improves the sealing of the stop device, as the lubricant can form a 360° bead.

[0020] Advantageously, the sealing portion of said sealing joint comprises an axial skirt which radially surrounds said cavity.

[0021] Said axial skirt forms a barrier stopping polluting particles before they reach said cavity of the sealing portion of said sealing joint. The service life and effectiveness of the lubricant are thus improved.

[0022] Optionally, the sealing portion of said sealing joint extends purely axially.

[0023] In one embodiment, said cavity of the sealing portion of said sealing joint is open both radially and axially with respect to said other cover, said cavity being formed at a free end of the sealing portion.

[0024] The sealing portion of said sealing joint may include at least one bead extending radially in projection towards said other cover, said bead delimiting at least in part said cavity.

[0025] In a particular embodiment, the device comprises at least first and second cavities formed on the sealing portion of said seal and filled with lubricant, the second cavity being offset axially with respect to the first cavity on the side of said hood and offset radially with respect to the first cavity on the side of said other hood, the first and second cavities being immediately successive in the axial direction.

[0026] Said first and second cavities filled with lubricant further improve the seal between the sealing portion of said sealing joint and said other cover.

[0027] As previously stated, said sealing gasket may be overmolded onto said hood. Alternatively, said sealing gasket may be fixed to said hood by any other suitable means.

[0028] Advantageously, said sealing joint comprises an annular heel integral with said hood, the sealing portion extending from said annular heel.

[0029] Advantageously, the free end of said upper support hood skirt is axially offset downwards relative to the free end of the sealing portion of said sealing joint.

[0030] According to a first design, the sealing gasket is arranged radially, at least in part, between the bearing and an external skirt of the upper support cover which radially surrounds said sealing gasket. The sealing gasket thus forms an external sealing gasket.

[0031] Alternatively, according to a second design, the seal is arranged radially between the bearing and an internal skirt of the support cover which extends at least partially into the bore of said support cover. The seal thus forms an internal seal.

[0032] According to a third design, the device comprises both a sealing gasket external and an internal sealing gasket as described previously.

[0033] Advantageously, the sealing portion of said sealing joint leaves an annular space between said cavity and said other cover. Brief description of the figures

[0034] The present invention will be better understood upon study of the detailed description of embodiments, taken by way of non-limiting examples and illustrated by the accompanying drawings in which:

[0035] [Fig-1] is an axial cross-sectional view of a suspension stop device according to a first example of the realization of the invention;

[0036] [Fig.2] is a detail view of [Fig.1];

[0037] [Fig.3] is a detail view of a suspension stop device according to a second example of the realization of the invention;

[0038] [Fig.4] is a detail view of a suspension stop device according to a third example of the implementation of the invention;

[0039] [Fig.5] is a detail view of a suspension stop device according to a fourth example of an embodiment of the invention and

[0040] [Fig.6] is a detail view of a suspension stop device according to a fifth example of an implementation of the invention. Detailed description of the invention

[0041] The suspension stop device 2 shown in [Fig. 1] is adapted to be installed between a cup or upper support seat in contact with a fixed chassis element of a motor vehicle, and a helical suspension spring. In [Fig. 1], the device 2 is shown in a position assumed to be vertical.

[0042] The device 2, with axis X-X', comprises an upper support cover 4, a cover of lower support 6, and a bearing 8 interposed axially between said hoods 4, 6.

[0043] In the illustrated example, the upper support cover 4 and the lower support cover 6 are mounted in direct contact with the bearing 8 without the interposition of an intermediate element. Alternatively, the upper support cover 4 and the lower support cover 6 can be mounted in indirect contact with the bearing 8 with the interposition of an intermediate element.

[0044] As will be described in more detail later, the device 2 further includes an external annular seal 10 to prevent the intrusion of pollutants towards the bearing 8.

[0045] In the illustrated example, the sealing gasket 10 is fixed to the upper support cover 4 and extends towards the lower support cover 6. The sealing gasket 10 can be fixed to the upper support cover 4 by any other suitable means, for example by axial and / or radial interference with the upper support cover 4, by gluing, by overmolding etc.

[0046] The upper support cover 4 can 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.

[0047] The upper support cover 4, with axis X-X', comprises a radial portion 12, a skirt internal 14 axial annular, and an external 16 axial annular skirt radially surrounding the internal skirt 14.

[0048] The radial portion 12 of the upper support cover 4 has an upper surface (not referenced) intended to be aligned with the upper support seat, and an opposing lower surface (not referenced) in contact with the bearing 8. These upper and lower surfaces define the thickness of the radial portion 12 of the upper support cover 4. In the illustrated example, the radial portion 12 of the upper support cover 4 has a stepped shape. In the illustrated embodiment, the sealing gasket 10 is fixed to the radial portion 12 of the upper support cover 4.

[0049] The outer skirt 16 of the upper support cover 4 radially surrounds part of the lower support cover 6, the outer skirt 16 extending axially from the radial portion 12 of the upper support cover 4. In the illustrated example, the outer skirt 16 of the upper support cover 4 extends a large-diameter edge of the radial portion 12 of the upper support cover 4. The outer skirt 16 radially surrounds the sealing gasket 10

[0050] The inner skirt 14 of the upper support cover 4 extends inside the bore of the lower support cover 6. The inner and outer skirts 14, 16 of the upper support cover 4 extend axially downwards from the radial portion 12 of the upper support cover 4. The inner skirt 14 extends a small-diameter edge of the radial portion 12 of the upper support cover 4.

[0051] The lower support cover 6, with axis X-X', includes an annular radial portion 20 in the shape of a plate, and an annular axial skirt 22 extending a small diameter edge of the radial portion 20 of the lower support cover 6.

[0052] The skirt 22 of the lower support cover 6 extends axially opposite the upper support cover 4 and the bearing 8. The skirt 22 of the lower support cover 6 allows the centering of the suspension spring.

[0053] The radial portion 20 of the lower support cover 6 has a lower annular radial surface delimiting a bearing surface for the suspension spring.

[0054] The upper support cover 4 comprises a plurality of internal hooks 24 arranged on the inner skirt 14 of the upper support cover 4 and extending radially outwards towards the lower support cover 6. In the illustrated example, the The 24 brackets are spaced circumferentially from each other. Alternatively, it might be possible to use a single annular 24 bracket.

[0055] The lower support cover 6 comprises a plurality of internal hooks 26 arranged on the radial portion 20 of the lower support cover 6 and extending radially inwards towards the upper support cover 4, said plurality of internal hooks 26 being adapted to interfere diametrically with the plurality of internal hooks 24 of the upper support cover 4. Alternatively, it could be possible to provide a single annular hook 26.

[0056] The hooks 24, 26 form retaining means allowing the upper support cover 4 and the lower support cover 6 to be axially retained relative to each other.

[0057] The bearing 8 is entirely situated radially between the skirts 14, 16 of the upper support cover 4. The bearing 8 comprises an upper ring 28 in contact with the upper support cover 4, a lower ring 30 in contact with the lower support cover 6, and a row of rolling elements 32, here balls, arranged between the raceways formed on the rings 28, 30. In the illustrated example, the bearing is of the angular contact type. The upper ring 28 is in contact with the lower surface of the radial portion 12 of the upper support cover 4. The lower ring 30 is in contact with an upper surface of the lower support cover 6, said upper surface being complementary in shape to the lower ring 30 of the bearing 8.

[0058] The lower support cover 6 is here made of a body made in one 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.

[0059] An annular radial space 34 exists between the lower support cover 6 and the outer skirt 16 of the upper support cover 4.

[0060] The sealing ring 10 is annular and radially surrounds the lower support cover 6. The sealing ring 10 is mounted radially around the bearing 8 and the outer surface of the lower support cover 6.

[0061] As more visibly illustrated in [Fig.2], the sealing gasket 10 comprises an annular heel 38 fixed on the upper support cover 4, and an annular sealing portion 40 extending from the heel 38 towards the lower support cover 6.

[0062] A cavity 42 is formed on the sealing portion 40 of the sealing joint 10 and is open towards the lower support cover 6.

[0063] An annular space remains between the cavity 42 of the sealing portion 40 and the lower support cover 6. The cavity 42 of the sealing portion 40 is filled with a lubricant 44, which forms a seal by contact with the lower support cover 6. The lubricant 44 comes into contact with the lower support cover 6. The lubricant 44 comprises, for example, grease.

[0064] The lubricant 44 filling the cavity 42 of the sealing portion 40 ensures good sealing properties between the sealing portion 40 of the sealing gasket 10 and the lower support cover 6. The lubricant 44 also allows for a thrust bearing 2 with reduced friction torque.

[0065] The lubricant 44 closes the existing annular radial space between the sealing portion 40 of the sealing joint 10 and the lower support cover 6.

[0066] The sealing portion 40 of the sealing gasket 10 extends here purely axially from the heel 38 of the sealing gasket 10. Alternatively, the sealing portion 40 of the sealing gasket 10 can extend both axially towards the lower support cover 6 and radially inwards.

[0067] The sealing portion 40 of the sealing joint 10 is provided with an axial cylindrical inner surface 46 forming a bore and an opposing axial cylindrical outer surface 48. The inner 46 and outer 48 surfaces define the radial thickness of the sealing portion 40 of the sealing joint 10.

[0068] The sealing portion 40 of the sealing joint 10 includes an axial skirt 50 radially surrounding the cavity 42 of the sealing portion 40, said axial skirt 50 forming a barrier stopping polluting particles crossing the radial space 34 before they reach the cavity 42 of the sealing portion 40.

[0069] The cavity 42 of the sealing portion 40 is annular. The cavity 42 is delimited radially by an annular axial surface 42a of the sealing portion 40 and axially by an annular radial surface 42b of the sealing portion 40. The annular radial surface 42b extends radially outwards from the axial inner surface 46 of the sealing portion 40. The annular axial surface 42a extends axially from a large-diameter edge of the annular radial portion 42b of the sealing portion 40 towards the axial free end of the sealing portion 40. The axial surface 42a radially delimits the skirt 50 on the inner side.

[0070] The free end of the outer skirt 16 of the upper support cover 4 is axially offset downwards relative to the free end of the sealing portion 40 of the sealing joint 10. Thus, the outer skirt 16 of the upper support cover 4 forms a barrier stopping polluting particles heading towards the sealing joint 10.

[0071] Alternatively, the sealing portion 40 may comprise a plurality of cavities 42 open towards the lower support cover 6, each cavity 42 extending along a limited sector in the circumferential direction, the cavities 42 of the sealing portion 40 being formed at identical or different axial positions.

[0072] In the example shown, the cavity 42 of the sealing portion 40 is formed at the free axial end of the sealing portion 40 of the sealing joint 10, the free axial end being opposite the heel 38 of the sealing joint 10, the cavity 42 of the sealing portion 40 being open both radially inwards and axially towards the lower support cover 6.

[0073] Alternatively, the cavity 42 of the sealing portion 40 can be opened only radially inwards with respect to the lower support cover 6.

[0074] The sealing gasket 10 can, for example, be made of an elastically deformable material, for example nitrile or elastomer. The sealing gasket 10 can also be made of a more rigid material, for example polyoxymethylene (POM) or steel.

[0075] The embodiment illustrated in [Fig.3], in which the identical elements bear the same references, differs from the previous example in that the sealing portion 40 of the sealing joint 10 comprises a plurality of annular cavities 52, 54 open towards the lower support cover 6.

[0076] A first cavity 52 and a second cavity 54 are formed on the sealing portion 40 of the sealing joint 10 and filled with the lubricant 44.

[0077] The second cavity 54 is axially offset relative to the first cavity 52 on the side of the upper support cover 4.

[0078] The second cavity 54 is radially offset relative to the first cavity 52 on the side of the lower support cover 6.

[0079] The first and second cavities 52, 54 are immediately successive in the axial direction. An annular axial surface 60 of the sealing portion 40 delimiting the second cavity 54 in the radial direction extends from an annular radial surface 62 of the sealing portion 40 delimiting the first cavity 52 in the axial direction.

[0080] An annular axial surface 64 of the sealing portion 40 delimiting in the radial direction the first cavity 52 is radially offset outwards with respect to the axial surface 60 of the sealing portion 40 delimiting in the radial direction the second cavity 54. The axial surface 60 extends axially along a small diameter edge of the radial surface 62 while the axial surface 64 extends axially along a large diameter edge of the radial surface 62.

[0081] Alternatively, the first and second cavities 52, 54 may not be immediately successive, i.e. axially spaced from each other, and / or the sealing portion 40 of the sealing joint 10 may comprise more than two cavities.

[0082] The embodiment illustrated in [Fig.4], in which the identical elements bear the same references, differs mainly from the second embodiment in that the outer skirt 16 of the upper support cover 4 includes through holes 66 for overmolding the sealing gasket 10.

[0083] The heel 38 of the sealing gasket 10 is overmolded onto the outer skirt 16 of the upper support cover 4 so as to extend into the through holes 66, improving the grip of the heel 38 of the sealing gasket 10 on the outer skirt 16 of the support cover 4 superior.

[0084] The embodiment illustrated in [Fig.5], in which the identical elements bear the same references, differs from the first embodiment in that the heel 38 of the sealing gasket 10 is fixed to the upper support cover 4 by radial interference with the external skirt 16.

[0085] The sealing portion 40 of the sealing joint 10 extends here obliquely towards the lower support cover 6 from the heel 38 of the sealing joint.

[0086] The sealing portion 40 of the sealing gasket 10 includes an annular bead 68 extending radially in projection towards the lower support cover 6 while remaining radially distant from it. The bead 68 is axially offset from the free end of the sealing portion 40 of the sealing gasket 10, the cavity 42 being formed on the sealing portion 40 of the sealing gasket 10 axially below the bead 68. In other words, the bead 68 axially delimits the cavity 42 of the sealing portion 40. The inner surface of the sealing portion 40 radially delimits the cavity 42 on its inner side.

[0087] The cavity 42 of the sealing portion 40 is filled with the lubricant 44 to form the seal with the lower support cover 6.

[0088] Advantageously, lubricant 44 is also arranged radially between the bead 68 and the outer surface of the lower support cover 6 in order to further improve the sealing of the stop device 2.

[0089] Alternatively, the sealing portion 40 of the sealing joint 10 may include a plurality of beads 68 at different axial positions extending radially in projection towards the lower support cover 6 as well as a plurality of radial cavities 42.

[0090] The embodiment illustrated in [Fig.6], in which the identical elements bear the same references, differs mainly from the first embodiment in that the sealing gasket 10 is monobloc of the outer skirt 16 of the upper support cover 4, the sealing gasket 10 and the outer skirt 16 of the upper support cover 4 being made in one piece.

[0091] In the illustrated embodiments, the device 2 comprises a single external sealing gasket 10 located radially between the support cover 6 and the external skirt 16 of the upper support cover 4. Alternatively or in combination, the device 2 may comprise an internal sealing gasket 10 located radially between the support cover 6 and the internal skirt 14 of the upper support cover 4.

[0092] In the illustrated embodiments, the device 2 comprises a single external sealing gasket 10 with a single sealing portion 40. Alternatively, the device 2 may comprise a plurality of external sealing gaskets 10 or a single sealing gasket 10 with a plurality of sealing portions 40.

[0093] In the illustrated embodiments, the sealing gasket 10 is fixed to the hood upper support 4. Alternatively, the sealing gasket 10 could be fixed to the lower support cover 6.

[0094] In the illustrated embodiments, the device 2 comprises a bearing 8 with an angular contact bearing and one row of balls. The device 2 may include other types of bearings, for example, a bearing with four contact points and / or with at least two rows of balls. The bearing may include other types of rolling elements 32, for example, rollers. In another embodiment, the bearing of the device 2 may include a sliding bearing without rolling elements and equipped with one or more rings.

Claims

Claims

1. Suspension stop device (2) comprising: - an upper support cover (4) with a radial portion (12), an annular axial internal skirt (14) extending a small diameter edge of the radial portion (12), and an annular axial external skirt (16) extending axially from a large diameter edge of the radial portion (12) and radially surrounding the internal skirt (14); - a lower support cover (6) with an annular radial portion (20) in the form of a plate, and an annular axial skirt (22) extending a small diameter edge of the radial portion (20), said radial portion (20) having a lower annular radial surface delimiting a bearing surface for a suspension spring, and the external skirt (16) of the upper bearing cover (4) radially partially surrounding the lower support cover (6); - at least one bearing (8) arranged between said covers (4, 6), entirely located radially between the skirts (14), (16) of the upper support cover (4), said bearing (8) comprising an upper ring (28) in contact with the upper support cover (4), a lower ring (30) in contact with the lower support cover (6), and a row of rolling elements (32) arranged between the raceways formed on the rings (28), (30); and - at least one annular seal (10) arranged radially at least in part between the outer skirt (16) of the upper support cover (4) and the bearing (8), said seal (10) radially surrounding the outer surface of the lower support cover (6), said outer skirt (16) radially surrounding said seal (10), said seal (10) being integral with the radial portion (12) of the upper support cover (4), and being provided with a sealing portion (40) extending in the direction of the lower support cover (6), characterized in that the seal (10) comprises an annular heel (38) integral with the radial portion (12) of the upper support cover (4), the annular sealing portion (40) extending purely axially from the heel (38) and comprising an axial skirt (50) forming a barrier stopping the polluting particles, and at least a cavity (42, 52,54) annular formed at a free end of the sealing portion (40) and open both radially inwards and axially towards the outer surface of the lower support cover (6), the, axial skirt (50) radially surrounding said cavity (42, 52, 54), the at least one cavity (42, 52, 54) being filled with a lubricant (44) forming a seal by contact with the lower support cover (6).

2. Device (2) according to any one of the preceding claims, in which the sealing portion (40) of said seal (10) comprises at least one bead (68) extending radially in projection towards said other cover (4, 6), said bead (68) at least partly delimiting said cavity (42, 52, 54).

3. Device (2) according to any one of the preceding claims, comprising at least first and second cavities (52, 54) formed on the sealing portion (40) of said seal and filled with the lubricant (44), the second cavity (54) being axially offset relative to the first cavity (52) on the side of said cover (4, 6) and radially offset relative to the first cavity (52) on the side of said other cover (4, 6), the first and second cavities (52, 54) being immediately successive in the axial direction.

4. Device (2) according to any one of the preceding claims, wherein said seal (10) is overmolded onto said cover (4, 6).

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