Suspension stop device with sealing gasket

Abstract

[Suspension stop device with sealing gasket] This suspension stop device (2) includes a lower support cover (6), an upper support cover (4) and at least one bearing (8) disposed between said covers (4, 6), the device (2) including at least one sealing gasket (10) overmolded on the upper support cover (4) and having a sealing portion (40) extending towards the lower support cover (6) to form a seal with said lower support cover (6), the upper support cover (4) including an external skirt (16) radially surrounding said sealing gasket (10).

Description

Title of the invention: Suspension stop device with sealing joint 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 steered wheels. State of the 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 making it possible to provide the interface between said rings and the surrounding elements.

[0003] The suspension stop 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 connected to the vehicle body. The suspension spring, of the helical spring type, comes to bear axially directly or indirectly on the lower cover of the suspension stop device.

[0004] The suspension stop device makes it possible to transmit axial and radial forces between the suspension spring and the vehicle body while allowing a relative rotational movement between the lower cover and the upper cover resulting from a turning of the vehicle's steered 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 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.

[0006] The hooks form retaining means for axially retaining the upper and lower covers relative to each other. These hooks also form narrow passages in order to limit the intrusion of polluting particles radially between the external 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 external skirt of the upper cover and the lower cover, then be directed towards the bearing and be introduced inside the latter.

[0009] To overcome this drawback, it is known from patent application DE- Al-10 2020 201 404 (SKF) to provide an external seal 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 and to reduce the packaging used for 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 and at least one bearing arranged between said covers.

[0012] According to a general characteristic, the device comprises at least one sealing gasket overmolded on the upper support cover and provided with a sealing portion extending towards the lower support cover to form a seal with said lower support cover.

[0013] The upper support cover comprises an external skirt radially surrounding said seal.

[0014] The overmolding of the seal makes it possible to eliminate an operation during the assembly of the stop device. In addition, this also makes it possible to eliminate a packaging element for the seal which is conventionally provided in stop devices comprising a seal which is separated and then assembled on one of the covers.

[0015] Furthermore, the external skirt of the upper support cover radially surrounding said seal protects it during handling of the suspension stop device, in particular from impacts during its transport.

[0016] In a first embodiment, the sealing portion of said seal forms a seal by narrow passage(s) with the lower support cover.

[0017] In a second alternative embodiment, the sealing portion of said seal forms a seal by frictional contact with the lower support cover.

[0018] In a third alternative embodiment, the sealing portion of said seal can form both a seal by narrow passage(s) and a seal by frictional contact with the lower support cover.

[0019] According to a first design, the sealing portion of said seal extends purely axially.

[0020] According to a second alternative design, the sealing portion of said seal extends obliquely towards the lower support cover.

[0021] Advantageously, at least one cavity is formed on the sealing portion and is open towards the lower support cover, said cavity being filled with lubricant forming the seal with the lower support cover.

[0022] The cavity of the sealing portion filled with lubricant ensures the seal between the sealing portion of said seal and the lower support cover by forming a barrier stopping the polluting particles heading towards the bearing. In addition, the lubricant reduces the friction between the sealing portion of said seal and the lower support cover, reducing the wear of the seal and the friction torque of the stop device.

[0023] According to a first design, the sealing portion of said seal remains at a distance from the lower support cover. In this case, only the lubricant comes into contact against the lower support cover.

[0024] According to a second alternative design, the sealing portion of said seal can bear against the lower support cover.

[0025] Advantageously, said cavity of the sealing portion of said seal is annular. Thus, the sealing of the stop device is further improved to the extent that the lubricant can form a bead over 360°.

[0026] Advantageously, the sealing portion of said seal comprises an axial skirt which radially surrounds said cavity.

[0027] Said axial skirt forms a barrier stopping polluting particles before they reach said cavity of the sealing portion of said seal. The service life and effectiveness of the lubricant are thus improved. In one embodiment, said cavity of the sealing portion of said seal is open both radially and axially opposite the lower support cover, said cavity being formed at a free end of the sealing portion.

[0028] The sealing portion of said seal may comprise at least one bead extending radially in projection towards the lower support cover, said bead at least partially delimiting said cavity.

[0029] In a particular embodiment, the device comprises at least first and second cavities formed on the sealing portion of said seal and filled with the lubricant, the second cavity being axially offset relative to the first cavity on the side of the upper support cover and radially offset relative to the first cavity on the side of the lower support cover, the first and second cavities being immediately successive in the axial direction.

[0030] Said first and second cavities filled with lubricant further improve the sealing between the sealing portion of said seal and the lower support cover.

[0031] Advantageously, said seal comprises an annular heel overmolded on the upper support cover, the sealing portion extending from said annular heel.

[0032] Advantageously, the external skirt of the upper support cover comprises a surface beveled inner surface, said inner surface being located axially opposite the lower support cover, the annular heel of the seal being in contact with the beveled inner surface of the outer skirt of the upper support cover.

[0033] Said beveled inner surface makes it possible to improve the attachment of the sealing gasket to the external skirt of the support cover and facilitates the overmolding of the sealing gasket.

[0034] Advantageously, the free end of the external skirt of the upper support cover is offset axially downwards relative to the free end of the sealing portion of said seal.

[0035] Advantageously, the upper support cover comprises at least one attachment groove, said sealing gasket being partially overmolded in said attachment groove.

[0036] The attachment groove further improves the attachment of the seal to the hood. superior support and facilitated overmolding of the seal.

[0037] Advantageously, the sealing portion of said seal leaves an annular space between said cavity and the lower support cover. Brief description of the figures

[0038] The present invention will be better understood upon studying the detailed description of embodiments, taken as non-limiting examples and illustrated by the appended drawings in which:

[0039] [Fig-1] is an axial sectional view of a suspension stop device according to a first example of embodiment of the invention;

[0040] [Fig.2] is a detailed view of the device of [Fig.l];

[0041] [Fig.3] is a detail view of a suspension stop device according to a second example of embodiment of the invention; and

[0042] [Fig.4] is a detail view of a suspension stop device according to a third exemplary embodiment of the invention. Detailed description of the invention

[0043] The suspension stop device 2 shown in [Fig.l] is adapted to be installed between an upper support cup or seat coming into contact with an element of the fixed chassis of a motor vehicle, and a helical type suspension spring. In [Fig.l], the device 2 is shown in a supposed vertical position.

[0044] The device 2, of axis X-X', comprises an upper support cover 4, a lower support cover 6, and a rolling bearing 8 interposed axially between said covers. 4, 6.

[0045] In the example illustrated, the upper support 4 and lower support 6 covers are mounted in direct contact with the bearing 8 without the interposition of an intermediate element. Alternatively, the upper support 4 and lower support 6 covers may be mounted in indirect contact with the bearing 8 with the interposition of an intermediate element.

[0046] As will be described in more detail later, the device 2 further comprises an external annular seal 10 to prevent the intrusion of pollutants towards the bearing 8.

[0047] The sealing gasket 10 is overmolded onto the upper support cover 4 and extends towards the lower support cover 6.

[0048] The upper support cover 4 may be made of a single piece, for example made of plastic material, for example such as a polyamide PA 6.6, which may or may not be reinforced with glass fibers.

[0049] The upper support cover 4, of axis X-X', comprises a radial portion 12, an annular axial internal skirt 14, and an annular axial external skirt 16 radially surrounding the internal skirt 14.

[0050] The radial portion 12 of the upper support cover 4 has an upper surface (not referenced) intended to come opposite the upper support seat, and an opposite lower surface (not referenced) in contact with the bearing 8. Said upper and lower surfaces define the thickness of the radial portion 12 of the upper support cover 4. In the example illustrated, the radial portion 12 of the upper support cover 4 has a stepped shape. In the example embodiment illustrated, the seal 10 is overmolded onto the radial portion 12 of the upper support cover 4.

[0051] The outer skirt 16 of the upper support cover 4 radially partially surrounds the lower support cover 6, the outer skirt 16 extending axially from the radial portion 12 of the upper support cover 4. In the example illustrated, 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 seal 10

[0052] The inner skirt 14 of the upper support cap 4 extends inside the bore of the lower support cap 6. The inner and outer skirts 14, 16 of the upper support cap 4 extend axially downward from the radial portion 12 of the upper support cap 4. The inner skirt 14 extends a small diameter edge of the radial portion 12 of the upper support cap 4.

[0053] The lower support cover 6, of axis X-X', comprises 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 of the lower support cover 6.

[0054] 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.

[0055] The radial portion 20 of the lower support cover 6 has a lower annular radial surface delimiting a bearing surface for the suspension spring.

[0056] The upper support cover 4 comprises a plurality of internal hooks 24 arranged on the internal skirt 14 of the upper support cover 4 and extending radially outwardly towards the lower support cover 6. In the example illustrated, the hooks 24 are spaced apart from each other in the circumferential direction. Alternatively, it could be possible to provide a single annular hook 24.

[0057] 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.

[0058] The hooks 24, 26 form retaining means making it possible to axially retain the upper support 4 and lower support 6 covers relative to each other.

[0059] The bearing 8 is entirely located 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 example illustrated, 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 of a shape complementary to the lower ring 30 of the bearing 8.

[0060] The lower support cover 6 here consists of a body made in a single piece, for example made of plastic material, for example such as a polyamide PA 6.6, which may or may not be reinforced with glass fibers.

[0061] An annular radial space 34 exists between the lower support cover 6 and the external skirt 16 of the upper support cover 4.

[0062] The seal 10 is annular and radially surrounds the lower support cover 6. The seal 10 is overmolded onto the upper support cover 4 so as to be mounted radially around the bearing 8 and the outer surface of the lower support cover 6.

[0063] As illustrated more visibly in [Fig.2], the seal 10 comprises a annular heel 38 overmolded on the upper support cover 4, and an annular sealing portion 40 extending from the heel 38 towards the lower support cover 6.

[0064] In order to improve the grip of the annular heel 38 of the seal 10 on the upper support cover 4, a plurality of gripping grooves 41 are formed on the upper support cover 4. In the illustrated embodiment, the gripping grooves 41 are regularly spaced in the circumferential direction and extend radially. The annular heel 38 of the seal 10 is overmolded in the gripping grooves 41.

[0065] Alternatively, it is possible to provide hooking grooves 41 irregularly spaced in the circumferential direction or a single annular hooking groove 41.

[0066] In the illustrated embodiment, a cavity 42 is formed on the sealing portion 40 of the seal 10 and is open towards the lower support cover 6.

[0067] 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 forming a seal by contact with the lower support cover 6. The lubricant 44 comes into contact against the lower support cover 6. The lubricant 44 comprises, for example, grease.

[0068] The lubricant 44 filling the cavity 42 of the sealing portion 40 ensures good sealing properties between the sealing portion 40 of the seal 10 and the lower support cover 6. The lubricant 44 also makes it possible to obtain a stop device 2 having a reduced friction torque.

[0069] The lubricant 44 closes the annular radial space existing between the sealing portion 40 of the seal 10 and the lower support cover 6.

[0070] The sealing portion 40 of the seal 10 here extends purely axially from the heel 38 of the seal 10. Alternatively, the sealing portion 40 of the seal 10 may extend both axially towards the lower support cover 6 and radially inwards.

[0071] The sealing portion 40 of the seal 10 is provided with a cylindrical axial inner surface 46 forming a bore and an opposite cylindrical axial outer surface 48. The inner surfaces 46 and the outer surfaces 48 delimit the radial thickness of the sealing portion 40 of the seal 10.

[0072] The sealing portion 40 of the seal 10 comprises an axial skirt 50 radially surrounding the cavity 42 of the sealing portion 40, said axial skirt 50 forming a barrier stopping the polluting particles passing through the radial space 34 before they reach the cavity 42 of the sealing portion 40.

[0073] The cavity 42 of the sealing portion 40 is here annular. The cavity 42 is delimited in the radial direction by an annular axial surface 42a of the sealing portion 40 and in the axial direction by an annular radial surface 42b of the sealing portion 40. The annular radial surface 42b extends radially outwards the axial inner surface 46 of the sealing portion 40. The annular axial surface 42a axially extends a large diameter edge of the annular radial portion 42b of the sealing portion 40 in the direction of the axial free end of the sealing portion 40. The axial surface 42a delimits the skirt 50 radially on the inner side.

[0074] The free end of the external skirt 16 of the upper support cover 4 is offset axially downwards relative to the free end of the sealing portion 40 of the seal 10. Thus, the external skirt 16 of the upper support cover 4 forms a barrier stopping the polluting particles heading towards the seal 10.

[0075] 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 sector limited in the circumferential direction, the cavities 42 of the sealing portion 40 being formed at identical or different axial positions.

[0076] 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 seal 10, the free axial end being opposite the heel 38 of the seal 10, the cavity 42 of the sealing portion 40 being open both radially inwards and axially towards the lower support cover 6.

[0077] Alternatively, the cavity 42 of the sealing portion 40 may be open only radially inwards opposite the lower support cover 6.

[0078] The seal 10 may for example be made of elastically deformable material, for example nitrile or elastomer. The seal 10 may also be made of a more rigid material, for example polyoxymethylene (POM) or even steel.

[0079] The embodiment illustrated in [Fig. 3], in which identical elements bear the same references, differs from the previous example in that the sealing portion 40 of the seal 10 comprises a plurality of annular cavities 52, 54 open in the direction of the lower support cover 6.

[0080] A first cavity 52 and a second cavity 54 are formed on the sealing portion 40 of the seal 10 and filled with the lubricant 44.

[0081] The second cavity 54 is axially offset relative to the first cavity 52 on the side of the upper support cover 4.

[0082] The second cavity 54 is radially offset relative to the first cavity 52 on the side of the lower support cover 6.

[0083] 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 in the radial direction the second cavity 54 extends from an annular radial surface 62 of the sealing portion 40 delimiting the first cavity 52 in the axial direction.

[0084] An annular axial surface 64 of the sealing portion 40 delimiting in the radial direction the first cavity 52 is radially offset outwards relative to the axial surface 60 of the sealing portion 40 delimiting in the radial direction the second cavity 54. The axial surface 60 axially extends a small diameter edge of the radial surface 62 while the axial surface 64 axially extends a large diameter edge of the radial surface 62.

[0085] Alternatively, the first and second cavities 52, 54 may not be immediately successive, i.e. axially spaced from one another, and / or the sealing portion 40 of the seal 10 may comprise more than two cavities.

[0086] The embodiment illustrated in [Fig. 4], in which identical elements bear the same references, differs mainly from the second embodiment in that the external skirt 16 of the upper support cover 4 comprises through orifices 66 for overmolding the sealing gasket 10.

[0087] The heel 38 of the seal 10 is overmolded onto the external skirt 16 of the upper support cover 4 so as to extend into the through orifices 66, improving the attachment of the heel 38 of the seal 10 to the external skirt 16 of the upper support cover 4.

[0088] The outer skirt 16 of the upper support cover 4 comprises an annular inner surface 67 beveled outwards. The beveled inner surface 67 of the outer skirt 16 is located axially opposite the lower support cover 6. The heel 38 of the seal 10 is overmolded onto the outer skirt 16 of the upper support cover 4 so as to extend against the beveled inner surface 67 of the outer skirt 16 of the upper support cover 4, improving the attachment of the heel 38 of the seal 10 to the outer skirt 16 of the upper support cover 4. Alternatively, the outer skirt 16 of the upper support cover 4 may comprise a plurality of beveled inner surfaces 67 extending along a limited sector in the circumferential direction.

[0089] Optionally, the sealing portion 40 of the seal 10 may comprise an annular bead or a plurality of beads each extending along a sector limited in the circumferential direction (not shown) extending radially projecting towards the lower support cover 6 while remaining radially at a distance therefrom. The bead may be axially offset from the free end of the sealing portion 40 of the seal 10 so that the cavity 42 is formed on the sealing portion 40 of the seal 10 axially below the bead. In other words, the bead may axially delimit the cavity 42 of the sealing portion 40, the inner surface 46 of the sealing portion 40 then radially delimiting the cavity 42 of the inside side.

[0090] Advantageously, lubricant 44 may also be arranged radially between the bead and the outer surface of the lower support cover 6 in order to further improve the sealing of the stop device 2.

[0091] Alternatively, the sealing portion 40 of the seal 10 may comprise a plurality of beads at different axial positions extending radially in projection towards the lower support cover 6 as well as a plurality of radial cavities 42.

[0092] In the illustrated embodiments, the sealing portion 40 of the seal is equipped with at least one cavity. Alternatively, the sealing portion 40 of the seal may be without a cavity.

[0093] In the illustrated embodiments, the device 2 comprises a single external seal 10 located radially between the support cover 6 and the external skirt 16 of the upper support cover 4. In combination, the device 2 may comprise an internal seal 10 located radially between the support cover 6 and the internal skirt 14 of the upper support cover 4.

[0094] In the illustrated embodiments, the device 2 comprises a single external seal 10 provided with a single sealing portion 40. As a variant, the device 2 may comprise a plurality of external seals 10 or a single seal 10 provided with a plurality of sealing portions 40.

[0095] In the illustrated embodiments, the device 2 comprises an angular contact rolling bearing 8 provided with a row of balls. The device 2 may comprise 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 comprise other types of rolling elements 32, for example rollers. In another variant, the bearing of the device 2 may comprise a sliding bearing without rolling elements and provided with one or more rings.

Claims

Claims

1. Suspension stop device (2) comprising a lower support cover (6), an upper support cover (4), at least one bearing (8) arranged between said covers (4, 6), and at least one seal (10) overmolded on the upper support cover (4) and provided with a sealing portion (40) extending towards the lower support cover (6) to form a seal with said lower support cover (6), the upper support cover (4) comprising an external skirt (16) radially surrounding said seal (10), characterized in that the external skirt (16) of the upper support cover (4) comprises a beveled inner surface (67), said inner surface (67) being located axially opposite the lower support cover (6), said seal (10) comprising an annular heel (38) in contact with the beveled inner surface (67) of the external skirt (16) of the upper support cover (4).

2. Device (2) according to claim 1, wherein the sealing portion (40) of said seal (10) extends purely axially.

3. Device (2) according to one of claims 1 and 2, wherein at least one cavity (42, 52, 54) is formed on the sealing portion (40) and is open towards the lower support cover (6), said cavity (42, 52, 54) being filled with lubricant (44) forming the seal with the lower support cover (6).

4. Device (2) according to claim 3, wherein said cavity (42, 52, 54) of the sealing portion (40) of said seal (10) is annular.

5. Device (2) according to one of claims 3 and 4, wherein the sealing portion (40) of said seal (10) comprises an axial skirt (50) which radially surrounds said cavity (42, 52, 54).

6. Device (2) according to any one of claims 3 to 5, wherein said cavity (42, 52, 54) of the sealing portion (40) of said seal (10) is open both radially and axially opposite the lower support cover (6), said cavity (42, 52, 54) being formed at a free axial end of the sealing portion (40).

7. Device (2) according to any one of claims 3 to 6, comprising at least first and second cavities (52, 54) formed on the sealing portion (40) of said seal (10) and filled

8.

9. lubricant (44), the second cavity (54) being axially offset relative to the first cavity (52) on the side of the upper support cover (4) and radially offset relative to the first cavity (52) on the side of the lower support cover (6), the first and second cavities (52, 54) being immediately successive in the axial direction. Device (2) according to any one of the preceding claims, in which the free end of the external skirt (16) of the upper support cover (4) is offset axially downwards relative to the free end of the sealing portion (40) of said seal (10). Device (2) according to any one of the preceding claims, in which the upper support cover (4) comprises at least one hooking groove (41), said sealing gasket (10) being partly overmolded in said hooking groove (41).

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