Suspension stop device with sealing portion

Abstract

[Suspension stop device with sealing portion] This suspension stop device (2) comprises a lower support cover (6), an upper support cover (4) made in one piece and comprising an external skirt (16), at least one bearing (8) disposed between said covers (4, 6), the upper support cover (4) comprising at least one sealing portion (10) radially surrounding the bearing (8) and extending towards the lower support cover (6) while remaining at a distance from it, the external skirt (16) radially surrounding said sealing portion (10) of the upper support cover (4), the lower support cover (6) comprising at least one shoulder (34) in the axial extension of said sealing portion (10), the shoulder (34) being formed by first and second surfaces (36, 38) of the lower support cover (6),the first surface (36) extending at least axially and the second surface (38) extending at least radially and radially extending inwards from the first surface (36). Figure for the abbreviation: Fig. 2,

Description

Title of the invention: Suspension stop device with sealing portion 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-AÏ -10 1818 181 404 (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. Summary of the invention

[0011] The invention relates to a suspension stop device comprising a lower support cover, an upper support cover made in one piece and comprising an external skirt, at least one bearing arranged between said covers.

[0012] According to a general characteristic, the upper support cover further comprises at least one sealing portion radially surrounding the bearing and extending towards the lower support cover while remaining at a distance from the latter.

[0013] The outer skirt of the upper support cover radially surrounds said sealing portion of the upper support cover.

[0014] The lower support cover comprises at least one shoulder in the axial extension of said sealing portion.

[0015] Said shoulder is formed by first and second surfaces of the lower support cover, the first surface extending at least axially and the second surface extending at least radially and extending radially inwardly the first surface.

[0016] Said shoulder of the lower support cover, in particular the first surface of said shoulder of the lower support cover, and the external skirt of the upper support cover form barriers making it possible to stop and redirect towards the outside a flow of polluting particles heading towards said sealing portion of the upper support cover.

[0017] Said sealing portion of the upper support cover, located downstream of the shoulder and the external skirt, makes it possible to stop polluting particles heading towards the bearing of the stop device which could have passed the shoulder and the external skirt.

[0018] Advantageously, said sealing portion of the upper support cover extends towards the lower support cover to form a labyrinth-type seal with the lower support cover.

[0019] Said sealing portion of the upper support cover, the external skirt of the upper support cover and said shoulder of the lower support cover thus form at least one narrow passage between the upper support cover and the lower support cover.

[0020] Advantageously, the free end of the external skirt of the upper support cover is offset axially downwards relative to the free end of said sealing portion. This makes it possible to further increase the effectiveness of the external skirt.

[0021] "Axially downwards" means the axial direction from the upper support cover to the lower support cover.

[0022] Optionally, the free end of the outer skirt of the upper support cover is axially offset downwards relative to the second surface of said shoulder of the lower support cover. Again, this makes it possible to further increase the effectiveness of the outer skirt.

[0023] Advantageously, the second surface of said shoulder of the lower support cover extends radially outwards beyond said sealing portion of the upper support cover.

[0024] According to a first design, the second surface of said shoulder of the lower support cover extends both radially outwardly and axially downwardly.

[0025] Thus, the polluting particles arriving on the second surface of said shoulder of the lower support cover are naturally evacuated by gravity.

[0026] According to a second alternative design, the second surface of said shoulder of the lower support cover extends purely radially.

[0027] Preferably, said sealing portion of the upper support cover is annular.

[0028] Advantageously, said sealing portion of the upper support cover extends purely axially. Alternatively, said sealing portion of the upper support cover may extend obliquely.

[0029] According to a particular design, the first surface of said shoulder of the lower support cover extends purely axially.

[0030] According to an alternative design, the first surface of said shoulder of the lower support cover extends both radially inwardly and axially downwardly.

[0031] According to another alternative design, the first surface of said shoulder of the lower support cover extends both radially outwardly and axially downwardly.

[0032] In a particular embodiment, at least one cavity is formed on said sealing portion of the upper support cover and is open towards the lower support cover, said cavity being filled with lubricant to form a seal with the lower support cover.

[0033] The cavity of said sealing portion of the upper bearing cover filled with lubricant ensures the seal between said sealing portion of the upper bearing cover 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 said sealing portion of the upper bearing cover and the support cover lower, reducing the wear of the upper support cover and the friction torque of the stop device.

[0034] Advantageously, said sealing portion of the upper support cover remains at a distance from the lower support cover. In this case, only the lubricant comes into contact against the lower support cover.

[0035] Advantageously, said cavity of said sealing portion of the upper support cover is annular. Thus, the sealing of the stop device is further improved to the extent that the lubricant can form a bead over 360°.

[0036] Advantageously, said cavity of said sealing portion of the upper support cover comprises an axial skirt which radially surrounds said cavity.

[0037] Said axial skirt forms a barrier stopping polluting particles before they reach said cavity of said sealing portion of the upper support cover. The service life and efficiency of the lubricant are thus improved.

[0038] In one embodiment, said cavity of said sealing portion of the upper support cover is open both radially and axially opposite the lower support cover, said cavity being formed at a free end of said sealing portion of the upper support cover.

[0039] In a particular embodiment, the device comprises at least first and second cavities formed on said sealing portion of the upper support cover 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.

[0040] Said first and second cavities filled with lubricant further improve the sealing between said sealing portion of the upper support cover and the lower support cover.

[0041] Advantageously, the upper support cover is formed by molding from a single material. Brief description of the figures

[0042] 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:

[0043] [Fig-1] is an axial sectional view of a suspension stop device according to a first example of embodiment of the invention;

[0044] [Fig.2] is a detail view of [Fig.l];

[0045] [Fig.3] is a detail view of a suspension stop device according to a second example of embodiment of the invention; and

[0046] [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

[0047] The suspension stop device 2 shown in [Fig. 1] 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.

[0048] 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.

[0049] 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.

[0050] As will be described in more detail below, the upper bearing cover 4 comprises an annular sealing portion 10 to prevent the intrusion of pollutants towards the bearing 8.

[0051] The sealing portion is made in one piece with the upper support cover 4 and extends towards the lower support cover 6.

[0052] The upper support cover 4 is 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.

[0053] The upper support cover 4 is, for example, formed by molding from a single material. The upper support cover 4 is made in one piece.

[0054] 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.

[0055] The sealing portion 10 of the upper support cover 4 is integral with the radial portion 12 of the upper support cover 4.

[0056] 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.

[0057] 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 sealing portion 10 of the upper support cover 4.

[0058] 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.

[0059] The lower support cover 6, of axis X-X', comprises an annular radial portion 18 in the form of a plate, and an annular axial skirt 20 extending a small diameter edge of the radial portion 18 of the lower support cover 6.

[0060] The skirt 20 of the lower support cover 6 extends axially opposite the upper support cover 4 and the bearing 8. The skirt 20 of the lower support cover 6 allows the centering of the suspension spring.

[0061] The radial portion 18 of the lower support cover 6 has a lower annular radial surface delimiting a bearing surface for the suspension spring.

[0062] The upper support cover 4 comprises a plurality of internal hooks 22 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 22 are spaced apart from each other in the circumferential direction. Alternatively, it could be possible to provide a single annular hook 22.

[0063] The lower support cover 6 comprises a plurality of internal hooks 24 arranged on the radial portion 18 of the lower support cover 6 and extending radially inwards towards the upper support cover 4, said plurality of internal hooks 24 being adapted to interfere diametrically with the plurality of internal hooks 22 of the upper support cover 4. Alternatively, it could be possible to provide a single annular hook 24.

[0064] The hooks 22, 24 form retaining means making it possible to axially retain the upper support 4 and lower support 6 covers relative to each other.

[0065] 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 26 in contact with the upper support cover 4, a lower ring 28 in contact with the lower support cover 6, and a row of rolling elements 30, here balls, arranged between the raceways formed on the rings 26, 28. In the example illustrated, the bearing is of the angular contact type. The upper ring 26 is in contact with the lower surface of the radial portion 12 of the upper support cover 4. The lower ring 28 is in contact with an upper surface of the lower support cover 6, said upper surface being of complementary shape to the lower ring 28 of the bearing 8.

[0066] 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.

[0067] An annular radial space 32 exists between the lower support cover 6 and the external skirt 16 of the upper support cover 4.

[0068] The sealing portion 10 of the upper support cover 4 is annular and radially surrounds the bearing 8 and the outer surface of the lower support cover 6 while remaining at a distance from the lower support cover 6.

[0069] As illustrated more visibly in [Fig.2], the sealing portion 10 of the upper support cover 4 extends purely axially towards the lower support cover 6 to form a labyrinth-type seal with the lower support cover 6.

[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 10 of the upper support cover 4. The outer skirt 16 of the upper support cover 4 forms a barrier stopping the polluting particles heading towards the sealing portion 10 of the upper support cover 4.

[0071] Furthermore, the lower support cover 6 comprises a shoulder 34 in the axial extension of the sealing portion 10 of the upper support cover 4. In other words, the sealing portion 10 is located axially above the shoulder 34.

[0072] The shoulder 34 of the lower support cover 6 is formed by a first surface 36 of the lower support cover 6 extending purely axially and by a second surface 38 of the lower support cover 6 extending purely radially. The first surface 36 of the lower support cover 6 extends from a large diameter edge of the second surface 38 of the lower support cover 6.

[0073] An annular axial space remains between the free end of the external skirt 16 of the upper support cover 4 and the lower support cover 6.

[0074] An annular radial space remains between the first surface 36 of the shoulder 38 of the lower support cover 6 and the external skirt 16 of the upper support cover 4.

[0075] An annular radial space remains between the sealing portion 10 of the upper support cover 4 and the external skirt 16 of the upper support cover 4.

[0076] An annular axial space remains between the second surface 38 of the shoulder 38 of the lower support cover 6 and the sealing portion 10 of the upper support cover 4.

[0077] An annular radial space remains between the free end of the sealing portion 10 of the upper support cover 4 and the lower support cover 6.

[0078] Said spaces form a labyrinth-type seal between the upper support cover 4 and the lower support cover 6, by forming a succession of narrow passages between the upper support cover 4 and the lower support cover 6.

[0079] The second surface 38 of the shoulder 34 of the lower support cover 6 is here axially aligned with the free end of the external skirt 16 of the upper support cover 4.

[0080] Alternatively, the free end of the outer skirt 16 of the upper support cover 4 may be offset axially downwards relative to the second surface 38 of the shoulder 34 of the lower support cover 6. In other words, the second surface 38 of the shoulder 36 of the lower support cover 6 may be located axially between the free end of the sealing portion 10 of the upper support cover 4 and the free end of the outer skirt 16 of the upper support cover 4, in particular in order to further improve the sealing between the upper support cover 4 and the lower support cover 6.

[0081] In the illustrated embodiment, a cavity 40 is formed on the sealing portion 10 of the upper support cover 4 and is open towards the lower support cover 6.

[0082] An annular space remains between the cavity 40 of the sealing portion 10 and the lower support cover 6. The cavity 40 of the sealing portion 10 is filled with a lubricant 42 forming a seal by contact with the lower support cover 6. The lubricant 42 comes into contact against the lower support cover 6. The lubricant 42 comprises, for example, grease.

[0083] The lubricant 42 filling the cavity 40 of the sealing portion 10 ensures good sealing properties between the sealing portion 10 of the upper support cover 4 and the lower support cover 6. The lubricant 42 also makes it possible to obtain a stop device 2 having a reduced friction torque.

[0084] The lubricant 42 closes the annular radial space existing between the sealing portion 10 of the upper support cover 4 and the lower support cover 6.

[0085] The sealing portion 10 of the upper support cover 4 here extends purely axially from the radial portion 12 of the upper support cover 4. Alternatively, the sealing portion 10 of the upper support cover 4 may extend both axially towards the lower support cover 6 and radially inwards.

[0086] The sealing portion 10 of the upper support cover 4 is provided with a cylindrical axial inner surface 44 forming a bore and an opposite cylindrical axial outer surface 46. The inner surfaces 44 and the outer surfaces 46 delimit the radial thickness of the sealing portion 10 of the upper support cover 4.

[0087] The first surface 36 of the shoulder 34 of the lower support cover 6 is located in the axial extension of the outer surface 46 of the sealing portion 10 of the upper support cover 4.

[0088] The sealing portion 10 of the upper support cover 4 comprises an axial skirt 48 radially surrounding the cavity 40 of the sealing portion 10, said axial skirt 48 forming a barrier stopping the polluting particles passing through the radial space 32 before they reach the cavity 40 of the sealing portion 10.

[0089] The cavity 40 of the sealing portion 10 is here annular. The cavity 40 is delimited in the radial direction by an annular axial surface 50 of the sealing portion 10 and in the axial direction by an annular radial surface 52 of the sealing portion 10. The annular radial surface 52 extends radially outwardly the axial inner surface 44 of the sealing portion 10. The annular axial surface 50 axially extends a large diameter edge of the annular radial portion 52 of the sealing portion 10 in the direction of the axial free end of the sealing portion 10. The axial surface 50 delimits the skirt 48 radially on the inner side.

[0090] Alternatively, the sealing portion 10 of the upper support cover 4 may comprise a plurality of cavities 40 open towards the lower support cover 6, each cavity 40 extending along a sector limited in the circumferential direction, the cavities 40 of the sealing portion 10 being formed at identical or different axial positions.

[0091] In the example shown, the cavity 40 of the sealing portion 10 is formed at the free axial end of the sealing portion 10 of the upper support cover 4, the free axial end being opposite the radial portion 12 of the upper support cover 4, the cavity 40 of the sealing portion 10 being open both radially inwards and axially towards the lower support cover 6.

[0092] Alternatively, the cavity 40 of the sealing portion 10 may be open only radially inwards opposite the lower support cover 6.

[0093] The embodiment illustrated in [Fig. 3], in which identical elements bear the same references, differs from the first embodiment in that the sealing portion 10 of the upper support cover 4 does not include a cavity.

[0094] Furthermore, in this example, the second surface 38 of the shoulder 34 of the lower support cover 6 extends both radially outward and axially downward.

[0095] Optionally, lubricant 42 may be applied between the sealing portion 10 of the upper support cover 4 and the outer surface of the lower support cover 6.

[0096] The embodiment illustrated in [Fig. 4], in which identical elements bear the same references, differs from the first embodiment in that the second surface 38 of the shoulder 34 of the lower support cover 6 extends radially outwardly beyond the sealing portion 10 of the upper support cover 4. In other words, the first surface 36 of the shoulder 34 of the lower support cover 6 is offset radially outwardly relative to the outer surface 46 of the sealing portion 10 of the upper support cover 4.

[0097] Furthermore, in this example, the sealing portion 10 of the upper support cover 4 comprises a plurality of annular cavities 54, 56 open towards the lower support cover 6.

[0098] A first cavity 54 and a second cavity 56 are formed on the sealing portion 10 of the upper support cover 4 and filled with the lubricant 42.

[0099] The second cavity 56 is axially offset relative to the first cavity 54 on the side of the upper support cover 4.

[0100] The second cavity 56 is radially offset relative to the first cavity 54 on the side of the lower support cover 6.

[0101] The first and second cavities 54, 56 are immediately successive in the axial direction. An annular axial surface 58 of the sealing portion 10 delimiting the second cavity 56 in the radial direction extends from an annular radial surface 60 of the sealing portion 10 delimiting the first cavity 54 in the axial direction.

[0102] An annular axial surface 62 of the sealing portion 10 delimiting in the radial direction the first cavity 54 is radially offset outwards relative to the axial surface 58 of the sealing portion 10 delimiting in the radial direction the second cavity 56. The axial surface 58 axially extends a small diameter edge of the radial surface 60 while the axial surface 62 axially extends a large diameter edge of the radial surface 60.

[0103] Alternatively, the first and second cavities 54, 56 may not be immediately successive, i.e. axially spaced from one another, and / or the sealing portion 10 of the upper support cover 4 may comprise more than two cavities.

[0104] Furthermore, the second surface 38 of the shoulder 34 of the lower support cover 6 extends both radially outward and axially downward.

[0105] In the illustrated embodiments, the device 2 comprises a single external sealing portion 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 sealing portion 10 located radially between the support cover 6 and the internal skirt 14 of the upper support cover 4.

[0106] In the illustrated embodiments, the device 2 comprises a single external sealing portion 10. Alternatively, the device 2 may comprise a plurality of external sealing portions 10.

[0107] In the illustrated embodiments, the first surface 36 of the shoulder 34 of the lower support cover 6 extends purely axially. Alternatively, the first surface 36 of the shoulder 34 of the lower support cover 6 may extend both axially downward and radially inward or axially downward and radially outward.

[0108] In the illustrated embodiments, the lower support cover 6 comprises a single shoulder 34. Alternatively, the lower support cover 6 may comprise a plurality of shoulders.

[0109] In the illustrated embodiments, the sealing portion 10 of the upper support cover 4 is annular. Alternatively, the upper support cover 4 may comprise a plurality of sealing portions 10 extending along a sector limited in the circumferential direction.

[0110] In the illustrated embodiments, the device 2 comprises a bearing 8 with angular contact bearing provided with a row of balls. The device 2 may comprise other types of rolling bearings, for example a bearing with four points of contact and / or with at least two rows of balls. The rolling bearing may comprise other types of rolling elements 30, 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

1. Claims Suspension stop device (2) comprising: - a lower support cover (6), - an upper support cover (4) made in one piece and comprising an external skirt (16), with a radial space (32) between the lower support cover (6) and the external skirt (16) of the upper support cover (4), - at least one bearing (8) arranged between said covers (4, 6), and - at least one annular sealing portion (10) radially surrounding the bearing (8) and extending purely axially towards the lower support cover (6) while remaining at a distance therefrom, the external skirt (16) radially surrounding said sealing portion (10) of the upper support cover (4), said sealing portion (10) being provided with a cylindrical axial inner surface (44) forming a bore and an opposite cylindrical axial outer surface (46), the inner (44) outer (46) surfaces delimiting the radial thickness of the sealing portion (10), the lower support cover (6) comprising at least one shoulder (34) in the axial extension of said sealing portion (10), the shoulder (34) being formed by first and second surfaces (36, 38) of the lower support cover (6), the first surface (36) extending at least axially and the second surface (38) extending at least radially and extending radially inwards the first surface (36), characterized in that at least one annular cavity (40, 54, 56) is formed on said sealing portion (10) of the upper support cover (4) and is open towards the lower support cover (6), and delimited in the radial direction by an annular axial surface (50) and in the axial direction by an annular radial surface (52) of the sealing portion (10), the annular radial surface (52) extending radially outwards the axial inner surface (44) and the annular axial surface (50) axially extending a large diameter edge of the annular radial portion (52) in the direction of the axial free end of the sealing portion (10), the sealing portion (10) comprising an axial skirt (48) radially surrounding the cavity (40) of the sealing portion (10), said axial skirt (48) forming a barrier stopping polluting particles passing through the radial space (32) before they reach the cavity (40) of the sealing portion 10, the axial surface (50) delimiting a skirt (48) radially on the inner side, and said cavity (40, 54, 56) being filled with lubricant (42) to form a seal with the lower support cover (6).

2. Device (2) according to claim 1, wherein said sealing portion (10) of the upper support cover (4) extends towards the lower support cover (6) to form a labyrinth-type seal with the lower support cover (6).

3. 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 said sealing portion (10).

4. 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 second surface (38) of said shoulder (34) of the lower support cover (6).

5. Device (2) according to any one of the preceding claims, wherein the second surface (38) of said shoulder (34) of the lower support cover (6) extends radially outwards beyond said sealing portion (10) of the upper support cover (4).

6. Device (2) according to any one of the preceding claims, wherein the second surface (38) of said shoulder (34) of the lower support cover (6) extends both radially outwards and axially downwards.

7. Device (2) according to any one of the preceding claims, in which the upper support cover (4) is formed by molding from a single material.

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