Sealed suspension stop device

Abstract

The device comprises a lower support cover 16, an upper support cover 14, at least one bearing 18 arranged between said covers, and at least one annular seal 32. The seal 32 comprises a fixing portion 40 secured by mechanical connection to the lower support cover 16, a sealing portion 42 extending from the fixing portion 40 towards the upper support cover 14, and a heel 44 extending axially from the sealing portion 42 and bearing against a portion 34a of the upper surface 34 of the lower support cover 16. Figure for the abstract: Figure 1

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 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 or inner 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 or internal skirt of the upper cover and the lower cover.

[0007] However, a suspension stop device is generally exposed to various types of pollution. With such a device, polluting particles and water can easily infiltrate between the outer or inner skirt of the upper cover and the lower cover, then be directed towards the bearing and be introduced inside the latter. It is common to provide at least one seal of rigid material or flexible so as to form a barrier to prevent the entry of pollution into the space between the hoods.

[0008] The present invention aims to provide a sealing joint of improved efficiency and assembly. Summary of the invention

[0009] The invention relates to a suspension stop device comprising a lower support cover, an upper support cover, at least one bearing arranged between an upper surface of the lower support cover and a lower surface of the upper support cover, and at least one annular seal arranged radially at least in part between an outer skirt of the upper support cover and the bearing.

[0010] According to the invention, the seal comprises a fixing portion secured by mechanical connection to the lower support cover, a sealing portion extending from the fixing portion towards the upper support cover, and a heel extending axially from the sealing portion and bearing against a portion of the upper surface of the lower support cover, said seal being formed in one piece.

[0011] The seal makes it possible to limit the intrusion of dust, water and other types of polluting particles inside the bearing. The free end part of said sealing portion of said seal forms a dynamic seal with the upper support cover, this dynamic seal being able to be by sliding contact with a portion of the inner surface of the upper support cover or by labyrinth. By "dynamic seal" is meant a seal between two parts capable of relative movement. Said sealing portion of said seal makes it possible to stop the flow of water and to return it to the opposite side of the bearing.

[0012] The fixing portion makes it possible to ensure a mechanical connection of said seal with the lower support cover in order to limit any relative displacement in translation or in rotation. The seal is held in position when the suspension stop device is in operation to ensure the sealing function of the annular space defined between the upper support and lower support covers in which the bearing is housed.

[0013] The support heel allows the positioning of the seal relative to the lower support cover. The position of the seal in the space defined between the covers is precise and optimized to ensure the effectiveness of the sealing of the sealing portion relative to the upper support cover.

[0014] According to advantageous but not mandatory aspects of the invention, such a suspension stop device may incorporate one or more of the following features taken in any technically admissible combination:

[0015] - The sealing portion of the gasket consists of at least one lip in sliding contact with an inner surface portion of the upper bearing cover. The at least one lip has a free end in radial contact with an axial inner surface portion of the upper support cover. The at least one lip has a free end in axial contact with a radial inner surface portion of the upper support cover. The at least one lip has a free end provided with a projecting bead and in contact with a portion of the inner surface of the upper support cover. The at least one lip extends radially. The sealing portion is annular. The bead is annular. The lower support cover comprises a rim projecting axially towards the upper support cover, said rim being provided with a circumferential groove open radially facing the outer skirt of the upper support cover, the fixing portion of the sealing gasket being at least partly housed in said groove. The fixing portion comprises an axial tab and a radially projecting hook housed in the circumferential annular groove, said hook defining a rim in axial retention with a wall of said groove. The edge of the lower support cover is annular. The fixing portion is annular. The fixing portion comprises a plurality of circumferentially distributed sections. The heel is located radially between the sealing portion and the fixing portion of the seal. The heel is annular. The heel comprises a plurality of circumferentially distributed sections. A groove axially open towards the lower support cover is defined between the heel and the fixing portion. An annular hollow is defined between the at least one radial lip of the sealing portion and the axial heel. The body of the lower support cover is made of polyamide type plastic (e.g. PA6 to PA6.6), which can optionally be reinforced with glass fiber (e.g. GF 30 to 60). The gasket is made of a rigid material, for example polyoxymethylene (POM). - The seal is made of polymer material, for example thermoplastic elastomer (TPE). - The bearing is a rolling bearing comprising a first ring supported by an upper face of the annular radial support portion, a second ring supported by a lower face of the upper support cover, and a plurality of rolling elements housed between said rings. - The upper face of the annular radial support portion comprises an annular axial projection provided with an annular concave surface in shape matching and forming a support for the first ring of the rolling bearing. Brief description of the figures

[0016] 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:

[0017] [Fig-1] is a sectional view of a suspension stop device according to the invention, And

[0018] [Fig.2] is a detailed sectional view of a seal of the device of [Fig.l]. Detailed description of the invention

[0019] The suspension stop device 10 shown in [Fig.l] is adapted to be installed between an upper support cup or seat coming into contact against an element of the fixed chassis of a motor vehicle, and a helical type suspension spring. In [Fig.l], the device 10 is shown in a supposed vertical position.

[0020] The device 10 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 may be mounted in indirect contact with the bearing 18 with the interposition of an intermediate element.

[0021] As will be described in more detail hereinafter, the device 10 further comprises an external seal 32 to prevent the intrusion of pollutants towards the bearing 18. The seal 32 closes the axial space defined between the lower support cover 16 and the upper support cover 14 taking into account the interposition of the bearing 18 between these covers.

[0022] The upper support cover 14 comprises a radial portion 14a, an annular axial inner skirt 14b, and an annular axial outer skirt 14c radially surrounding the internal skirt. The radial portion 14a has an upper surface 15 intended to come opposite the upper support 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.

[0023] 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 illustrated, the outer skirt 14c extends a large diameter edge of the radial portion 14a.

[0024] The inner skirt 14b of the support cap extends inside the bore of the lower support cap 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.

[0025] The upper support cover 14 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.

[0026] The bearing 18 is entirely located 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 24 in contact with the lower support cover 16, and a row of rolling elements 22, here balls, arranged between the raceways formed on the rings. In the example illustrated, the bearing 18 is of the angular contact type. The upper ring 20 is in contact with the lower surface 17 of the upper support cover. The lower ring 24 is in contact with an upper surface of the lower support cover 16.

[0027] The lower support cover 16 comprises a body 26, a stiffening insert 28, and a shock absorber 30.

[0028] The body 26 of the lower support cap 16 comprises an annular radial portion 26a in the form of a plate, and an annular axial skirt 26b which extends a small diameter edge of the radial portion 26a. The skirt 26b extends axially opposite the upper support cap 14 and the bearing 18. The skirt 26b allows the centering of a suspension spring (not shown). The radial portion 26a has a lower annular radial surface, and an upper surface 34 in contact with the lower ring 24 of the bearing and of complementary shape. Advantageously, the upper surface 34 comprises an annular axial projection 26c provided with an annular concave surface in conformity of shape and forming a support for the lower ring 24 of the rolling bearing 18.

[0029] The body 26 of the lower support cover 16 is made of a single piece of plastic material, for example such as a polyamide PA 6 to 6.6, which may or may not be reinforced with GF 30 to 60 glass fibers.

[0030] In the example illustrated, the support cover 16 comprises a damper 30 provided on the lower surface of the body 26. The damper is made in one piece from elastic material, and comprises a first portion on the lower radial surface of the radial portion 26a, and a second portion on the outer cylindrical surface of the axial skirt 26b. The damper 30 has a lower annular radial surface 36 providing support for a suspension spring. The damper 30 makes it possible to absorb the shocks and vibrations transmitted by the suspension spring to the lower support cover 16. Alternatively, the lower support cover 16 does not comprise a damper, the lower annular radial surface of the radial portion 26a of the body 26 then forming a direct support for the suspension spring.

[0031] The lower support cover 16 further comprises a stiffening insert 28 with an annular radial insert portion 28a extending into the annular radial support portion 26a of the body 26, and an annular axial tubular insert portion 28b extending into the annular axial support skirt 26b, said axial tubular insert portion extending a small diameter edge of said radial insert portion.

[0032] The stiffening insert 28 is formed from a metallic material, for example steel. The plastic material of the body 26 of the lower cover 16 is overmolded around the insert 28.

[0033] As indicated previously, an external seal 32 is provided between the lower support cover 16 and the upper support cover 14 in order to ensure the sealing of the bearing housed in the radial annular space defined between said covers. The seal 32 is fixed relative to the support cover 16.

[0034] The seal 32 is annular and radially surrounds the bearing 18. The bearing 18 is located radially on the inner side of the seal 32. The seal 32 is located upstream of the bearing 18 on the outer side of the device 10. The seal 32 is located radially in part between the outer skirt 14c of the support cover and the bearing 18.

[0035] The sealing joint 32 comprises a fixing portion 40 secured by mechanical connection to the lower support cover 16, a sealing portion 42 extending from the fixing portion 40 towards and in the immediate vicinity of the upper support cover 14, and a heel 44 extending axially from the sealing portion 42 and coming to bear against a portion 34a of the upper surface 34 of the body 26.

[0036] The radial portion 26a of the body 26 of the lower support cover 16 comprises a rim 46 projecting axially towards the upper support cover 14. In the example illustrated in [Fig.l], the rim 46 takes the form of an annular shoulder 46. The upper surface 34 of the portion 26a is thus stepped, and defines a surface portion 34a below the shoulder 46. Said shoulder 46 further comprises a circumferential groove 46a with an axial face, said groove being radially open facing the outer skirt 14c of the upper support cover 14. The circumferential groove 46a is axially delimited between an upper wall and the surface portion 34a. The fixing portion 40 of the sealing gasket 32 is partly housed in said groove 46a.

[0037] More specifically, and as illustrated in [Fig.2], the fixing portion 40 comprises a tongue 40a extending axially and provided with a radially projecting hook 40b. Once the seal 32 is mounted on the body 26 of the lower support cover 16, the hook 40b is housed inside the circumferential groove 46a of the shoulder 46 provided on the body 26. The hook 40b defines a rim of radial upper surface 40c in axial retention with the upper wall of said groove 46a. The seal 32 is thus in mechanical connection with the cover 26 by cooperation with the groove 46a. According to one variant, the fixing portion 40 is annular. According to another variant, the fixing portion 40 comprises a plurality of sections distributed circumferentially.

[0038] The seal 32 is also provided with an annular sealing portion 42 which extends towards the support cover 14. The sealing portion 42 closes the axial space existing between the lower support cover 16 and the upper support cover 14. The sealing portion 42 closes the axial space on the outer side of the device 10. Said axial space is formed between the lower surface 17 of the upper support cover and the upper surface 34 of the support cover. The sealing portion 42 radially surrounds the bearing 18.

[0039] The sealing portion 42 of the seal radially extends from the fixing portion 40 towards the outer skirt 14c of the upper support cover 14. The sealing portion 42 of the seal extends outwards from the heel 40.

[0040] In the illustrated embodiment, the sealing portion 42 consists of a sealing lip extending radially outwards from the heel 40, the free end of which comes into sliding axial contact with a radial inner surface portion of the radial portion 14a of the upper support cover 14. In the illustrated example, the lip 42 has a free end provided with an axially projecting bead 42a in contact with the upper support cover 14. Advantageously, the bead 42a is annular.

[0041] According to a variant not illustrated, the lip 42 has a free end in sliding radial contact with a portion of the axial inner surface of the upper support cover, for example an inner surface of the outer skirt 14c. According to a variant not illustrated, the lip 42 provides a labyrinthine seal which does not contact the upper support cover 14. According to another variant not illustrated, the sealing portion 42 comprises a plurality of lips.

[0042] The seal 32 is finally provided with a heel 44 projecting radially from the sealing portion 42 towards the lower support cover 16. The heel 44 is located radially between the sealing portion 42 and the fixing portion 40 of the seal 32.

[0043] The heel 44 defines a lower bearing surface 44a bearing against the portion 34a of the upper surface 34 of the body 26. The heel is annular. When the fixing portion 40 is in mechanical connection with the circumferential groove 46a provided in the body 26 of the lower support cover 16, the surface 44a bears axially and abuts against the surface 34a in order to ensure stable and controlled positioning of the seal 32. Advantageously, the heel 44 is annular. According to a variant, the heel 44 comprises a plurality of sections distributed circumferentially.

[0044] An annular groove 50 open axially towards the lower support cover 16 is defined between the heel 44 and the tongue 40a of the fixing portion 40. This groove 50 makes it possible to give flexibility to the tongue 40a when clipping the hook 40b into the associated groove 46a during the assembly of the sealing gasket 32 with the cover 16.

[0045] An annular hollow 52 is defined between the radial lip 42 of the sealing portion and the axial heel 44. This hollow 52 makes it possible to give flexibility to the lip 52. The lip 42 can thus deform elastically and ensure sliding contact in the event of relative oscillation between the upper 14 and lower 16 covers.

[0046] The sealing portion 42 of the seal forms a dynamic seal with the support cover 14 over 360°. The fixing portion 40 of the seal 32 is in static sealing contact with the support cover 16 over 360°.

[0047] The seal 32 is formed in one piece, for example by molding. The seal 32 may for example be made of a rigid material, for example polyoxymethylene (POM). Alternatively, the seal 32 may also be made of a less rigid material, for example nitrile or elastomer.

[0048] In the illustrated embodiments, the device comprises an angular contact rolling bearing provided with a row of balls. The device 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, for example rollers. In another variant, the device may comprise a sliding bearing without rolling elements and provided with one or more rings.

Claims

Claims

1. Suspension stop device (10) comprising a lower support cover (16), an upper support cover (14), at least one bearing (18) arranged between an upper surface (34) of the lower support cover (16) and a lower surface (17) of the upper support cover (14), and at least one annular seal (32) arranged radially at least in part between an outer skirt (14c) of the upper support cover (14) and the bearing (18), the seal (32) comprises a fixing portion (40) secured by mechanical connection to the lower support cover (16), a sealing portion (42) extending from the fixing portion (40) towards the upper support cover (14), and a heel (44) extending axially from the sealing portion (42) and bearing against a portion (34a) of the upper surface (34) of the cover lower support (16), said seal (32) being formed in one piece,characterized in that the lower support cover (16) comprises a rim (46) projecting axially towards the upper support cover (14), said rim (46) being provided with a circumferential groove (46a) open radially facing the outer skirt (14c) of the upper support cover (14), the fixing portion (40) of the seal (32) comprising an axial tab (40a) and a radially projecting hook (40b) housed in the circumferential annular groove (46a), said hook (40b) defining a rim (40c) in axial retention with a wall of said groove (46a).,

2. Device according to claim 1, in which the sealing portion (42) of the seal (32) consists of at least one lip extending radially and in sliding contact with an inner surface portion of the upper support cover (14).

3. Device according to claim 2, in which the at least one lip (42) has a free end provided with a protruding bead (42a) and in contact with a portion of the inner surface of the upper support cover (14).

4. Device according to any one of the preceding claims, in which the heel (44) is located radially between the sealing portion (42) and the fixing portion (40) of the sealing gasket (32).

5. Device according to claim 4, in which a groove (50) open axially towards the lower support cover (16) is defined between the

6. heel (44) and the fixing portion (40). Device according to any one of claims 4 or 5, in which the sealing portion (42) of the seal (32) consists of at least one radially extending lip, an annular hollow (52) being defined between said radial lip (42) and the axial heel (44).

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