Suspension bearing unit with gasket

Abstract

To provide a suspension bearing unit with a gasket.SOLUTION: A suspension bearing unit (2) of the present invention comprises a lower support cap (6), an upper bearing cap (4), and at least one bearing (8) arranged between the lower support cap (6) and the upper bearing cap (4). The lower support cap (6) comprises an annular radial portion (32), and the annular radial portion (32) is at least partially recessed so as to leave a plurality of ribs (34) disposed at intervals from one another in the circumferential direction. The suspension bearing unit (2) further comprises a gasket (10), and the gasket (10) comprises a heel (36) overmolded on the recessed part of the recessed annular radial portion (32) and on the ribs (34), and comprises a seal portion (38) that is supported by the heel (36) and extends towards the upper bearing cap (4). The distal end of the seal portion (38) of the gasket (10) forms a dynamic annular seal with the upper bearing cap (4).SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to the field of suspension bearing units, in particular those used in suspension struts of steering wheels of motor vehicles. [Background technology]

[0002] A suspension bearing unit generally comprises a bearing forming an axial thrust bearing, and upper and lower caps forming a housing for a ring of the bearing and providing an interface between said ring and adjacent elements.

[0003] The suspension bearing unit is located on the top of the suspension strut between the suspension spring and the vehicle body. The suspension spring is attached around the shock absorber piston rod, and its end is connected to the vehicle body. The helical suspension spring is journaled directly or indirectly to the lower cap of the suspension bearing unit.

[0004] The suspension bearing unit allows axial and radial forces to be transmitted between the suspension spring and the vehicle body while allowing relative rotational movement between the lower cap and upper cap as a result of the vehicle's steered wheels being rotated and / or the suspension spring being compressed.

[0005] Typically, the upper cap of the suspension bearing unit is disposed on an outer skirt and includes a plurality of hooks designed to radially engage with a plurality of hooks on the lower cap, the hooks on each cap being circumferentially spaced apart from one another.

[0006] The hooks form a retention means for axially holding the upper and lower caps together, and also form a narrow passageway to limit the ingress of contaminant particles radially between the outer skirt of the upper cap and the lower cap.

[0007] However, such suspension bearing units are generally exposed to various types of contamination.

[0008] Specifically, contaminant particles can easily penetrate between the outer skirt of the upper cap and the lower cap, and are then guided towards and introduced into the bearing.

[0009] To overcome this drawback, Patent Document 1 discloses providing an external gasket that is fixed by a clamp between the bearing and the lower cap of the suspension bearing unit and has at least one sealing lip that interacts with the upper cap. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] German Patent Application No. 10 2020 201 404 Summary of the Invention [Problem to be solved by the invention]

[0011] The object of the present invention is to simplify the manufacture of this type of suspension bearing unit. [Means for solving the problem]

[0012] The present invention relates to a suspension bearing unit comprising a lower support cap, an upper bearing cap and at least one bearing disposed between said caps.

[0013] The lower support cap includes an annular radial portion that is at least partially recessed to leave a plurality of circumferentially spaced ribs.

[0014] The suspension bearing unit further includes a gasket having a heel overmolded onto the recess and rib of the concave annular radial portion, and a sealing portion supported by the heel and extending toward the upper bearing cap.

[0015] The distal end of the sealing portion of the gasket forms a dynamic annular seal with the upper bearing cap.

[0016] The annular radial portion of the lower support cap, leaving a plurality of ribs, improves the grip of the heel of the gasket to the lower support cap and facilitates overmolding of the gasket.

[0017] Overmolding the gasket eliminates a step during assembly of the bearing unit and also eliminates the need for packaging for the gasket that is traditionally provided with bearing units in which the gasket is separate and assembled to one of the caps.

[0018] Additionally, the provision of ribs can further improve the connection between the overmolded gasket and the lower support cap, particularly in the circumferential direction.

[0019] The distal end of the sealing portion of the gasket, which forms a dynamic annular seal with the upper bearing cap, forms a barrier to prevent contaminant particles from migrating toward the bearing.

[0020] Preferably, the gasket is annular.

[0021] Preferably, the gasket is one piece.

[0022] In a first embodiment, the sealing portion of the gasket forms a seal by frictional contact with the upper bearing cap.

[0023] In a second alternative embodiment, the sealing portion of the gasket forms a seal with the upper bearing cap through one or more narrow passages.

[0024] In an alternative third embodiment, the sealing portion of the gasket may form both a seal with the upper bearing cap through one or more narrow passages and a seal by frictional contact with the upper bearing cap.

[0025] Advantageously, said sealing portion comprises an intermediate portion extending at least axially from the heel of the gasket towards the upper bearing cap, and a distal portion extending at least radially inwardly from said sealing portion intermediate portion.

[0026] Optionally, an intermediate portion of said sealing portion extends radially outwardly and axially towards the upper bearing cap.

[0027] Optionally, a distal portion of said sealing portion extends radially inwardly and axially towards the upper bearing cap.

[0028] This means that the sealing portion of the gasket is axially flexible.

[0029] According to a particular design, the intermediate portion of said sealing portion extends from the radially inner edge of the heel of the gasket and is spaced apart from the radially outer edge of the heel of the gasket.

[0030] This means that the flexibility of the sealing portion of the gasket is improved.

[0031] Advantageously, the concave annular radial portion defines a groove, with each rib extending from the bottom of said groove.

[0032] Optionally, each rib is spaced from the radially inner edge of the concave annular radial portion.

[0033] According to a particular design, the lower support cap comprises an annular radial portion and a shoulder extending from said radial portion towards the upper bearing cap and comprising said annular radial portion that is concave.

[0034] Optionally, the concave annular radial portion is spaced from the large diameter edge of the shoulder of the lower support cap.

[0035] According to a particular design, the upper support cap comprises an annular outer skirt that radially surrounds said gasket, said annular outer skirt of the upper support cap protecting said gasket from shocks during handling, in particular during transportation, of the suspension bearing unit.

[0036] Advantageously, said sealing portion is spaced from the annular outer skirt of the upper bearing cap.

[0037] Alternatively, the sealing portion may radially contact the inner surface of the annular outer skirt of the upper bearing cap.

[0038] Advantageously, the distal end of said sealing portion is in axial contact with the upper bearing cap, in particular with a radial portion of the upper bearing cap.

[0039] Optionally, at least one cavity is formed in the sealing portion, opening toward the upper bearing cap, and the cavity is filled with lubricant. The lubricant-filled cavity in the sealing portion improves the seal between the sealing portion of the gasket and the upper bearing cap and forms a barrier to prevent contaminant particles from migrating toward the bearing. Furthermore, the lubricant reduces friction between the sealing portion of the gasket and the upper bearing cap, reducing gasket wear and frictional torque of the bearing unit.

[0040] The invention will be better understood from a consideration of the detailed description of embodiments given as non-limiting examples and illustrated by the accompanying drawings, in which: [Brief explanation of the drawings]

[0041] [Figure 1] 1 is an axial cross-sectional view of a suspension bearing unit according to an exemplary embodiment of the present invention; [Figure 2] FIG. 2 is a detailed view of the unit of FIG. 1. [Figure 3] FIG. 2 is a detailed view of the unit of FIG. 1. [Figure 4] FIG. 2 is a perspective view of a portion of a gasket of the bearing unit of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0042] The suspension bearing unit 2 shown in Figure 1 is designed to be mounted between a helical suspension spring and a cup or upper bearing seat that contacts a fixed chassis element of a motor vehicle. In Figure 1, the unit 2 is shown in an assumed vertical position.

[0043] The unit 2 having an axis XX' comprises an upper bearing cap 4, a lower support cap 6 and a rolling bearing 8 axially interposed between the upper bearing cap 4 and the lower support cap 6.

[0044] In the illustrated example, the upper bearing cap 4 and the lower support cap 6 are mounted in direct contact with the bearing 8 without any intermediate element. Alternatively, the upper bearing cap 4 and the lower support cap 6 may be mounted in indirect contact with the bearing 8 via an intermediate element.

[0045] As will be described in more detail below, the unit 2 also includes an external annular gasket 10 for preventing the ingress of contaminants into the bearing 8, the gasket 10 being overmolded onto the lower support cap 6 and extending toward the upper bearing cap 4.

[0046] The gasket 10 is made, for example, from an elastically deformable material, such as nitrile or an elastomer. The gasket 10 may also be made from a harder material, such as polyoxymethylene (POM), or steel.

[0047] The upper bearing cap 4 consists of a single piece of plastic material, for example polyamide PA6.6, which may or may not be reinforced with glass fibre.

[0048] The upper bearing cap 4 has an axis X-X' and comprises a radial portion 12, an annular axial inner skirt 14 and an annular axial outer skirt 16 radially surrounding the inner skirt 14.

[0049] The radial portion 12 of the upper bearing cap 4 has an upper surface (not numbered) facing the upper bearing seat and an opposite lower surface (not numbered) in contact with the bearing 8. The upper and lower surfaces define the thickness of the radial portion 12 of the upper bearing cap 4.

[0050] The outer skirt 16 of the upper bearing cap 4 extends axially from the radial portion 12 of the upper bearing cap 4. In the illustrated example, the outer skirt 16 of the upper bearing cap 4 continues to the larger diameter edge of the radial portion 12 of the upper bearing cap 4. In particular, the outer skirt 16 radially surrounds the gasket 10.

[0051] The inner skirt 14 of the upper bearing cap 4 extends into the bore of the lower support cap 6. The inner skirt 14 and the outer skirt 16 of the upper bearing cap 4 extend axially downward from the radial portion 12 of the upper bearing cap 4. The inner skirt 14 continues from the smaller diameter edge of the radial portion 12 of the upper bearing cap 4. The outer skirt 16 continues from the larger diameter edge of the radial portion 12 of the upper bearing cap 4.

[0052] The lower support cap 6 here consists of a one-piece moulding made of plastic material, for example polyamide PA6.6, which may or may not be reinforced with glass fibre.

[0053] The lower support cap 6 has an axis XX' and comprises a plate-shaped annular radial portion 18 and an annular axial skirt 20 that continues from the smaller diameter edge of the radial portion 18 of the lower support cap 6.

[0054] An axial skirt 20 of the lower support cap 6 extends axially downward away from the upper bearing cap 4 and the bearing 8. The axial skirt 20 of the lower support cap 6 allows for centering of the suspension spring.

[0055] The radial portion 18 of the lower support cap 6 has a lower annular radial surface (not numbered) which defines a bearing surface for the suspension spring.

[0056] The upper support cap 4 includes a plurality of internal hooks 22 disposed on the inner skirt 14 of the upper support cap 4 and extending radially outwardly of the lower support cap 6. In the example shown, the hooks 22 are circumferentially spaced apart from one another. Alternatively, a single annular hook 22 could be provided.

[0057] The lower support cap 6 comprises a plurality of internal hooks 24 arranged on a radial portion 18 of the lower support cap 6 and extending radially inward of the upper bearing cap 4, said internal hooks 24 being designed to radially engage with the internal hooks 22 of the upper bearing cap 4. In a variant, a single annular hook 24 could also be provided.

[0058] The hooks 22, 24 form a retaining means for axially retaining the upper bearing cap 4 and the lower support cap 6 together.

[0059] The bearing 8 is arranged radially between the inner skirt 14 and the outer skirt 16 of the upper bearing cap 4. The bearing 8 comprises an upper ring 26 in contact with the upper bearing cap 4, a lower ring 28 in contact with the lower support cap 6, and a row of rolling elements 30 (balls in this case) arranged between raceways formed in the rings 26, 28. In the illustrated example, the rolling 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 bearing cap 4, and the lower surface has a shape complementary to that of the upper ring 26 of the bearing 8. The lower ring 28 is in contact with the upper surface of the lower support cap 6, and the upper surface has a shape complementary to that of the lower ring 28 of the bearing 8.

[0060] 2 and 3, the lower support cap 6 includes an annular radial portion 32 that is recessed to leave a plurality of circumferentially spaced ribs 34. More specifically, the recessed annular radial portion 32 forms a groove, with each rib 34 extending from the bottom of the groove. The ribs 34 are regularly spaced circumferentially. Alternatively, the ribs 34 may be irregularly spaced circumferentially.

[0061] Gasket 10 includes a heel 36 overmolded onto the recess of concave annular radial portion 32 and onto rib 34, and a sealing portion 38 supported by heel 36 and extending toward upper bearing cap 4. Gasket 10 is annular and mounted radially around bearing 8.

[0062] The distal end of the sealing portion 38 of the gasket 10 forms a dynamic annular seal with the upper bearing cap 4, where the distal end of the sealing portion 38 is in axial contact with the upper bearing cap 4, more specifically with the underside of the radial portion 12 of the upper bearing cap 4. Here, the distal end of the sealing portion 38 is offset radially outward relative to the bearing 8.

[0063] Furthermore, the lower support cap 6 includes a shoulder 40 on the axial extension of the outer skirt 16 of the upper bearing cap 4, and this shoulder 40 defines a concave annular radial portion 32. In other words, the outer skirt 16 of the upper support cap 4 is located axially above the shoulder 40.

[0064] The shoulder 40 of the lower support cap 6 is formed by a first surface 42 of the lower support cap 6, which is concave, and a second surface 44 of the lower support cap 6, which extends purely radially. The first surface 42 of the lower support cap 6 extends from the large diameter edge of the second surface 44 of the lower support cap 6.

[0065] In a variant, the first surface 42 of the shoulder 40 may be flat and extend purely axially, or may extend both axially and radially, i.e., obliquely. In a variant, the second surface 44 of the shoulder 40 may extend both radially outward and axially downward.

[0066] The concave annular radial portion 32 is here spaced apart from the large diameter edge of the shoulder 40 of the lower support cap 6 , in particular from the first surface 42 of the shoulder 40 .

[0067] Each rib 34 extends from the bottom of the concave annular radial portion 32, is radially spaced from the radially inner edge of the concave annular radial portion 32, and is axially spaced from the second surface 44 of the shoulder 40.

[0068] The sealing portion 38 of the gasket 10 is located radially between the outer skirt 16 of the upper bearing cap 4 and the bearing 8, and extends into an annular space 46 located axially between the radial portion 12 of the upper bearing cap 4 and a second surface 44 of the shoulder 40. Here, the sealing portion 38 of the gasket 10 is spaced apart from the annular outer skirt 16 of the upper bearing cap 4, which improves the flexibility of the sealing portion 38 of the gasket 10.

[0069] The gasket 10 has an S-shaped cross section. In particular, the sealing portion 38 of the gasket 10 includes an intermediate portion 48 that extends radially outward and axially from the heel 36 of the gasket 10 toward the upper bearing cap 4, and a distal portion 50 that extends radially inward and axially from the intermediate portion 48 of the sealing portion 38 toward the upper bearing cap 4.

[0070] More specifically, intermediate portion 48 of sealing portion 38 extends from the radially inner edge of heel 36 of gasket 10 and is spaced apart from the radially outer edge of heel 36 of gasket 10 .

[0071] As shown in FIG. 4, a plurality of notches 52 are formed in the heel 36 of the gasket 10 by each rib.

[0072] In the illustrated exemplary embodiment, the unit 2 comprises a single external gasket 10 disposed radially between the lower support cap 6 and the outer skirt 16 of the upper bearing cap 4. In combination, the unit 2 may comprise an internal gasket disposed radially between the lower support cap 6 and the inner skirt 14 of the upper bearing cap 4.

[0073] In the illustrated exemplary embodiment, the unit 2 includes a single external gasket 10 with a single sealing portion. In alternative embodiments, the unit 2 may include multiple external gaskets or a single gasket with multiple sealing portions.

[0074] In the illustrated exemplary embodiment, unit 2 comprises an angular contact rolling bearing 8 with a row of balls. Unit 2 may also comprise other types of rolling bearings, for example bearings with four-point contact and / or at least two rows of balls. The rolling bearing may also comprise other types of rolling elements 30, for example rollers. In another variant, the bearing of unit 2 may comprise a plain bearing without rolling elements, with one or more rings. [Explanation of symbols]

[0075] 2 Suspension bearing units 4 Upper bearing cap 6 Bottom support cap 8. Bearings 10 Gasket 18 Annular radial section 32 Annular radial section 34 Ribs 36 Heels 38 Seal part 40 Shoulder 48 Middle part 50 distal portion

Claims

1. A suspension bearing unit (2) comprising a lower support cap (6), an upper bearing cap (4), and at least one bearing (8) disposed between the lower support cap (6) and the upper bearing cap (4), - said lower support cap (6) comprises an annular radial portion (32) which is at least partially recessed to leave a plurality of circumferentially spaced apart ribs (34); the suspension bearing unit (2) further comprises a gasket (10) comprising a heel (36) overmolded onto the recess of the concave annular radial portion (32) and onto the rib (34), and a sealing portion (38) supported by the heel (36) and extending towards the upper bearing cap (4); A suspension bearing unit (2), characterized in that the distal end of said sealing portion (38) of said gasket (10) forms a dynamic annular seal with said upper bearing cap (4).

2. 2. The suspension bearing unit (2) of claim 1, wherein the gasket (10) comprises an intermediate portion (48) extending at least axially from the heel (36) of the gasket (10) toward the upper bearing cap (4), and a distal portion (50) of the sealing portion (38) extending at least radially inward from the intermediate portion (48).

3. 3. The suspension bearing unit (2) of claim 2, wherein the intermediate portion (48) of the sealing portion (38) extends radially outward and axially toward the upper bearing cap (4), and the distal portion (50) of the sealing portion (38) extends radially inward and axially toward the upper bearing cap (4).

4. 4. The suspension bearing unit (2) according to claim 2 or 3, wherein the intermediate portion (48) of the sealing portion (38) extends from a radially inner edge of the heel (36) of the gasket (10) and is spaced apart from a radially outer edge of the heel (36) of the gasket (10).

5. 5. A suspension bearing unit (2) according to any one of claims 1 to 4, wherein the concave annular radial portion (32) defines a groove, and each of the ribs (34) extends from the bottom of the groove.

6. 6. A suspension bearing unit (2) according to any one of claims 1 to 5, wherein each said rib (34) is spaced from the radially inner end of said concave annular radial portion (32).

7. 7. The suspension bearing unit (2) according to claim 1, wherein the lower support cap (6) comprises an annular radial portion (18) and a shoulder (40) extending from the radial portion (18) towards the upper bearing cap (4) and comprising the annular radial portion (32) that is concave.

8. 8. Suspension bearing unit (2) according to claim 7, wherein the concave annular radial portion (32) is spaced apart from the large diameter edge of the shoulder (40) of the lower support cap (6).

9. Suspension bearing unit (2) according to any one of claims 1 to 8, wherein the sealing portion (38) is spaced apart from the annular outer skirt (16) of the upper bearing cap (4).

10. 10. The suspension bearing unit (2) according to any one of claims 1 to 9, wherein a distal end of the sealing portion (38) is in axial contact with the upper bearing cap (4).

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