SEALING ELEMENT FOR A BALL-AND-SOCKET JOINT

Abstract

A sealing element for a ball joint. The sealing element has a sealing area on the housing side and a sealing area a distance away therefrom in an axial direction of the sealing element on the stud side. Arranged between the housing-side sealing area and the stud-side sealing area is an outlet opening which extends through the sealing element to allow the passage of spent lubricant. The outlet opening extends in the axial direction of the sealing element, passing all the way through the sealing element in the axial direction. Further, a ball joint having a sealing element and a two-point control arm with such a ball joint.

Claims

1-19. (canceled)

20. A sealing element (1) for a ball joint (2), the sealing element (1) comprising a sealing area (3) on a housing side and a sealing area (4) on a stud side a distance away therefrom in an axial direction (a) of the sealing element (1), and an outlet opening (5) is arranged between the sealing area (3) on the housing side and the sealing area (4) on the stud side and extends through the sealing element (1) to allow passage of spent lubricant, the outlet opening (5) extends in the axial direction (a) of the sealing element (1), passing completely through the sealing element (1) in the axial direction (a) thereof.

21. The sealing element (1) according to claim 20, wherein the outlet opening (5) in the axial direction (a) of the sealing element (1) extends substantially from the sealing area (3) on the housing side to the sealing area (4) on the stud side.

22. The sealing element (1) according to claim 20, wherein the outlet opening (5) is in the shape of either a slim truncated cone or pyramid.

23. The sealing element (1) according to claim 20, wherein the sealing element (1) has at an end (13) on the stud side, a stud-side geometrical area (14) undercut relative to the axial direction (a) of the sealing element (1), to enable interlocking connection of an annular dish-shaped plate (15) to the sealing element (1).

24. The sealing element (1) according to claim 23, wherein to enable the interlocking connection of the annular dish-shaped plate (15), the geometrical area (14) undercut has an inner groove (16) facing away from the sealing area (4) on the stud side and, adjacent to it in the axial direction (a), at the same time a bead (17) facing toward the sealing area (4) on the stud side.

25. The sealing element (1) according to claim 20, wherein the sealing element (1) is solidly formed so that, in a fitted condition, the sealing element will restrict deflection movements of a ball stud (6) of the ball joint (2) relative to a housing (7) of the ball joint (2).

26. The sealing element (1) according to claim 20, wherein at an end face (9) of the sealing element (1) on the stud side, the outlet opening (5) has an aperture (10) that opens in a trench-like annular groove (11) of the sealing element (1) formed in the end face (9) on the stud side.

27. The sealing element (1) according to claim 20, wherein in an end face (9) on the stud side the sealing element (1) has at least one radial lubricant groove (12) formed to enable spent lubricant to drain away, the said groove extending straight in a radial direction (r) perpendicular to the axial direction (a) of the sealing element (1).

28. The sealing element according to claim 27, wherein the radial lubricant groove (12) opens into a geometrical area (14) of the sealing element (1) undercut relative to the axial direction (a) thereof on the stud side, which serves to enable interlocking connection of an annular dish-shaped plate (15) to the sealing element (1).

29. The sealing element (1) according to claim 20, wherein two outer circumferential areas of the sealing element (1) opposite one another in a radial direction (r) of the sealing element (1) perpendicular to the axial direction (a) thereof are drawn in, in such manner that the outer circumferential areas form a narrowing (26) that extends in the axial direction (a) of the sealing element (1), and as a result, in a radial section through the narrowing (26) the sealing element (1) has a substantially elliptical outer circumference.

30. The sealing element (1) according to claim 20, wherein on an inner circumferential surface which in a fitted condition is in contact with a ball stud (6), the sealing element (1) has an all-round undulating contour (8) which, in the fitted condition, forms in combination with the ball stud (6) a gap seal.

31. The sealing element (1) according to claim 20, wherein the sealing area (3) on the housing side has a geometrical area (18) undercut relative to the axial direction (a) of the sealing element (1), to enable interlocking connection of the sealing element (1) to a housing (7) of a lubricated ball joint (2).

32. The sealing element (1) according to claim 20, wherein at an end (13) on the stud side the sealing element (1) has an all-round, annular outer elastic lip (29) so as, in a fitted condition, to prevent any entry of dirt into the ball joint (2), the annular outer elastic lip (29) being orientated in the axial direction (a) of the sealing element (1) and having an outer circumferential surface which is part of an outer circumferential surface of the sealing element (1).

33. A ball joint (2) with a sealing element (1) having a sealing area (3) on a housing side and a sealing area (4) on a stud side a distance away therefrom in an axial direction (a) of the sealing element (1), and an outlet opening (5) is arranged between the sealing area (3) on the housing side and the sealing area (4) on the stud side and extends through the sealing element (1) to allow passage of spent lubricant, the outlet opening (5) extends in the axial direction (a) of the sealing element (1), passing completely through the sealing element (1) in the axial direction (a) thereof, and the sealing element (1) is securely fixed onto the ball joint (2) and the ball joint (2) comprises an annular dish-shaped plate (15) securely connected to the sealing element (1).

34. The ball joint (2) according to claim 33, wherein the annular dish-shaped plate (15) has a smaller outer diameter than the sealing element (1).

35. The ball joint (2) according to claims 33, wherein to produce the secure connection an all-round collar (22) of the annular dish-shaped plate (15) engages with interlock in an inner groove of an undercut geometrical area (14) on the stud side of the sealing element (1).

36. The ball joint (2) according to claim 35, wherein a gap (23) remains between the all-round collar (22) and the inner groove (16) to allow passage of spent lubricant.

37. The ball joint (2) according to claim 33, wherein the annular dish-shaped plate (15) has an all-round bead (24) on an inside circumference thereof, which at least partially blocks the outlet opening (5).

38. A two-point control arm (20) with a ball joint (2) having a sealing element (1) that has a sealing area (3) on a housing side and a sealing area (4) on a stud side a distance away therefrom in an axial direction (a) of the sealing element (1), and an outlet opening (5) is arranged between the sealing area (3) on the housing side and the sealing area (4) on the stud side and extends through the sealing element (1) to allow passage of spent lubricant, the outlet opening (5) extends in the axial direction (a) of the sealing element (1), passing completely through the sealing element (1) in the axial direction (a) thereof, and the sealing element (1) is securely fixed onto the ball joint (2) and the ball joint (2) comprises an annular dish-shaped plate (15) securely connected to the sealing element (1), and the two-point control arm is in the form of either a steering rod (20) or a track rod.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Below, the invention is explained in greater detail with reference to embodiments shown only as examples in the drawings, in which the same indexes relate to the same components or elements and which show:

[0038] FIG. 1: A sectioned representation of a sealing element according to a first embodiment of the invention;

[0039] FIG. 2: An enlarged view of the detail Y in FIG. 1;

[0040] FIG. 3: A perspective view from below of the sealing element in FIG. 1;

[0041] FIG. 4: A perspective view of a two-point control arm according to the invention;

[0042] FIG. 5: A sectioned representation of a lubricated ball joint from FIG. 4 with a sealing element according to a second embodiment of the invention;

[0043] FIG. 6: An enlarged sectioned view of part of the ball joint in FIG. 5;

[0044] FIG. 7: An enlarged view of the detail Z in FIG. 5;

[0045] FIG. 8: A sectioned view along the section 8-8 in FIG. 6, and

[0046] FIG. 9: A sectioned representation of a sealing element according to a third embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0047] FIG. 1 shows a sealing element 1 for a lubricated ball joint 2, wherein the sealing element 1 consists of polyurethane (PUR) and is made by an injection molding process. The sealing element 1 has a sealing area 3 on the housing side and a sealing area 4 on the stud side a distance away from it in an axial direction a. In addition the sealing element 1 has six outlet openings 5 arranged between the housing-side sealing area 3 and the stud-side sealing area 4, which therefore extend through the sealing element 1 to allow the passage of spent lubricant. The outlet openings 5, of which only two can be seen in the figure, extend in a straight line in the axial direction a of the sealing element 1 and pass completely through the sealing element 1 in its axial direction a in such manner that if the sealing element 1 were viewed in its axial direction a, one could see through the outlet openings 5. Furthermore, the outlet openings 5 extend in the axial direction a of the sealing element 1 essentially from the housing-side sealing area 3 to the stud-side sealing area 4. The outlet openings 5 are in the shape of slim truncated cones and each has an inside surface that has not been machined. At the level of the housing-side sealing area 3 the outlet openings each have a diameter of 3 millimeters and at the level of the stud-side sealing area 4 a diameter of 2 millimeters.

[0048] The sealing element 1 is essentially of solid structure so that when fitted, it restricts deflection movements of a ball stud 6 of the ball joint 2 relative to a housing 7 of the ball joint 2. Furthermore, on an inner circumferential surface which when fitted is in contact with the ball stud 6 the sealing element 1 has an all-round undulating contour 8 which, in the fitted condition, acts as a gap seal in combination with the ball stud 6 of the ball joint 2. On a stud-side end face 9 of the sealing element 1 the outlet openings each lead with an aperture 10 into a trench-like all-round annular groove 11 formed in the stud-side end face 9 of the sealing element 1. Also formed in the stud-side end face 9 there are four trench-like radial lubricant grooves 12 for draining spent lubricant away, which grooves extend straight in a radial direction r perpendicular to the axial direction a of the sealing element 1.

[0049] FIG. 2 shows that the sealing element 1 has at a stud-side end 13 a geometrical area 14 which is undercut relative to the axial direction a of the sealing element 1, to enable the interlocking connection of an annular dish-shaped plate 15 to the sealing element 1. It can also be seen that the stud-side undercut geometrical area 14 for the interlocking connection of the annular dish-shaped plate 15 has an inner groove 16 facing away from the stud-side sealing area 4 in the radial direction r and adjacent to it in the axial direction a and at the same time a bead 17 facing toward the stud-side sealing area 4 in the radial direction r. The radial lubricant groove 12 opens into the stud-side undercut geometrical area 14. Furthermore, it can be seen that the housing-side sealing area 3 has a housing-side geometrical area 18 undercut relative to the axial direction a of the sealing element 1 to enable the interlocking connection of the sealing element 1 to the housing 7 of the lubricated ball joint 2. To simplify the assembly of the sealing element 1, the housing-side sealing area 3 has an all-round inner chamfer 19 which widens out toward an end face on the housing side.

[0050] In FIG. 3 it can be seen that two outlet openings 5 opposite one another in the radial direction r open with their apertures 10 each into a radial lubricant groove 12 and at the same time into the all-round annular groove 11. FIG. 4 shows a two-point control arm 20 with two respective lubricated ball joints 2 at its ends, the two-point control arm being in the form of a length-adjustable steering rod 20. For reasons of fitting space the steering rod 20 is bent so that in a fitted condition collisions with nearby components are avoided. Owing to its bent shape the center of gravity 28 of the steering rod 20 is located away from a connection line, indicated by the broken line, that passes through the two ball joints 2 arranged at the ends of the steering rod 20. Due to this geometrical configuration, in its fitted condition the steering rod 20 is acted upon by a turning moment M.

[0051] FIG. 5 shows one of the two lubricated ball joints 2 in FIG. 4, wherein a sealing element 1 is connected securely to the ball joint 2 and wherein, furthermore, the ball joint 2 also comprises an annular dish-shaped plate 15 fixed securely on the sealing element 1. A ball stud 6 of the ball joint 2 is shown in a non-deflected null position, in which a central axis of the ball stud 6 extends in an axial direction that coincides with the axial direction a of the sealing element 1. A partially represented shank 21 formed integrally with a housing 7 of the ball joint 2 extends in a radial direction r, perpendicularly to the axial direction a, and for that reason the ball joint is also called a radial ball joint 2. The shank 21 serves for connecting the radial ball joint 2 to a connecting tube of the steering rod 20 in FIG. 4. A conical area of the ball stud 6 is clamped by a crown nut via a cone connection rotationally fixed to a steering column lever. The housing 7 has an all-round annular groove in which there engages with interlock a bead of a housing-side undercut geometrical area 18 of the sealing element 1 provided with an inner chamfer 19 in order to produce the aforesaid secure connection. Two outer circumferential areas of the sealing element 1 opposite one another in the radial direction r have an in-drawn shape such that these outer circumferential areas form a narrowing 26 that extends in the axial direction a of the sealing element 1. Thanks to this narrowing 26, the resistance against deflection of the ball stud 6 away from its null position is lower compared with the circumferential areas of the sealing element 1 that have no narrowing 26.

[0052] In FIG. 6 it can be seen that the annular dish-shaped plate 15 has a smaller outer diameter than the sealing element 1. The ball joint 2 has a lubrication nipple 25 through which fresh lubricant can be fed into the ball joint 2. Furthermore the ball joint 2 has a schematically indicated rotation prevention device 27 which comprises a part on the housing side and a part on the sealing element side. The housing-side part is formed integrally with the housing 7 and the sealing element part integrally with the sealing element 1. The two parts engage in one another with interlock to prevent any rotation of the sealing element 1 relative to the housing 7. The rotation prevention device 27 ensures that the above-mentioned deflection of the ball stud 6, which is favored by the narrowing 26, is always allowed only in the same, predefined direction with no fear of collision with nearby components. In this case the same, predefined direction is along the longitudinal direction of the steering rod 20. The two outer circumferential areas arranged opposite one another in the radial direction r and at the same time drawn inward, which form the narrowing 26 of the sealing element 1, are therefore aligned with the longitudinal direction of the steering rod 20 as can be seen in FIG. 4. In contrast, two areas of the sealing element 1 offset in the circumferential direction of the sealing element 1 by 90 degrees relative to the oppositely arranged and at the same time drawn-in outer circumferential areas are not narrowed but are solidly formed so as to be able to support the turning moment M during driving operation.

[0053] As can be seen in FIG. 7, to produce the secure connection an all-round collar 22 of the dish-shaped plate 15 engages in an inner groove 16 of a stud-side undercut geometrical area 14 of the sealing element 1. Between the all-round collar 22 and the inner groove 16 there remains a gap 23 to allow the passage of spent lubricant. At its inside circumference the annular dish-shaped plate 15 has an all-round bead 24 by which an outlet opening 5 is partially blocked. More precisely, an aperture 10 of the outlet opening 5 is partially blocked. The broken line indicates the path that the spent lubricant must follow in order to emerge from the ball joint 2. For this, the spent lubricant is displaced by fresh lubricant fed into the ball joint 2 through the lubrication nipple 25.

[0054] FIG. 8 shows the two outer circumferential areas of the sealing element 1 opposite one another in the radial direction r and at the same time drawn in to form the above-mentioned narrowing 26. In the section through the narrowing 26 shown, the outer contour of the sealing element 1 is essentially elliptical.

[0055] FIG. 9 shows a sealing element 1 which, at a stud-side end 13, has an all-round annular outer elastic lip 29 so that in the fitted condition it will prevent any entry of dirt into the ball joint 2. The annular outer elastic lip 29 is orientated in the axial direction a of the sealing element 1 and has an outer circumferential surface which is part of an outer circumferential surface of the sealing element 1. The annular outer elastic lip 29 extends in the axial direction a of the sealing element 1 at the same height as an annular inner elastic lip 30 which is also orientated in the axial direction a of the sealing element 1, and which has an inner circumferential surface which is part of the inner circumferential surface of the sealing element 1. An aperture 10 of an outlet opening bis arranged between the annular outer elastic lip 29 and the annular inner elastic lip 30. The sealing element 1 can be used both for the lubricated ball joint 2 and for low-maintenance and maintenance-free ball joints.

INDEXES

[0056] 1 Sealing element [0057] 2 Lubricated ball joint, lubricated radial bail joint [0058] 3 Sealing area on the housing side [0059] 4 Sealing area on the stud side [0060] 5 Outlet opening [0061] 6 Ball stud [0062] 7 Housing of the lubricated bail joint [0063] 9 Undulating contour [0064] 9 End face on the stud [0065] 10 Aperture of the outlet opening [0066] 11 All-round annular groove [0067] 12 Radial lubricant groove [0068] 13 End of the sealing element on the stud side [0069] 14 Undercut geometrical area on the stud side [0070] 15 Annular dish-shaped plate [0071] 16 Inner groove [0072] 17 Bead [0073] 18 Undercut geometrical area on the housing side [0074] 19 Inner chamfer [0075] 20 Two-point control arm, steering rod [0076] 21 Shank [0077] 22 Collar of the annular dish-shaped plate [0078] 23 Gap [0079] 24 AH-round bead [0080] 25 Lubrication nipple [0081] 26 Narrowing [0082] 27 Secure connection [0083] 28 Center of gravity [0084] 29 Annular outer elastic lip [0085] 30 Annular inner elastic lip [0086] a Axial direction [0087] r Radial direction [0088] M Turning moment