UNIVERSAL JOINT FOR A STEERING SHAFT OF A MOTOR VEHICLE

Abstract

A universal joint may include a joint cross having two pairs of journals arranged at right angles to one another and two joint yokes that each have opposing arms. Each journal may be rotatably mounted in the opposing arms about a journal axis in a journal bearing that has a pot-shaped outer bushing that is fixed in the respective arms and that has an outer pot base disposed opposite an end side of the journal. A convexly projecting contact region may contact the outer pot base. Further, an inner bushing may be fixed on the journal, and rolling bodies may be disposed between the inner bushing and the pot-shaped outer bushing. The convexly projecting contact region may project axially on the end side relative to a surface of the inner bushing that acts as a raceway for the rollable rolling bodies.

Claims

1-11. (canceled)

12. A universal joint for a steering shaft of a motor vehicle, the universal joint comprising: a joint cross having two pairs of journals that are arranged at right angles to one another; and two joint yokes that are connectable to the steering shaft, each joint yoke having two mutually opposite arms, wherein in each of the arms one of the journals is rotatably mounted about a journal axis in a journal bearing, wherein each journal bearing includes a pot-shaped outer bushing that is fixed in the respective arm and has an outer pot base disposed opposite an end side of the respective journal, wherein each outer pot base is contacted by a convexly projecting contact region, wherein an inner bushing is fixed on each journal, wherein in each case rollable rolling bodies are disposed between the inner bushing and the pot-shaped outer bushing, wherein the convexly projecting contact region projects axially relative to a portion of the inner bushing that acts as a raceway for the rolling bodies.

13. The universal joint of claim 12 wherein the inner bushing is pot shaped with an inner pot having an end-side inner pot base that includes the convexly projecting contact region.

14. The universal joint of claim 13 wherein the convexly projecting contact region disposed on the inner pot is axially resilient.

15. The universal joint of claim 13 wherein the convexly projecting contact region is configured as a spherical cap disposed on the end-side inner pot base.

16. The universal joint of claim 15 wherein the end-side inner pot base is at least 50% planar outside of the convexly projecting contact region.

17. The universal joint of claim 15 wherein the end-side inner pot base is axially spaced apart from the end side of the journal.

18. The universal joint of claim 12 wherein the outer pot base is flat.

19. The universal joint of claim 12 wherein the inner bushing includes an outwardly projecting flange portion.

20. The universal joint of claim 12 wherein the pot-shaped outer bushing includes a radially projecting holding portion.

21. The universal joint of claim 12 comprising a sealing element disposed between the pot-shaped outer bushing and the inner bushing.

22. The universal joint of claim 12 wherein the inner bushing is connected to the journal by or in at least one of a force-fitting manner, a form-fitting manner, or substance-to-substance bonding.

23. The universal joint of claim 12 wherein the pot-shaped outer bushing is connected to the arm by or in at least one of a force-fitting manner, a form-fitting manner, or substance-to-substance bonding.

24. A universal joint comprising: a joint cross having two pairs of journals that are arranged at right angles to one another; and two joint yokes, each joint yoke having opposing arms, wherein in each arm one of the journals is rotatably mounted about a journal axis in a journal bearing, wherein each journal bearing includes a pot-shaped outer bushing that is fixed in the respective arm and has an outer pot base disposed opposite an axial end side of the respective journal, wherein each outer pot base is contacted by a convexly projecting contact region of an inner bushing that is fixed on each journal, wherein in each case a rollable rolling body is disposed between the inner bushing and the pot-shaped outer bushing, wherein the convexly projecting contact region protrudes axially relative to the rolling body.

25. The universal joint of claim 24 wherein the convexly projecting contact region protrudes axially relative to a portion of the inner bushing that acts as a raceway for the rolling body.

26. The universal joint of claim 24 wherein the inner bushing is pot shaped with an inner pot having an end-side inner pot base that includes the convexly projecting contact region.

27. The universal joint of claim 26 wherein the convexly projecting contact region disposed on the inner pot is axially resilient.

28. The universal joint of claim 26 wherein the convexly projecting contact region is configured as a spherical cap disposed on the end-side inner pot base.

29. The universal joint of claim 24 wherein a surface area of the end-side inner pot base outside of the convexly projecting contact region is at least 50% planar.

30. The universal joint of claim 24 wherein the end-side inner pot base is axially spaced apart from the axial end side of the journal at a center of the end-side inner pot base.

31. The universal joint of claim 24 comprising a sealing element disposed between the pot-shaped outer bushing and the inner bushing.

Description

DESCRIPTION OF THE DRAWINGS

[0036] Advantageous embodiments of the invention will be explained in more detail below with reference to the drawings, in which in detail:

[0037] FIG. 1 shows a steering column in a schematic perspective view,

[0038] FIG. 2 shows a universal joint of a steering column according to FIG. 1 in a schematic perspective view,

[0039] FIG. 3 shows a longitudinal section through a journal bearing according to the invention of a universal joint according to FIG. 2 in a first embodiment,

[0040] FIG. 4 shows a longitudinal section through a journal bearing according to the invention of a universal joint according to FIG. 2 in a second embodiment,

[0041] FIG. 5 shows a longitudinal section through a journal bearing according to the invention of a universal joint according to FIG. 2 in a third embodiment,

[0042] FIG. 6 shows a longitudinal section through a journal bearing according to the invention of a universal joint according to FIG. 2 in a fourth embodiment,

[0043] FIG. 7 shows a longitudinal section through a journal bearing according to the invention of a universal joint according to FIG. 2 in a fifth embodiment,

[0044] FIG. 8 shows a partially exploded illustration of the universal joint according to FIG. 2 in the first embodiment according to FIG. 3,

[0045] FIG. 9 shows a longitudinal section through a journal bearing according to the invention of a universal joint according to FIG. 2 in a sixth embodiment,

[0046] FIG. 10 shows a partially exploded illustration of the universal joint according to FIG. 7,

[0047] FIG. 11 shows a partially exploded illustration of the universal joint according to FIG. 5.

EMBODIMENTS OF THE INVENTION

[0048] In the various figures, identical parts are always provided with the same reference signs and are therefore as a rule also in each case only named or mentioned once.

[0049] FIG. 1 shows a steering column 1 according to the invention schematically in a perspective view obliquely from behind (with respect to the direction of travel of a motor vehicle that has not been shown).

[0050] The steering column 1 comprises an adjustment unit 2, having a casing unit 21, in which a casing tube 22 is received. A steering spindle 23 is mounted in the casing unit 21 so as to be rotatable about a longitudinal axis L. The steering spindle 23 forms a rear or upper part of the steering shaft and has at its rear end a connection portion 24 for a steering wheel (not shown).

[0051] The adjustment unit 2 is mounted in its front region on a carrier unit 3, which can be fitted to a body (not shown) of a motor vehicle, in a pivot bearing 31 so as to be pivotable about a horizontal pivot axis, with the result that, to adjust the height of the steering wheel in the region of the connection portion 24, the steering spindle 23 is pivotable in a height direction H.

[0052] In the rear region of the adjustment unit 2 there is situated, at a distance from the pivot bearing 31, a clamping device 4 which, by actuating a clamping lever 41, makes it possible for the adjustment unit 2 to be releasably clamped with the carrier unit 2 in order to fix the set height adjustment. By releasing the clamping device 4, it is furthermore possible, for the purpose of the length adjustment, to adjust the casing tube 22 telescopically relative to the casing unit 21. Upon fixing of the clamping device 4, the casing tube 22 is likewise releasably clamped in the casing unit 21, thereby fixing the length setting.

[0053] At its front end projecting out of the casing unit 21 in FIG. 1 to the left, the steering spindle 22 is coupled in an articulated manner, via a universal joint 5, to an intermediate shaft 52 which is rotatable about a shaft axis W inclined with respect to the longitudinal axis L.

[0054] The joint 5 has a first joint yoke 51, which is fixedly connected to the steering spindle 22 and which has two arms 52 situated opposite to one another with respect to the longitudinal axis L. A joint yoke 53 of identical design is mounted on the intermediate shaft 25 and has two arms 54 situated opposite to one another with respect to the shaft axis W.

[0055] The joint yokes 51 and 53 are connected to one another in an articulated manner via a joint cross 55, also referred to as a journal cross.

[0056] FIG. 2 illustrates the joint 5 on an enlarged scale, with only the joint yoke 51 being depicted for the sake of better clarity. The joint cross 55 has two pairs of oppositely radially projecting journals 56, also referred to as joint journals, which are arranged on journal axes Z and Y crossing at right angles. The two journals 56 of a pair are each mounted in a journal bearing 6 in an arm 52, 54 of a joint yoke 51, 53 so as to be rotatable about their respective journal axes Z and Y, which extend transversely with respect to the longitudinal axis L or to the shaft axis W through the arms 52 and 54.

[0057] Since the invention relates to the design of the journal bearings 6, and the first arrangement in the arms 52 of the yoke 51 is substantially identical to the second arrangement in the arms 54 of the joint yoke 53, only the reference signs of the first arrangement will be mentioned below, with the second arrangement being analogously covered thereby.

[0058] FIG. 3 shows a section along the journal axis Z through the joint cross 55. It can be seen therein that the journal 56 is formed in one piece with a basic body of the joint cross 55, which is preferably manufactured as a steel cold-pressed part.

[0059] The journal bearing 6 has an outer bushing in the form of an outer pot 61 having a substantially flat outer pot base 611 which closes a cylindrical outer sleeve 612 on the end side. The outer sleeve 612 is fixedly connected to the arm 52, for example being pressed into an opening 521.

[0060] An inner bushing in the form of an inner pot 62 has a tubular inner sleeve 622 which is fixedly mounted on the journal 56, for example by being pressed on, and which is closed on the end side by an inner pot base 621, and, on the other hand, in the non-preloaded state, is axially spaced apart, by means of a gap 600, from the end side of the journal 56, beyond a projection 58 of the journal 56 that serves as a contact region.

[0061] The journal bearing 6 takes the form of a radial rolling bearing, with the rolling body 63 being constituted by cylindrical needles which are arranged such that they are able to roll between the rolling body raceways formed on the inner lateral surface of the outer sleeve 612 and the outer lateral surface of the inner sleeve 622.

[0062] The inner pot base 621 has on the end side a convexly projecting contact region 64 which lies from the inside against the outer pot base 611. In the example shown, the contact region 64 takes the form of a frustoconical spherical cap which is connected by the inner pot base 621 to the inner sleeve 622 so as to be axially spring-elastic in the direction of the journal axis Z. As a result, the contact region 64 can spring in axially elastically in the direction of the journal axis Z, counter to the spring force exerted by the inner pot base 621, against the end side of the journal 56, thereby making it possible for the journal 56 to be braced elastically against the outer pot base 611 in the direction of the journal axis Z.

[0063] In the illustration of FIG. 3, the joint cross 55 is pressed to the right by the spring force exerted by the axially elastic inner pot 62 via the contact region 64, with the result that the joint cross 55 is in direct contact by way of its end side, in particular via the projection 58, with the inner pot base 621. By virtue of the journal bearing formed in mirror-image fashion thereto on the other, opposite journal 56 of the pair, a spring force of equal size, directed to the left, is correspondingly exerted, with the result that the joint cross is braced elastically between the arms 52 of the joint yoke 51 by this spring force.

[0064] An elastomer sealing ring 7, which axially between a flange 65, which projects radially outward in the manner of a collar, on the inner sleeve 622 and a holding projection 66, which projects inwardly from the outer sleeve 612, serves to seal to the outside the interior of the journal bearing 6 that receives the needles 63.

[0065] FIG. 8 shows the individual constituent parts in isolation in an exploded view.

[0066] FIG. 4 shows an embodiment as in FIG. 3, in which the arm 52 has the caulkings 57, which form plastic deformations for fixing the outer pot 61 in the opening 521 in a form-fitting manner, and, unlike FIG. 3, shows a preloaded journal bearing 6.

[0067] The embodiment shown in FIG. 5 corresponds in principle to the embodiment according FIG. 3 or 4. In this case, the inner pot 62 additionally has, on the inner pot base 621, in the region of the contact surface, a central centering prong 67 which projects axially on the end side and which is mounted in a corresponding depression 613 so as to be rotatable about the journal axis Z. The end side of the journal is axially spaced apart from the inner pot base 621 via the gap 600. The centering prong 67 acts as a contact region with the outer pot base 611.

[0068] FIG. 11 shows the individual constituent parts in isolation in an exploded view. What is illustrated here is that at least one journal 56 has a flat or planar contact surface 56a onto which the inner bushing 62 is pressed.

[0069] FIG. 6 shows a possible development of the embodiments illustrated in FIG. 3, 4 or 5, in which development connecting means 68, for example form-fitting elements such as knurled or roughened formations or the like, are arranged in the region of the connecting surface between the arm 52 and the outer pot 61 on the inner surface of the opening 521 and/or on the outer surface of the outer pot 61.

[0070] In the alternative embodiment according to FIG. 7, the inner bushing 62 takes the form of an inner sleeve 622 which is open on both sides and which thus has no inner pot base on the end side. In this case, the convexly projecting contact region 64 is arranged on a projection 58 of the journal 56 that projects centrally on the end side. The projection 58 is formed integrally on the journal 56 and projects out of the inner sleeve 622 on the end side and lies against the outer pot base 611. Here, the outer pot base 611 can be designed to be axially spring-elastic in the direction of the journal axis Z.

[0071] FIG. 10 shows the individual constituent parts in isolation in an exploded view. The projection 58 of the journal 56 serves as centering means for the outer bushing 61.

[0072] FIG. 9 shows a possible development of the embodiments illustrated in FIG. 3, 4 or 5, wherein, on the one hand, the inner pot base 621 is spaced apart axially from the projection 58 of the journal 56 via a gap 600 and, on the other hand, lies against the outer pot base 611. The pot base of the inner pot 62 is designed to be corrugated and, in the preloading state, lies both against the outer pot base 611 and against the projection 58 of the journal.

LIST OF REFERENCE SIGNS

[0073] 1 Steering column [0074] 2 Adjustment unit [0075] 21 Casing unit [0076] 22 Casing tube [0077] 23 Steering spindle [0078] 24 Connection portion [0079] 25 Intermediate shaft [0080] 3 Carrier unit [0081] 31 Pivot bearing [0082] 4 Clamping device [0083] 41 Clamping lever [0084] 5 Universal joint [0085] 51, 53 Joint yokes [0086] 52, 54 Arm [0087] 521 Opening [0088] 55 Joint cross (journal cross) [0089] 56 Journal (joint journal) [0090] 57 Caulking [0091] 58 Projection [0092] 6 Journal bearing [0093] 61 Outer pot [0094] 611 Outer pot base [0095] 612 Outer sleeve [0096] 613 Depression [0097] 62 Inner pot [0098] 621 Inner pot base [0099] 622 Inner sleeve [0100] 63 Rolling body [0101] 64 Contact region [0102] 65 Flange [0103] 66 Holding projection [0104] 67 Centering prong [0105] 68 Connecting means [0106] 7 Sealing ring [0107] L Longitudinal axis [0108] W Shaft axis [0109] Z, Y Journal axis