FORM 2
THE PATENT ACT 197 0 (39 of 1970)
The Patents Rules, 2003 COMPLETE SPECIFICATION [See Section 10, and rule 13)
TITLE OF INVENTION
JOINT AND/OR BEARING ARRANGEMENT

APPLICANT (S)
a) Name
b) Nationality
c) Address

ZF FRIEDRICHSHAFEN AG GERMAN Company 88038 FRIEDRICHSHAFEN GERMANY

3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed : -

The invention relates to a joint and/or bearing arrangement according to the preamble of Claim 1 as well as a motor vehicle with one or a plurality of joint and/or bearing arrangement(s) of this kind, in particular in chassis and/or steering parts.
In the case of joint arrangements having a pin which is to be retained in a mobile manner with its head region in a joint shell, this joint shell must be formed from a relatively soft material in order to achieve sufficient damping and quiet operation of the joint or bearing arrangement. A POM plastics material is used for a joint shell, for example. This gives rise to the difficulty of plastics materials which are suitable for the above-mentioned requirements of the joint shell frequently reaching their yield point at a high temperature, for example even at approximately 80°C, and/ or when loaded, so that plastic and therefore irreversible deformation, for instance thinning, of the joint shell can occur under a radial load, which leads to play in the joint and reduced stability of the joint shell.
The invention is based on the problem of achieving lasting improvement of the dimensional stability and stability of the joint shell, in particular where radially stressed joints are concerned.
The invention solves this problem by means of a joint or bearing arrangement having the features of Claim 1 as well as by means of a motor vehicle having the features of Claim 12. The additional Claims 3 to 11 are to be referred to regarding advantageous configurations and developments of the invention.
The invention reliably prevents the material of the joint or bearing shell from yielding through mechanical constraint. In the ideal case the pressure occurring under a radial load through the head region of the pin on the circumferential walls of the joint or bearing shell cannot lead to yielding of the wall material in the axial direction - or else only to a reduced extent - on account of the axial barriers. Therefore the wall thickness cannot decrease, material thinning is prevented.

Provided that the axial barriers lie directly against the joint shell in an extension of its circumferential walls, this is retained with its circumferential walls free from play in the skirt; an axial yielding movement thereof is completely suppressed.
The axial barrier can in particular be formed at the through-region of the pin as an encircling edge, projecting inwards from the inner wall of the housing, of the skirt and cover at least 10% of the diameter of the housing, i.e. a region of the diameter which is greater than the actual thickness of he encircling wall of the joint. Yielding of the joint shell material is thereby prevented in a particularly reliable manner.
In a manner favourable for the stability and production of the skirt, this forms an intermediate housing which is at least substantially closed outside of a through-region for the joint pin, which housing can also be in one piece, for example. The intermediate housing can be completely closed like a trough in the region lying opposite the through-opening.
The outer housing does not have to form a separate joint component, but can also be formed as an injection coating of the joint shell, for instance as a control arm of a chassis, according to the purpose of use. The joint arrangement can then still be replaceable by pressing out in order to be able to continue using the control arm if required when the joint is changed.
Since, when assembling joints which are only radially stressed during operation, an axial path for the joint pin can nevertheless be available, the provision of an anti-twist mechanism in the housing for the skirt is particularly helpful. This can be formed, for example, by a bolt which engages in a slotted recess of the skirt.
It is highly expedient to form the skirt from steel or a plastics material which is harder when compared with the joint shell.

Preloading of the joint and/or bearing arrangement effects play- and rattle-free operation.
The invention can in particular be used for joint arrangements which are only axially stressed in the fitting phase and only radially stressed during operation.
Further features and advantages of the invention will emerge from embodiments of the subject matter of the invention which are represented in the drawings and described in the following.
In the drawings:
Fig. 1 is a schematic, cutaway general drawing of a joint and/or bearing
arrangement according to the invention with a one-piece skirt and an anti-twist mechanism for this,
Fig. 2 is a view similar to Figure 1 of an alternative joint arrangement
according to the invention with a substantially annular skirt which is open axially outside of barriers arranged in the outer region of the housing diameter, and a joint shell, which is likewise annular,
Fig. 3 shows the joint or bearing arrangement according to Fig. 2 in a fitted
position, pressed into a control arm.
The joint arrangement 1 according to Figure 1 comprises an axially extended joint pin 2 with a widened head region 3 which is formed by a substantially spherical formation, for example. This can be retained in a mobile manner in and with respect to a joint or bearing shell 4, which as a rule is prelubricated and accommodates the head region. The joint shell 4 according to Figure 1 is substantially closed outside of the pin passage, whereas the joint shell 4 according to Figure 2 is rather annular.

The joint shell 4 is also in turn partly surrounded at least on the radial outside by an accommodation space acting as a housing 5. The housing 5 does not have to form a separate construction unit, but can also be an integral component part of a control arm 6 which embraces the joint arrangement 1 in the assembled state, for example.
A control arm 6 of this kind can be produced by injection coating or casting coating with liquid, hot material, for example by zinc die-casting, in which case, after subsequent cooling in a mould, the control arm 6 is rigid and dimensionally stable and can form an integral housing 5 without further finishing.
The joint and/or bearing arrangement 1 also comprises a sealing sleeve which is frequently formed as sealing bellows and is not drawn in here. It adjoins the joint shell 4 in the region of the through-opening 7, left by the housing 5, for the pin 2.
The embodiment shows a joint 1 which is only radially loaded during operation and which, however, retains axial play As which is required for assembling and disassembling the control arm 6, for example, inside the chassis. There is no axial load on this joint 1 during regular operation; the joint arrangement remains individually replaceable even when embedded in a control arm 6 formed on by injection coating.
The joint shell 4, which in the first version according to Figure 1 is closed outside of the through-opening 7 for the pin 2 and outside of apertures for the expansion wings and in the second version according to Figures 2 and 3 is of almost annular formation, can be formed, for example, from a PA, POM, PBT, PEEK or crosslinked types of these materials (for example by electron beam crosslinking). These afford the required thermal stability and are nevertheless sufficiently soft and resiliently compliant in order to offer a high level of comfort and a low noise level during operation.

Since, on account of the radial load during operation, radial forces 8 act on the circumferential walls 9 of the shell 4, so that these, in contrast, show a tendency, giving way, to yield in the axial direction, in particular under a high load and/or high temperatures, a skirt 10, which embraces the joint shell in regions, with axial barriers 11 is here arranged between the joint shell 4 and the housing 5. Axial barriers 11 are understood to be barriers which protect the material of the joint shell 4 against axial yielding and themselves project radially inwards with a component from the outer edge of the skirt 10.
The barriers 11 can also extend obliquely as a housing wall, in particular in the case of the closed intermediate housing 10 according to Figure 1.
Generally speaking a plurality of - for example overlapping - skirts 10 would also be possible.
The axial barriers 11 lie directly against the joint shell 4, so that this is enclosed firmly and free from play at the axial boundary edges of its circumferential walls 9. It is as a result completely impossible for material of the joint shell 4 to yield in the axial direction. The housing edge 15 can be closed after introducing the joint shell 4 and the skirt 10 by beading, for example.
In the embodiment according to Figure 1 the skirt 10 forms an intermediate housing which is at least substantially closed outside of a through-region 7 for the joint pin 2 - outside of apertures for the formation and movement of expansion wings. Here the skirt 10 is formed in one piece for a simple production process.
However at the through-region 7 of the pin 2 the barrier 11 protecting against axial yielding here is formed as an encircling edge, projecting inwards from the inner wall of the housing, of the skirt, covering approximately at least 10%, better 15% - 20%, of the diameter of the joint shell 4. Therefore on the one hand a sufficiently large through-region 7 also remains for a pivotal movement of the pin 2, yet on the other

hand the walls 9 of the joint shell are overlapped as far as possible to an extent such that it is practically impossible for material yielding of the joint shell 4 to take place past the barriers 11, even under a high radial load 8. In the region lying axially opposite the through-opening 7 an even greater part of the diameter is preferably covered by the barriers 11 provided there.
In order to effectively prevent material yield or creep, the skirt 10 is formed from steel or a plastics material which is harder when compared with the joint shell 4, for instance PEEK, at least in the region of the axially active barriers. Yielding deformation of the barriers 11 can as a result be excluded, even under a high load. Fibre reinforcement is in addition possible. The skirt 10 can also be formed in multiple layers and have on the outside a lubricating lacquer or a plastics coating, for instance, for improving the tribological properties.
Where the joint arrangements 1 represented in the drawings are concerned, for assembly purposes the joint shells 4, equipped with the pin 2 and assembled in their respective skirt 19, can be inserted in the housing 5 in an axially displaceable manner. An anti-twist mechanism 12 is provided in order to facilitate assembly. Here this comprises a bolt, lobe 14 or similar which engages in an axially extended elongated hole 13 of the joint shell 4, the axial length of the elongated hole 13 at least corresponding to the displacement path As in the housing 5. Other anti-twist mechanisms are also possible.
In order to enable occurring axial and/or radial forces to be absorbed and to guarantee play- and rattle-free operation, a fit which is still mobile of the head region 3 in the joint shell 4 and a tight fit of the joint shell 4 in the skirt 10, which may be axially displaceable with respect to the housing 5, are to be guaranteed. A preload can be introduced into the joint shell 4 through the skirt 10, this remaining at least almost constant throughout the service life.

Joint and/or bearing arrangements 1 of this kind can be used to advantage in the formation according to the invention in particular inside chassis and/or steering parts of motor vehicles, also, for example, in order to compensate for design-induced tolerances between the control arm and the wheel carrier when assembled in the vehicle.

List of reference characters
1 joint and/or bearing arrangement
2 pin
3 head region
4 joint shell
5 housing
6 control arm
7 through-opening
8 radial forces
9 circumferential walls
10 skirt
11 barriers
12 anti-twist mechanism
13 elongated hole
14 pin, lobe
15 housing edge

WE CLAIM:
1. Joint and/or bearing arrangement (1) with a joint pin (2) whose head region
(3) is mobile with respect to an accommodating joint shell (4), wherein the
joint shell (4) is arranged in an accommodation space acting as a housing (5)
in the assembled position,
characterised in
that at least one skirt (10), which embraces the joint shell (4) in regions, with
axial barriers (11) is arranged between the joint shell (4) and the housing (5).
2. Joint and/or bearing arrangement (1) according to Claim 1,
characterised in
that the axial barriers (11) lie directly against the joint shell (4).
3. Joint and/ or bearing arrangement (1) according to either of Claims 1 and 2,
characterised in
that the skirt (10) forms an intermediate housing which is at least substantially closed outside of a through-region (7) for the joint pin (2).
4. Joint and/or bearing arrangement (1) according to any one of Claims 1 to 3,
characterised in
that the housing (5) is formed as an injection coating (6) of the joint shell (4).
5. Joint and/or bearing arrangement (1) according to any one of Claims 1 to 4,
characterised in
that the axial barrier (11) is formed at the through-region (7) of the pin (2) as an encircling edge, projecting inwards from the inner wall of the housing (5), of the skirt (10).

Joint and/or bearing arrangement (1) according to Claim 5,
characterised in
that the axial barrier covers at least 10% of the diameter of the joint shell (4).
Joint and/or bearing arrangement (1) according to any one of Claims 1 to 6,
characterised in
that the skirt (10) is formed in one piece.
Joint and/or bearing arrangement (1) according to any one of Claims 1 to 7,
characterised in
that the skirt (10) is retained in the housing (5) by an anti-twist mechanism
(12).
Joint and/or bearing arrangement (1) according to any one of Claims 1 to 8, characterised in
that the skirt (10) is formed from steel or a plastics material which is harder when compared with the joint shell (4).
Joint and/or bearing arrangement (1) according to any one of Claims 1 to 9,
characterised in
that the joint shell (4) is preloaded during operation.
Joint and/or bearing arrangement (1) according to Claim 10, characterised in
that this is essentially axially stressed during fitting and essentially radially stressed during operation.

12. Motor vehicle with at least one joint and/or bearing arrangement (1) according to any one of Claims 1 to 11, in particular inside chassis and/or steering parts.
Dated this 24th day of December, 2008