The present invention relates generally to a joint and, more particularly, to a supporting joint and/or ball and socket joint with a plain bearing film.
Various supporting joints and/or ball and socket joints for steering mechanisms in motor vehicles are known in the art. An example of a ball and socket joint is described in D.E. Application No. 10 2007 016 713, which includes a spherical rod end (also referred to as a ball head) and a spherical pivotal bearing. The pivotal bearing includes a multi-layer plain-bearing shell which is split in two. The plain-bearing shell includes an inner sliding layer of polytetrafluoroethylene (PTFE) that is stuck to a load-bearing layer such as, for example, a steel mesh. The steel mesh is applied to an elastic layer containing an elastomer by means of an adhesion promoting layer. Such a pivotal bearing may be operated without the addition of a lubricant and has improved absorption quality due to the application of the elastic layer. The ball head is enclosed by a total of two stable plain-bearing shell components; i.e., a lower hemispherical first plain-bearing shell component and a ring-shaped second plain-bearing shell component situated above the first plain-bearing shell component. The second plain-bearing shell component must be slid over the ball pin by assembly of the pivotal bearing, which is costly.
Another example of a pivotal bearing is described in D.E. Application No. 10 2008 003 730, which includes a spherical inner body that is encompassed by two housing half shells outside. Each of the two housing half shells is furnished inside with a plain-bearing film.
The pivotal bearings are manufactured as described above so that a specially designed plain-bearing film is applied to the interior of the unformed housing components with, for example, adhesive. The housing components are subsequently cold formed so that the components adapt to the surface of the spherical inner body and are converted to the housing half shells.
The object of the present invention is to provide a supporting joint that may accommodate relatively high loads, and a relatively stiff bearing.
According to an aspect of the invention, a joint is provided that includes a pin connected to a ball head that is movably mounted in an outer body having a recess, and a sliding element made from a flexible plain-bearing film arranged between the ball head and the outer body. The plain-bearing film includes a plurality of plain-bearing film strips arranged relative to each other at least approximately in a star shape. The strips are formed integrally with each other and are separated by slits. The plain-bearing film is placed between the outer body and the ball head such that edges of the plain-bearing film strips lie as tightly as possible against each other without, for example, overlaps and/or folds.
The joint may be configured as a supporting joint and/or a ball joint. In some embodiments, therefore, the pin may be a ball pin, tapered pin, cylinder pin or lug.
The joint may include a single, one-piece plain-bearing film. In addition, the joint may have a relatively high stiffness, and may be included in performance handling systems of motor vehicles.
The joint may have a high transmittable axial and radial load capacity. The joint has a low friction coefficient, a small installation space and a light weight. The joint also has a relatively high operating temperature range.
In some embodiments, the plain-bearing film is constructed from Nordglide™ M material, which is made by Saint-Gobain Performance Plastics Pampus GmbH in D-47877 Willich, Germany. Such a plain-bearing film may provide a relatively maintenance-free bearing film with a high load capacity made of a metallic mesh and hard-wearing PTFE compound. Such a plain-bearing film includes a plain-bearing material made out of a PTFE compound which is sintered to a flexible metallic mesh ridge. The PTFE compound may include thirty percent (30%) filler content, where the filler includes fiber glass and/or graphite. The metallic mesh may be a stainless steel mesh made of wire that may be connected to the intersections. Such a plain-bearing film may have a total thickness of, for example, 0.5 mm.
In some embodiments, the plain-bearing film may be inserted in the joint without additional lubricant(s). In other embodiments, the joint includes a lubricant.
In some embodiments, the sated plain-bearing film with its individual plain-bearing film strips fits around the ball head in a spherical shell shape more than a hemispherical shell shape. The plain-bearing film with its plain-bearing film strips may enclose the ball head—starting at the deepest point of the ball head axially—for more than half of the diameter of the ball head; e.g., up to approximately ⅔ of the diameter of the ball head. Thus, the plain-bearing film may almost completely cover the ball head to provide an optimal plain-bearing of the ball head in the outer body. The individual plain-bearing film strips duly lie next to each other as seamlessly as possible.
In some embodiments, the outer body of the joint includes a housing and/or a bearing shell. An at least hemispherical recess for receiving the ball head and a ring-shaped, additional recess for receiving the ring-shaped bearing shell situated above the hemispherical recess are provided in the housing.
In some embodiments, a ring-shaped lug is provided either in the outer body and/or the bearing shell, if the latter is used, as an axial limit for the plain-bearing film
In some embodiments, in order to protect the supporting joint, a ring nut may be screwed to the bearing shell using a thread in the outer body and/or the housing. An axial protection of the whole supporting joint is thereby provided.
In some embodiments, the slits which runs from the radial exterior to the radial interior on a center of the plain-bearing film, if the flexible plain-bearing film is stretched flat, are designed to be tapered from the outside to the inside; e.g., at least approximately triangular. As a result, it has proved favorable to curve the individual plain-bearing film strips viewed in a radial direction to the outside and then to arrange them in a tapered form. It should be ensured that, with the spherical shell-shaped coverings of the ball head, the individual plain-bearing film strips lie as close to each other as possible so that only very small gaps are left, or ideally, so that no gaps remain at all. The plain-bearing film should be substantially without folds and/or overlaps on the ball head.
In some embodiments, the plain-bearing film includes a central opening having a round geometry. Such a central opening significantly eases the operation of the plain-bearing film during assembly, since a device can grip this opening and then hold the plain-bearing film in place.
In some embodiments, the plain-bearing film may include a sintered compound with PTFE or a sintered PTFE compound. For this purpose, a PTFE compound is sintered to a metallic mesh ridge. With the assembly of such a plain-bearing film in the recess of the outer body, then of the housing of the supporting joint, the PTFE layer faces the ball head, while the metallic mesh points towards the housing and/or the outer body.
In some embodiments, the contour of the plain-bearing film may be manufactured as a simple pressed part with individual, one-piece plain-bearing film strips facing each other, where the strips are separated from each other by slits. The special outer contour of the plain-bearing film may, however, also be separated from a continuous plain-bearing film strip in some other way, e.g. by cutting it out.
In some embodiments, the plain-bearing film inserted in the joint is equipped with an upper flange that is formed by the respective free ends of the plain-bearing film strips. The flange is arranged such that it runs at the same height from the lowest point of the ball head. Thus, the upper flange of the plain-bearing film runs in a straight line when mounted. The upper flange may be fastened safely to the aforementioned lug to provide an optimal accommodation of the plain-bearing film.
These and other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of preferred embodiments thereof, as illustrated in the accompanying drawings.
In the following diagrams, unless otherwise indicated, identical reference characters always designate identical parts with the same meaning.
A plain-bearing film 20 is arranged between the ball head 13 and the hemispherical shell-shaped recess 15 of the housing 18 and the inner wall of the ring-shaped bearing shell 16. The plain-bearing film 20 is cup-shaped and/or partially spherically shell-shaped in the slit-shaped, spherical opening formed between the ball head 13 and the housing 18 on the one hand and between the inner wall of the ring-shaped bearing shell 16 and the ball head 13 on the other hand.
Referring to
Referring to
The bulbous contour permits the individual plain-bearing film strips 22 to wrap around the ball head 13 without unnecessarily broad slits 21 remaining as illustrated in
Although it is perfectly possible to add a lubricant to the plain-bearing film 20, it is not necessary. A lubricant-free supporting joint, for example, is presentable with such a contoured plain-bearing film 20.
Additional embodiments of a supporting joint 10 are illustrated in
Referring to
The housing 45 is mounted in an outer part 50 and secured axially with a locking ring 47. The bearing shell 46 is on a nut 53. An O-ring 52 may be placed between the nut 53 and the bearing shell 46.
The supporting joint in
The outer part 60 of the bearing shell 62 of
Although the plain-bearing film 20 was represented in connection with
Although the present invention has been illustrated and described with respect to several preferred embodiments thereof, various changes, omissions and additions to the faun and detail thereof, may be made therein, without departing from the spirit and scope of the invention.
Number | Date | Country | Kind |
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10 2009 041 807.5 | Sep 2009 | DE | national |
This patent application claims priority from PCT Application No. PCT/EP 2010/004606 filed Jul. 28, 2010 and German Application No. 10 2009 041 807.5 filed Sep. 18, 2009, each of which is hereby incorporated by reference in its entirety.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2010/004606 | 7/28/2010 | WO | 00 | 5/9/2012 |