Ball socket with film backing

Abstract

A bearing shell for a ball and socket joint has a core made of plastic, which is jacketed by a film at least in some areas.

Description

CROSS REFERENCE TO RELATED APPLICATION [0001] This application is a divisional application under 37 CFR 1.53(b) of pending prior application Ser. No. 10 / 895,146 filed Jul. 20, 2004.FIELD OF THE INVENTION [0002] The present invention pertains to a ball socket for a ball and socket joint especially for motor vehicles, to the process for manufacturing a ball socket, as well as to the ball and socket joint per se. BACKGROUND OF THE INVENTION [0003] Bearing shells for ball and socket joints especially for motor vehicles are known, for example, from DE 29 617 276 U1. DE 29 617 276 U1 discloses a ball and socket joint, which is extrusion-coated according to a one-component process and in which the bearing shell is produced from a single plastic according to the injection molding technology. This design leads in practice to the problem that when a relatively favorable plastic is used, it is either well suited tribologically in the unreinforced form but lacks sufficient strength, or it posse...

AI Technical Summary

Benefits of technology

[0006] The object of the present invention is to provide a bearing shell that can be manufactured with good strength and creep properties, coupled with good tribological properties, simply and inexpensively.

[0007] The bearing shell according to the present invention, which may be either a one-part or multipart design, has a reinforced plastic, which is jacketed by a film in the area of the joint ball contact surface. Due to the jacketing, the reinforced plastic is advantageously separated from being in direct contact with the joint ball, so that the risk for wear, which may develop on the joint ball due to fibers or mica added for reinforcement, is reduced. This advantageously leads to prolonged service life, because the contact surfaces of the joint ball are protected without having to miss the strength and creep properties improved by the reinforcement.

[0008] The process for manufacturing the bearing shell according to the present invention begins with the insertion of a film into an injection mold. After the mold has been closed, a plastic, which forms the core of the bearing shell, is injected behind the film. A bearing shell, which has a film with good tribological properties at least in the area of the joint ball, is thus formed after cooling. Depending on the plastic processed, either the conventional injection molding or the low-pressure process is employed. Components that are largely free from internal stress and have low distortion can be advantageously obtained by the low-pressure process because of the uniform pressure distribution and the comparatively short flow paths. This one-step process is especially advantageous for the processing of duroplastics. Both the conventional injection molding and the low-pressure process may be used to process thermoplastics. Due to the good adhesive properties of duroplastics and thermoplastics, the adhesion between the film and the core does not usually pose any problem. The film and the core adhere to one another without the need for an additional adhesive or an additional heat treatment.

[0009] The film and the core may be advantageously manufactured from the said basic material, as a result of which the material costs are reduced. Thermoplastics frequently tend to creep under load at high temperatures. The strength values also decrease as the operating temperature increases. The strength and creep properties can be improved by adding fibers, micas, minerals and / or beads to the core of the bearing shell. An individual adaptation to the strength and creep values required corresponding to the load is possible simply by selecting the quantity of the reinforcing additives to be added to the basic material. Duroplastics have the property of not creeping under load and have a high stability. Moreover, the strength can be increased and the thermal expansion reduced by means of suitable additives.

[0010] The good tribological properties of the basic material and consequently also of the film used, which is backed with the reinforced material, avoid abrasive wear on the joint ball of the ball and socket joint, which may develop due to the friction of additives on the joint ball during the operation.

[0011] In another embodiment, the bearing shell has slots in the core area, which make possible the tolerance compensation of the bearing shell during the operation. Another possibility of compensating tolerances is offered by the mounting of a rubber ring under the bearing shell.

Problems solved by technology

Thermoplastics frequently tend to creep under load at high temperatures.

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