Such a ball-and-socket joint has been known from, e.g., DE 43 06 006 A1. It has a hollow cylindrical housing, into the interior space of which a bearing shell is inserted for receiving the joint ball of a ball pivot in a slidingly movable manner. The bearing shell of the prior-art ball-and-socket joints, which have a very simple design, consists of plastic, which guarantees optimal friction conditions for the joint ball to be mounted. The bearing shell disclosed in the said document has a ring collar, which is supported on one side at the end face of the housing. On the side located opposite the ring collar, a ring collet is made in one piece with the bearing shell, and in the preassembled state the said ring collet has an axial extension and external dimensions relative to the central longitudinal axis of the bearing shell that correspond to the external dimensions of the bearing shell. During the assembly of the prior-art ball-and-socket joint, the bearing shell is inserted into the housing, so that the ring collar is supported at the end face of the housing and the ring collet can be deformed on the opposite side of the housing by means of a deformation process. An ultrasonic deformation process is proposed for the deformation of the ring collet in the cited document. After the conclusion of the ultrasonic deformation, the ring collet forms a bead on the housing, as a result of which the bearing shell is fixed at the housing.
A very essential problem in the prior-art ball-and-socket joint designs is that the bearing shell fixed on the housing by means of ultrasonic deformation does not engage in a permanently fixed connection with the housing and loosening of the bearing shell cannot therefore be ruled out over the lifetime of the ball-and-socket joint. The friction generated by the relative movements between the housing and the bearing shell leads to an increase in wear, so that the ball-and-socket joint may ultimately fail. Moreover, penetrating contaminants act as factors accelerating the failure of the joint as a consequence of the abrasion due to the increasing wear of the bearing shell.
To prevent the bearing shell from loosening and from performing, e.g., rotary movements around the central longitudinal axis of the housing, notches are currently prepared in the edge area of the housing blank after the manufacturing of the housing blank, and the material of the bearing shell, softened by the ultrasonic deformation, can later flow into the said notches at least in some sections. However, the notches, prepared in the housing according to an impression process, lead to deformations of the housing, so that the latter will have unacceptable tolerances, run-outs, conicities and/or errors in plane parallelism.
It was, furthermore, observed that the material of the softened bearing shell material sometimes flows into the notches of the housing during the ultrasonic deformation to a limited extent only. Thus, separation of the bearing shell from the housing and a resulting mobility of the bearing shell in relation to the housing cannot be ruled out with certainty even in the case of these improved designs.