The present invention relates to a constant velocity universal ball joint and a method of producing the same. The joint has a bell-shaped outer joint part which is open at one end. The outer joint part includes longitudinally extending circumferentially distributed outer ball tracks. An inner joint part which includes longitudinally extending circumferentially distributed inner ball tracks is positioned within the outer part. The outer and inner tracks are arranged radially opposite one another to form pairs. In each case, the opposing tracks receive a torque transmitting ball. A cage is arranged between the outer joint part and the inner joint part. The cage holds the balls in a common plane in circumferentially distributed cage windows and guides the balls onto the angle bisecting plane when the axes of the outer and inner joint part are articulated relative to one another. The outer joint part is preferably produced by extrusion, forging or deep-drawing. The outer ball tracks, if viewed from the open end, are axially undercut-free and inner faces are positioned between the outer ball tracks.
Joints of this type are the so-called UF joints (undercut-free joints). In UF joints, one side of the outer joint part is closed by a joint base, whereas the opposed other open end, in an axial view, includes outer joint tracks which, from the outside, are undercut-free. The cage and thus the inner joint part are either directly inwardly supported relative to the outer joint part on cage guiding faces provided in the outer joint part between the ball tracks, or indirectly supported via the balls on which the cage is directly supported via the walls of its cage window.
When viewing the track shape supporting the cage, if viewed from the open joint end, and thus the inner joint part relative to the outer joint part, the outer joint part requires outer joint part faces which are provided with an undercut. From DE-PS 25 22 670, it is known to provide a separate annular member at the outer joint part. This measure is complicated and unsatisfactory from a strength point of view. In the case of a one-piece design, producing the latter cage guiding faces of the above-mentioned joint type is extremely complicated and expensive.
If a joint of this type is produced with a one-piece outer joint part with cage guiding faces which include an undercut, the assembly of the inner joint part, cage and outer joint part involves complicated operational movements where the axes of the parts are positioned to intersect one another and parts of the cage guiding faces are inserted into the cage windows.