Motor-vehicle constant-velocity joint

The constant-velocity joint comprising:

• an outer member formed centered on an axis with three radially inwardly open and axially extending channels each having a pair of angularly confronting and substantially axially extending inner running surfaces that are each concave toward the other inner running surface of the respective pair;
• an inner member formed centered on a respective axis generally coaxial with the outer member axis with three trunnions projecting radially outwardly of the inner member axis and each engaged in a respective one of the channels and defining and centered on respective trunnion axes extending substantially radially of the inner member axis;
• and
• respective annular rollers rotatable on the trunnions about the respective trunnion axes and each including
• an inner part rotatable and fixed on the respective trunnion against movement thereon along the respective trunnion axis and
• an outer part having an outer surface forming a respective outer running surface riding on and pivoting relative to the inner running surface of the respective channel on deflection of the inner-member axis relative to the outer member axis and radially outwardly convex relative to the respective trunnion axis and a respective inner surface engaging and slidable along the trunnion axis on the respective inner part axially relative to the respective trunnion axis,
• one of the inner running surfaces and of the outer running surfaces being formed with a central noncontact strip offset away from the other respective running surface;
• the outer and inner running surfaces engaging each other in line contact to either side of the noncontact strip;
• the outer running surfaces each being of a radius of curvature at most equal to a radius of curvature of the respective inner running surfaces;
• and
• each of the outer parts being formed at the respective outer surface as a single unitary piece.