Universal joints

Abstract

A plunging constant velocity universal joint of the kind comprising a hollow outer member and an inner member, torque-transmitting balls which are located in apertures in a cage disposed between said members and are each engaged in and between a pair of opposed longitudinal grooves in said members so as to be movable therealong to permit relative angular and axial movement between the members, and a guide ring mounted on the inner member, the cage having a convex part-spherical outer surface engaging the surface of a cylindrical bore in the outer member so that the cage is movable relative to said member axially of the latter, and a concave part-spherical inner surface engaging a complementary convex part-spherical surface on the guide ring, the centers of the part-spherical surfaces of the cage being offset by equal amounts on opposite sides of the joint center along the joint axis whereby the cage assists in maintaining the balls in the bisector plane of the joint. The guide ring is axially movable relative to the inner member to a limited extent to allow the torque-transmitting balls to roll rather than skid with respect to the surfaces of the grooves in the inner and outer members over part only of the permitted plunging movement of the joint substantially less than the whole range of permitted plunging movement, preferably over only a minor part of the permitted plunging movement at the commencement of plunging movement. The guide ring comprises an annular part slidable on the inner member and an annular part which overlaps axially the grooves in the inner member and is formed with slots to accommodate the balls.