A ball nut and screw system has a ball screw mounting a coaxial
ball seat nut. A ball train is disposed in the helical trackway defined by the helical grooves of the nut and screw. A ball end return assembly is provided for the nut which has separate end walls carrying generally radially extending return tracks which communicate with the trackway and the nut has an external ball return surface in communication with the tracks. Interengaging parts on the end walls partially envelop the nut and interconnect the end walls.
A ball nut and screw assembly has been devised in which the load bearing train of balls is returned by way of a ball return guide cap which traps the balls between an exterior surface of the nut and the cap, and permits top loading of the balls into the assembly in the first place. An end closure system for the nut is made up of interengaging end closures or walls which snap together without the need for fasteners and a ball guide cap is configured to snap-fit into an opening in the end closure system and also secure without the need for fasteners.
