Abstract: A linear motion assembly and recirculation insert therefor is provided. The assembly includes a ball nut having a through bore with an internal helical groove and a screw having an external helical groove. The external helical groove is radially aligned with the internal helical groove to define a plurality of ball raceways. A plurality of inserts is fixed within the bore of the ball nut. The inserts each have a central body fixed within a recessed pocket of the ball nut, with the body having a radially inwardly facing, generally s-shaped groove to route the balls between adjacent turns. A pair of legs extends in opposite directions from the central body, wherein the legs are sized for a clearance fit with the external helical groove. The legs merge with the central body over a smooth transition region that minimizes stress concentrations at the joint between the legs and central body.

Abstract: A linear motion assembly includes a screw having a helical external groove extending over a plurality of turns with a radially outwardly extending helical land formed between adjacent turns and a ball nut having a through bore configured for receipt of the screw. The ball nut has a helical internal groove extending over a plurality of turns with a radially inwardly extending helical land formed between adjacent turns. The helical land of the ball nut is radially aligned with the external groove of the screw and the helical land of the screw is radially aligned with the internal groove of the ball nut. At least one helical recirculation insert having a circuitous recirculation groove is configured in radial alignment with the radially inwardly extending helical land of the ball nut and the external groove of the screw, wherein a plurality of balls are received in the circuitous recirculation groove.