Kugelumlaufspindeltrieb

摘要

A multiple circuit, ball nut and screw assembly has a helically externally grooved screw (11) providing a screw ball race (14) and a nut (12) having a complemental internal helical groove (13) providing a nut ball race. The nut has a first internal axial ball return passage (23) leading endwisely outwardly from a location interjacent the ends of the nut ball race and a second internal axial ball return passage (24) leading endwisely outwardly in the opposite direction from this location. Return members (17/18) at the outer ends of the ball return passage are configured for moving balls to and from the ball races from and to the first and second ball return passages. The nut has a radially extending slot (21) at said location leading from the exterior circumferential surface of the nut through to the nut ball race and a drop-in insert (22), having a pair of adjacent end return elements is received in the slot. Each element has a circumferentially extending tongue (37) extending inwardly into the screw ball race and an adjacent generally radially angularly directed channel (25/26) leading to one of the ball return passages, the tongues extending to deflect the balls from the screw ball race into the adjacent channels or to guide them back to the races from the adjacent channels, dependent on the relative direction of travel of the nut and screw.