Abstract: Double nut is capable of adjustment in a ball screw unit so as to regulate tension between the nut and the ball screw with their ball bearings such as to avoid or repair backlash in or maintain precision with the unit. The adjustment may be made without removal of the ball screw unit from a machine in which it operates or automatically. The double nut can be employed with or in methods of making, repair or adjustment of, and manufacturing with the ball screw unit with such a nut. A wiping contrivance for a ball screw nut or unit can be a member in annular form, and made and used in aspects analogous to those of the double nut. A depending foot, ball bearing return may be employed in a ball screw nut or unit in aspects analogous to those of the double nut.

Abstract: Ball screw nut includes first and second ball bearing accommodating inserts that can be part of a ball bearing return system in the nut with the first and/or second inserts having a body with a passage for ball bearings, which opens in a first direction; and a depending foot having a heel and toe, which joins the body and which has below the body in the toe of the foot for the ball bearings a channel that faces in a second direction substantially perpendicular to the first direction and that can communicate ball bearings with the passage in the body to or from a spiral raceway of the nut and an associated ball screw shaft.