Abstract: A system for forming a precision shaft for a permanent magnet motor employs a working surface region of the precision shaft and a coaxially arranged rotor region. A cutting tool is used to make a first machining or cutting pass along the entire length of the working and rotor regions. Subsequent passes of the cutting tool are limited to the working region of the motor shaft to form a threaded ball screw shaft portion. The rotor region, however, remains with but a continuous shallow groove that is surrounded by a helical shaft portion having the original diameter of the precision shaft. Thus, preparation of the shaft to effect bonding of the magnetic rotor does not affect the shaft diameter. The depth of the shallow groove in the rotor region is approximately between 0.001″ and 0.004″, and preferably 0.003″. The permanent magnet rotor is bonded to the rotor surface region of the precision shaft by an A+B heat cured type of epoxy.

Abstract: A system for forming a precision shaft for a permanent magnet motor employs a working surface region of the precision shaft and a coaxially arranged rotor region. A cutting tool is used to make a first machining or cutting pass along the entire length of the working and rotor regions. Subsequent passes of the cutting tool are limited to the working region of the motor shaft to form a threaded ball screw shaft portion. The rotor region, however, remains with but a continuous shallow groove that is surrounded by a helical shaft portion having the original diameter of the precision shaft. Thus, preparation of the shaft to effect bonding of the magnetic rotor does not affect the shaft diameter. The depth of the shallow groove in the rotor region is approximately between 0.001″ and 0.004″, and preferably 0.003″. The permanent magnet rotor is bonded to the rotor surface region of the precision shaft by an A+B heat cured type of epoxy.

Abstract: An axial displacement arrangement in the form of a ball screw and nut achieves a highly compact configuration by effecting ball recirculation entirely within the ball screw shaft. The ball recirculation portion of the ball screw shaft is axially short with respect to an elongated driven nut. As the nut is rotated, illustratively by an electric motor coupled thereto, the ball screw shaft is displaced axially along an axial support member. The axial support member has radially outward extending splines, and the ball recirculation portion of the ball screw shaft has radially inward extending splines, the inward and outward splines being arranged to face one another whereby a linear ball bearing region is formed. The linear ball bearing permits the ball recirculation arrangement and its associated actuation element to be displaced axially along the support element, but is precluded from rotating.

Abstract: A ball nut for use in combination with a ball screw and a plurality of ball bearings wherein said ball nut has a metallic sleeve segment including a longitudinal opening and a plurality of equidistant arcuate grooves. A polymeric deflector segment is included, having a plurality of S-shaped return grooves spaced apart sufficiently to cooperate with the plurality of arcuate grooves of the sleeve segment for completing a plurality of bearing race circuits inside the ball nut. A polymeric ball nut body encases the sleeve segment including a longitudinal slot for receiving the deflector segment sufficiently to place the plurality of equal distant arcuate grooves into cooperation relationship with the S-shaped return grooves.

Abstract: An improved ball screw assembly is disclosed in which a return tube has a pair of minor legs which enter into two ends of the internal helical groove within a nut to return ball bearings between the two ends. Apertures are formed within the nut such that the return tube can be mounted as a one-piece item by moving it perpendicular to the central axis of the screw into the two apertures. The apertures are formed by removing all material which would normally be radially outward of the minor legs, and would prevent mounting of the return tube by moving it perpendicular to the axis of the screw. Due to this improved arrangement between the return tube and the nut, a one-piece return tube can be utilized which contacts the end of the helical groove at an angle parallel to the helix angle and tangent to the helical groove at the ends.

Abstract: A ball deflector for a recirculating ball screw and nut assembly provides a plurality of adjustable semi-spherical locator bosses along an elongated body portion thereof for enhancing fitment of said deflector within a segment of the nut groove during assembly. In a preferred form, the bosses are disposed in adjacent quadrants on an upper body portion of the elongated deflector body, and are arranged in pairs, each disposed at opposite ends of the deflector body and located adjacent the ends of the deflector. The bosses are adjusted by a grinder or other metal removal device to compensate for tolerance variations.

Abstract: A ball screw and nut assembly includes an improved ball return system designed to avoid abrupt directional changes in the recirculation path of ball bearings from one end of a nut to the other. A return tube, secured to the nut, is formed in two sections, each having a major leg and a minor leg. The ends of respective major legs are adapted to butt together along the centerline of the ball screw nut. The minor legs, joined by elbows to the major legs, are disposed at angles equal to ninety degrees minus the helix angle of the ball screw and nut. The nut contains transverse apertures at its respective ends to provide counterbores for support of the minor legs, each leg also extending tangentially to the groove in the nut at the location of its interface with the groove. The result is a return tube system which avoids abrupt directional changes in the travel path of the balls.