Abstract: A ball spline having reinforcement bush parts includes a spline shaft having concave track grooves formed to extend along the longitudinal direction thereof; a nut part in which the spline shaft is inserted and movable along the longitudinal direction thereof; and a plurality of balls provided between the nut part and the spline shaft to circulate, wherein: the nut part includes a nut which is a hollow body where the spline shaft is inserted, and retainers which are hollow bodies which are provided at longitudinally opposite sides of the nut and into which the spline shaft is inserted; two spline parts and two reinforcement bush parts are provided at the nut part; some of the balls circulate and move between a track groove and a load track groove and along a no-load circulation part; and the remainder of the balls roll circulate and move along the reinforcement bush parts.

Abstract: A ball spline with detour tracks includes spline shaft, nut part movable along a longitudinal direction of the spline shaft, and balls between the nut part and the spline shaft, wherein the nut part includes nut adapted to insert the spline shaft thereinto and retainers on longitudinal sides of the nut, the spline shaft includes tracks extended along the longitudinal direction, the nut includes load track grooves formed in longitudinal direction on inner peripheral surface into which the spline shaft is inserted and non-load circulating portions formed in the longitudinal direction, each retainer includes circulating grooves on the inner peripheral surface to face the load track groove and non-load circulating portion, the balls run between the tracks and the load track grooves, and each track includes track groove formed in longitudinal direction of the spline shaft and detour tracks whose longitudinal sides are connected to the track groove.

Abstract: A linear motion guide unit is provided, which is capable of preventing the variation in the position of a roller cage assembly caused by sliding motions of the roller cage assembly between a first guide rail and a second guide rail, without reducing the number of rollers. The linear motion guide unit includes first and second guide rails having track portions formed concavedly to have a V-shaped section on the faces opposing each other; and a roller cage assembly disposed between the first and second guide rails and having a plurality of rollers located between the first and second guide rails and ring-shaped pinions adapted to surround the rollers.

Abstract: A linear motion guide unit is provided, which is capable of preventing the variation in the position of a roller cage assembly caused by sliding motions of the roller cage assembly between a first guide rail and a second guide rail, without reducing the number of rollers. The linear motion guide unit includes first and second guide rails having track portions formed concavedly to have a V-shaped section on the faces opposing each other; and a roller cage assembly disposed between the first and second guide rails and having a plurality of rollers located between the first and second guide rails and ring-shaped pinions adapted to surround the rollers.