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.