Motion guide device

Abstract

The invention relates to a motion guide device with two columns of balls arranged within a circulation path in a staggered form for achieving compactness of a carriage and durability of a retainer. The circulation path, which comprises a rolling path (C1), a return path (C2) and a turn path (C3), is provided with at least one retainer (71) with two columns of balls (6) arranged therein in a staggered form. Viewing from a vertical direction relative to a plane consisting of the rolling path (C1) and the return path (C2) (referring to Fig. 7(a)), at an end of the rolling path (C1) of the turn path (C3) and an end of the return path (C2), a first turn path (21) for a first column of balls is arranged toward the outside more than a second turn path (22) for a second column of balls, and at a top of the turn path (C3), the first turn path (21) is arranged toward the inside more than the second turn path (22). The retainer (71) comprises a center band (72) between the two columns of balls (6), and two side bands (73) outside of the two columns of balls (6). Viewing from a longitudinal direction of the retainer (71), the two columns of balls (6) are separated.