Patent ID: 7988360
Filing Date: 2011-08-02
Classification: F16C

Abstract:
1. A motion guide device comprising: a track member having a ball rolling groove formed therein; a moving member having formed therein a loaded ball rolling groove facing the ball rolling groove, a ball return path extending in parallel with the loaded ball rolling groove and a direction change path connecting the loaded ball rolling groove and the ball return path; and a plurality of balls arranged in a ball circulation path including the loaded ball rolling groove, the ball return path and the direction change path, after rolling in the ball rolling groove of the track member each of the balls being scooped up into the direction change path by a scooping portion of the direction change path, and the ball in the direction change path being returned to the ball rolling groove by the scooping portion, wherein the direction change path is inclined relative to a contact angle line connecting a center of the ball and a bottom of the ball rolling groove, when seen in an axial direction of the track member, the direction change path including the scooping portion has a cross section of Gothic arch groove shape formed of two arcs in such a manner that the ball is in contact with the direction change path at two points, and the direction change path is twisted in such a manner that a locus of top of the Gothic arch groove shape approaches the contact angle line at the scooping portion.