Patent ID: 9103423
Filing Date: 2015-08-11
Classification: F16H,H02K,Y10T

Abstract:
1. A linear actuator comprising: an output shaft formed with a helical groove; a retainer having a cylindrical shape which receives the output shaft therein, and provided with a plurality of concave portions spaced from each other at positions of an inner peripheral surface thereof along the helical groove; a pair of sleeves having a cylindrical shape and mounted on a circumference of the retainer from a front side and a rear side in an axial direction; a rotor magnet fixed in surrounding relation to the retainer; and balls which are retained in the plurality of concave portions, respectively, wherein when the retainer is rotated, the balls are moved along the helical groove of the output shaft in a state where the balls are retained in the concave portions, wherein the pair of sleeves have edge portions opposing each other, and each of the edge portions is provided with a concavo-convex structure, wherein the retainer is divided into segments along lines extending substantially parallel to a longitudinal axis thereof such that it includes a first retainer segment, a second retainer segment, and a third retainer segment, and wherein the third retainer segment is provided with a protrusion inserted between and in contact with the concavo-convex structures of the sleeves so that the protrusion positions the concavo-convex structures of the pair of sleeves relative to each other and prevents rotation of the pair of sleeves.