LINEAR ACTUATOR

摘要

Provided is a linear actuator which is simplified in structure with a stopper function added to a detent mechanism and capable of preventing occurrence of radial load. The linear actuator includes a ball screw mechanism (20) to which rotational drive force is transferred and which converts rotational motion into linear motion. The ball screw mechanism (20) includes a guide projection (36, 37) which is provided in a linear motion element (24) and radially projected. Also included is a guide groove (40c) which is formed in a fixed portion (14b) opposed to the linear motion element (24) and engaged with the guide projection (36, 37) to guide the guide projection (36, 37) in the axial direction. The guide projection (36) has a projected portion (36a) which projects by a predetermined length while being engaged with the guide groove (40c) at the stroke end of the linear motion element (24), allowing the projected portion (36a) of the guide projection (36) to contact and stop a retainer portion (25d) provided on a rotational motion element (22).