LOAD HOLDING MECHANISM FOR LIFT MECHANISM

摘要

A load holding mechanism for a lift mechanism which vertically moves a nut member (9) engaged through threads with a screw shaft (4) comprises: a cylinder member (25) which is rotationally driven by power from a motor (1); an outer ring (24) disposed so as to be concentric with the cylinder member; a one-way clutch mechanism (23) which is provided between the cylinder member and the outer ring and which permits relative rotation between the cylinder member and the outer ring in one direction and prohibits the relative rotation in the other direction; and an electromagnetic brake (15) which holds the outer ring by a frictional force. The configuration reduces stress occurring when the lift mechanism suddenly stops during lowering operation.