Patent ID: 8347779

Claim:
A rotary actuator comprising: a housing forming a cylinder chamber therein, the cylinder chamber axially reciprocably accommodating a rack to both ends of which piston portions are provided; a rotary shaft rotatably mounted in the housing, and provided with a pinion meshing with the rack; an outer ring fixed to an outer surface of the housing; an inner ring incorporated inside the outer ring and attached to the rotary shaft to rotate and drive a swung member; and a rolling element mounted between an inner peripheral surface of the outer ring and an outer peripheral surface of the inner ring, wherein the rotary shaft and the inner ring are rotatably supported by the outer ring via the rolling element, wherein a flange provided on the rotary shaft so as to radially outwardly extend is caused to abut on an inner end face of the inner ring, and the inner ring and the rotary shaft are attached by a screw member fastened to the flange.