Abstract: A portion of the one valve rod which extends outward is pivotally supported, the valve shaft cylindrical portion which is connected to the valve rod shaft supporting portion is made of material different from that of the valve body, a slanting surface is formed between the inner peripheral surface and the outer peripheral surface of the sheet ring, an angle and a width formed by the slanting surface and the outer peripheral side surface are the greatest at a position intersecting with the valve shaft at right angles and are the smallest at a position of the valve shaft, a central portion of an inner peripheral surface of the valve body is allowed to project inward to form an engaging projection, the sheet ring is brought into contact with the inner peripheral surface of the valve body under pressure in the opposite sides of the recess groove, the cylindrical bush whose one end is closed is mounted to the other valve rod which pivotally supports the valve element, and the other valve rod is sealed.

Abstract: The purpose of this invention is to provide an actuator for valve driving without enlarging its size, without increasing the cost, and without reducing the pressure receiving area of the pistons.

Abstract: A portion of the one valve rod which extends outward is pivotally supported, the valve shaft cylindrical portion which is connected to the valve rod shaft supporting portion is made of material different from that of the valve body, a slanting surface is formed between the inner peripheral surface and the outer peripheral surface of the sheet ring, an angle and a width formed by the slanting surface and the outer peripheral side surface are the greatest at a position intersecting with the valve shaft at right angles and are the smallest at a position of the valve shaft, a central portion of an inner peripheral surface of the valve body is allowed to project inward to form an engaging projection, the sheet ring is brought into contact with the inner peripheral surface of the valve body under pressure in the opposite sides of the recess groove, the cylindrical bush whose one end is closed is mounted to the other valve rod which pivotally supports the valve element, and the other valve rod is sealed.