PURPOSE: To enable an output section to be continuously rotated by forming a space consisting of two sections the inner diameters of whose inner walls are large and small respectively, providing pressurized oil supply/empty ports at both the ends of the inner wall with a small inner diameter, and thereby rotatably disposing an output body in a circular shape in cross section at the circumference of which valves are provided in such a way as to freely appear frequently.

CONSTITUTION: A space 11 is formed in an outer body 1 by the use of an inner wall 1a with a large inner diameter and an inner wall 1b with a small inner diameter. And pressurized oil supply/empty ports 12 and 13 are formed at both the ends of the inner wall 1b with a small diameter so as to be communicated with the space 11. In this case, the range of the inner wall 1b with a small diameter is set narrower than that of the inner wall 1a with a large diameter. An output body 2 which houses valves 3 in each recessed hole 22 provided for its outer circumference, is housed in the space 11 in such a way that the valves freely appear frequently. A hexagon socket 21 with which a nut and the like can be engaged, is provided at the center of the output body 2. The hexagon socket 21 is not required when a large scale rotor is rotated. Each head section of the valves 3 is formed by a a large curvature, and each valve is energized to the projected direction by each spring 4. Pressurized oil is supplied with/emptied of through the pressurized oil supply/empty ports, so that the output body 2 is thereby rotated.