Patent ID: 7429161

Claim:
An axial turbine comprising: a turbine rotor; a stationary body inner wall located outside of said rotor; stationary blades provided on the inside of said stationary body inner wall; and moving blades provided on said turbine rotor; wherein a plurality of turbine stages is formed by said stationary blades and said moving blades, each of turbine stages comprising said stationary blades adjacent to each other along the turbine circumferential direction and said moving blades adjacent to each other along the circumferential direction, said moving blades being opposed to said stationary blades at the downstream of said stationary blades at the downstream of said stationary blades alone a flow direction of a working fluid; wherein the stationary blade of which the radial height of an outlet thereof is higher than the radial height of an inlet thereof is formed so that an intersection line between a plane containing the central axis of the turbine and the outer peripheral portion of the stationary blade, has a portion that includes the outlet of the stationary blade and that extends in the extending direction of the central axis of the turbine; wherein a surface of the stationary body inner wall opposed to the outer peripheral side of the moving blade in a stage having the portion that extends in the extending direction of the central axis of the turbine, is located radially outside of the portion that extends in the extending direction of the central axis of the turbine; and wherein, when out of the length of the moving blade, a portion that effectively performs the function of converting energy of the working fluid into a rotational power is defined as a moving blade effective length, the height in the turbine radial direction, of the portion that extends in the extending direction of the central axis of the turbine, is set to be the height in the turbine radial direction, of the effective length of the moving blade in the same stage.