Patent ID: 6848884

Claim:
An axial-flow turbine stage comprising: a plurality of moving blades fixedly mounted on a rotor shaft in a circumferential arrangement about an axis of the rotor shaft; and a plurality of stationary blades disposed axially opposite to the moving blades in a circumferential arrangement about the axis of the rotor shaft; wherein each of the plurality of stationary blades has a trailing edge convex toward a face side with respect to a radial line radially extending from the axis of the rotor shaft, a blade center-of-gravity line of each of the plurality of moving blades is convex toward the face side with respect to a radial line radially extending from the axis of the rotor shaft, and shapes of the stationary blades and the moving blades meet conditions expressed by: 1<θ nr /θ nt 1<θ bt /θ br where, as viewed from a direction of the axis of the rotor shaft: θ nt is an angle between a tangent to a trailing edge of the stationary blade at a tip of the stationary blade and a radial line passing the tip of the stationary blade and radially extending from the axis of the rotor shaft; θ nr is an angle between a tangent to the trailing edge of the stationary blade at a root of the stationary blade and a radial line passing the root of the stationary blade and radially extending from the axis of the rotor shaft; θ bt is an angle between a tangent to the blade center-of-gravity line of the moving blade at a tip of the moving blade and a radial line passing the tip of the moving blade and radially extending from the axis of the rotor shaft; and θ br is an angle between a tangent to the blade center-of-gravity line of the moving blade at the root of the moving blade and a radial line passing the root of the moving blade and radially extending from the axis of the rotor shaft.