Patent ID: 6733238
Filing Date: 2004-05-11
Classification: F01D

Abstract:
An axial-flow turbine comprisingan exhaust chamber; a turbine including multiple stage rotor blades, said multiple stage rotor blades including terminal stage rotor blades, an annular diffuser located between the turbine and the exhaust chamber; and an annular axial-flow turbine passage defined by the turbine, the diffuser and the exhaust chamber, wherein fluid flows through the axial-flow turbine passage toward the exhaust chamber, and an annular stepped portion which inwardly projects in a radial direction is formed on the portion of an inner wall of the axial-flow turbine passage that is located on the downstream side of a trailing edge of a tip portion of the terminal stage rotor blades provided in the flow direction of the fluid, and the distance between the central axis of the turbine and the stepped portion is substantially identical to that between the central axis of the turbine and the tip portion trailing edge of the terminal stage rotor blades.