Steam turbine

A turbine comprising:

• a shaft body;
• a turbine blade fixed to the shaft body and disposed on a flow path through which a fluid flows;
• a tip shroud formed at a tip of the turbine blade;
• a structure;
• and
• a plurality of turbine blade side seal fins protruded from the structure,
• wherein:
• the structure is located close to the tip shroud so that a space is provided between the tip shroud and the plurality of turbine blade side seal fins,
• the plurality of turbine blade side seal fins are configured to form small clearances which are provided between the tip shroud and the plurality of turbine blade side seal fins,
• the tip shroud has a stepped part in cross section,
• the plurality of turbine blade side seal fins correspond to stages of the tip shroud,
• dead water region-filling sections are formed in spaces defined by the tip shroud, the structure, and the plurality of turbine blade side seal fins and in which a vortex flow of the fluid is generated, such that dead water regions that the vortex flow cannot reach are filled,
• the dead water region-filling sections are formed in both of a first corner of each of the spaces and a second corner of each of the spaces,
• the first corner of each of the spaces is formed by a first axial direction wall surface disposed on an upstream side along an axial direction of the turbine blade and a radial direction wall surface disposed along a radial direction of the turbine blade,
• the radial direction wall surface is connected between the first axial direction wall surface and a second axial direction wall surface disposed closer to a structure side than the first axial direction wall surface and disposed on a downstream side,
• the first corner of each of the spaces is continuously formed between the first axial direction wall surface and the second axial direction wall surface, and
• the second corner of each of the spaces is formed by the structure and a surface facing toward an upstream side of one of the plurality of turbine blade side seal fins opposed to the second axial direction wall surface.