Abstract: The turbine (1) according to the present invention includes: a blade body (50) having a blade (59) provided at one of a rotor rotatably supported and a stator provided around the rotor and extending in a radial direction toward the other side from one side and a shroud (51) extending in a circumferential direction at a tip portion in the radial direction of the blade (59); and an accommodating concave body (11) provided at the other of the rotor and the stator, extending in the circumferential direction, accommodating the shroud (51) with a gap (G) interposed therebetween, and relatively rotating with respect to the blade body (50), wherein leakage flow (L) leaked from main flow (M) flowing along the blade (59) flows into the gap (G); and wherein the shroud is provided with a guide curved surface formed between a peripheral surface (53C) facing the accommodating concave body (11) and a trailing edge end portion (56) formed closer to the main flow (M) side in a downstream of the leakage flow (L) than the perip

Abstract: A turbine is provided including an annular turbine blade body (50) disposed on a flow path, a diaphragm outer ring (11) installed at a tip side of the blade body via a clearance, and seal fins (12A, 12B, 12C) formed to protrude from the diaphragm outer ring (11) and configured to form small clearances (13A, 13B, 13C) with the annular turbine blade body (50), wherein dead water region-filling sections (15, 17, 19) are formed in cavities (C1, C2, C3) in which main vortexes (SU1, SU2, SU3) are generated, such that a dead water region that the main vortexes (SU1, SU2, SU3) cannot reach is filled.

Abstract: A seal structure includes shrouds that are provided at tips of a plurality of blades on which a main flow of fluid impinges and that come into contact with adjacent shrouds to form a cylindrical shape; a sealing part connected to a structure body facing the shrouds; and a space that is defined by downstream sides of the shrouds, a downstream side of the sealing part, and a wall on a downstream side of the structure body, and that communicates with the main flow of fluid that has impinged on the blades. An end of the wall on the downstream side of the structure body is formed so as to be disposed a predetermined distance away from a shroud extension and away from a sealing-part extension and so as to be located on the opposite side of the shroud extension with respect to the sealing-part extension.

Abstract: A turbine (1) of the present invention comprises that at one part of a tip part (51) of the blade (50) and an area (11a) of the structure (11) corresponding to the tip part (51) of the blade, a stepped part (52) is formed, a seal fin (15) is provided at the another part of the tip part (51) of the blade and the area (11a) of the structure (11), a cavity (C) is formed between the tip part (51) of the blade and the area (11a) of the structure (11) and between the seal fin (15) and a partition wall (54, 15). The seal fin (15) comprises a fin main body part (16), and a space restriction part (17). Thus, the present invention provides a high performance turbine in which the leakage flow rate is reduced.