Turbine

摘要

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 (11 a) 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.

主权项

1. A turbine comprising:
a blade; and a structure spaced apart from a tip side of the blade by a space and relatively rotated around a rotation axis of a shaft body with respect to the blade, wherein a stepped part having a flat surface and a step surface protruding toward the structure is formed at a tip part of the blade, and the flat surface and the step surface are formed alternately from an upstream side toward a downstream side of the structure in a direction of the rotation axis, a seal fin is provided to the structure at a position facing an upstream part of the flat surface, and extends toward the stepped part, and a first cavity is formed between the tip part of the blade and the structure, and formed between the seal fin and a partition wall facing toward the seal fin at the upstream side, and wherein the seal fin comprises: a space restriction part that extends from the structure and has an inner circumference wall surface facing the flat surface, a side surface facing toward the upstream side, and a fin main body part that extends toward the tip part of the blade from a downstream portion of the inner circumference wall surface in the direction of the rotation axis and forms a small space between the flat surface, wherein a second cavity smaller than the first cavity is formed by the flat surface, the space restriction part, and the fin main body part, in an upstream portion of the fin main body part in the direction of the rotation axis, wherein the second cavity is formed at the downstream side of the first cavity, wherein the fin main body part is provided so as to be in one-to-one correspondence with the flat surface, and wherein a height from the flat surface to the structure is larger than a height from the flat surface to the inner circumference wall surface.