Turbo Machinery

Abstract

Turbo machinery includes a rotating body, a stator, and a labyrinth seal disposed in a gap between the rotating body and the stator. The labyrinth seal includes a first seal fin and a second seal fin both of which protrude from a portion of one of the rotating body and the stator toward an opposing portion of the other one of the rotating body and the stator. The first seal fin is disposed on the high-pressure side of the center of the labyrinth seal in the axial direction of the rotating body. The second seal fin is disposed on the low-pressure side of the first seal fin to form a cavity together with the first seal fin. A gap to the portion opposing the first seal fin is smaller than a gap to the portion opposing the second seal fin.

1 . Turbo machinery comprising:
 a rotating body;   a stator disposed around the rotating body, but with a gap to the rotating body; and   a labyrinth seal disposed in a gap between the rotating body and the stator to reduce the flow of leakage flowing in the gap from the high-pressure side to the low-pressure side;   wherein the labyrinth seal includes   a first seal fin protruding from a portion of one of the rotating body and the stator toward an opposing portion of the other one of the rotating body and the stator and disposed on the high-pressure side of the center of the labyrinth seal in the axial direction of the rotating body, and   a second seal fin disposed on the low-pressure side of the first seal fin to form a cavity together with the first seal fin and protruding from a portion of one of the rotating body and the stator toward an opposing portion of the other one of the rotating body and the stator,   a gap to the portion opposing the first seal fin being smaller than a gap to the portion opposing the second seal fin.   
     
     
         2 . The turbo machinery according to  claim 1 , wherein the portion opposing the first seal fin is provided with an abradable layer. 
     
     
         3 . The turbo machinery according to  claim 1 , wherein the portion opposing the first seal fin is provided with a third seal fin protruding toward the first seal fin; and wherein one of the first seal fin and the third seal fin has a greater axial thickness than the other one of the first seal fin and the third seal fin. 
     
     
         4 . The turbo machinery according to  claim 2 , wherein the portion opposing the first seal fin is provided with a third seal fin protruding toward the first seal fin; and wherein one of the first seal fin and the third seal fin has a greater axial thickness than the other one of the first seal fin and the third seal fin. 
     
     
         5 . The turbo machinery according to  claim 1 , wherein the first seal fin is a seal fin disposed closer to a high-pressure section than any other seal fins included in the labyrinth seal. 
     
     
         6 . The turbo machinery according to  claim 2 , wherein the first seal fin is a seal fin disposed closer to a high-pressure section than any other seal fins included in the labyrinth seal. 
     
     
         7 . The turbo machinery according to  claim 3 , wherein the first seal fin is a seal fin disposed closer to a high-pressure section than any other seal fins included in the labyrinth seal. 
     
     
         8 . The turbo machinery according to  claim 4 , wherein the first seal fin is a seal fin disposed closer to a high-pressure section than any other seal fins included in the labyrinth seal.