Gas turbine moving blade having a platform, a method of forming the moving blade, a sealing plate, and a gas turbine having these elements

Abstract

A platform of a gas turbine moving blade suppresses the effects of thermal elongation and thus improves cooling performance. A structure is constituted by a peripheral edge of a platform of a gas turbine moving blade, a bottom of the platform, and a shank of the moving blade. A cavity is blocked by disposing a sealing plate so as to seal the recessed section, while a supply route is formed for supplying air from cooling passages through an interior of the shank to the cavity, each of the passages being for air-cooling the interior of the gas turbine moving blade with air blown out from the cavity to a surface of the platform. A method of appropriately installing the sealing plate is also disclosed.

1 . A gas turbine moving blade having a platform, comprising: 
 a recessed section constituted by a peripheral edge of said platform, a bottom thereof, and a shank of the moving blade, said recessed section being formed with a cavity closed by disposing a sealing plate between the peripheral edge of said platform and the shank;    said cavity being formed with a supply route for supplying air from cooling passages through the interior of the shank to said cavity, each of said cooling passages configured for air-cooling the interior of the gas turbine moving blade; and    said cavity being provided with a plurality of cooling passage holes, each of said cooling passage holes configured for allowing air to flow from said cavity to a surface of said platform.    
   
   
       2 . A gas turbine moving blade having a platform according to  claim 1 , wherein said sealing plate is fixed at least at one end to either a groove provided at a lower end of the peripheral edge of said platform or to a groove provided in the shank.  
   
   
       3 . A gas turbine moving blade having a platform according to claim I or  2 , wherein each of said cooling passages is bored for the air to flow from the surface of said platform radially in a direction away from the blade.  
   
   
       4 . A gas turbine moving blade having a platform according to claim I or  2 , wherein, at a longitudinal cross section of said cavity, the width of said cross section is narrowed along the peripheral edge of said platform.  
   
   
       5 . A gas turbine moving blade having a platform according to  claim 2 , wherein said sealing plate is inserted into grooves and then welded or brazed for fixing.  
   
   
       6 . A gas turbine moving blade having a platform according to  claim 1 , wherein said sealing plate is inclined toward the peripheral edge of said platform.  
   
   
       7 . A gas turbine moving blade having a platform according to  claim 1 , wherein a dimpled plate is used as said sealing plate.  
   
   
       8 . A gas turbine moving blade having a platform according to  claim 7 , wherein said sealing plate has a dimple that has a thin and long shape.  
   
   
       9 . A gas turbine moving blade having a platform according to  claim 7 , wherein said sealing plate has a plurality of dimples.  
   
   
       10 . A gas turbine moving blade having a platform according to  claim 1 , wherein said sealing plate is a plate formed by connecting a plurality of plates to one another in a lateral direction.  
   
   
       11 . A gas turbine moving blade having a platform according to  claim 1 , wherein said sealing plate is a plate that has a curved shape.  
   
   
       12 . A sealing plate for a gas turbine moving blade cavity, comprising a plurality of protruding pieces on peripheral sections of said sealing plate.  
   
   
       13 . A sealing plate for a gas turbine moving blade cavity according to  claim 12 , including a through-hole in each of said plurality of protruding pieces.  
   
   
       14 . A sealing plate for a gas turbine moving blade cavity according to  claim 13 , having a notch outside each of said plurality of holed protruding pieces.  
   
   
       15 . A method for forming a gas turbine moving blade having a platform, comprising: 
 forming a recessed section by using a peripheral edge of said platform, a bottom thereof, and a shank of the moving blade;    inserting at least one end of a sealing plate having protruding pieces into either a groove previously provided in a lower end portion of a platform peripheral edge or in said shank section of the moving blade;    fixing each of said protruding pieces to said groove; and    fixing a peripheral edge of said sealing plate.    
   
   
       16 . The platform-forming method for a gas turbine moving blade having a platform according to  claim 15 , wherein, a notch formed in each of said protruding pieces is cut open and spread outward for fixing.  
   
   
       17 . A gas turbine using a gas turbine moving blade, having a platform, comprising: 
 a recessed section constituted by a peripheral edge of said platform, a bottom thereof, and a shank of the moving blade, said recessed section being formed with a cavity closed by disposing a sealing plate between the peripheral edge of said platform and the shank;    said cavity being formed with a supply route for supplying air from cooling passages through the interior of the shank to said cavity, each of said cooling passages configured for air-cooling the interior of the gas turbine moving blade; and    said cavity being provided with a plurality of cooling passage holes, each of said cooling passage holes configured for allowing air to flow from said cavity to a surface of said platform.