Perimeter-cooled stage 1 bucket core stabilizing device and related method

Abstract

A core for use in casting a gas turbine bucket, the core comprising a solid upper body portion and a pair of legs extending downwardly from the solid upper body portion, the pair of legs separated by an elongated slot, and a pair of pegs projecting axially from opposite sides of the upper body portion, above the elongated slot but spaced from an upper edge of the upper body portion.

1 . A core for use in casting a gas turbine bucket, the core comprising a solid upper body portion and a pair of legs extending downwardly from said solid upper body portion, said pair of legs separated by an elongated slot, and a pair of pegs projecting axially from opposite sides of the upper body portion, above said elongated slot but spaced from an upper edge of said upper body portion.  
   
   
       2 . The core of  claim 1  wherein said solid upper body portion is curved, forming opposite concave and convex surfaces, and said legs are substantially planar, said pegs extending from the convex surface of said solid upper body portion.  
   
   
       3 . The core of  claim 1  wherein said pegs are elliptical in cross section.  
   
   
       4 . The core of  claim 2  wherein said pegs are elliptical in cross section.  
   
   
       5 . The core of  claim 1  wherein said solid upper body portion has an upper edge, and further wherein, in a radial direction, said pegs are closer to said elongated slot than to said upper edge.  
   
   
       6 . The core of  claim 1  wherein said pegs are laterally aligned.  
   
   
       7 . A core for use in casting a gas turbine bucket, the core comprising a solid upper body portion and a pair of legs extending downwardly from said solid upper body portion, said pair of legs separated by an elongated slot, and a pair of pegs projecting axially from opposite sides of the upper body portion, above said elongated slot but spaced from an upper edge of said upper body portion; and wherein said pegs are elliptical in cross section.  
   
   
       8 . The core of  claim 7  wherein said solid upper body portion is curved, forming opposite concave and convex surfaces, and said legs are substantially planar, said pegs extending from the convex surface of said solid upper body portion.  
   
   
       9 . The core of  claim 6  wherein said pegs are substantially laterally aligned.  
   
   
       10 . A method of controlling wall thickness in the shank portion of a turbine bucket during casting comprising: 
 a) providing a core comprising a solid upper body portion and a pair of legs extending downwardly from said solid upper body portion, said legs separated by an elongated slot;    b) supporting the core within a shell die by a pair of laterally aligned pegs extending from opposite ends of the solid upper body portion, said pegs located above said slot and below an upper edge of said upper body portion.    
   
   
       11 . The method of  claim 10  wherein said solid upper body portion is curved, forming opposite concave and convex surfaces, and said legs are substantially planar, said pegs extending from the convex surface of said solid upper body portion.  
   
   
       12 . The method of  claim 10  wherein said pegs are elliptical in cross section.  
   
   
       13 . The method of  claim 11  wherein said pegs are elliptical in cross section.  
   
   
       14 . The method of  claim 10  wherein said solid upper body portion has an upper edge, and further wherein, in a radial direction, said pegs are closer to said elongated slot than to said upper edge.  
   
   
       15 . The method of  claim 10  wherein said pegs are laterally aligned.