Mechanical repair of damaged airfoil structure

Abstract

A process is provided for repairing an airfoil structure adapted for use in a gas turbine engine comprising: providing an airfoil structure having a section with a defect; removing airfoil structure material comprising the section with the defect such that a through hole is created; providing a replacement element; providing interlocking structure; positioning the replacement element relative to the through hole; and securing the replacement element to the airfoil structure via the interlocking structure such that the through hole is covered.

What is claimed is: 
     
         1 . A process for repairing an airfoil structure adapted for use in a gas turbine engine comprising:
 providing an airfoil structure having a section with a defect;   removing airfoil structure material comprising said section with the defect such that a through hole is created;   providing a replacement element;   providing interlocking structure;   positioned said replacement element relative to said through hole; and   securing said replacement element to said airfoil structure via said interlocking structure such that said through hole is covered.   
     
     
         2 . The process as set out in  claim 1 , wherein said removing comprises forming a through hole comprising a first outer section and a second inner section, said first section having a diameter greater than said second section. 
     
     
         3 . The process as set out in  claim 2 , wherein said replacement element comprises a first outer portion and a second inner portion, said first portion having a diameter slightly less than said diameter of said through hole first section and said second portion having a diameter slightly less than said diameter of said through hole second section, wherein said first outer portion is received in said through hole first section and said second portion is received in said through hole second section. 
     
     
         4 . The process as set out in  claim 3 , wherein said interlocking structure comprises threads on said replacement element and a section of said airfoil structure adjacent said through hole. 
     
     
         5 . The process as set out in  claim 4 , further comprising sealing said replacement element to said airfoil structure. 
     
     
         6 . The process as set out in  claim 3 , wherein said interlocking structure comprises a pin positioned through said replacement element and a section adjacent said through hole. 
     
     
         7 . The process as set out in  claim 6 , further comprising sealing said replacement element and said pin to said airfoil structure. 
     
     
         8 . The process as set out in  claim 6 , wherein said pin is threaded. 
     
     
         9 . The process as set out in  claim 6 , wherein said pin is positioned at a non-orthogonal angle to an outer surface of said replacement element. 
     
     
         10 . The process as set out in  claim 1 , wherein said airfoil structure comprises a vane or a blade. 
     
     
         11 . The process as set out in  claim 1 , wherein said replacement element comprises a main body portion and said interlocking structure comprises at least one tongue extending from said main body portion and further comprising forming at least one groove in a section of said airfoil structure adjacent said through hole, said tongue being adapted to be received in said groove. 
     
     
         12 . The process as set out in  claim 11 , wherein said interlocking structure comprises first, second, third and fourth tongues extending out from said main body portion and said forming comprises forming first, second, third and fourth grooves in said section adjacent said through hole. 
     
     
         13 . The process as set out in  claim 12 , wherein said first, second, third and fourth tongues have curved shapes and said first, second, third and fourth grooves have curved shapes. 
     
     
         14 . The process as set out in  claim 13 , wherein said positioning comprises positioning said replacement element upside down relative to an outer surface of said airfoil structure and said securing comprises rotating said replacement element 180 degrees such that said first and second tongues move through said third and fourth grooves and then into said first and second grooves and said third and fourth tongues move into said third and fourth grooves when said first and second tongues move into said first and second grooves. 
     
     
         15 . A repaired airfoil structure comprising:
 an airfoil structure having a through hole formed therein so as to remove a section with a defect;   a replacement element positioned in said through hole; and   interlocking structure to mechanically couple said replacement element to said airfoil structure.   
     
     
         16 . The repaired airfoil structure as set out in  claim 15 , wherein:
 said through hole comprises a first outer section and a second inner section, said first section having a diameter greater than said second section; and   said replacement element comprises a first outer portion and a second inner portion, said first portion having a diameter slightly less than said diameter of said through hole first section and said second portion having a diameter slightly less than said diameter of said through hole second section, wherein said first outer portion is received in said through hole first section and said second portion is received in said through hole second section.   
     
     
         17 . The repaired airfoil structure as set out in  claim 15 , wherein said interlocking structure comprises threads on said replacement element and a section of said airfoil structure adjacent said through hole. 
     
     
         18 . The repaired airfoil structure as set out in  claim 15 , wherein said interlocking structure comprises a pin positioned through said replacement element and a section adjacent said through hole. 
     
     
         19 . The repaired airfoil structure as set out in  claim 18 , wherein said pin is threaded. 
     
     
         20 . The repaired airfoil structure as set out in  claim 19 , wherein said pin is positioned at a non-orthogonal angle to an outer surface of said replacement element.