Gas turbine vane attachment

Abstract

Base hooks of a vane includes an approximate two times thicker radial geometry, with dimensioning and tolerancing that results in a line-line to loose fit on the forward OD hook surface and the aft ID hook surface. Tolerances thus stack up on the opposite, non-critical surfaces of the hooks (the forward ID hook surface and the aft OD hook surface). The base of the vane is curved to match that of the casing. An interface between the vane base and the casing groove includes a metal alloy liner. Also, a wear coating is provided on the vane attachment hooks. The liner protects the casing groove from wear damage, while the hook coating and the liner provide a wear coupling between the vane base and the casing that provides a barrier between the vane bases and the casing to decrease the wear rate.

1 . An apparatus, comprising:
 a vane having a base with a hook portion on both a forward facing portion of the base and an aft facing portion of the base; and   a casing having a groove that is configured to receive the base of the vane;   wherein the hook portions each has an overall dimension with respect to a dimension of the casing groove that provides for contact between the vane base at a forward outer diameter (OD) hook surface and at an aft inner diameter (ID) hook surface, thereby allowing tolerances to stack up on a forward ID hook surface and an aft OD hook surface.   
   
   
       2 . The apparatus of  claim 1 , wherein the casing groove is curved at a predetermined radial amount. 
   
   
       3 . The apparatus of  claim 2 , wherein the vane base is curved at the same predetermined radial amount as that of the casing groove. 
   
   
       4 . The apparatus of  claim 1 , further comprising a material interface between the vane base and the casing groove. 
   
   
       5 . The apparatus of  claim 4 , wherein the material interface includes a liner that interfaces between the vane base and the casing groove. 
   
   
       6 . The apparatus of  claim 5 , wherein the liner comprises a metal alloy. 
   
   
       7 . The apparatus of  claim 6 , wherein the metal alloy comprises a cobalt-based metal alloy. 
   
   
       8 . The apparatus of  claim 6 , wherein the metal alloy comprises a stainless steel with a thermal spray coating on an inner surface of the liner. 
   
   
       9 . The apparatus of  claim 4 , wherein the material interface comprises a wear coating disposed on the hook portions. 
   
   
       10 . The apparatus of  claim 9 , wherein the wear coating comprises a metal alloy. 
   
   
       11 . The apparatus of  claim 9 , wherein the wear coating comprises a cobalt-based metal alloy. 
   
   
       12 . The apparatus of  claim 9 , wherein the wear coating comprises tungsten carbide or chromium carbide. 
   
   
       13 . An apparatus, comprising:
 a vane having a base with a hook portion on both a forward facing portion of the base and an aft facing portion of the base;   a casing having a groove that is configured to receive the base of the vane; and   a liner disposed between the vane base and the casing groove.   
   
   
       14 . The apparatus of  claim 13 , further comprising a wear coating disposed on the hook portions. 
   
   
       15 . The apparatus of  claim 14 , wherein the wear coating comprises a metal alloy. 
   
   
       16 . The apparatus of  claim 14 , wherein the wear coating comprises a cobalt-based metal alloy. 
   
   
       17 . The apparatus of  claim 13 , wherein the casing groove is curved at a predetermined radial amount. 
   
   
       18 . The apparatus of  claim 17 , wherein the vane base is curved at the same predetermined radial amount as that of the casing groove. 
   
   
       19 . The apparatus of  claim 13 , wherein the liner comprises a metal alloy. 
   
   
       20 . The apparatus of  claim 13 , wherein the liner comprises a cobalt-based metal alloy.