Radial spline arrangement for lpt vane clusters

Abstract

A full hoop stator vane cluster includes an inner hoop and an outer hoop both being substantially cylindrical and coaxial. A plurality of airfoils extend radially between the hoops, and a plurality of vane splines extend radially outward from the outer hoop for attaching the vane cluster to a gas turbine engine.

1 . A full hoop stator vane cluster comprising:
 an inner hoop having a substantially cylindrical shape;   an outer hoop having a substantially cylindrical shape and being substantially coaxial with the inner hoop;   a plurality of airfoils extending radially between the inner hoop and the outer hoop; and   a plurality of vane splines extending radially outward from the outer hoop for attaching the vane cluster to a gas turbine engine.   
     
     
         2 . The vane cluster of  claim 1 , wherein a vane spline comprises:
 two substantially parallel vane prongs that are circumferentially separated from each other.   
     
     
         3 . The vane cluster of  claim 2 , wherein the prongs are joined circumferentially outward from the outer hoop, such that each vane spline includes a closed ring. 
     
     
         4 . The vane cluster of  claim 2 , wherein an amount of circumferential separation between the vane prongs is wider than a circumferential width of each vane prong. 
     
     
         5 . The vane cluster of  claim 2 , wherein an amount of circumferential separation between two consecutive vane splines is wider than a circumferential width of an individual vane spline. 
     
     
         6 . A gas turbine engine comprising:
 a full hoop stator vane cluster comprising:
 an inner hoop having a substantially cylindrical shape; 
 an outer hoop having a substantially cylindrical shape and being substantially coaxial with the inner hoop; 
 a plurality of airfoils extending radially between the inner hoop and the outer hoop; and 
 a plurality of vane splines extending radially outward from the outer hoop; and 
   a case having a substantially cylindrical shape and including a first plurality of case splines extending radially inward for attaching to the vane cluster.   
     
     
         7 . The gas turbine engine of  claim 6 , wherein a vane spline comprises:
 two substantially parallel vane prongs that are circumferentially separated from each other.   
     
     
         8 . The gas turbine engine of  claim 7 , wherein the vane prongs are joined circumferentially outward from the outer hoop, such that each vane spline forms a closed ring. 
     
     
         9 . The gas turbine engine of  claim 7 , wherein an amount of circumferential separation between two consecutive vane splines is wider than a circumferential width of an individual vane spline. 
     
     
         10 . The gas turbine engine of  claim 6 , wherein a case spline comprises:
 two substantially parallel case prongs that are circumferentially separated from each other.   
     
     
         11 . The gas turbine engine of  claim 10 , wherein the case prongs are joined circumferentially inward from the case, such that each case spline forms a closed ring. 
     
     
         12 . The gas turbine engine of  claim 10 , wherein an amount of circumferential separation between two consecutive case splines is wider than a circumferential width of an individual case spline. 
     
     
         13 . The gas turbine engine of  claim 6 , wherein the vane splines and the case splines are substantially the same shape. 
     
     
         14 . The gas turbine engine of  claim 6 , and further comprising:
 a second plurality of case splines axially separated from the first plurality of case splines such that the plurality of vane splines can be interposed between the first and second pluralities of case splines.   
     
     
         15 . The gas turbine engine of  claim 6 , and further comprising:
 a plurality of fasteners oriented substantially axially that attach the vane cluster to the case, each fastener connecting a vane spline to a case spline.   
     
     
         16 . The gas turbine engine of  claim 6 , wherein an amount of circumferential separation between two consecutive vane splines is wider than a circumferential width of an individual case spline. 
     
     
         17 . The gas turbine engine of  claim 6 , wherein an amount of circumferential separation between two consecutive case splines is wider than a circumferential width of an individual vane spline. 
     
     
         18 . A method of installing a full hoop stator vane cluster into a gas turbine engine, the method comprising:
 inserting the vane cluster axially into a case of the gas turbine engine;   offsetting circumferentially the vane splines from the case splines, such that the vane splines are aligned between the case splines;   rotating the vane cluster such that the vane splines are circumferentially aligned with the case splines; and   attaching a vane spline to a case spline to substantially restrain relative axial and circumferential movement.   
     
     
         19 . The method of  claim 18 , and further comprising:
 moving the vane splines axially between two sets of case splines.   
     
     
         20 . The method of  claim 18 , wherein attaching the vane spline to the case spline comprises:
 inserting a fastener substantially axially between the case prongs of the case spline and between the vane prongs of the vane spline.