Two-Part Shroud or Shroud Section for a Stator Stage with Vanes of an Axial Compressor

Abstract

A shroud or shroud section for a stator stage with vanes of an axial compressor is made of composite material and is built in two parts, each having a series of notches corresponding to a half of the profile of the vanes, so as to form apertures that follow the shape of the vanes when the two parts are assembled. The two parts also include mutual fastening members or means adapted to ensure their assembly.

1 . A shroud for a stator stage with vanes of an axial compressor, comprising:
 at least one first curved element having at least one first notch, each first notch corresponding to a first portion of a contour of an end of one of the vanes; and   at least one second curved element having at least one second notch, each second notch corresponding to a second portion of the contour of the end of the vane, the first and second curved elements being adapted to be arranged axially against one another, so as to confine the ends of the vanes in corresponding pairs of first and second notches.   
     
     
         2 . The shroud according to  claim 1 , wherein each of the first and second curved elements comprises:
 an assembly edge in a plane that is perpendicular to a main axis of the compressor, the assembly edges being adapted to come into mutual contact during the assembly of the two curved elements by becoming closer in a direction generally corresponding to a flow direction through the compressor.   
     
     
         3 . The shroud according to  claim 1 , wherein each first portion of the contour of the end of a vane generally corresponds to half of the profile of the end of such vane in a flow direction of the compressor. 
     
     
         4 . The shroud according to  claim 1 , further comprising:
 a first assembly edge disposed on the first curved element; and   a second assembly edge disposed on the second curved element;   wherein the first assembly edge cooperates by insertion with the second assembly edge during assembly of the first curved element and the second curved element by becoming closer in a direction corresponding to a flow direction of the compressor.   
     
     
         5 . The shroud according to  claim 1 , further comprising:
 a groove disposed along the curved direction of one of the first assembly edge and second assembly edge; and   a projecting part disposed along the curved direction of the other of the first assembly edge and second assembly edge;   wherein the groove and the projecting part are interrupted by the respective first and second notches of the first and second curved elements.   
     
     
         6 . The shroud according to  claim 1 , further comprising:
 an internal U-shaped section having an opening of the U-shape directed toward the center of the shroud, so as to form a recess adapted to received an abradable material.   
     
     
         7 . The shroud according to  claim 6 , wherein the first and second curved elements intersect at approximately the center of the U-shape. 
     
     
         8 . The shroud according to  claim 1 , further comprising:
 clip-type fastening members disposed on the first and second assembly edges.   
     
     
         9 . The shroud according to  claim 8 , wherein the clip-type fastening members cooperate by elastic engagement of positive contact surfaces when the first and second curved elements become closer together along a direction corresponding to a flow direction of the compressor. 
     
     
         10 . The shroud according to  claim 8 , wherein the clip-type fastening members comprise:
 a plurality of spaced elements projecting beyond one of the first and second curved elements along a direction corresponding approximately to the direction for moving the first and second curved elements closer together.   
     
     
         11 . The shroud according to  claim 8 , wherein the clip-type fastening members are arranged radially interior to the respective assembly edges of the first and second curved elements. 
     
     
         12 . The shroud according to  claim 1 , wherein the first curved element and the second curved element are each formed by a plurality of curved sections, the end of each section having a profile that corresponds to the end of a vane, such that the junction between adjacent curved sections corresponds to the vane profile. 
     
     
         13 . The shroud according to  claim 1 , wherein at least one of the first curved element and the second curved element is formed by a plurality of curved sections, the end of each section having a profile that corresponds to a portion of the end of a vane, such that the junction between adjacent curved sections corresponds to a portion of the vane profile. 
     
     
         14 . The shroud according to  claim 13 , wherein each end of each curved section includes a means for connecting to an adjacent section, each means for connecting including a positive contact on both sides of the junction on each of the first and second curved elements. 
     
     
         15 . The shroud according to  claim 1 , wherein each of the first and second curved elements is in the shape of a closed ring. 
     
     
         16 . The shroud according to  claim 1 , wherein one of the first and second curved elements forms a closed ring shape, and the other of the first and second curved elements is formed by a plurality of curved sections corresponding to the closed ring shape, each curved section being successively arranged against the closed ring shape so as to confine, over the entire perimeter of the closed ring shape, the roots of the vanes in corresponding pairs of first and second notches. 
     
     
         17 . The shroud according to  claim 1 , wherein the shroud forms a shroud section of the compressor. 
     
     
         18 . The shroud according to  claim 1 , wherein the shroud is made of a composite material.