Turbine guide vane

Abstract

A turbine guide vane ( 10 ) has a platform ( 12 ) from which at least a guide vane blade ( 13 ) extends. The platform ( 12 ) has a front rail ( 18 ) and a rear rail ( 20 ) arranged to be housed in guide vane carrier seats ( 19, 21 ). The front and rear rails ( 18, 20 ) have projecting pads ( 23, 24 ) arranged to rest against the guide vane carrier seats ( 19, 21 ). The front and rear rails ( 18, 20 ) have at least two pads ( 23 ) extending from one side of the front and rear rails ( 18, 20 ) and at least two further pads ( 24 ) extending from an opposite side of the front and rear rails ( 18, 20 ). The pads ( 23, 24 ) extend from opposite circumferential portions ( 26 ) of the front and rear rails ( 18, 20 ). The pads ( 23, 24 ) extending from the same circumferential portion ( 26 ) of the front and rear rails ( 18, 20 ) are at least partly staggered with respect to one another.

1 . A guide vane of a gas turbine, the gas turbine including guide vane carrier seats, the guide vane comprising:
 a platform; and   at least one guide vane blade extending from the platform;   wherein said platform has a front rail and a rear rail configured and arranged to be housed in the guide vane carrier seats, said front and rear rails having projecting pads configured and arranged to rest against the guide vane carrier seats, said front and rear rails having at least two first pads extending from one side of the front and rear rails and at least two second pads extending from an opposite side of the front and rear rails, said pads extending from opposite circumferential portions of the front and rear rails, and said pads extending from the same circumferential portion of the front and rear rails being at least partly staggered with respect to one another.   
     
     
         2 . A guide vane as claimed in  claim 1 , wherein said pads extend from opposite radial sides of said front and rear rails. 
     
     
         3 . A guide vane as claimed in  claim 2 , wherein said pads extend from a side of the front and rear rails facing the guide vane blade, and from a side opposite the guide vane blades. 
     
     
         4 . A guide vane as claimed in  claim 1 , wherein:
 one of each of the first and second pads form a pair;   each pair of pads is located at the same circumferential portion of each front and rear rail; and   the pads extending from the side of the front and rear rails facing the guide vane blades are farther from the respective rail end than those opposite the guide vanes blades.   
     
     
         5 . A guide vane as claimed in  claim 1 , wherein:
 the guide vane defines an axis; and   said pads are symmetrically disposed with respect to the guide vane axis.   
     
     
         6 . A guide vane as claimed in  claim 1 , wherein:
 the guide vane defines an axis; and   said pads are not symmetrically disposed with respect to the guide vane axis.   
     
     
         7 . A guide vane as claimed in  claim 1 , wherein said at least one guide vane blade comprises a plurality of guide vane blades. 
     
     
         8 . A guide vane as claimed in  claim 7 , wherein said plurality of guide vane blades comprises at least three guide vane blades. 
     
     
         9 . A guide vane as claimed in  claim 1 , wherein the rails and the pads are configured and arranged so that, when the rails are housed in the guide vane carrier seats, a gap is formed between the pads and the guide vane carrier seats.