Turbine blade assembly arrangement and corresponding assembly tool

Abstract

A blade and an assembly tool for assembling a blade set to a rotor disc. The blade has a root portion, an aerofoil and a shroud, the root portion has two lateral sides each defining at least one bearing surface and at least one end surface, the blade has a centre-of-resistance line which passes through the root portion and is generally parallel to a plane of at least one bearing surface, the centre-of-resistance line intersects the at least one end surface at an intersection point, the at least one end surface has an assembly feature having a contact surface arranged about the intersection point.

1 . A blade for assembling to a rotor disc comprising:
 a root portion, an aerofoil, and a shroud,   wherein the root portion has two lateral sides each defining at least one bearing surface and at least one end surface,   wherein the blade has a centre-of-resistance line which passes through the root portion and is generally parallel to a plane of at least one bearing surface,   wherein the centre-of-resistance line intersects the at least one end surface at an intersection point,   wherein the at least one end surface comprises an assembly feature having a contact surface arranged about the intersection point.   
     
     
         2 . The blade as claimed in  claim 1 ,
 wherein the centre-of-resistance line is generally parallel to a plane of at least one bearing surface.   
     
     
         3 . The blade as claimed in  claim 1 ,
 wherein the assembly feature comprises the contact surface recessed in the at least one end surface.   
     
     
         4 . The blade as claimed in  claim 1 ,
 wherein the assembly feature comprises a projection extending from the at least one end surface.   
     
     
         5 . The blade as claimed in  claim 1 ,
 wherein the assembly feature defines a generally flat contact surface that is generally perpendicular to the centre-of-resistance line.   
     
     
         6 . The blade as claimed in  claim 5 ,
 wherein the generally flat contact surface is not parallel to the at least one end surface.   
     
     
         7 . The blade as claimed in  claim 1 ,
 wherein the assembly feature defines a curved contact surface that intersects the centre-of-resistance line, the curved contact surface can be any one of the group comprising convex or concave shapes.   
     
     
         8 . The blade as claimed in  claim 1 ,
 wherein the assembly feature defines a lip at least partly surrounding the contact surface.   
     
     
         9 . The blade as claimed in  claim 1 ,
 wherein the shroud is an interlocking shroud.   
     
     
         10 . An assembly tool for assembling an array of blades to a rotor disc, the assembly tool comprising:
 a slave disc having an axis,   a ring mountable to the slave disc via a slidable mounting and defining an array of generally axially extending fingers for engaging an assembly feature on each blade of the array of blades,   wherein the slidable mounting is arranged to have a slide angle θ to the axis,   wherein the fingers comprise a contact surface configured for engagement with a contact surface of an assembly feature on the blades.   
     
     
         11 . The assembly tool as claimed in  claim 10 ,
 wherein each finger of the annular array of fingers extending from the ring in a direction along a longitudinal axis, the longitudinal axis is arranged to have an angle θ from the axis.   
     
     
         12 . The assembly tool as claimed in  claim 10 ,
 wherein the contact surface is flat or curved.   
     
     
         13 . The assembly tool as claimed in  claim 10 ,
 wherein the finger defines a recess in which the contact surface is located.   
     
     
         14 . The assembly tool as claimed in  claim 10 ,
 wherein the contact surface has a shape of any one of the group comprising flat, curved, convex and concave.