Turbine blade root configurations

Abstract

A rotor blade for use in a turbine engine, the rotor blade comprising a root and, extending in a radial direction from the root, an airfoil, wherein the root includes at least one root aligned surface that is tilted. Tilted may comprises a non-radial orientation. The root aligned surfaces may comprise the surfaces along the root that are configured to align with and be relatively closely spaced from or in contact with the root aligned surfaces of the root of a neighboring rotor blade. The rotor blade may comprise at least two root aligned surfaces, one of which resides on a pressure side of the rotor blade and the other of which resides on a suction side of the rotor blade. All of the root aligned surfaces may be tilted.

1 . A rotor blade for use in a turbine engine, the rotor blade comprising a root and, extending in a radial direction from the root, an airfoil, wherein the root includes at least one root aligned surface that is tilted. 
   
   
       2 . The rotor blade according to  claim 1 , wherein tilted comprises a non-radial orientation. 
   
   
       3 . The rotor blade according to  claim 1 , wherein:
 the root aligned surfaces comprise the surfaces along the root that are configured to align with and be relatively closely spaced from or in contact with the root aligned surfaces of the root of a neighboring rotor blade;   the rotor blade comprises at least two root aligned surfaces, one of which resides on a pressure side of the rotor blade and the other of which resides on a suction side of the rotor blade; and   all of the root aligned surfaces are tilted.   
   
   
       4 . The rotor blade according to  claim 3 , wherein the root comprises a shank and a dovetail, the shank extending from the dovetail and comprising a platform at a radial outward surface;
 wherein:
 the platform comprises an axially and circumferentially oriented surface that defines, at least in part, the inner most radial boundary of the flow path through the turbine; and 
 the airfoil extends in an outward radial direction from the platform. 
   
   
   
       5 . The rotor blade according to  claim 3 , wherein, upon the proper installation of the rotor blade in the turbine engine, the root aligned surface that resides on the pressure side of the rotor blade and the root aligned surface that resides on the suction side of the rotor blade are configured to align with and be relatively closely spaced from or in contact with each other if a rotor blade of the same design were properly installed one each side and adjacent to the rotor blade in the turbine engine. 
   
   
       6 . The rotor blade according to  claim 1 , wherein the tilted root aligned surface comprises a substantially flat surface that is oriented in a non-radial direction. 
   
   
       7 . The rotor blade according to  claim 1 , wherein the root aligned surface comprises an approximately planar lateral surface that is configured to oppose, align with and be relatively closely spaced from or in contact with a root aligned surface of a neighboring rotor blade upon the proper installation of the rotor blade in the turbine engine. 
   
   
       8 . The rotor blade according to  claim 7 , wherein the root aligned surface comprises a configuration that forms an approximately linear junction line with an opposing root aligned surfaces that, upon the proper installation of the rotor blade in the turbine engine, is oriented such that the junction line forms an angle θ with a radially oriented reference line; and
 wherein the angle θ comprises a value of between approximately 0° and 60°.   
   
   
       9 . The rotor blade according to  claim 8 , wherein the angle θ comprises a value of between approximately 15° and 45°. 
   
   
       10 . The rotor blade according to  claim 8 , wherein the angle θ comprises a value of between approximately 25° and 35°. 
   
   
       11 . The rotor blade according to  claim 8 , wherein the angle θ comprises a value of approximately 30°. 
   
   
       12 . The rotor blade according to  claim 4 , wherein:
 the shank includes at least one coverplate, the coverplate comprising a relatively thin rectangular plate that substantially covers a leading face of the shank or a trailing face of the shank; and   the root aligned surfaces include at least one of the sides of the coverplate.   
   
   
       13 . The rotor blade according to  claim 4 , wherein the root aligned surfaces comprise portions of the shank along a pressure face of the root and portions of the shank along a suction face of the root. 
   
   
       14 . The rotor blade according to  claim 13 , wherein the root aligned surfaces comprise a pressure edge of the platform on the pressure face of the root and a suction edge of the platform on the suction face of the root. 
   
   
       15 . The rotor blade according to  claim 4 , wherein the dovetail is substantially linear and the platform is curved. 
   
   
       16 . The rotor blade according to  claim 15 , wherein the linear dovetail comprises one or more tangs and is configured to engage a linear dovetail groove. 
   
   
       17 . The rotor blade according to  claim 15 , wherein the linear dovetail is configured to engage one of a linear dovetail that is parallel in relation to the direction of the centerline axis and a linear dovetail that skewed in relation to the direction of the centerline axis. 
   
   
       18 . The rotor blade according to  claim 15 , wherein:
 the platform comprises a pressure edge that coincides with a pressure side of the airfoil and a suction edge that coincides with a suction side of the airfoil;   both the pressure edge and the suction edge are curved; and   the pressure edge comprises a concave curve and the suction edge comprises a convex curve.   
   
   
       19 . The rotor blade according to  claim 18 , wherein the curvature of the concave curve of the pressure edge and the curvature of the convex curve of the suction edge comprises the arc of an approximate circle. 
   
   
       20 . The rotor blade according to  claim 1 , wherein the blade is configured to operate as a rotor blade in one of a turbine and a compressor of a gas turbine engine.