Turbine disc with reduced neck stress concentration

Abstract

A disc with two sides includes a hub having a bore and a bore radius, a neck, and a rim. The neck is connected to and radially outward of the hub and has an inner wedge with a curved section on one side of the disc, an outer wedge with a curved section on that same side of the disc, and a center section between the wedges with a flat side on that same side of the disc. The rim is connected to and radially outward of the neck, the rim having a radius that is no more than seven times greater than the bore radius.

1 . A disc with a first side and a second side, the disc comprising:
 a hub including a bore with a bore radius;   a neck connected to and radially outward of the hub, the neck comprising:
 an inner wedge with a first concave curved section on the first side of the disc including a first radius of curvature; 
 an outer wedge with a second concave curved section on the first side of the disc including a second radius of curvature; and 
 a center section extending between the inner wedge and the outer wedge, the center section including a first flat side on the first side of the disc; and 
   a rim connected to and radially outward of the neck, the rim including a rim radius that is no more than seven times greater than the bore radius.   
     
     
         2 . The disc of  claim 1 , wherein the first flat side includes a length that is at least 0.1 times greater than the smaller of the first radius of curvature and the second radius of curvature. 
     
     
         3 . The disc of  claim 1 , wherein the first flat side is tangent to the first concave curved section and tangent to the second concave curved section. 
     
     
         4 . The disc of  claim 1 , wherein the first flat side extends substantially radially. 
     
     
         5 . The disc of  claim 1 , further comprising:
 a third concave curved section on the inner wedge on the second side of the disc that includes a third radius of curvature that is substantially the same as the first radius of curvature;   a fourth concave curved section on the outer wedge on the second side of the disc that includes a fourth radius of curvature that is substantially the same as the second radius of curvature; and   a generally radial second flat side on the center section on the second side of the disc extending between the inner wedge and the outer wedge.   
     
     
         6 . The disc of  claim 1 , wherein the first radius of curvature is substantially the same as the second radius of curvature. 
     
     
         7 . The disc of  claim 1 , wherein the disc is configured to react to a stress in the neck by distributing the stress to a first stress concentration of a first magnitude in the neck and a second stress concentration of a second magnitude in the neck, the first stress concentration and the second stress concentration separated by a region in the center section, the region having stress of a third magnitude that is lower than both the first magnitude and the second magnitude. 
     
     
         8 . A gas turbine engine comprising:
 a compressor section;   a combustor section downstream of the compressor section, the combustor section including an inner radius; and   a turbine section downstream of the combustor section, the turbine section including a rotor with an outer radius that is no more than  0 . 83  times as large as the inner radius of the combustor, the rotor including a disc with a first side, a second side and a neck comprising:
 an inner wedge with a first concave curved section on the first side of the disc; 
 an outer wedge with a second concave curved section on the first side of the disc; and 
 a center section extending between the inner wedge and the outer wedge, the center section including a first flat side on the first side of the disc. 
   
     
     
         9 . The gas turbine engine of  claim 8 , wherein the first flat side includes a length that is at least 0.1 times greater than the smaller of the first radius of curvature and the second radius of curvature. 
     
     
         10 . The gas turbine engine of  claim 8 , wherein the disc is configured to react to a stress in the neck by distributing the stress to a first stress concentration of a first magnitude in the neck and a second stress concentration of a second magnitude in the neck, the first stress concentration and the second stress concentration separated by a region in the center section, the region having stress of a third magnitude that is lower than both the first magnitude and the second magnitude. 
     
     
         11 . The gas turbine engine of  claim 8 , wherein the first flat side is tangent to the first concave curved section and tangent to the second concave curved section. 
     
     
         12 . The gas turbine engine of  claim 8 , wherein the first flat side extends substantially radially. 
     
     
         13 . The gas turbine engine of  claim 8 , further comprising:
 a third concave curved section on the inner wedge on the second side of the disc that includes a third radius of curvature that is substantially the same as the first radius of curvature;   a fourth concave curved section on the outer wedge on the second side of the disc that includes a fourth radius of curvature that is substantially the same as the second radius of curvature; and   a generally radial second flat side on the center section on the second side of the disc extending between the inner wedge and the outer wedge.   
     
     
         14 . The gas turbine engine of  claim 8 , wherein the first radius of curvature is substantially the same as the second radius of curvature. 
     
     
         15 . The gas turbine engine of  claim 8 , further comprising:
 a hub with a bore radius connected to and radially inward of the neck; and   a rim connected to and radially outward of the neck, the rim including a rim radius that is no more than seven times greater than the bore radius.   
     
     
         16 . The gas turbine engine of  claim 8 , wherein the turbine section is substantially surrounded by the combustor section. 
     
     
         17 . A gas turbine engine comprising:
 a compressor section;   a combustor section downstream of the compressor section; and   a turbine section downstream of and substantially surrounded by the combustor section, the turbine section including a disc with a first side, a second side and a neck comprising:
 an inner wedge with a first concave curved section on the first side of the disc; 
 an outer wedge with a second concave curved section on the first side of the disc; and 
 a center section extending between the inner wedge and the outer wedge, the center section including a first flat side on the first side of the disc. 
   
     
     
         18 . The gas turbine engine of  claim 17 , wherein the first flat side includes a length that is at least 0.1 times greater than the smaller of the first radius of curvature and the second radius of curvature. 
     
     
         19 . The gas turbine engine of  claim 17 , wherein the combustor section includes an inner radius, and the turbine section includes a rotor that includes the disc, the rotor including an outer radius that is no more than 0.83 times as large as the inner radius of the combustor. 
     
     
         20 . The gas turbine engine of  claim 17 , wherein the disc is configured to react to a stress in the neck by distributing the stress to a first stress concentration of a first magnitude in the neck and a second stress concentration of a second magnitude in the neck, the first stress concentration and the second stress concentration separated by a region in the center section, the region having stress of a third magnitude that is lower than both the first magnitude and the second magnitude.