Knife Edge Seal for Gas Turbine Engine

Abstract

A seal for a gas turbine engine and a gas turbine engine employing such a seal are disclosed. More specifically, the engine includes a knife edge seal which is better able to withstand the extremely high temperatures and mechanical loads to which gas turbine engine components are increasingly subjected. By moving the knife edge seal to the aft hub and cantilevering its angle off of vertical, thermal and mechanical loads are balanced and thus thermal mechanical fatigue life is improved while low cycle fatigue is maintained.

What is claimed is: 
     
         1 . A gas turbine engine, comprising;
 a fan;   a compressor section downstream of the fan;   a combustor section downstream of the compressor section;   a turbine section downstream of the combustor section;   an aft hub downstream of the compressor section; and   a knife edge seal extending radially outward from the aft hub, the knife edge seal being transverse to a center axis of the engine.   
     
     
         2 . The gas turbine engine of  claim 1 , wherein the compressor section includes a plurality of blades radially extending between a plurality of vanes, the knife edge seal being transverse to the plurality of blades. 
     
     
         3 . The gas turbine engine of  claim 2 , wherein the knife edge seal includes a base from which first and second knife edges extend. 
     
     
         4 . The gas turbine engine of  claim 3 , further including a neck between the base and the first and second knife edges, the neck having a reduced thickness relative to the base. 
     
     
         5 . The gas turbine engine of  claim 1 , further including an aft hub bore extending radially inward from the aft hub, the knife edge seal extending from the aft hub proximate the aft hub bore. 
     
     
         6 . The gas turbine engine of  claim 1 , wherein the knife edge seal extends radially outward and axially forward from the aft hub. 
     
     
         7 . The gas turbine engine of  claim 1 , wherein the knife edge seal extends radially outward and axially rearward from the aft hub. 
     
     
         8 . The gas turbine engine of  claim 2 , wherein the knife edge seal is provided at angle relative to rotor blades of less than 90° and greater than 0°. 
     
     
         9 . A seal for a gas turbine engine comprising:
 an aft hub;   a knife edge seal extending radially outward from the aft hub, the knife edge seal being transverse to a center axis of the engine.   
     
     
         10 . The seal of  claim 9 , wherein the knife edge seal extends radially outward and axially forward relative to the gas turbine engine. 
     
     
         11 . The seal of  claim 9 , wherein the knife edge seal extends radially outward and axially rearward relative to the gas turbine engine. 
     
     
         12 . The seal of  claim 9 , wherein the knife edge seal includes a base from which first and second knife edges extend. 
     
     
         13 . The seal of  claim 12 , wherein the knife edge seal further includes a neck between the base and the first and second knife edges, the neck having a reduced thickness relative to the base. 
     
     
         14 . The seal of  claim 9 , wherein the knife edge seal is manufactured from nickel alloy with an alumina coating. 
     
     
         15 . The seal of  claim 9 , wherein the knife edge seal extends from the aft hub at an angle of less than 90°. 
     
     
         16 . A gas turbine engine, comprising:
 a stator;   a rotor rotatably mounted within the stator;   an aft hub extending rearwardly from the rotor; and   a knife edge seal extending from the aft hub and at an angle transverse to the rotor.   
     
     
         17 . The gas turbine engine of  claim 16 , wherein the knife edge seal extends radially outward from the aft hub and is angled axially forward toward the rotor. 
     
     
         18 . The gas turbine engine of  claim 16 , wherein the knife edge seal extends radially outward from the aft hub and is angled axially rearward away from the rotor. 
     
     
         19 . The gas turbine engine of  claim 16 , further including an aft hub bore radially inwardly extending from the aft hub and parallel to the rotor, the knife edge seal extending from the aft hub proximate the aft hub bore. 
     
     
         20 . The gas turbine engine of  claim 16 , wherein the rotor includes a plurality of radially outwardly directed blades and the knife edge seal extends relative to the plurality of blades at an angle of less than 90° and more than 0°.