Thrust balance system for gas turbine engine

Abstract

A gas turbine engine has a thrust balance chamber defined between a static housing and a rotating component. The thrust balance chamber is sealed by a first non-contact seal at a radially inner location and a second non-contact seal at a radially outer location.

1 . A gas turbine engine comprising:
 a turbine section and an air moving section upstream of the turbine section; and   a thrust balance chamber defined within one of said air moving and turbine sections, said thrust balance chamber being defined between a static structure and a rotating component that is part of at least one of said air moving section and said turbine section, and said thrust balance chamber being sealed by a first non-contact seal at a radially inner location and a second non-contact seal at a radially outer location.   
     
     
         2 . The gas turbine engine as set forth in  claim 1 , wherein said air moving section includes one of a fan and a compressor. 
     
     
         3 . The gas turbine engine as set forth in  claim 1 , wherein said turbine section drives a fan through a gear reduction. 
     
     
         4 . The gas turbine engine as set forth in  claim 1 , wherein said first and second non-contact seals each include a shoe which is biased radially inwardly and outwardly relative to a carrier at least in part based upon a spring force. 
     
     
         5 . The gas turbine engine as set forth in  claim 4 , wherein high pressure air is delivered into a cavity within each said non-contact seal to drive said shoe toward an opposed surface. 
     
     
         6 . The gas turbine engine as set forth in  claim 5 , wherein a dynamic pressure between the seals and the opposed surfaces tends to bias said shoes away from said surfaces. 
     
     
         7 . The gas turbine engine as set forth in  claim 6 , wherein said seal is attached to said static structure, and said surface is a rotating surface that rotates with one of said compressor and turbine sections. 
     
     
         8 . The gas turbine engine as set forth in  claim 4 , wherein said shoe and said carrier are formed in segments. 
     
     
         9 . The gas turbine engine as set forth in  claim 1 , wherein at least one of said first and second non-contact seals sealing on a surface which is radially inwardly of said at least one of said first and second non-contact seals. 
     
     
         10 . The gas turbine engine as set forth in  claim 1 , wherein at least one of said first and second non-contact seals sealing on a surface which is radially outwardly of said at least one of said first and second non-contact seals. 
     
     
         11 . The gas turbine engine as set forth in  claim 1 , wherein said thrust balance chamber is defined at a most upstream turbine blade row in the turbine section. 
     
     
         12 . A gas turbine engine comprising:
 a fan, a compressor section, said compressor section include a low pressure compressor and a high pressure compressor, a high pressure turbine, and a low pressure turbine and said low pressure turbine driving said low pressure compressor, and driving said fan through a gear reduction, and said high pressure turbine driving said high pressure compressor; and   at least one thrust balance chamber defined within one of said fan, compressor and turbine sections, said thrust balance chamber being defined between a static structure and a rotating component that is part of at least one of said compressor section and said turbine section, and said thrust balance chamber being sealed by a first non-contact seal at a radially inner location and a second non-contact seal at a radially outer location.   
     
     
         13 . The gas turbine engine as set forth in  claim 12 , wherein said first and second non-contact seals each include a shoe which is biased radially inwardly and outwardly relative to a carrier at least in part based upon a spring force created by an arm structure. 
     
     
         14 . The gas turbine engine as set forth in  claim 13 , wherein high pressure air is delivered into a cavity within each said non-contact seal to drive said shoe toward an opposed surface. 
     
     
         15 . The gas turbine engine as set forth in  claim 13 , wherein a dynamic pressure between the seals and the opposed surfaces tends to bias said shoes away from said surfaces. 
     
     
         16 . The gas turbine engine as set forth in  claim 15 , wherein said seal is attached to said static structure, and said surface is a rotating surface that rotates with at least one of said compressor and turbine sections. 
     
     
         17 . The gas turbine engine as set forth in  claim 13 , wherein said shoe and said carrier are formed in segments. 
     
     
         18 . The gas turbine engine as set forth in  claim 12 , wherein at least one of said first and second non-contact seals sealing on a surface which is radially inwardly of said at least one of said first and second non-contact seals. 
     
     
         19 . The gas turbine engine as set forth in  claim 12 , wherein at least one of said first and second non-contact seals sealing on a surface which is radially outwardly of said at least one of said first and second non-contact seals. 
     
     
         20 . The gas turbine engine as set forth in  claim 12 , wherein said thrust balance chamber is defined at a most upstream turbine blade row in the turbine section. 
     
     
         21 . The gas turbine engine as set forth in  claim 20 , wherein said thrust balance chamber in combination with many other thrust balance chambers counteracts the net load developed by the combination of all the thrust surfaces within said other modules.