Seal and airfoil tip clearance control

Abstract

A turbine section includes a housing and a blade outer air seal to be mounted on the housing. A flex beam mounts the blade outer air seal onto the housing, with the flex beam being supported on the housing, but free to move relative to the housing. A pressure air chamber is formed on an opposed side of the flex beam from the blade outer air seal. A source of pressurized air is delivered into the chamber to cause the flex beam to move the blade outer air seal toward and away from a central axis of the housing.

1 . A housing section for a gas turbine engine comprising:
 a housing;   a flex beam mounting a blade outer air seal onto said housing, with said flex beam being supported on said housing, and free to move relative to said housing; and   a pressure chamber formed on an opposed side of said flex beam from said blade outer air seal, and a source of pressurized air to be delivered into said pressure chamber to cause said flex beam to move said blade outer air seal toward and away from a central axis of said housing.   
     
     
         2 . The housing as set forth in  claim 1 , wherein said source of pressurized air includes a valve controlled by a controller to control the pressure of air delivered into said pressure chamber. 
     
     
         3 . The housing as set forth in  claim 1 , wherein said flex beam is supported within said housing at axially upstream and downstream ends, but free to move in an axial direction. 
     
     
         4 . The housing as set forth in  claim 3 , wherein a seal is positioned between said flex beam and said housing. 
     
     
         5 . The housing as set forth in  claim 4 , wherein said seal on said flex beam extends along at least one axial side of said flex beam, and at least a portion of two circumferential edges. 
     
     
         6 . The housing as set forth in  claim 1 , wherein said flex beam removably mounts said blade outer air seal. 
     
     
         7 . The housing as set forth in  claim 1 , wherein said flex beam includes a two-bar connection which guides said flex beam during flexing movement relative to said housing. 
     
     
         8 . The housing as set forth in  claim 1 , wherein there are a plurality of adjacent flex beam portions extending over a portion of a circumferential extent of the housing. 
     
     
         9 . The housing as set forth in  claim 8 , wherein each of said flex beam portions have opposed circumferential edges that interfit with an adjacent one of said flex beams, and a seal positioned between said circumferential edges. 
     
     
         10 . The housing as set forth in  claim 1 , wherein said housing is utilized as part of a turbine section in a gas turbine engine. 
     
     
         11 . The housing as set forth in  claim 1 , wherein a space is defined radially between a side of said flex beam which faces said blade outer air seal, and a radially outer portion of said blade outer air seal to facilitate radially inward flexing of the flex beam. 
     
     
         12 . The housing as set forth in  claim 11 , wherein said flex beam is relatively thin at least in an area aligned with said space, and between 0.030-0.050 inches. 
     
     
         13 . A turbine section for a gas turbine engine comprising:
 a turbine rotor carrying a plurality of blades, said blades having a radial outer tip;   a housing;   a flex beam removably mounting a blade outer air seal onto said housing, with said flex beam being supported on said housing, but free to move relative to said housing;   a pressure chamber formed on an opposed side of said flex beam from said blade outer air seal, and a source of pressurized air to be delivered into said chamber to cause said flex beam to move said blade outer air seal toward and away from a central axis of said housing; and   said source of pressurized air includes a valve controlled by an controller to control the pressure of air delivered into said pressure chamber.   
     
     
         14 . The turbine section as set forth in  claim 13 , wherein said flex beam is supported within said housing at axially upstream and downstream ends, but free to move in an axial direction. 
     
     
         15 . The turbine section as set forth in  claim 13 , wherein a seal is positioned between said flex beam and said housing. 
     
     
         16 . The turbine section as set forth in  claim 15 , wherein said seal on said flex beam extends along at least one axial side of said flex beam, and at least a portion of two circumferential edges. 
     
     
         17 . The turbine section as set forth in  claim 13 , wherein said flex beam includes a two-bar connection which guides said flex beam during flexing movement relative to said housing. 
     
     
         18 . The turbine section as set forth in  claim 13 , wherein there are a plurality of adjacent flex beam portions extending over a portion of a circumferential extent of the housing. 
     
     
         19 . The turbine section as set forth in  claim 13 , wherein a space is defined radially between the face of said flex beam which faces said blade outer air seal, and a radially outer portion of said blade outer air seal to facilitate radially inward flexing of the flex beam, said flex beam is relatively thin at least in an area aligned with said space, and between 0.030-0.050 inches. 
     
     
         20 . A turbine section for a gas turbine engine comprising:
 a turbine rotor carrying a plurality of blades, said blades having a radial outer tip;   a housing;   
       a plurality of adjacent flex beam portions extending over a portion of a circumferential extent of the housing, each of said flex beam portions removably mounting a blade outer air seal portion onto said housing, with said flex beam portions being supported on said housing, but free to move relative to said housing;
 a pressure chamber formed on an opposed side of each said flex beam portion from said blade outer air seal portions, and a source of pressurized air to be delivered into said pressure chamber to cause said flex beam portion to move said blade outer air seal toward and away from a central axis of said housing; 
 said source of pressurized air includes a valve controlled by a controller to control the pressure of air delivered into said pressure chamber; 
 a space defined radially between a side face of said flex beam which faces said blade outer air seal portion, and a radially outer portion of said blade outer air seal portion to facilitate radially inward flexing of the flex beam; and 
 said flex beam portion is relatively thin at least in an area aligned with said space, and between 0.030-0.050 inches.