Mid-turbine frame hpt seal support meshing

Abstract

A seal support comprises a body, a seal carrier disposed circumferentially around an outer surface of the body, and a meshing ring extending axially forward of the seal carrier.

1 . A mid-turbine frame for a gas turbine engine, the mid-turbine frame comprising:
 a radially outer case;   a radially inner case disposed inward from the radially outer case, the radially outer and inner cases defining an annular passage therebetween;   a plurality of load spokes extending through the annular passage securing the outer case with the inner case; and   a circumferential seal support disposed axially forward of the inner case, the circumferential seal support including a seal carrier and a meshing ring extending axially forward of the seal carrier.   
     
     
         2 . The mid-turbine frame of  claim 1 , wherein the meshing ring extends axially toward a pocket formed in a first turbine rotor assembly, the first turbine rotor assembly disposed upstream of the mid-turbine frame. 
     
     
         3 . The mid-turbine frame of  claim 1 , wherein the circumferential seal support is integral with the inner case assembly. 
     
     
         4 . The mid-turbine frame of  claim 1 , wherein the circumferential seal support is a separately formed seal support and is removably securable to a forward portion of the inner case. 
     
     
         5 . The mid-turbine frame of  claim 1 , wherein the seal carrier supports a piston ring seal engaging with an outer wall of a vane pack disposed in the annular cavity between the outer case and the inner case. 
     
     
         6 . The mid-turbine frame of  claim 5 , wherein the meshing ring is disposed closer to a first turbine rotor upstream of the mid-turbine frame as compared to an axial distance between a forward end of the vane ring and the turbine rotor immediately upstream of the mid-turbine frame. 
     
     
         7 . The mid-turbine frame of  claim 6 , wherein the meshing ring extends into a pocket formed at an aft end of the upstream turbine rotor. 
     
     
         8 . A case assembly comprising:
 a substantially cylindrical case element; and   a circumferential seal support disposed axially forward of the inner case, the seal support including a seal carrier and a meshing ring extending axially forward of the seal carrier.   
     
     
         9 . The case assembly of  claim 8 , wherein the circumferential seal support is integral with the inner case assembly. 
     
     
         10 . The case assembly of  claim 8 , wherein the circumferential seal support is a separately formed seal support and is removably securable to a forward portion of the inner case. 
     
     
         11 . The case assembly of  claim 10 , wherein the circumferential seal support has a bulk modulus value lower than a bulk modulus value of the inner case. 
     
     
         12 . The case assembly of  claim 8 , wherein the meshing ring is disposed axially adjacent to an adjacent turbine rotor upstream of the inner case assembly. 
     
     
         13 . The case assembly of  claim 12 , wherein the meshing ring engages a pocket formed on an aft end of the adjacent turbine rotor. 
     
     
         14 . The case assembly of  claim 8 , wherein the seal carrier is configured to support a piston ring seal in conjunction with a vane ring disposed radially adjacent to the case assembly. 
     
     
         15 . A seal support comprising:
 a substantially cylindrical body;   a seal carrier disposed circumferentially around an outer surface of the body; and   a meshing ring extending axially forward of the seal carrier.   
     
     
         16 . The seal support of  claim 15 , wherein the circumferential seal support is configured to have a stiffness value in a range between about 50% to about 80% of a stiffness value of a complementary inner case element. 
     
     
         17 . The seal support of  claim 15 , wherein the seal support is formed integrally with an inner case element. 
     
     
         18 . The seal support of  claim 15 , wherein the meshing ring is disposed axially adjacent to an adjacent turbine rotor upstream of the seal support. 
     
     
         19 . The seal support of  claim 18 , wherein the meshing ring engages a pocket formed on an aft end of the adjacent turbine rotor. 
     
     
         20 . The seal support of  claim 15 , wherein the seal carrier is configured to support a piston ring seal in conjunction with a vane ring radially outward of the seal support.