Interstage seal assembly for gas turbine engine

A seal assembly for a turbine engine including adjacent upstream and downstream rotating rotor disks supporting respective rows of blades, a row of stationary vanes located between said rows of blades, and axially extending forward and rearward rotor arms supported on said upstream and downstream rotor disks, respectively, and located radially inward from said blades, the seal assembly comprising:

• an annular labyrinth seal holder supported on a radially inner end of said vanes and having a radially inner surface and a downstream axially facing surface;
• a plurality of radially extending labyrinth seal elements supported on said radially inner surface of said labyrinth seal holder in axially spaced relation to each other, and said labyrinth seal elements are all the same length from said inner surface of said labyrinth seal holder to an end of said labyrinth seal elements, distal from said labyrinth seal holder;
• a brush seal assembly supported to said labyrinth seal holder downstream from said labyrinth seal elements and having a radially inner surface, said brush seal assembly including a brush seal holder and a brush seal extending radially to said rearward rotor arm, said brush seal holder being bolted to said downstream facing surface of said labyrinth seal holder;
• a seal plate defining a detachable labyrinth seal element extending radially inward from said labyrinth seal holder to said rearward rotor arm at a location upstream of said brush seal, said seal plate being sandwiched between said labyrinth seal holder and said brush seal holder;
• and
• said rotor arms including seal surfaces that face radially outward toward said inner surfaces of said labyrinth seal holder and said brush seal holder, said seal surfaces being smooth surfaces, extending in the axial direction, defining a constant radial distance from said seal surface on said forward and rearward rotor arms to said inner surface of said labyrinth seal holder and to said inner surface of said brush seal holder;
• wherein said brush seal assembly is mounted to said labyrinth seal holder by a plurality of circumferentially spaced bolts extending through said brush seal holder and said labyrinth seal holder, and said bolts extend through holes in said seal plate to circumferentially position said seal plate.