Engine mounts provide for the transfer of engine thrust to the aircraft, but the first engine mount, or in a case of a single plane mount engine, the single plane mount, also generally transfers loads onto the gas turbine engine during operation. The engine includes various support components which are directly or indirectly connected to the first mount or single plane mount and to the engine core, defining various load paths for transmission of propeller loads from the mount. The propeller loads can thus potentially cause deflections of such support components.
The high pressure turbine rotor located at the exit of the combustor is usually surrounded by a shroud on which cooling air is circulated, for example through impingement cooling. A tight tip clearance must generally be maintained between the shroud and the tip of the rotor blades. The shroud is generally attached to and located by the adjacent vane ring to limit deflections and movement of the shroud during operation. However, air leakage may occur, for example between the shroud and the adjacent turbine support case supporting other stators of the turbine section. The possible tip clearance may also be limited. The structure necessary for attachment of the shroud to the adjacent vane may also impede impingement cooling of the shroud.
USPTO Backgrounds
USPTO Backgrounds