Mid turbine frame system for gas turbine engine
AssigneePratt & Whitney Canada Corp.
InventorsEric DUROCHER, John PIETROBON, Lam NGUYEN
Life of this patent
Estimating the term…
Abstract
A gas turbine engine has an engine casing component, such as a mid turbine frame system, which may includes an outer case surrounding a spoke or strut casing. Load transfer spokes of the spoke casing extend between the outer case and an inner case of the spoke casing. A bearing housing supported by the engine casing may include a fuse arrangement for isolating bearing seizure loads from the engine casing. A seal arrangement may be provided to centralize the rotors after the fuse fails. The mid turbine frame may be provided to have a desired flexibility through the configuration of the casing and bearings in design.
Claims17
A gas turbine engine comprising an annular engine casing having at least one annular bearing support leg extending inwardly of the casing, the bearing support leg supporting a main shaft bearing assembly about a main shaft of the engine, the bearing support leg extending as a hollow cone from the engine casing to an axially extending bearing support to which the bearing assembly is mounted, the bearing support leg including a mechanical fuse portion between the bearing support and the engine casing, the fuse portion configured to fail if a torsional load through the fuse portion exceeds a predetermined maximum torsional load, the mechanical fuse provided by an area of reduced cross-section relative to a remainder of the bearing support leg, the bearing support leg further including a seal housing support mounted to the bearing support leg between the fuse portion and the engine case, the seal support housing having a seal mounted thereto extending between the seal support housing and the engine main shaft, the seal configured to substantially centralize the main shaft after the fuse portion fails.
A gas turbine engine having concentric main shafts and a mid turbine frame system, the gas turbine engine defining a central axis, the mid turbine frame comprising:
- an annular outer case having at least three spokes extending inwardly from the outer case to an annular inner support case, the inner support case including a first axially-extending cylindrical wall to which the spokes are mounted, a first truncated conical section smoothly connected to the first cylindrical wall and extending axially forwardly therefrom to a second truncated conical section, the second truncated conical section smoothly connected to the first truncated conical section and extending axially rearwardly therefrom to a second axially-extending cylindrical wall disposed coaxially within the first cylindrical wall, the first and second cylindrical walls extending from the respected truncated conical walls to respective free ends, the first cylindrical wall, the first truncated conical section, the second truncated conical section and the second cylindrical wall co-operating to provide a substantially axially extending U-shape when viewed in axial cross-section, the second cylindrical wall having a first and second frustoconcial bearing support legs extending inwardly therefrom to support a first and second bearing assemblies, the first and second bearing support legs extending from a common axial location on the second annular axial wall, the first bearing assembly supporting a first of the concentric shafts and the second bearing assembly supporting a second of the concentric shafts.
Dependencies are inferred from the claim text.