US Patent 8430622 Turbofan gas turbine engine

In a turbofan gas turbine engine, a fan shaft is rotatably mounted and radially supported by a bearing in a bearing support structure supported from a fixed engine structure by radially frangible bolts and radially extending spokes. The radially inner ends of the radially extending spokes are mounted on a common member that engages the bearing support structure. The radially outer ends of the radially extending spokes are mounted on a fixed engine structure located radially outwardly of the bearing support structure. The radially extending spokes are held in tension and include a super elastic material to exert a radially inward restoring force on the bearing support structure, subsequent to any radial excursion of at least part of the fan shaft relative to an engine rotational axis (X) following any fracture of the frangible bolts.