Abstract: A gas turbine engine is provided, with a compressor section including a fan driven by an engine shaft about a rotation axis, the engine shaft defining a bore extending axially therethrough from a hot gas inlet to a hot gas outlet, the hot gas inlet located downstream of the compressor section, a nose cone mounted to the fan and defining a cavity therewithin, a first impeller and a second impeller mounted within the cavity, the first impeller having an inlet facing a forward direction of the gas turbine engine, the inlet of the first impeller in fluid flow communication with an air inlet defined in an outer surface of the nose cone, the second impeller having an inlet facing a rearward direction of the gas turbine engine, the inlet of the second impeller being in fluid flow communication with the hot gas outlet of the engine shaft.

Abstract: A gas turbine engine is provided, with a compressor section including a fan driven by an engine shaft about a rotation axis, the engine shaft defining a bore extending axially therethrough from a hot gas inlet to a hot gas outlet, the hot gas inlet located downstream of the compressor section, a nose cone mounted to the fan and defining a cavity therewithin, a first impeller and a second impeller mounted within the cavity, the first impeller having an inlet facing a forward direction of the gas turbine engine, the inlet of the first impeller in fluid flow communication with an air inlet defined in an outer surface of the nose cone, the second impeller having an inlet facing a rearward direction of the gas turbine engine, the inlet of the second impeller being in fluid flow communication with the hot gas outlet of the engine shaft.

Abstract: An assembly of a shaft and a rotor disk comprises a shaft configured to rotate at a first angular speed S1 about a shaft rotational axis. A bladed rotor includes a disk adapted to support blades, the disk having a rotor rotational axis, the disk being integrally and monolithically formed with at least one rotor gear, the rotor gear being concentric with the disk about the rotor rotational axis. A gear train includes a shaft gear fixed to the shaft, the gear train having at least one gear meshed with the rotor gear for imparting a rotation to the bladed rotor at angular speed S2, wherein the angular speed S1?the angular speed S2.