Abstract: A gas turbine engine including a first rotor assembly comprising a first drive shaft extended along a longitudinal direction; a housing coupled to the first rotor assembly to provide rotation of the first rotor assembly around an axial centerline; a first accessory assembly, wherein the first accessory assembly sends and/or extracts energy to and from the first rotor assembly; and a first clutch assembly disposed between the first rotor assembly and the first accessory assembly. The first clutch assembly engages and disengages the first rotor assembly to and from the first accessory assembly.

Abstract: A power transmission system includes a shaft, a stator disposed within the shaft and substantially concentric with the shaft; and at least one supporting element positioned between the stator and the shaft and configured to support the shaft on the stator to reduce a vibration of the shaft and allow the shaft to rotate relative to the stator. A gas turbine engine including the power transmission system is also described.

Abstract: A fan rotor apparatus includes: a rotatable fan disk defining a central aperture and carrying an array of airfoil-shaped fan blades around its periphery, the disk having a forward end and an aft end; and an annular, generally axially-extending forward fan shaft extending through the aperture and coupled to the fan disk for rotation therewith, where the forward fan shaft joins the fan disk at or near the forward end.