Patent ID: 8402742

Claim:
A gas turbine engine having an axis comprising: a first annular gas flow path; a second annular gas flow path located radially outboard of the first gas flow path; a third annular gas flow path located radially outboard of the second gas flow path; a first rotatable set of blades extending radially from the axis and operative to interact with gas moving along the first gas flow path and the second gas flow path; a second rotatable set of blades extending radially from the axis and located downstream of the first set of blades and operative to interact with gas moving along the first gas flow path, the second gas flow path and the third gas flow path; a differential gear assembly having a plurality of outputs operative to receive a torque input from an engine shaft and differentially apply the outputs from the torque input to the first set of blades and the second set of blades; the differential gear assembly having a first epicyclic gear and a second epicyclic gear which are axially spaced from one another and driven by a single sun gear; and wherein the first annular gas flow path, the second annular gas flow path, and the third annular gas flow path are partitioned from one another at a location upstream of the second rotatable set of blades.