RTX Corporation
GEARED TURBOFAN WITH FOUR STAR/PLANETARY GEAR REDUCTION

Abstract:

A turbofan engine assembly includes a nacelle and a turbofan engine. The turbofan engine includes a fan, which includes a fan rotor having fan blades, and a nacelle enclosing the fan rotor and the blades. A turbine rotor drives the fan rotor. An epicyclic gear reduction is positioned between the fan rotor and the turbine rotor. The epicyclic gear reduction includes a ring gear, a sun gear, and four intermediate gears that engage the sun gear and the ring gear. A gear ratio of the gear reduction is greater than 3.06. The fan drive turbine drives the sun gear to, in turn, drive the fan rotor.