RTX Corporation
Flexible coupling for geared turbine engine

Abstract:

A gas turbine engine includes a fan, a fan shaft coupled with the fan and arranged along an engine central axis, and a frame supporting the fan shaft. The frame defines a lateral frame stiffness (LFS). An epicyclic gear system is coupled to the fan shaft, and a non-rotatable flexible coupling and a rotatable flexible coupling support the epicyclic gear system. The non-rotatable flexible coupling and the rotatable flexible coupling each have a stiffness of a common stiffness type under a common type of motion with respect to the engine central axis. The stiffness is defined with respect to the LFS. The stiffness of the rotatable flexible coupling is greater than the stiffness of the non-rotatable flexible coupling.