The Boeing Company
Mechanical flywheel for bowed rotor mitigation

Abstract:

A mechanical flywheel used to power an aircraft system. In one example, the flywheel is used to rotate a rotor shaft in the aircraft's engine and prevent bowing of the rotor shaft caused by a thermal gradient. In another example, the mechanical flywheel provides electrical power at peak demand times. In yet another example, the flywheel is used as a load source or sink by the engine's control system so as to aid engine operability and engine acceleration rates during abnormal flight conditions.