Embodiments of systems and methods for operating a gas turbine engine defining a bowed rotor condition are generally provided. The systems and methods include rotating a rotor assembly defining a bowed rotor condition from approximately zero revolutions per minute (RPM) to within a bowed rotor mitigation speed range, in which the bowed rotor mitigation speed range is defined by a lower speed limit greater than zero RPM and an upper speed limit less than or equal to an idle speed condition of the gas turbine engine; applying a load at the rotor assembly via an energy storage device; adjusting the load to limit rotational speed or acceleration of the rotor assembly to within the bowed rotor mitigation speed range for a period of time; and removing the load to enable rotation of the rotor assembly to the idle speed condition following the period of time.

A composite flywheel (13), comprising a primary flywheel (15) integral with an input shaft (31) and a secondary flywheel (17) coaxial with the primary flywheel (15). The secondary flywheel (17) and the primary flywheel (15) are constrained so that they can rotate freely with respect to each other. A coupling device (61) is further provided, adapted selectively to: transmit power from the input shaft (31) to the secondary flywheel (17); and disengage the secondary flywheel (17) from the input shaft (31).

A clutch assembly for an aircraft drive wheel drive system to move an aircraft independently on the ground is provided. The clutch is mounted within an aircraft drive wheel to be operatively engaged and disengaged to selectively actuate a roller traction or other drive system to activate a non-engine drive means to drive the wheel and the aircraft. One embodiment of the clutch assembly includes a plurality of pivoted sprag elements selectively activatable to transmit torque between inner and outer clutch members and activate the drive wheel drive system. The clutch assembly may also include mating crown gear and straight gear elements integrated with the drive system to reduce stresses on the drive system as the drive means is actuated. Various arrangements of sprags and clutch assembly components may be provided to monitor and selectively control disengagement of the clutch assembly and communicate disengagement to selectively prevent drive system actuation.

The hydraulic power recovery turbine comprises a casing and a rotor arranged for rotation in the casing. The rotor comprises a rotor shaft and at least one impeller mounted on the rotor shaft. The rotor shaft is supported by bearings arranged in respective bearing housings. The drive-end bearing housing further houses a clutch, which connects the rotor shaft to an output shaft of the hydraulic power recovery turbine extending from the drive-end bearing housing.

An apparatus for connecting a rotational drive member to a rotational driven member brakes rotation when either the torque transmitted between the members exceeds a predetermined torque limit or the rotational speed of the drive member exceeds a predetermined rotational speed limit. The apparatus includes a torque limiter configured to actuate a braking mechanism or disconnect transmission when the torque limit is exceeded, and an over-speed governor configured to trigger the torque limiter when the rotational speed of the input element exceeds the rotational speed limit. The over-speed governor may trigger the torque limiter by reducing the torque limit of the torque limiter, or by introducing rotational drag in the apparatus to increase transmitted torque.

A flywheel is attached to a shaft of a turbine. As the shaft rotates, the flywheel swings outwards away from the shaft and regulates the angular velocity of the rotating shaft. In an embodiment, there are multiple flywheels attached to the shaft. In another embodiment there is a first flywheel that controls a second flywheel. In another embodiment, the flywheel has adjustable or centrifugal displacement of counterbalanced masses for effective rotational diameter with effective rotational balance. In another embodiment, a small pilot centrifugal displacement flywheel may control a clutch by rotational velocity and may include a hysteresis control. An example of a clutch may limit that degree to which the arms of the flywheel may be extended and/or retracted. In another embodiment, a small pilot centrifugal displacement flywheel controls the hysteresis of a centrifugal flywheel displacement.

A flywheel is attached to a shaft of a turbine. As the shaft rotates, the flywheel swings outwards away from the shaft and regulates the angular velocity of the rotating shaft. In an embodiment, there are multiple flywheels attached to the shaft. In another embodiment there is a first flywheel that controls a second flywheel. In another embodiment, the flywheel has adjustable or centrifugal displacement of counterbalanced masses for effective rotational diameter with effective rotational balance. In another embodiment, a small pilot centrifugal displacement flywheel may control a clutch by rotational velocity and may include a hysteresis control. An example of a clutch may limit that degree to which the arms of the flywheel may be extended and/or retracted. In another embodiment, a small pilot centrifugal displacement flywheel controls the hysteresis of a centrifugal flywheel displacement.

One aspect is a wrap spring clutch with a rotatable input and a spring having a first and a second end and having an equilibrium state and a flexed state, the spring engaged with the input through one of the first and second ends such that the spring rotates with the input and with an input torque transmitted exclusively through one of the first and second ends when the input rotates. A damper mechanism is engaged with one of the first and second ends such that the damper mechanism causes the spring to change from its equilibrium to its flexed state when the input transitions from stationary to rotational, and such that the damper mechanism allows the spring to change from its flexed to its equilibrium state when the input transitions from rotational to stationary. A rotatable output is positioned relative to the spring such that the output synchronously rotates with the input when the spring is in its flexed state and rotates independently of the input when the spring is in its equilibrium state.

The present clutch operating device includes a drive motor and a speed reduction mechanism. The speed reduction mechanism includes a link bar receiving a driving force of the drive motor, a clutch lever that is rotatably coupled to a first end of the link bar while being disposed rotatably with respect to a second cover, and a main roller that is rotatably attached to a second end of the link bar while being disposed to roll on the second cover.

The present clutch operating device includes a drive motor and a speed reduction mechanism. The speed reduction mechanism includes a link bar receiving a driving force of the drive motor, a clutch lever that is rotatably coupled to a first end of the link bar while being disposed rotatably with respect to a second cover, and a main roller that is rotatably attached to a second end of the link bar while being disposed to roll on the second cover.