An engine assembly is provided that includes a geartrain, a device and a fluid damper. The geartrain is configured as or otherwise includes an epicyclic gear system. A first component of the geartrain is rotatable about an axis. The device is configured to brake and/or lock rotation of the first component of the geartrain about the axis. The device is configured as or otherwise includes a device structure. The fluid damper engages the device structure. The fluid damper is configured to damp vibrations in the device.

An aircraft assembly includes a geartrain with a first gear system and a second gear system. The first gear system includes a first sun gear, a first ring gear, a plurality of first intermediate gears and a first carrier. The first sun gear and the first ring gear are each rotatable about an axis. The first intermediate gears are between and meshed with the first sun gear and the first ring gear. Each of the first intermediate gears is rotatably mounted to the first carrier. The second gear system is interconnected with the first gear system. The second gear system includes a second sun gear, a second ring gear, a plurality of second intermediate gears and a second carrier. The second intermediate gears are between and meshed with the second sun gear and the second ring gear. Each of the second intermediate gears is rotatably mounted to the second carrier.

Systems, methods, and devices are provided for a turbine driven pump gearbox. A turbine engine may drive a primary shaft having gears. The gears may selectably engage with gears of a secondary shaft that drives a machine (e.g., pump). By changing which gears of the primary shaft engage with which gears of the secondary shaft, a gear ratio may be changed. A power takeoff device (e.g., a generator) may be connected to the primary shaft and may be operated in reverse as a motor to rotate, slow, stop, and/or reverse rotation of the primary shaft. Brakes may be associated with one or more of the primary and secondary shafts. The power takeoff device and one or more of the brakes may be controlled to shift engagement of the shafts between different positions, changing the gear ratio and/or disengaging the shafts from each other.

A turbine engine having a longitudinal centerline axis. The turbine engine including a fan comprising a plurality of fan blades that rotate about the longitudinal centerline axis and a rotational component coupled to the fan. The turbine engine including a fluid circuit for supplying fuel or lubricant to the turbine engine and a hydraulic fan brake coupled to the fluid circuit to prevent rotation of the rotational component, thus preventing rotation of the fan. The hydraulic fan brake including a hydraulic cylinder fluidly coupled to the fluid circuit and a valve coupled to the hydraulic cylinder and having a first valve position that disengages the hydraulic fan brake to allow rotation of the rotational component and a second valve position that engages the hydraulic fan brake to prevent rotation of the rotational component.

An assembly is provided for an aircraft. This assembly includes a geartrain, a first propulsor rotor and a rotating structure. The geartrain includes a sun gear, a ring gear, a plurality of intermediate gears and a carrier. The ring gear circumscribes the sun gear and is rotatable about an axis. Each of the intermediate gears is between and meshed with the sun gear and the ring gear. Each of the intermediate gears is rotatably mounted to the carrier. The carrier is rotatable about the axis. The first propulsor rotor is coupled to the carrier. The rotating structure is coupled to the ring gear. The rotating structure includes a turbine rotor. The rotating structure is configured to drive rotation of the first propulsor rotor through the geartrain.

Systems, methods, and devices are provided for a turbine driven pump gearbox. A turbine engine may drive a primary shaft having gears. The gears may selectably engage with gears of a secondary shaft that drives a machine (e.g., pump). By changing which gears of the primary shaft engage with which gears of the secondary shaft, a gear ratio may be changed. A power takeoff device (e.g., a generator) may be connected to the primary shaft and may be operated in reverse as a motor to rotate, slow, stop, and/or reverse rotation of the primary shaft. Brakes may be associated with one or more of the primary and secondary shafts. The power takeoff device and one or more of the brakes may be controlled to shift engagement of the shafts between different positions, changing the gear ratio and/or disengaging the shafts from each other.

A turbine engine includes a turbo-engine, a fan including a plurality of fan blades that rotate about a longitudinal centerline axis, a rotational component coupled to the fan, a fluid circuit for supplying a fluid to the turbine engine, and a hydraulic fan brake in fluid communication with the fluid circuit. The hydraulic fan brake includes a hydraulic actuator fluidly coupled to the fluid circuit and a brake pad operably coupled to the hydraulic actuator such that the hydraulic actuator moves the brake pad, relative to the rotational component, between a disengaged position, in which the brake pad disengages the rotational component and allows rotation of the rotational component, and an engaged position, in which the brake pad engages the rotational component and prevents rotation of the rotational component, thus preventing rotation of the fan.

A turbine engine has a longitudinal centerline axis. The turbine engine includes a fan, a turbo-engine, and a unidirectional brake. The fan includes a plurality of fan blades that rotate in a first direction about the longitudinal centerline axis. The turbo-engine includes a combustor that combusts compressed air and fuel to generate combustion gases and a low-pressure turbine including a low-pressure shaft. The low-pressure turbine receives the combustion gases to rotate the low-pressure turbine. The fan is coupled to the low-pressure shaft such that rotation of the low-pressure shaft causes the fan to rotate in the first direction. A unidirectional brake is coupled to the low-pressure shaft to prevent rotation of the low-pressure shaft and, thus, the fan in a second direction opposite the first direction.