Abstract: An aircraft oil management system includes a generator, pump, and pump control system. The generator is mechanically coupled to a prime mover via a the rotor shaft and is configured to output three-phase power. The pump is mechanically decoupled from the rotor shaft and delivers oil to the generator. The pump control system drives the pump independent of a rotational speed of the rotor shaft.

Abstract: A generator shaft assembly including a primary shaft, a disconnect shaft housed within the primary shaft, where a first end of the disconnect shaft is configured to couple with the primary mover and a second end of the disconnect shaft is configured to mate with the generator. A retainer ring housed within the primary shaft having at least a landing and a groove on an inner surface thereof and a retainer member positioned between the landing of the retainer ring and an outer surface of the disconnect shaft configured to limit axial motion of the disconnect shaft relative to the primary shaft.

Abstract: A shaft system includes an outer shaft including an inner surface defining a conduit and an inner shaft extending within the conduit. The inner shaft includes a radially extending passage having a first end and a second end. A centrifugal force activated damper extends between the outer shaft and the inner shaft. The centrifugal force activated damper includes a first member arranged between the inner shaft and the inner surface at the first end of the radially extending passage, a second member arranged between the inner shaft and the inner surface at the second end of the radially extending passage, and a connecting member extending through the radially extending passage. Rotation of the shaft system causes the first member and the connecting member to shift away from the second member into the inner surface of the outer shaft.

Abstract: An aircraft power system includes an auxiliary power unit (APU), a transmission unit, and a generator. The APU is configured to output a first APU rotational power in response to determining a first condition and a second APU rotational power in response to a determining a second condition. The transmission unit is configured to receive the first APU rotational output power from the APU. The transmission unit outputs a transmission rotational power based on the first APU rotational output power and outputs the transmission rotational power based on the second APU rotational output power. The generator receives the transmission rotational power and produces an alternating current (AC) voltage having a target frequency based on the transmission rotational power.

Abstract: A jet engine includes a housing, an intake portion leading into the housing, and an exhaust portion leading from the housing. The exhaust portion includes an exhaust duct and a tail cone arranged radially inwardly of the exhaust duct. An engine portion is arranged in the housing between the intake portion and the exhaust portion. A generator is arranged in the tail cone and is operatively connected to the engine portion. A drive shaft extends from the engine portion to the generator. The drive shaft includes a first end coupled to the engine portion, a second end connected to the generator, and an intermediate portion extending therebetween. The intermediate portion includes a cooling passage that extends from the second end toward a terminal end that terminates short of the first end of the drive shaft.

Abstract: A method includes pumping coolant into a cooling system of a generator while the generator is generating electrical power. The method includes regulating flow into the cooling system using a pressure relief valve to recirculate a portion of the coolant back to an inlet of the pump. Using the pressure relief valve includes actuating the pressure relief valve based on input from the cooling system and/or from the generator.

Abstract: An aircraft oil management system includes a generator, pump, and pump control system. The generator is mechanically coupled to a prime mover via a the rotor shaft and is configured to output three-phase power. The pump is mechanically decoupled from the rotor shaft and delivers oil to the generator. The pump control system drives the pump independent of a rotational speed of the rotor shaft.

Abstract: An aircraft power system includes an auxiliary power unit (APU), a transmission unit, and a generator. The APU is configured to output a first APU rotational power in response to determining a first condition and a second APU rotational power in response to a determining a second condition. The transmission unit is configured to receive the first APU rotational output power from the APU. The transmission unit outputs a transmission rotational power based on the first APU rotational output power and outputs the transmission rotational power based on the second APU rotational output power. The generator receives the transmission rotational power and produces an alternating current (AC) voltage having a target frequency based on the transmission rotational power.

Abstract: A torsion shaft assembly includes a torque carrying shaft including a driven end configured for receiving torque input to the torque carrying shaft and a driving end configured for outputting torque output from the toque carrying shaft. The torque carrying shaft includes an axial facing damping interface surface axially between the driven end and the driving end. A friction tube is disposed outboard of the torque carrying shaft. The friction tube is connected at a first axial location to be driven by the torque carrying shaft. The friction tube includes an axial facing damping interface surface that abuts the axial facing damping interface surface of the torque carrying shaft, forming a damping interface to provide frictional dampening against angular vibrations occurring as differential angular displacement between the driven end and the driving end of the torque carrying shaft.

Abstract: An aircraft power system includes an auxiliary power unit (APU), a generator, and a constant speed drive (CSD). The APU drives an APU drive shaft at a first rotational speed during a first condition and a second rotational speed during a second condition. The generator is rotatably coupled to a generator shaft and produces an AC voltage having a target frequency in response to rotation of the generator shaft at a target rotational speed. The CSD unit receives the first rotational speed from the APU drive shaft and rotates the generator shaft at the target rotational speed based on the first rotational speed. The CSD further receives the second rotational speed from the APU drive shaft and rotates the generator shaft at the target rotational speed based on the second rotational speed.

Abstract: Tail cone assemblies for gas turbine engines are described. The tail cone assemblies include a generator housing having an electrical connector, the generator housing defining a longitudinal axis. A first casing is arranged radially outward from the generator housing relative to the longitudinal axis and a second casing arranged radially outward from the first casing relative to the longitudinal axis. A hollow strut extends radially between the first casing and the second casing and defining an interior cavity, the hollow strut located circumferentially relative to the longitudinal axis at a location radially aligned with the electrical connector of the generator housing. An electrical conductor is arranged within the interior cavity of the hollow strut and an adapter is configured to electrically connect the electrical conductor with the electrical conductor.

Abstract: A vibration damping assembly for use with a second shaft nested within an interior of a first shaft is provided including a collar rotatable with the first shaft, and a cage rotatable with the second shaft and having at least one window formed therein. The collar and the cage are mounted concentrically. At least one damping mechanism is positioned within the at least one window. The at least one damping mechanism includes at least one flyweight and at least one support wedge. The at least one flyweight movable relative to the cage to frictionally engage an adjacent surface of the collar.

Abstract: A jet engine includes a housing, an intake portion leading into the housing, and an exhaust portion leading from the housing. The exhaust portion includes an exhaust duct and a tail cone arranged radially inwardly of the exhaust duct. An engine portion is arranged in the housing between the intake portion and the exhaust portion. A generator is arranged in the tail cone and is operatively connected to the engine portion. A drive shaft extends from the engine portion to the generator. The drive shaft includes a first end coupled to the engine portion, a second end connected to the generator, and an intermediate portion extending therebetween. The intermediate portion includes a cooling passage that extends from the second end toward a terminal end that terminates short of the first end of the drive shaft.

Abstract: A lamination for use in an integrated drive generator is formed from a plurality of plates having a body including a pair of opposed cylindrical surfaces. Non-cylindrical ditches are defined circumferentially intermediate the pair of cylindrical surfaces. A plurality of passages are formed in an outer periphery of the cylindrical surfaces including relatively large holes extending through a slot to the outer periphery. Grooves are formed intermediate the relatively large holes.

Abstract: A torsion shaft assembly includes a torque carrying shaft including a driven end configured for receiving torque input to the torque carrying shaft and a driving end configured for outputting torque output from the toque carrying shaft. The torque carrying shaft includes an axial facing damping interface surface axially between the driven end and the driving end. A friction tube is disposed outboard of the torque carrying shaft. The friction tube is connected at a first axial location to be driven by the torque carrying shaft. The friction tube includes an axial facing damping interface surface that abuts the axial facing damping interface surface of the torque carrying shaft, forming a damping interface to provide frictional dampening against angular vibrations occurring as differential angular displacement between the driven end and the driving end of the torque carrying shaft.

Abstract: A torsion shaft assembly includes a torque carrying shaft including a driven end configured for receiving torque input to the torque carrying shaft and a driving end configured for outputting torque output from the toque carrying shaft. The torque carrying shaft includes an axial facing damping interface surface axially between the driven end and the driving end. A friction tube is disposed outboard of the torque carrying shaft. The friction tube is connected at a first axial location to be driven by the torque carrying shaft. The friction tube includes an axial facing damping interface surface that abuts the axial facing damping interface surface of the torque carrying shaft, forming a damping interface to provide frictional dampening against angular vibrations occurring as differential angular displacement between the driven end and the driving end of the torque carrying shaft.

Abstract: A torsion shaft assembly includes a torque carrying shaft including a driven end configured for receiving torque input to the torque carrying shaft and a driving end configured for outputting torque output from the toque carrying shaft. The torque carrying shaft includes an axial facing damping interface surface axially between the driven end and the driving end. A friction tube is disposed outboard of the torque carrying shaft. The friction tube is connected at a first axial location to be driven by the torque carrying shaft. The friction tube includes an axial facing damping interface surface that abuts the axial facing damping interface surface of the torque carrying shaft, forming a damping interface to provide frictional dampening against angular vibrations occurring as differential angular displacement between the driven end and the driving end of the torque carrying shaft.

Abstract: A terminal assembly of an electric machine includes an electric machine housing including a terminal opening defined in the electric machine housing. A conductive terminal extends through the terminal opening, from an inside of the electric machine housing to an outside of the electric machine housing. An insulator is located at the terminal. The insulator is positioned between the terminal and a housing wall of the terminal opening. The insulator is sized and configured for installation into the terminal opening after installation of the terminal in the terminal opening.

Abstract: A multispeed turbomachine transmission can include an input shaft and a plurality of input shaft gears disposed on the input shaft. The transmission can include one or more clutch shafts, one or more clutch shaft input gears disposed on the one or more clutch shafts, each meshed with at least one of the plurality of input shaft gears, at least one clutch shaft output gear mounted to each clutch shaft, a clutch connected to each clutch shaft and configured to selectively connect the one or more clutch shaft input gears to the at least one clutch shaft output gear. The transmission can include an output shaft and at least one output shaft gear connected to the output shaft and meshed with the at least one clutch shaft output gear.

Abstract: A sealing assembly of an input shaft includes a support structure, a bearing assembly, and an input seal. The input seal including an input seal housing having a first portion and a second portion. The first portion is arranged adjacent the bearing assembly. At least one face plate anti-rotation pin is coupled to the input seal housing and positioned adjacent the input shaft. A face plate is positioned adjacent the second portion. The face plate is configured to directly contact the input shaft.