Abstract: A system includes a variable displacement pump (VDP) with an inlet and an outlet, a fixed displacement motor (FDM) with an inlet and an outlet. A first line connects the outlet of the VDP to the inlet of the FDM. A second line connects the outlet of the FDM to the inlet of the VDP. A crossover line is in fluid communication between the first and second lines, with a valving system in the crossover line configured so that the flow through the crossover line can switch directions to allow a change in power flow direction between the FDM and the VDP.

Abstract: A hybrid drive system can include a shaft, an electrical machine comprising a rotor and a stator, and a mechanical disconnect system connecting the rotor to the shaft. The mechanical disconnect system is configured to mechanically connect the rotor to the shaft in a first state and to mechanically disconnect the rotor from the shaft in a second state such that rotor does not drive the shaft or such that the rotor is not driven by the shaft. The rotor can be a permanent magnet rotor, for example.

Abstract: An integrated turbo-compressor includes a compressor with a compressor outlet, a turbine with a turbine inlet, the turbine operatively connected to the compressor by an interconnect shaft, and a compounding drive. The compounding drive is connected to the turbine and has a variable gear ratio and an output member, the variable gear ratio coupling the turbine to the output member to compound output of an internal combustion engine using energy recovered from an exhaust flow received from the internal combustion engine and in excess of energy required to compress combustion air provided to the internal combustion engine. Internal combustion engines, aircraft, and methods of compounding output of internal combustion engines are also described.

Abstract: A compounding drive includes an input member, an epicyclical gear arrangement connected to the input member, an output member connected to the epicyclical gear arrangement, and a hydraulic pump/motor set. The hydraulic pump/motor set connects the epicyclical gear arrangement to the output member through an overrunning clutch for unidirectional communication of mechanical rotation between the input member and the output member. Engine arrangements, aircraft, and methods of compounding internal combustion engines are also described.

Abstract: A hybrid drive system can include a shaft, an electrical machine comprising a rotor and a stator, and a mechanical disconnect system connecting the rotor to the shaft. The mechanical disconnect system is configured to mechanically connect the rotor to the shaft in a first state and to mechanically disconnect the rotor from the shaft in a second state such that rotor does not drive the shaft or such that the rotor is not driven by the shaft. The rotor can be a permanent magnet rotor, for example.

Abstract: A hybrid drive system can include a shaft, an electrical machine comprising a rotor and a stator, and a mechanical disconnect system connecting the rotor to the shaft. The mechanical disconnect system is configured to mechanically connect the rotor to the shaft in a first state and to mechanically disconnect the rotor from the shaft in a second state such that rotor does not drive the shaft or such that the rotor is not driven by the shaft. The rotor can be a permanent magnet rotor, for example.

Abstract: A hybrid drive system can include a shaft, an electrical machine comprising a rotor and a stator, and a mechanical disconnect system connecting the rotor to the shaft. The mechanical disconnect system is configured to mechanically connect the rotor to the shaft in a first state and to mechanically disconnect the rotor from the shaft in a second state such that rotor does not drive the shaft or such that the rotor is not driven by the shaft. The rotor can be a permanent magnet rotor, for example.

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.

Abstract: A system for relieving pressure from within a generator casing can include a generator shaft defining a shaft channel therein and at least one rotating valve disposed within the shaft channel of the generator shaft and in fluid communication with an interior of the generator casing and the atmosphere. The rotating valve is configured to allow fluid within the generator casing to flow through the generator shaft to the atmosphere in an open state and while rotating. The rotating valve is configured to prevent fluid within the generator casing from flowing in a closed state.

Abstract: An electrical terminal device adapted to mount to a structure, and including a electrically non-conductive substructure, an electrically non-conductive cover, a heat resistant shroud, and an electric terminal. The substructure is in contact with the structure. The cover is engaged to the substructure. The substructure and the cover define a chamber, and the substructure defines, at least in-part, a sealed passage in communication with the chamber. The heat resistant shroud substantially covers the cover. The cover is substantially located between the shroud and the substructure. The electric terminal is located in the chamber and is attached to the substructure.

Abstract: A seal includes a carbon seal that is disposed about an axis and extends between a first axial end and a second axial end. The second axial end includes a seal surface and a radially outer edge of the seal surface is axially spaced from a radially inner edge of the seal surface along the axis.

Abstract: A sun gear for an integrated drive generator (IDG) includes a sun gear body having an outer diametric edge and an inner diametric wall. The outer diametric edge includes 33 gear teeth.

Abstract: An electrical terminal device adapted to mount to a structure, and including a electrically non-conductive substructure, an electrically non-conductive cover, a heat resistant shroud, and an electric terminal. The substructure is in contact with the structure. The cover is engaged to the substructure. The substructure and the cover define a chamber, and the substructure defines, at least in-part, a sealed passage in communication with the chamber. The heat resistant shroud substantially covers the cover. The cover is substantially located between the shroud and the substructure. The electric terminal is located in the chamber and is attached to the substructure.

Abstract: An automatic disconnect coupling includes a retainer and a biasing member. The biasing member is coupled to the retainer and is arranged to communicate excitation from a generator input member to the retainer. The retainer and the biasing member have a fundamental frequency tuned to the rotational speed of the generator input member to automatically disconnect the input member from a drive member when rotating unbalance of the input member exceeds a predetermined level.

Abstract: A generator assembly includes a generator shaft defining an interior vent space. A valve assembly is positioned within the vent space configured to selectively allow venting of air through the generator shaft. A radial vent is positioned within the valve assembly configured to prevent oil from flowing through the vent space during operation and release air through the vent space during shutdown.

Abstract: An automatic disconnect coupling includes a retainer and a biasing member. The biasing member is coupled to the retainer and is arranged to communicate excitation from a generator input member to the retainer. The retainer and the biasing member have a fundamental frequency tuned to the rotational speed of the generator input member to automatically disconnect the input member from a drive member when rotating unbalance of the input member exceeds a predetermined level.

Abstract: A seal assembly includes a first sealing ring defining a plurality of circumferentially spaced depressions configured to form a lift off seal with the first sealing ring rotating and to prevent leakage radially with the first sealing ring at rest. At least one ventilation channel extends from a respective edge of one of the depressions to an edge of the first sealing ring and is configured to relieve pressure with the first sealing ring at rest. The first sealing ring can have an inner diameter and an outer diameter such that the plurality of depressions are defined between the inner and outer diameters.

Abstract: Embodiments herein relate to piece-part, sub-assembly, assembly, and component levels of a differential composed of a sun gear configuration and utilized in an integrated drive generator. An integrated drive generator is a hydro-mechanical transmission that drives a synchronous salient pole generator. The integrated drive generator is a constant speed output, variable speed input transmission that includes the differential and a hydraulic unit. In general, the integrated drive generator utilizes the variable speed input from an accessory gear box of an engine to drive or control a hydraulic unit, which in turn drives or controls a churn leg member of the differential. As the differential is driven, speeds of each speed member of the differential are then summed to generate the constant speed output to drive the synchronous salient pole generator.

Abstract: A planet gear for an integrated drive generator includes a planet gear body having an outer diametric surface provided with fifteen (15) gear teeth. The integrated drive generator can include a housing that surrounds an input system. The input system can be operatively coupled to a variable speed drive source. The integrated drive generator can also include a generator and an epicyclic differential gear system.

Abstract: Embodiments herein relate to piece-part, sub-assembly, assembly, and component levels of a differential composed of a sun gear configuration and utilized in an integrated drive generator. An integrated drive generator is a hydro-mechanical transmission that drives a synchronous salient pole generator. The integrated drive generator is a constant speed output, variable speed input transmission that includes the differential and a hydraulic unit. In general, the integrated drive generator utilizes the variable speed input from an accessory gear box of an engine to drive or control a hydraulic unit, which in turn drives or controls a churn leg member of the differential. As the differential is driven, speeds of each speed member of the differential are then summed to generate the constant speed output to drive the synchronous salient pole generator.