An engine system includes a turbine engine having a high pressure spool and a low pressure spool. A transmission includes an input shaft connected to one of the high pressure spool and the low pressure spool, and an output shaft. A clutch is arranged between the input shaft and the output shaft. A generator is connected to the output shaft. A clutch controller activates the clutch when one of the high pressure spool and the low pressure spool, and the generator are operating at a selected speed range.

A turbine engine with a turbine core that includes a compressor section having a compressor coupled to a high speed shaft, a combustion section, a turbine section having a high pressure turbine coupled to the high speed shaft and a low pressure turbine coupled to a low speed shaft, and a nozzle section. The turbine engine also includes an electric machine that can operate in a first starting mode and a second generating mode.

A gas turbine engine includes a compressor section and a turbine section. A first spool is rotatable with a first turbine of the turbine section and a first compressor of the compressor section. Additionally, a second spool is rotatable with a second turbine of the turbine section and a second compressor of the compressor section. An electric machine is positioned at least partially inward of the core air flowpath of the gas turbine engine along a radial direction of the gas turbine engine. Additionally, the exemplary gas turbine engine includes a gear assembly mechanically coupled to both the first spool and the second spool, such that the first and second spools may each drive the electric machine.

A redundant oil and fuel pumping system for use with a gas turbine engine. The pumping system includes a plurality of power supplies, a fuel system and an oil system. The fuel system pump being driven by electric motors controlled via variable frequency drives powered by the plurality of power supplies. The oil system pump being driven by electric motors controlled via variable frequency drives powered by the plurality of power supplies.

A propulsion system includes a first compressor in fluid communication with a fluid source. A first conduit is coupled to the first compressor, and a heat exchanger is in fluid communication with the first compressor via the first conduit. A second conduit is positioned proximal to the heat exchanger. A combustor is in fluid communication with the heat exchanger via the second conduit and is configured to generate a high-temperature gas stream. A third conduit is coupled to the combustor, and a first thrust augmentation device is in fluid communication with the combustor via the third conduit. The heat exchanger is positioned within the gas stream generated by the combustor.

A system comprises a gas turbine engine. The gas turbine engine has a flow diffuser system, a combustor, a modified compressor section, and a turbine coupled to a shaft. The system includes a low pressure intercooled compressor, a high pressure intercooled compressor, a recuperator, and a compressed air storage tank. The compressed air storage tank is in selective fluid communication with the low pressure intercooled compressor via the high pressure intercooled compressor, and the recuperator. The high pressure intercooled compressor is configured to selectively receive compressed air from the low pressure intercooled compressor and is further configured to selectively compress the compressed air to a highly compressed air for storage in the compressed air storage tank. Each of the compressed air storage tank and the low pressure intercooled compressor is selectively and fluidly coupled to the gas turbine engine.

Systems and methods for preventing rotation of an ESP motor when the motor is not powered on, thereby preventing the motor from acting as a generator when fluid flowing through the pump section of the ESP applies a torque to the motor. In one embodiment, an ESP has a motor section, a pump section. The ESP may include a directional coupling that allows unidirectional rotation between the motor shaft and a pump shaft of the pump section, and a directional lock that allows unidirectional rotation between the motor shaft and a housing of the motor section. The directional coupling and directional lock allow the pump shaft to freewheel in the forward direction without causing the motor shaft to rotate, and prevent the pump shaft and motor from rotating in the reverse direction.

A method and decoupler for disengaging an output shaft from an engine in a back drive event with a backdrive decoupler. The backdrive decoupler includes a threaded shaft and a retention mechanism selectively coupling the output shaft to the threaded shaft. In a backdrive event, the decoupler decouples the output shaft from a drive shaft.

A variable speed pumping system, for an aircraft, comprising: a first electrical machine, the first electrical machine comprising an electrical machine rotor shaft mechanically connected to an engine of the aircraft and electrical machine stator coils; an electric pump motor-generator, the electric pump motor-generator comprising an electric pump rotor shaft mechanically connected to the electrical machine rotor shaft via a one way drive arrangement and electric pump stator coils; wherein the electric pump rotor shaft is mechanically connected to a fluid pumping system.

A gas turbine engine includes a fan and a first drive shaft connected to the fan. A fan drive gear box connects the first drive shaft to a second drive shaft and is configured to allow the first drive shaft to rotate at a different speed than the second drive shaft. The gas turbine engine also includes a sprag clutch disposed circumferentially around the first shaft and connected to the first drive shaft. The sprag clutch is configured to allow rotation of the first drive shaft and the fan in a first direction while prohibiting rotation of the fan and the first drive shaft in a second direction.