Abstract: A method and a turbine rotor system for reducing over-speed potential of a turbine of a gas turbine engine involve mechanically connecting the turbine to at least two mechanical loads via first and second mechanical drives extending in opposite directions from the turbine.

Abstract: An aircraft power plant has a hybrid propulsion system having an electric motor, a combustion engine, an output shaft drivingly connectable to a thrust generator, a compressor, and a transmission having a first transmission drive path and a second transmission drive path, the combustion engine and the output shaft in driving engagement with the first transmission drive path, the electric motor selectively drivingly engageable to the compressor via either the first drive path or via the second drive path.

Abstract: An aircraft power plant has: a hybrid propulsion system having an electric motor, an output shaft drivingly connectable to a thrust generator, a combustion engine, a compressor, and a transmission having a first transmission drive path and a second transmission drive path selectively engageable to the first transmission drive path, the electric motor and the compressor in driving engagement with the first transmission drive path, the combustion engine and the output shaft in driving engagement with the second transmission drive path.

Abstract: An aircraft power plant has a hybrid propulsion system having an electric motor, an output shaft drivingly connectable to a thrust generator, a combustion engine, a compressor, and a planetary gear train having an Auxiliary Power Unit (APU) mode in which the electric motor is in driving engagement with the compressor via the planetary gear train while the combustion engine is disengaged from the output shaft, and a propulsion mode in which the combustion engine and the electric motor are in driving engagement with the output shaft via the planetary gear train.

Abstract: A hybrid propulsion system includes a heat engine configured to drive a heat engine shaft. An electric motor is configured to drive an electric motor shaft. A transmission system includes at least one gearbox. The transmission system is configured to receive rotational input power from each of the heat engine shaft and the electric motor shaft and to convert the rotation input power to output power.

Abstract: A hybrid propulsion system includes a heat engine configured to drive a heat engine shaft. An electric motor configured to drive a motor shaft. A transmission system is connected to receive rotational input power from each of the heat engine shaft and the motor shaft and to convert the rotation input power to output power. A first lubrication/coolant system is connected for circulating a first lubricant/coolant fluid through the heat engine. A second lubricant/coolant system in fluid isolation from the first lubrication/coolant system is connected for circulating a second lubricant/coolant fluid through the electric motor.

Abstract: A multi-spool gas turbine engine comprises a low pressure (LP) spool and a high pressure (HP) spool independently rotatable about a central axis extending through an accessory gear box (AGB). The LP spool has an LP compressor, which is axially positioned between the HP compressor of the HP spool and the AGB. A tower shaft drivingly connects the HP spool to the AGB.

Abstract: A turbo propeller engine comprises a housing circumferentially extending around a longitudinal axis and disposed around a gearbox. The turbo propeller engine includes a propeller outside of the housing and a shaft surrounded in part by the housing and extending along the longitudinal axis. The shaft has a front end and a rear end. The propeller is mounted to the front end. The rear end is in a driven engagement with an output of the gearbox. The shaft is rotatably supported by a first bearing and by a second bearing separated from the first bearing by an axial distance along the longitudinal axis. The first and second bearings are disposed on opposite sides of the gearbox. The first bearing is disposed between the shaft and the housing, the second bearing is disposed between the housing and a component of the gearbox to rotatingly support the component of the gearbox.

Abstract: A multi-spool gas turbine engine comprises a low pressure (LP) spool and a high pressure (HP) spool independently rotatable about a central axis extending through an accessory gear box (AGB). The LP spool has an LP compressor, which is axially positioned between the HP compressor of the HP spool and the AGB. A tower shaft drivingly connects the HP spool to the AGB.

Abstract: There is described herein methods and systems for detecting a shaft event in a gas turbine engine comprising a power turbine having a first shaft extending in a first direction and a second shaft extending in a second direction opposite from the first direction. A first speed measurement is obtained at a first location along the first shaft and a second speed measurement is obtained at a second location along the second shaft. A speed ratio is determined between the first speed measurement and the second speed measurement, and is compared to a detection threshold. The shaft event is detected when the speed ratio is beyond the detection threshold.

Abstract: The described accessory drive system for a gas turbine engine includes a gearbox driving a plurality of accessories including a cabin air compressor to provide cabin air and an engine starter to start the gas turbine engine. An electrical power supply separate from a main electrical power supply of the gas turbine engine is electrically coupled to the accessories. A clutch selectively engages an output of the gas turbine engine to mechanically couple the output to the gearbox. The clutch operates between an electrical drive state where it disengages from the output and only the electrical power supply provides electrical power to the cabin air compressor and the engine starter, and a mechanical drive state where the clutch engages the output and the gearbox drives at least one of the accessories.

Abstract: A multi spool gas turbine engine with a differential having a selectively rotatable member which rotational speed determines a variable ratio between rotational speeds of driven and driving members of the differential. The driven member is engaged to the first spool and a rotatable shaft independent of the other spools (e.g. connected to a compressor rotor) is engaged to the driving member. First and second power transfer devices are engaged to the first spool and the selectively rotatable member, respectively. A circuit interconnects the power transfer devices and allows a power transfer therebetween, and a control unit controls the power being transferred between the power transfer devices. Power can thus be transferred between the first spool and the selectively rotatable member to change the speed ratio between the first spool and the rotatable shaft.

Abstract: A turbo propeller engine comprises a housing circumferentially extending around a longitudinal axis and disposed around a gearbox. The turbo propeller engine includes a propeller outside of the housing and a shaft surrounded in part by the housing and extending along the longitudinal axis. The shaft has a front end and a rear end. The propeller is mounted to the front end. The rear end is in a driven engagement with an output of the gearbox. The shaft is rotatably supported by a first bearing and by a second bearing separated from the first bearing by an axial distance along the longitudinal axis. The first and second bearings are disposed on opposite sides of the gearbox. The first bearing is disposed between the shaft and the housing, the second bearing is disposed between the housing and a component of the gearbox to rotatingly support the component of the gearbox.

Abstract: A multi spool gas turbine engine with a differential having a selectively rotatable member which rotational speed determines a variable ratio between rotational speeds of driven and driving members of the differential. The driven member is engaged to the first spool and a rotatable shaft independent of the other spools (e.g. connected to a compressor rotor) is engaged to the driving member. First and second power transfer devices are engaged to the first spool and the selectively rotatable member, respectively. A circuit interconnects the power transfer devices and allows a power transfer therebetween, and a control unit controls the power being transferred between the power transfer devices. Power can thus be transferred between the first spool and the selectively rotatable member to change the speed ratio between the first spool and the rotatable shaft.

Abstract: A method and a turbine rotor system for reducing over-speed potential of a turbine of a gas turbine engine involve mechanically connecting the turbine to at least two mechanical loads via first and second mechanical drives extending in opposite directions from the turbine.

Abstract: A heat exchanger defines an annulus divided by a plurality of radial plates extending longitudinal along the annulus, into a plurality of channels. A first group of the channels form an oil passage and a second group of channels form a fuel passage. The channels in the respective first and second groups are circumferentially alternately positioned one to another, and heat transfer from the oil passage to the fuel passage takes place through the radial plates.

Abstract: A gas turbine engine has an engine core including a low pressure compressor, a high pressure compressor, a high pressure turbine and a low pressure turbine coaxially mounted about an engine axis and fluidly connected in series by a core gaspath. The low pressure turbine is drivingly connected to the low pressure compressor via an external shaft disposed radially outwardly of the core gaspath.

Abstract: There is described herein methods and systems for detecting a shaft event in a gas turbine engine comprising a power turbine having a first shaft extending in a first direction and a second shaft extending in a second direction opposite from the first direction. A first speed measurement is obtained at a first location along the first shaft and a second speed measurement is obtained at a second location along the second shaft. A speed ratio is determined between the first speed measurement and the second speed measurement, and is compared to a detection threshold. The shaft event is detected when the speed ratio is beyond the detection threshold.

Abstract: A gas turbine engine has an in-line mounted accessory gear box (AGB) and an accessory drivingly connected to the AGB, the accessory being oriented transversally to the engine centerline.

Abstract: A gas turbine engine has an engine case housing a low pressure compressor drivingly connected to a low pressure turbine by a low pressure compressor shaft extending along an engine axis. The low pressure turbine is disposed forward of the low pressure compressor. A low pressure turbine shaft is drivingly connected to the low pressure turbine and extends forwardly of the low pressure turbine. A reduction gear box (RGB) is drivingly connected to the low pressure turbine shaft. The RGB is offset from the engine axis to free an access to low pressure compressor shaft connection. The offset positioning of the RGB allows to provide an access port in an axially forwardly facing surface of the engine case to access the low pressure compressor shaft and more particularly a connection thereof to the LP turbine.