A hybrid multi-spool gas turbine engine, has: a LP spool and a HP spool rotatable about a central axis, the LP spool having an LP compressor and an LP turbine engaged to the LP compressor via an LP shaft, the LP shaft engaged to a rotatable load at a first end thereof, the HP spool having an HP turbine and an HP compressor engaged to the HP turbine via a HP shaft; an accessory gearbox (AGB) engaged to both of the LP shaft and the HP shaft and located proximate a second end thereof, the AGB having at least one accessory output drivingly engageable to at least one accessory and at least one input; and at least one electric motor drivingly engaged to the at least one input of the AGB, the at least one electric motor drivingly engaged to the rotatable load via the AGB and the LP shaft.

The invention concerns a power transmission system of a turbomachine, comprising: a speed reducer (12) comprising a sun gear (15) rotationally secured to a power shaft (5) with a longitudinal axis, an outer ring gear (18) rotating a rotor shaft along the longitudinal axis, and a planet carrier (17), and a device (40) for recovering oil ejected by centrifugal effect and comprising an annular gutter (41) for recovering the ejected oil, the gutter being attached to a fixed annular housing (26) and having a recovery chamber (42) and a first wall portion (43) disposed at least partially facing oil ejection means (30) of the speed reducer for directing the oil to the recovery chamber. According to the invention, the recovery chamber is provided with an inlet opening (45) directed radially outwardly and defined in a plane radially lower than a plane where an outlet port (33) of the ejection means is defined.

A gas turbine engine may include a high speed spool, a low speed spool, a first epicyclic gear system, and a second epicyclic gear system. Generally, the high speed spool mechanically connects a high pressure turbine to a high pressure compressor, and the low speed spool mechanically connects a low pressure turbine to at least one of a fan and a prop via the first epicyclic gear system and to a low pressure compressor via the second epicyclic gear system, according to various embodiments. The first epicyclic gear system and the second epicyclic gear system may include a common sun gear shaft.

A turboprop engine system for an aircraft includes an engine, a propeller, and a gear train coupled to and configured to provide power from the engine to the propeller at a predetermined gear reduction. The engine system also includes a gearbox that houses at least part of the gear train. The gearbox includes a gearbox flow structure and an inlet flow structure that is removably attached to the gearbox. The inlet flow structure and the gearbox flow structure cooperate to define an inlet flow passage to the engine. The inlet flow passage has an upstream end and a downstream end that are cooperatively defined by the inlet flow structure and the gearbox flow structure. The upstream end is configured to receive an airstream that is directed along the inlet flow passage to the downstream end and toward the engine.

A gas turbine engine includes an engine spool with a turbine section, a propeller, a motor, and a variable drive arrangement. The variable drive arrangement mechanically couples the engine spool to the propeller, and includes a first gear connection rotationally coupled to the propeller, a second gear connection rotationally coupled to the engine spool, and a sprag clutch rotationally coupled to the first gear connection. The sprag clutch is configured to passively decouple the motor from the first gear connection when a torque input from the engine spool exceeds a torque input from the motor, and is configured to passively couple the motor to the first gear connection when the torque input from motor exceeds a torque input from the engine spool.

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 low pressure turbine.

An electrical generator is housed in an annular cavity between the casing and the propeller shaft of a turboprop, while imposing little or no additional space requirement and with lightweight ancillary equipment. The rotor of the generator is mounted on an autonomous shaft end. A flange of the outer casing is removable in order to access the generator and to enable its easy removal and remounting.

The gas turbine engine for an aircraft includes at least a low pressure spool with a low pressure turbine shaft operatively connected to at least one turbine, the low pressure turbine shaft rotatable about an engine axis, and a low pressure compressor operatively connected to a low pressure compressor shaft that is independently rotatable relative to the low pressure turbine shaft. A differential gearbox has an input operatively connected to the low pressure turbine shaft, a first output and a second output, the first output of the differential gearbox operatively connected to the low pressure compressor shaft and the second output of the differential gearbox operatively connected to an output shaft of the gas turbine engine. The differential gearbox permits the output shaft, the low pressure compressor shaft and the low pressure turbine shaft to rotate at different speeds.

Methods and systems for operating a gas turbine engine are described. The method comprises obtaining, at a control system associated with the gas turbine engine, a measured engine core speed and an actual power demand for the gas turbine engine during operation thereof, determining an expected engine core speed based on the actual power demand from a predicted relationship between engine core speed and engine output power, comparing the measured engine core speed to the expected engine core speed, detecting a torque-related fault when the measured engine core speed differs from the expected engine core speed by more than a threshold; and accommodating the torque-related fault when detected.

A carrier assembly for a planetary gear assembly includes a planet frame defining a central aperture therethrough, the central aperture defining a rotation axis, the planet frame configured to rotatably support a plurality of planet gears, and a carrier connected to the planet frame via a stud. At least one of a portion of the carrier proximate the stud and a portion of the stud between the carrier and the planet frame has a dimension reduction, such as a thickness reduction, therein.