A method of integrating an electric motor or generator as part of an aircraft engine shaft. The motor is used to rotate the rotor so as to cool the rotor in a temperature gradient. The generator is used to provide power to the aircraft. In one or more examples, a power generation device includes a gas turbine engine including a rotor shaft and a first casing around the rotor shaft; a transmission connecting the rotor shaft to a gearbox, the transmission comprising a drive shaft and a second casing around the drive shaft; and a brushless DC motor integrated with the engine and including one or more permanent magnets and one or more coils.

A bowed-rotor prevention system for a turbomachine is disclosed. The system comprises a first turbomachine having a first shaft rotatably supported by a plurality of bearings, a second turbomachine having a second shaft rotatably coupled to the first rotatable shaft, and a pump having a third shaft rotatably coupled to the second shaft. The system further includes a gear box having a fourth shaft rotatably coupled to the third shaft by an clutch configured to operate in a freewheel condition when the first shaft is rotating faster than a first predetermined speed, and further configured to rotatably engage the fourth shaft to the third shaft when the first shaft is rotating slower than a second predetermined speed to thereby drive a rotation of the third shaft, wherein the first predetermined speed is faster than the second predetermined speed.

A gas turbine engine (10) includes a compressor section, a turbine section, and an accessory gearbox (100). A turning unit (200) for the gas turbine engine includes an output assembly (204) configured to be mechanically coupled to the gas turbine engine, and an electric motor (202). The electric motor is operable to rotate, through the output assembly, one or more components of the compressor section or the turbine section at a rotational speed less than about fifty revolutions per minute during a shut-down condition of the gas turbine engine.

A gas turbine engine (10) includes a compressor section, a turbine section, and an accessory gearbox (100). A turning unit (200) for the gas turbine engine includes an output assembly (204) configured to be mechanically coupled to the gas turbine engine, and an electric motor (202). The electric motor is operable to rotate, through the output assembly, one or more components of the compressor section or the turbine section at a rotational speed less than about fifty revolutions per minute during a shut-down condition of the gas turbine engine.

An output assembly for an accessory system of a gas turbine engine includes a first rotating member extending along an axis and including a mechanical connector for coupling the output assembly to an accessory system. The output assembly also including a second rotating member extending along the axis, the second rotating member coupled to the first rotating member at a first axial position and at a second axial position, the second rotating member coupled to the first rotating member at the second axial position through a one-way clutch. Additionally, the first rotating member of the output assembly further includes an extension member extending at least partially between the first axial position and the second axial position, the extension member including a designed fail point.

An output assembly for an accessory system of a gas turbine engine includes a first rotating member extending along an axis and including a mechanical connector for coupling the output assembly to an accessory system. The output assembly also including a second rotating member extending along the axis, the second rotating member coupled to the first rotating member at a first axial position and at a second axial position, the second rotating member coupled to the first rotating member at the second axial position through a one-way clutch. Additionally, the first rotating member of the output assembly further includes an extension member extending at least partially between the first axial position and the second axial position, the extension member including a designed fail point.

The invention relates to a method for starting a turbine engine in cold weather, including a starting system intended for rotating a drive shaft of the turbine engine, the method comprising the following steps: a pre-starting step in which a first starting signal is generated to control the drive shaft in a first direction of rotation about a longitudinal axis (X) and in a second opposite direction of rotation in an alternating manner; and a starting step in which a second starting signal is transmitted to the starting system in order for the latter to drive the drive shaft of the turbine engine in a normal direction of rotation and in which the drive shaft is rotated until a rotation speed that causes the turbine engine to start.

A method of reducing rotor bow in a high pressure rotor of a gas turbine engine that has in axial flow a low pressure rotor and a high pressure rotor. The method involves storing bleed air from the gas turbine engine when the engine is running to provide stored pneumatic energy; and using that stored pneumatic energy after the engine has been shut-down to rotate the high pressure rotor at a speed and for a duration that reduces rotor bow. A gas turbine engine wherein rotor bow in the high pressure rotor after engine shut-down has been reduced by carrying out the aforesaid method is also disclosed.

A method of reducing rotor bow in a high pressure rotor of a gas turbine engine that has in axial flow a low pressure rotor and a high pressure rotor. The method involves storing bleed air from the gas turbine engine when the engine is running to provide stored pneumatic energy; and using that stored pneumatic energy after the engine has been shut-down to rotate the high pressure rotor at a speed and for a duration that reduces rotor bow. A gas turbine engine wherein rotor bow in the high pressure rotor after engine shut-down has been reduced by carrying out the aforesaid method is also disclosed.

A system includes a gas turbine engine having a low speed spool, a high speed spool, and a combustor. The system also includes a low spool motor configured to augment rotational power of the low speed spool. The system further includes a controller configured to cause fuel flow. The controller is operable to control the low spool motor to drive rotation of the low speed spool responsive to a thrust command while the controller does not command fuel flow to the combustor.