A turbofan engine according to an example of the present disclosure includes, among other things, a fan, a compressor section, a turbine section including a fan drive turbine and a second turbine, an epicyclic gear system with a gear reduction, first and second bearings, and a fan drive shaft interconnecting the gear system and the fan. The fan drive turbine has a first exit area at a first exit point and is rotatable at a first speed. The second turbine has a second exit area at a second exit point and is rotatable at a second speed. A first performance quantity is defined as the product of the first speed squared and the first area. A second performance quantity is defined as the product of the second speed squared and the second area.

An impeller for a planet carrier of a epicyclic speed reduction gear of a turbine engine is fixed in rotation to the planet carrier and is rotatable about an axis of the reduction gear. The impeller has an annular shape about the axis and includes means for lubricating in particular planet gear bearings of the reduction gear. The lubricating means include an annular cavity located at the inner periphery of the impeller, wherein the impeller has an inner peripheral wall that closes the cavity in the radial direction. The impeller further includes an annular aperture that extends around the axis and opens in the axial direction into the cavity to supply lubricating oil thereto.

A hybrid electric propulsion system includes a gas turbine engine having a low speed spool and a high speed spool. The low speed spool includes a low pressure compressor and turbine, and the high speed spool includes a high pressure compressor and turbine. The hybrid electric propulsion system includes an electric generator configured to extract power from the low speed spool, an electric motor configured to augment rotational power of the high speed spool, and a controller. The controller is operable to determine a target operating condition of the low pressure compressor to achieve a compressor stability margin in the gas turbine engine, determine a current operating condition of the low pressure compressor, and control a power transfer between the electric generator of the low speed spool and the electric motor of the high speed spool to adjust the current operating condition based on the target operating condition.

A hybrid electric propulsion system includes a gas turbine engine having a low speed spool and a high speed spool. The low speed spool includes a low pressure compressor and turbine, and the high speed spool includes a high pressure compressor and turbine. The hybrid electric propulsion system includes an electric generator configured to extract power from the low speed spool, an electric motor configured to augment rotational power of the high speed spool, and a controller. The controller is operable to determine a target operating condition of the low pressure compressor to achieve a compressor stability margin in the gas turbine engine, determine a current operating condition of the low pressure compressor, and control a power transfer between the electric generator of the low speed spool and the electric motor of the high speed spool to adjust the current operating condition based on the target operating condition.

A system for starting a turbine engine. The system may comprise a gearbox, a first starter, and a second starter. The gearbox may have a gearbox input shaft. The gearbox may be coupled to the turbine engine. The gearbox input shaft may be rotatively coupled to a spool of the turbine engine. The first starter may be coupled to the gearbox input shaft. The second starter may have a second-starter output shaft. The second-starter output shaft may be coaxial with the gearbox input shaft. The second starter may be coupled to the gearbox input shaft through the first starter.

A gas turbine engine has an engine static structure. At least one component rotatable relative to the engine static structure about an engine axis of rotation. A fan is coupled to at least one component for rotation about the engine axis of rotation. An actuator is mounted to the engine static structure, wherein the actuator is activated to prevent the fan from rotation and is inactivated to allow the fan to rotate. A method for preventing rotation of a fan in a gas turbine engine is also disclosed.

A gas turbine engine has an engine static structure. At least one component rotatable relative to the engine static structure about an engine axis of rotation. A fan is coupled to at least one component for rotation about the engine axis of rotation. An actuator is mounted to the engine static structure, wherein the actuator is activated to prevent the fan from rotation and is inactivated to allow the fan to rotate. A method for preventing rotation of a fan in a gas turbine engine is also disclosed.

The invention relates to a device comprising at least one vertical pump (3) and at least one associated turbine (4) for transporting, over a level difference, a heat-transfer fluid brought to a high temperature, wherein the device further comprises a device for mechanically coupling the turbine (4) with the pump (3), comprising a gearbox (21) with a gimbal coupling (41) located on the turbine (4) side, allowing the mechanical energy produced by the turbine (4) to be reused to actuate the pump (3).

The invention relates to a device comprising at least one vertical pump (3) and at least one associated turbine (4) for transporting, over a level difference, a heat-transfer fluid brought to a high temperature, wherein the device further comprises a device for mechanically coupling the turbine (4) with the pump (3), comprising a gearbox (21) with a gimbal coupling (41) located on the turbine (4) side, allowing the mechanical energy produced by the turbine (4) to be reused to actuate the pump (3).

A turbomachine engine can include a fan assembly, a vane assembly, a core engine, a gearbox, and a gearbox efficiency rating. The fan assembly can include a plurality of fan blades. The vane assembly can include a plurality of vanes, and the vanes can, in some instances, be disposed aft of the fan blades. The core engine can include one or more compressor sections and one or more turbine sections. The gearbox includes an input and an output. The input is coupled to the one or more turbine sections of the core engine and comprises a first rotational speed, the output is coupled to the fan assembly and has a second rotational speed, and a gear ratio of the first rotational speed to the second rotational speed is within a range of 4.1-14.0. The gearbox efficiency rating is 0.10-1.8.