Systems, methods, and devices are provided for a turbine driven pump gearbox. A turbine engine may drive a primary shaft having gears. The gears may selectably engage with gears of a secondary shaft that drives a machine (e.g., pump). By changing which gears of the primary shaft engage with which gears of the secondary shaft, a gear ratio may be changed. A power takeoff device (e.g., a generator) may be connected to the primary shaft and may be operated in reverse as a motor to rotate, slow, stop, and/or reverse rotation of the primary shaft. Brakes may be associated with one or more of the primary and secondary shafts. The power takeoff device and one or more of the brakes may be controlled to shift engagement of the shafts between different positions, changing the gear ratio and/or disengaging the shafts from each other.

A braking system for the low pressure spool of a gas turbine engine includes a braking assembly connected to the low pressure spool and reversibly configurable between an actuated state and an unactuated state. The braking assembly in the unactuated state allows rotation of the low pressure spool without interference. The braking assembly in the actuated state applies a force opposing the rotation of the low pressure spool. A method of controlling the speed of rotation of a low pressure spool and a method of controlling the speed of rotation of low and high pressure spools are also discussed.

Fan (16), in particular for an aircraft cooling unit, having a wheel (128) comprising a hub (138) and an annular array of blades (140), a shaft assembly (136) for driving the wheel about an axis (A), and fusible means for connecting the hub of the wheel to the shaft assembly, said fusible connecting means comprising a first mounting sleeve through which the shaft assembly extends and which is surrounded by the hub, and fusible safety elements (174) which extend parallel to the axis (A) and are configured to break and to disengage the wheel from the shaft assembly when said wheel rotates and a driving torque of the wheel transmitted by the shaft assembly exceeds a certain threshold, characterised in that the connecting means comprise a second wearing sleeve (143) which is inserted between the first sleeve and the hub and through which the fusible elements extend, the second sleeve being made of a material which is different from that of the first sleeve and subject to wear by friction and/or by heating if the shaft assembly continues to rotate following the aforementioned disengagement.

A gas turbine engine has an engine static structure and 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, and an aircraft including the gas turbine engine. The gas turbine engine comprising: an engine core comprising a turbine, a compressor, and a shaft system connecting the turbine to the compressor. The shaft system is axially located by a thrust bearing located forward of the turbine, and the engine is configured such that, in the event of a shaft break which divides the shaft system into a front portion located by the thrust bearing and a rear portion unlocated by the thrust bearing, the rear portion is free to move axially rearwardly under a gas load; and the engine further comprises an axial movement sensor configured to register a shaft break when it detects the axial movement of the rear portion of the shaft system.

A guide vane segment 10 for a turbomachine includes a radially inner shroud plate 13 having a shroud plate surface 14 that is adapted to be configured in the turbomachine to face a rotor blade 20 adjacent to the guide vane segment, and thereby essentially extend along an outer conical surface K.sub.1 whose cone axis coincides with the axis of rotation A of a rotor shaft 30. In a radially inner region, a rotor blade 20 for a turbomachine has a base plate 23 having a base plate surface 24 that is adapted to be configured in the turbomachine to face a shroud of a guide vane row 10 adjacent to the rotor blade and thereby essentially extend along an outer conical surface K.sub.2 whose cone axis coincides with the axis of rotation A of a rotor shaft 30.

A low pressure compressor section of a gas turbine engine includes low pressure compressor stages spaced apart along an axis of rotation of the low pressure compressor section. The low pressure compressor section includes at least one of a fluid conduit extending between an air inlet of the gas turbine engine and the low pressure compression stages. The fluid conduit having at least one flow diverter displaceable between a first position and a second position to modulate air through the low pressure compressor stages. And/or a compressor stage disabler is engageable with at least one of the low pressure compressor stages and configured to reduce a rotation thereof.

A method of operating a twin engine helicopter power plant, the power plant comprising: two turboshaft engines each having an engine shaft with a turbine at a distal end and a one-way clutch at a proximal end; a gear box having an input driven by the one way clutch of each engine and an output driving a helicopter rotor; a bypass clutch disposed between the proximal end of each engine shaft and the input of the gear box; and power plant management system controls for activating the bypass clutch; the method comprising: detecting when a rotary speed of an associated engine shaft is less than a rotary speed of the gear box input; activating the bypass clutch to drive the associated engine shaft using the rotation of the gear box input; and starting an associated engine by injecting fuel when the bypass clutch is activated.

A gas turbine includes a main shaft connecting a turbine to a compressor and an additional shaft extending coaxially to the main shaft. The additional shaft has a first shaft section connected to the compressor and a second shaft section connected to the turbine, the shaft sections separated from each other by a gap. At mutually facing ends, the two shaft sections have mutually corresponding structures. The gap been the two shaft sections is dimensioned such that, upon a break of the main shaft, the mutually corresponding structures of the mutually facing ends of the two shaft sections come into interaction and rotate relative to one another as a result of their differing rotational speeds. The mutually corresponding structures are formed such that the two shaft sections are moved away from one other in the event of twisting of the two shaft sections.

The invention relates to a device (3) for driving actuators (7-10) for a thrust reverser, comprising a motorised drive unit (15) comprising a motor (22), a drive shaft (14) suitable for connecting to a flexible shaft (4, 5) for driving actuators (7-10), the drive shaft (14) being rotated by the motor (22) about a rotational axis (X), a manual drive unit (17) comprising a drive wheel (32) mounted such that it rotates about the rotational axis (X), and a clutch (18) comprising a clutch part (40) which is secured in rotation with the wheel (32) and mobile in translation in relation to the wheel (32), between an engaged position wherein the clutch part is connected to the drive shaft (14) in such a way as to secure the drive shaft (14) and the wheel (32) in rotation, and a disengaged position wherein the clutch part (40) is not connected to the drive shaft (14) so as to allow an independent rotation of the drive shaft (14) and the wheel (32).