A fan drive turbine drives a drive shaft. A compressor section and a turbine section rotate about a rotational axis, with the turbine section positioned in a downstream direction. A fan has fan blades and a fan hub positioned radially within a fan case, with the fan case defining a bypass duct. A fan inlet guide vane case is upstream of the fan blades and a fan exit guide vane case is mounted downstream. The drive shaft is mounted on at least one input drive shaft bearing inwardly of the fan inlet guide vane case. The drive shaft drives a flexible coupling to in turn drive a gear reduction. The gear reduction drives a fan drive shaft to in turn drive the fan hub. At least two fan drive shaft bearings support the fan drive shaft within the fan exit guide vane case. An aircraft is also disclosed.

A controlled collapse stub shaft allows controlled axial-movement of a mainline shaft joining a fan or compressor to a turbine. A first end of the stub shaft is joined to the mainline shaft. A second end of the stub shaft is joined to an engine part axially stationary relative to the mainline shaft controlled axial-movement. The stub shaft has an annular-body between first and second ends. The body contains plurality of axially-spaced circumferential rows of circumferentially-extending slots, inter-slot ligaments formed between each row slots. Successive rows are offset. The ligaments of the axially forwardmost and rearwardmost rows excepted, each ligament sandwiched between forward and rearward slots of neighbouring rows. Each ligament joined to adjacent ligaments of neighbouring rows by circumferentially-extending bars having thickness in axial direction corresponding to axial spacing between rows. The bars are axially-deflectable allowing the axial-distance between first and second ends of the stub shaft to decrease.

A gas turbine engine includes a planetary gear system including a sun gear, intermediate gears, and a ring gear. A lubricant recovery system for the planetary gear system includes fluid passages that extend through the planetary gear system. A gutter is located radially outward from the planetary gear system for collecting lubricant. At least a portion of the gutter is rigidly attached to the ring gear.

A controlled collapse stub shaft is provided for allowing controlled axial movement of a mainline shaft which joins a fan or compressor to a turbine of a gas turbine engine. A first end of the stub shaft is adapted to be joined to the mainline shaft. A second end of the stub shaft is adapted to be joined to a part of the engine which is axially stationary relative to the controlled axial movement of the mainline shaft. The stub shaft further has an annular body between the first and second ends. The body contains a plurality of axially-spaced circumferential rows of circumferentially-extending slots, inter-slot ligaments being formed between the slots of each row. Successive rows are offset. In this way, the ligaments of the axially forwardmost and rearwardmost rows excepted, each ligament is sandwiched between a forward slot and a rearward slot of its neighboring rows. Further, each ligament is joined to adjacent ligaments of its neighboring rows by circumferentially-extending bars having a thickness in the axial direction corresponding to the axial spacing between the rows. The bars are axially deflectable to allow the axial distance between the first and second ends of the stub shaft to decrease.

Disclosed is a gas turbine engine comprising: a low pressure spool having a low pressure compressor and a low pressure turbine connected by a low pressure shaft; a reduction gear train having a sun gear, a carrier having a plurality of planet gears attached thereto, and a ring gear, wherein the sun gear is driveably connected to the low pressure shaft, and either of carrier and ring gear provides an output drive connected to a propulsive fan; wherein the connection between the low pressure shaft and the sun gear includes a flexible drive shaft having serially connected concentrically nested first and second input shafts between the low pressure shaft and sun gear.

An engine system is provided that includes an engine rotating structure, an electric machine rotating structure and a flex coupler. The flex coupler rotatably connects the electric machine rotating structure to the engine rotating structure. The flex coupler includes a first mount, a second mount and a flex plate. The first mount includes a plurality of first mount fingers arranged circumferentially about an axis. The second mount includes a plurality of second mount fingers arranged circumferentially about the axis. The flex plate connects the first mount to the second mount. The flex plate includes a plurality of first flex plate fingers and a plurality of second flex plate fingers. Each of the first flex plate fingers is attached to a respective one of the first mount fingers. Each of the second flex plate fingers is attached to a respective one of the second mount fingers.

An interface device between first and second turbomachine elements is provided. The interface device includes an annular air inlet structure including opposite first and second parts, designed to come into contact with the first and second turbomachine elements respectively, in which the first part is configured to be in swivel contact with the first element; and an elastic return device that can be placed around the air inlet structure and designed to come into contact with at least the first turbomachine element.

A gas turbine engine includes a planetary gear system including a sun gear, intermediate gears, and a ring gear. A lubricant recovery system for the planetary gear system includes fluid passages that extend through the planetary gear system. A gutter is located radially outward from the planetary gear system for collecting lubricant. At least a portion of the gutter is rigidly attached to the ring gear.

Embodiments of a compliant shaft for engines are provided herein. In some embodiments, a compliant shaft for a turbine engine may include: a body having a first end configured to be coupled to a shaft of a turbine and a second end coupled to a gear of a gear box, wherein at least a portion of the body is flexible.

A gas turbine gearbox input shaft including a gear coupling engaged with an engine power gearbox and extending along a central engine axis thereof. The shaft may include a separable tuning segment coaxially joined to the gear coupling, and a spool coupling joined to the separable tuning segment opposite of the gear coupling, the spool coupling being engaged with an engine turbine spool. Methods of using the input shaft are also provided.