Abstract: Spaced apart counter-rotatable forward and aft rows of forward and aft propellers are mounted on forward and aft rotatable frames. Hydraulic rotary forward and aft pitch change actuators on the frames are operable for controlling pitch of the propellers. A hydraulic fluid supply outboard of the frames is connected to forward and aft rotary unions which are operable for transferring hydraulic fluid between forward and aft union stators to forward and aft union rotors mounted within the forward and aft rotary unions. The forward union rotor is operable to transfer the hydraulic fluid from the forward rotary union to the aft pitch change actuators and the aft union rotor is operable to transfer the hydraulic fluid from the aft rotary unions to the forward pitch change actuators. The forward and aft rotatable frames counter-rotatably mounted on a structural frame located forward or aft of the propellers.

Abstract: A tip turbine engine assembly includes an engine support structure with a rear case, exit guide vanes, an exhaust mixer, and engine mounts. The rear case is disposed about an engine centerline. The exit guide vanes extend radially inwardly from the rear case. The exhaust mixer extends in a flow path of a combustor to mix a high energy gas stream from the combustor with bypass air from a bypass fan. The engine mounts are located on the periphery of the rear case for mounting the engine to an aircraft. The rear case, exit guide vanes, exhaust mixer, and engine mounts form a unitary engine support structure which is installable as a single piece into an engine.

Abstract: Axially spaced apart counter-rotatable forward and aft rows of forward and aft propellers mounted on forward and aft rotatable frames includes a flowpath passing through the forward and aft rotatable frames. Hydraulic rotary forward and aft pitch change actuators mounted on the aft rotatable frames are connected to and operable for controlling and setting pitch of the aft propellers. The pitch change actuators are mounted radially inwardly of the flowpath in a one to one ratio with forward and aft rotatable struts extending radially across the flowpath. One or more rotatable shafts extend through one or more of the rotatable struts and connect one or more of the pitch change actuators to one or more of the propellers. The pitch change actuators may be ganged together by unison rings having ring teeth engaging gear teeth on gears connected to the pitch change actuators or connected to the rotatable shafts.

Abstract: A twin fan turbomachine with two contrarotating fans, one upstream and one downstream, driven by two contrarotating coaxial shafts each of which connects one fan impeller to at least one low-pressure turbine impeller located downstream, the downstream fan impeller being connected by its downstream part to its drive shaft.

Abstract: A two-stage turbofan system for use in a gas turbine engine comprises a first-stage fan shaft, a second-stage fan shaft, a stationary torque tube and a gear system. The second-stage fan shaft connects with a drive shaft in the gas turbine engine such that the second-stage fan shaft is driven at the speed of the drive shaft. The stationary torque tube is connected with a fan case in the gas turbine engine. The gear system is connected to the second-stage fan shaft and the torque tube. The first-stage fan shaft extends from the gear system such that the first-stage fan shaft is driven at a speed reduced from that of the drive shaft.

Abstract: A counter-rotatable low pressure turbine includes counter-rotatable outer and inner drum rotors. The outer drum rotor is connected to a sole shaft for transmitting torque and power out of the low pressure turbine. Low pressure outer drum turbine blade rows extend radially inwardly from an outer shell of the outer drum rotor. Low pressure inner drum turbine blade rows extend radially outwardly from the low pressure inner drum rotor. The outer drum turbine blade rows are interdigitated with the inner drum turbine blade rows. The drum rotors are geared together through an epicyclic gearbox for transmitting all the torque and power produced by the drum rotors to the shaft. The gearbox may be located aft of the drum rotors. A differential thrust bearing is disposed between the drum rotors. A single stage fan section of an engine is connected to the turbine by the shaft.

Abstract: A Brayton cycle internal combustion engine of the open, or constant pressure type, in which rotary power is produced by the pressure of hot gasses against confined, rotor protrusions.

Abstract: A gas turbine aircraft engine with power variability is provided. The gas turbine aircraft engine comprises a compressor and a turbine mounted on a common shaft, and, a continuously variable transmission coupled to the shaft for transmitting power to a propulsion load.

Abstract: A gas turbine engine booster includes one or more rotatable booster stages having booster blades extending radially inwardly from a rotatable drum and one or more non-rotatable vane stages having booster vanes extending radially outwardly from a non-rotatable shell. The booster stages may be interdigitated with the vane stages. The booster may be co-rotatable or counter-rotatable with respect to a fan stage of an aircraft gas turbine engine. The booster may be driven by a single turbine or one of counter-rotatable turbines or though a gearbox by these turbines. The booster blades and the booster vanes extend across a core engine inlet duct having an entrance downstream of the first fan stage. A fan section with the booster may have counter-rotatable first and second fan stages with fan blades of the second fan stages connected to and mounted radially outwardly of the rotatable drum.

Abstract: A representative gas turbine includes: a high pressure spool; a high pressure compressor; a high pressure turbine mechanically coupled to the high pressure spool; a lower pressure spool; a lower pressure turbine mechanically coupled to the lower pressure spool; a fan having a first set of fan blades and a second set of fan blades, the second set of fan blades being located downstream of the first set of fan blades and being operative to rotate at a rotational speed corresponding to a rotational speed of the lower pressure spool; and a gear assembly mechanically coupled to the lower pressure spool and engaging the first set of fan blades such that rotation of the lower pressure spool rotates the first set of fan blades at a lower rotational speed than the rotational speed of the second set of fan blades.

Abstract: A fan-turbine rotor assembly (24) includes one or more turbine ring rotors (32). Each turbine ring rotor is cast as a single integral annular ring. By forming the turbine as one or more rings, leakage between adjacent blade platforms is minimized which increases engine efficiency. Assembly of the turbine ring rotors to the diffuser ring (114) includes axial installation and radial locking of each turbine ring rotor.

Abstract: Spaced apart counter-rotatable forward and aft rows of forward and aft propellers are mounted on forward and aft rotatable frames. Hydraulic rotary forward and aft pitch change actuators on the frames are operable for controlling pitch of the propellers. A hydraulic fluid supply outboard of the frames is connected to forward and aft rotary unions which are operable for transferring hydraulic fluid between forward and aft union stators to forward and aft union rotors mounted within the forward and aft rotary unions. The forward union rotor is operable to transfer the hydraulic fluid from the forward rotary union to the aft pitch change actuators and the aft union rotor is operable to transfer the hydraulic fluid from the aft rotary unions to the forward pitch change actuators. The forward and aft rotatable frames counter-rotatably mounted on a structural frame located forward or aft of the propellers.

Abstract: Axially spaced apart counter-rotatable forward and aft rows of forward and aft propellers mounted on forward and aft rotatable frames includes a flowpath passing through the forward and aft rotatable frames. Hydraulic rotary forward and aft pitch change actuators mounted on the aft rotatable frames are connected to and operable for controlling and setting pitch of the aft propellers. The pitch change actuators are mounted radially inwardly of the flowpath in a one to one ratio with forward and aft rotatable struts extending radially across the flowpath. One or more rotatable shafts extend through one or more of the rotatable struts and connect one or more of the pitch change actuators to one or more of the propellers. The pitch change actuators may be ganged together by unison rings having ring teeth engaging gear teeth on gears connected to the pitch change actuators or connected to the rotatable shafts.

Abstract: An representative gas turbine includes: a first annular gas flow path; a second annular gas flow path located radially outwardly from the first gas flow path; in series order, a multi-stage fan, radially inboard portions of a first set of high pressure compressor blades, a second set of high pressure compressor blades, a combustion section and a high pressure turbine, positioned along the first gas flow path; and in series order, the multi-stage fan and radially outboard portions of the first set of high pressure compressor blades, positioned along the second gas flow path such that the inboard portions of the first set of high pressure compressor blades, the second set of high pressure compressor blades, the combustion section and the high pressure turbine are not positioned along the second gas flow path.

Abstract: A tip turbine engine (10) provides first and second turbines (32) rotatably driven by a combustor (30) generating a high-energy gas stream. The first turbine (32) is mounted at an outer periphery of a first fan (24a), such that the first fan is rotatably driven by the first turbine (32a). The second turbine (32b) is mounted at an outer periphery of a second fan (24b), and is rotatably driven by the high-energy gas stream. In one embodiment, the first turbine (32a) rotatably drives a plurality of stages of first compressor blades (54) in an axial compressor (22) in a first rotational direction, while the second turbine (32b) rotatably drives a plurality of stages of second compressor blades (52) in the axial compressor (22) in a second rotational direction opposite the first. By rotatably driving alternating stages of compressor blades in opposite directions, the efficiency of the axial compressor (22) is increased and/or the number of stages of compressor blades can be reduced.

Abstract: A drive mechanism comprising a first sprocket encircled by a tensioned chain and an orbit sprocket arranged to orbit the first sprocket in response to a resynchronisation signal. The orbit sprocket is arranged to displace the tensioned chain relative to the first sprocket. The first sprocket is rotatable and is coupled to an output drive sprocket by the tensioned chain such that the first and output drive sprockets are rotatable in synchronicity, whereby the orbit of the orbit sprocket alters the relative angular orientation of the first and output drive sprockets.

Abstract: A gas turbine engine includes a gear system driven by a first and second counter rotating low pressure shaft and a fan driven by the gear system.

Abstract: Gas turbine engine systems and related methods involving vane-blade count ratios greater than unity are provided. In this regard, a representative turbine stage for a gas turbine engine includes a first set of rotatable blades operative to be positioned downstream of and adjacent to a first set of vanes, a number of blades of the first set of blades being less than a number of vanes of the first set of vanes.

Abstract: A turbofan engine assembly includes a core gas turbine engine including a high-pressure compressor, a combustor, and a high-pressure turbine, a low-pressure turbine coupled to said core gas turbine engine, a counter-rotating booster compressor comprising a first rotor section configured to rotate in a first direction and a second rotor section configured to rotate in an opposite second direction, and a gearbox comprising an input and an output, said gearbox output coupled to at least one of said first and second rotor sections, said gearbox input coupled to said low-pressure turbine. A method of assembling the turbofan engine assembly described herein is also provided.

Abstract: A counter-rotating blade stage in lieu of a stator stage may compensate for relatively low rotational speed of a gas turbine engine spool. A first spool may have at least two compressor blade stage and at least two turbine blade stage. A combustor is located between the at least two compressor blade stage and the at least two turbine blade stage along a core flowpath. The at least two counter-rotating compressor blade stage is interspersed with the first spool at least two compressor blade stage. A transmission couples the at least two additional compressor blade stage to the first spool for counter-rotation about the engine axis.

Abstract: A tip turbine engine (10) provides an axial compressor rotor (46) that is counter-rotated relative to a fan (24). A planetary gearset (90) couples rotation of a fan (46) to an axial compressor rotor (46), such that the axial compressor rotor (46) is driven by rotation of the fan in a rotational direction opposite that of the fan. By counter-rotating the axial compressor rotor, a final stage of compressor vanes (54) between the final stage of compressor blades (52) and inlets (66) to the hollow fan blades (28) of the fan are eliminated. As a result, the length of the axial compressor (22) and the overall length of the tip turbine engine (10) are decreased.

Abstract: A turbofan engine assembly includes a core gas turbine engine including a high-pressure compressor, a combustor, and a high-pressure turbine, a booster compressor coupled upstream from the core gas turbine engine, an intermediate-pressure turbine coupled to the booster compressor, the intermediate-pressure turbine disposed downstream from the core gas turbine engine, a first fan assembly coupled to a low-pressure turbine, a second fan assembly disposed downstream from the first fan assembly, and a gearbox coupled between the second fan assembly and the low-pressure turbine. A method of assembling the above turbofan engine assembly is also described herein.

Abstract: A turbofan engine assembly includes a core gas turbine engine including a high-pressure compressor, a combustor, and a high-pressure turbine, a booster compressor coupled upstream from the core gas turbine engine, an intermediate-pressure turbine coupled to the booster compressor, the intermediate-pressure turbine disposed downstream from the core gas turbine engine, a counter-rotating fan assembly disposed upstream from the booster compressor, the counter-rotating fan assembly comprising a first fan configured to rotate in a first direction and a second fan configured to rotate in an opposite second direction, and a low-pressure turbine disposed downstream from the intermediate-pressure turbine, the low-pressure turbine configured to drive the counter-rotating fan assembly. A method of assembling the above turbofan engine assembly is also described herein.

Abstract: A turbofan engine assembly includes a core gas turbine engine including a high-pressure compressor, a combustor, and a high-pressure turbine, a booster compressor coupled upstream from the core gas turbine engine, an intermediate-pressure turbine coupled to the booster compressor, the intermediate-pressure turbine disposed downstream from the core gas turbine engine, a counter-rotating fan assembly disposed upstream from the booster compressor, the counter-rotating fan assembly comprising a first fan configured to rotate in a first direction and a second fan configured to rotate in an opposite second direction, and an intermediate-pressure turbine disposed downstream from the core gas turbine engine, wherein the intermediate-pressure turbine drives the booster compressor and the second fan assembly. A method of assembling the above turbofan engine assembly is also described herein.

Abstract: A turbofan engine assembly includes a core gas turbine engine including a high-pressure compressor, a combustor, and a high-pressure turbine, a first fan assembly disposed upstream from the core gas turbine engine, a first gearbox coupled to the first fan assembly, and a second gearbox coupled to a booster compressor such that the booster compressor rotates in a rotational direction that is opposite to the rotational direction of the first fan assembly. A method of assembling the above turbofan engine assembly is also described herein.

Abstract: An aircraft gas turbine engine includes a counter-rotatable generator driven by a turbine includes a generator stator and counter-rotatable radially inner pole and outer magnet rotors. A gearbox may be used for counter-rotating the pole and magnet rotors. Counter-rotatable first and second sets of booster stages may be co-rotatable with corresponding ones of the pole and magnet rotors. The generator and the gearbox may be disposed within a booster cavity or a tail cone of the engine. The magnet rotor, the pole rotor, and the stator may be concentric. A particular embodiment of generator includes the magnet rotor encircling the pole rotor, the pole rotor encircling the stator, a rotor air gap between the magnet and pole rotors, and a transformer air gap between the pole rotor and the stator. The counter-rotatable generator may be driven directly by a counter-rotatable turbine.

Abstract: A method for assembling a gas turbine engine includes coupling a low-pressure turbine to a core turbine engine, coupling a counter-rotating fan assembly including a forward fan assembly and an axially aft fan assembly to the low-pressure turbine such that the forward fan assembly rotates in a first direction and the aft fan assembly rotates in an opposite second direction, and coupling a booster compressor directly to the low-pressure turbine such that the booster compressor rotates in the first direction.

Abstract: A method of assembling a gas turbine assembly includes providing a core gas turbine engine including a high-pressure compressor, a combustor, and a turbine, coupling a low-pressure turbine to the core gas turbine engine, coupling a booster compressor to a gearbox, and coupling the gearbox to the low-pressure turbine such that the booster compressor is driven by the low-pressure turbine.

Abstract: A drive mechanism comprising a first sprocket encircled by a tensioned chain and an orbit sprocket arranged to orbit the first sprocket in response to a resynchronisation signal. The orbit sprocket is arranged to displace the tensioned chain relative to the first sprocket. The first sprocket is rotatable and is coupled to an output drive sprocket by the tensioned chain such that the first and output drive sprockets are rotatable in synchronicity, whereby the orbit of the orbit sprocket alters the relative angular orientation of the first and output drive sprockets.

Abstract: A counter-rotating blade stage in lieu of a stator stage may compensate for relatively low rotational speed of a gas turbine engine spool. A first spool may have at least one compressor blade stage and at least one turbine blade stage. A combustor is located between the at least one compressor blade stage and the at least one turbine blade stage along a core flowpath. The at least one counter-rotating compressor blade stage is interspersed with the first spool at least one compressor blade stage. A transmission couples the at least one additional compressor blade stage to the first spool for counter-rotation about the engine axis.

Abstract: Bypass aeronautical engine comprising a fan (1), an LP compressor (3) and an HP compressor (4), a combustion chamber (5), an HP turbine and at least one LP turbine stage, said LP stage comprising a first movable bladed wheel (9a, 10a) carried by a first turbine shaft and a second movable bladed wheel (9b, 10b, 11b) turning in the opposite direction to said first wheel, said fan being driven by said second wheel via a second turbine shaft (2b) and by said first shaft (2a) via a module for reversing its direction of rotation, wherein the reversing module is produced with the aid of two bevel pinions (19, 21) of the same size, carried respectively by the first and second LP turbine shafts, and with the aid of a reversing pinion (20), the two turbine shafts (2a, 2b) turning in absolute value at the same speed of rotation.

Abstract: A fan for an aircraft engine, particularly a gas turbine aircraft engine, is disclosed. The fan has a fan rotor with fan blades, which extend radially outwardly from a hub to an outer flow path wall of a fan flow path. The fan has an auxiliary rotor that is positioned upstream of the fan rotor and has auxiliary blades that extend radially outwardly from a hub and end at a distance from the outer flow path wall of the fan flow path. The auxiliary rotor and the fan rotor are designed as separate rotors, such that the auxiliary rotor can be operated at a higher speed than the fan rotor.

Abstract: A gas turbine engine assembly is provided. The gas turbine engine assembly includes a core engine. The gas turbine engine assembly further includes a first rotor spool including a first fan assembly, an intermediate-pressure turbine, and a first shaft. The first fan assembly includes a single stage fan assembly coupled upstream from the core engine. The intermediate-pressure turbine includes a single stage turbine coupled downstream from the core engine. The first shaft extends between the first fan assembly and the intermediate-pressure turbine. The gas turbine engine assembly further includes a second rotor spool including a second fan assembly, a low-pressure turbine, and a second shaft. The second fan assembly includes a single stage fan assembly coupled upstream from the first fan assembly. The low-pressure turbine includes a single stage turbine coupled downstream from the intermediate-pressure turbine. The second shaft extends between the second fan assembly and the low-pressure turbine.

Abstract: A method for assembling a gas turbine engine includes coupling a gearbox to a low-pressure turbine, the gearbox includes a plurality of planetary gears intermeshed with the sun gear, each of the planetary gears includes a first gear portion having a first diameter and a second gear portion having a second diameter that is different than the first diameter.

Abstract: A counter-rotatable low pressure turbine includes counter-rotatable outer and inner drum rotors. The outer drum rotor is connected to a sole shaft for transmitting torque and power out of the low pressure turbine. Low pressure outer drum turbine blade rows extend radially inwardly from an outer shell of the outer drum rotor. Low pressure inner drum turbine blade rows extend radially outwardly from the low pressure inner drum rotor. The outer drum turbine blade rows are interdigitated with the inner drum turbine blade rows. The drum rotors are geared together through an epicyclic gearbox for transmitting all the torque and power produced by the drum rotors to the shaft. The gearbox may be located aft of the drum rotors. A differential thrust bearing is disposed between the drum rotors. A single stage fan section of an engine is connected to the turbine by the shaft.

Abstract: An open-rotor gas turbine engine comprising a starter/generator, a first spool and a second spool, the second spool is of a lower pressure than the first spool; wherein the starter/generator is connected to the first and second spools via first and second clutches respectively. The method of operating the open-rotor engine comprises the step of supplying power to the starter/generator to drive the first spool via the first clutch to start the engine and, once the engine is self-propelling, a step of driving the starter/generator from the second spool via the second clutch to generate electricity.

Abstract: A method for assembling a gas turbine engine includes coupling a low-pressure turbine to a core turbine engine, and coupling a counter-rotating fan assembly including a first fan assembly and a second fan assembly to the low-pressure turbine such that the first fan assembly rotates in a first direction and the second fan assembly rotates in an opposite second direction.

Abstract: A gas turbine engine booster includes one or more rotatable booster stages having booster blades extending radially inwardly from a rotatable drum and one or more non-rotatable vane stages having booster vanes extending radially outwardly from a non-rotatable shell. The booster stages may be interdigitated with the vane stages. The booster may be co-rotatable or counter-rotatable with respect to a fan stage of an aircraft gas turbine engine. The booster may be driven by a single turbine or one of counter-rotatable turbines or though a gearbox by these turbines. The booster blades and the booster vanes extend across a core engine inlet duct having an entrance downstream of the first fan stage. A fan section with the booster may have counter-rotatable first and second fan stages with fan blades of the second fan stages connected to and mounted radially outwardly of the rotatable drum.

Abstract: A turbofan engine assembly includes a core gas turbine engine including a high-pressure compressor, a combustor disposed downstream from the high-pressure compressor, and a high-pressure turbine coupled to the high-pressure compressor using a shaft, counter-rotating booster compressor coupled to the core gas turbine engine, the counter-rotating booster compressor comprising a first rotor section configured to rotate in a first direction and a second rotor section configured to rotate in an opposite second direction, a single stage fan assembly coupled to the first rotor section, a drive shaft coupled between the low-pressure turbine and the fan assembly, and a gearbox coupled between the drive shaft and the second rotor section such that the low-pressure turbine drives the gearbox and such that the gearbox drives the second rotor section. A method of assembling the above turbofan engine assembly is also described herein.

Abstract: A method for assembling a gas turbine engine includes providing a core gas turbine engine including a high-pressure compressor, a combustor, and a turbine, and coupling a counter-rotating fan assembly to the core gas turbine engine such that air discharged from the counter-rotating fan assembly is channeled directly into an inlet of the gas turbine engine compressor.

Abstract: A method for assembling a gas turbine engine includes coupling a low-pressure turbine to a core turbine engine, coupling a gearbox to the low-pressure turbine, coupling a first fan assembly to the gearbox such that the first fan assembly rotates in a first direction, and coupling a mechanical fuse between the first fan assembly and the low-pressure turbine such that the mechanical fuse fails at a predetermined moment load.

Abstract: A turbofan engine includes a fan, compressor, combustor, high pressure turbine, and low pressure turbine joined in serial flow communication. The high pressure turbine includes two stages of rotor blades to effect corresponding exit swirl in the combustion gases discharged therefrom. A transition duct includes fairings extending between platforms for channeling the combustion gases to the low pressure turbine with corresponding swirl. First stage rotor blades in the low pressure turbine are oriented oppositely to the rotor blades in the high pressure turbine for counterrotation.

Abstract: A method for assembling a gas turbine engine includes coupling a low-pressure turbine to a core turbine engine, coupling a gearbox including an input, a first output, and a second output, to the low-pressure turbine, coupling a first fan assembly to the gearbox first output, and coupling a second fan assembly to the gearbox second output.

Abstract: A turbofan engine includes a fan, compressor, combustor, single-stage high pressure turbine, and low pressure turbine joined in serial flow communication. First stage rotor blades in the low pressure turbine are oriented oppositely to the rotor blades in the high pressure turbine for counterrotation. First stage stator vanes in the low pressure turbine have camber and twist for carrying swirl directly between the rotor blades of the high and low pressure turbines.

Abstract: A method for assembling a gas turbine engine includes coupling a low-pressure turbine to a core turbine engine, coupling a counter-rotating fan assembly including a forward fan assembly and an axially aft fan assembly to the low-pressure turbine such that the forward fan assembly rotates in a first direction and the aft fan assembly rotates in an opposite second direction, and coupling a booster compressor to the low-pressure turbine such that the booster compressor rotates in the first direction.

Abstract: A method for assembling a gas turbine engine including providing a core gas turbine engine at least partially defined by a frame and having a drive shaft rotatable about a longitudinal axis of the core gas turbine engine. A low-pressure turbine is coupled to a core turbine engine. A counter-rotating fan assembly is coupled to the low-pressure turbine. The counter-rotating fan assembly includes a first fan assembly and a second fan assembly. A booster compressor is coupled to the second fan assembly. A gearbox is securely coupled to the frame so that the gearbox is circumferentially positioned about the drive shaft. The first fan assembly is rotatably coupled to an input of the gearbox such that the first fan assembly rotates in a first direction. The second fan assembly is rotatably coupled to an output of the gearbox such that the second fan assembly rotates in a second direction opposite the first direction.

Abstract: A method facilitates assembling a gas turbine engine. The method comprises coupling a low-pressure turbine rotatable about a drive shaft to a counter-rotating fan assembly including a first fan assembly and a second fan assembly wherein the first fan assembly rotates in a first direction and the second fan assembly rotates in an opposite second direction. The method also comprises coupling a planetary gearbox substantially circumferentially about the drive shaft such that an input of the gearbox is coupled to the low-pressure turbine and an output of the gearbox is coupled to the counter-rotating fan assembly, and such that the gearbox is positioned within a lubrication fluid sump that substantially circumscribes the gearbox.

Abstract: A method for assembling a gas turbine engine including providing a core gas turbine engine at least partially defined by a frame. The gas turbine engine has a drive shaft that is rotatable about a longitudinal axis of the core gas turbine engine. A counter-rotating fan assembly is coupled to the low-pressure turbine. The counter-rotating fan includes a first fan assembly that rotates in a first direction and a second fan assembly that rotates in an opposite second direction. A booster compressor is coupled to the second fan assembly. A first bearing assembly is mounted between the drive shaft and the frame and operatively coupled to the first fan assembly to transmit thrust force from the first fan assembly to the frame. A second bearing assembly is mounted with respect to the second fan assembly and operatively coupled to the second fan assembly to transfer thrust force from at least one of the second fan assembly and the booster compressor to the second bearing assembly.

Abstract: A gearbox includes a support structure, at least one sun gear coupled within the support structure, and a plurality of planetary gears coupled within the support structure. The support structure includes a first portion, an axially aft second portion, and a thrust spring coupled between the first and second portions.

Abstract: A jet engine includes a fan arranged upstream of a core engine having a low pressure compressor, a high pressure compressor, a combustion chamber, a high pressure turbine, and a low pressure turbine. The high pressure turbine is drive-connected to the high pressure compressor. The low pressure turbine is drive-connected through a transmission to the low pressure compressor and to the fan, which are respectively driven in opposite rotation directions. A compressor disk of the low pressure compressor is positioned downstream directly after the fan so that a hub end section of the fan and the compressor disk together form a counter-rotating compressor stage.