Abstract: Separate structural units for an inner gear and a housing of a planetary gear device include an inner gear with a first raised portion formed on the outer peripheral surface of the inner gear, where the first raised portion extends towards in a direction that is inclined with respect to the axial direction of the inner gear. A housing includes a second raised portion formed on an inner peripheral surface, where the second raised portion extends in a direction that is inclined in respect to the axial direction. The housing contains the inner gear such that there is a gap formed between the inner peripheral surface of the housing and the outer peripheral surface of the inner gear. Movement of the inner gear within the interior of the housing is limited through linear contact of the first raised portion and the second raised portion.

Abstract: The present invention relates to a planetary wheel (10) for a planetary gear (14) with a planetary wheel bore (28) which runs coaxially or parallel to the planetary wheel axis of rotation (APR) and which at least partially runs through the planetary wheel axis (22). The invention also relates to a planetary carrier (44) for such a planetary wheel (10), comprising a carrier body (46) with a first disk-shaped body (48) which has at least one first bearing recess (60), which has at least one circumferentially extending first catching projection (64), and with a second disk-shaped body (50) having at least one second bearing recess (62), which has at least one circumferentially extending second catching projection (66).

Abstract: An aircraft turbomachine having a longitudinal axis includes a high-pressure (HP) body, a low-pressure (LP) body, a fan, and a reduction gear having an epicyclic gear train. The turbomachine includes three modules: a first module having the LP turbine and the LP shaft, a second module having the LP compressor and a journal secured to the rotor of the LP compressor, and a third module having an input shaft of the reduction gear, this input shaft having an upstream end for coupling to a sun gear of the reduction gear and a downstream end comprising first splines that are oriented parallel to the axis and are configured to be engaged in second complementary splines of said second module.

Abstract: A planetary gear arrangement including a sun gear configured to rotate about an axis of rotation, a plurality of planet gears driven by the sun gear, a ring gear engaged with the plurality of planet gears and a plurality of journal pins arranged in the plurality of planet gears forming a converging gap and a diverging gap therebetween. Each journal pin has at least one longitudinal groove along an outer surface thereof, configured to guide oil on the outer surface when the oil is carried from the converging gap towards the diverging gap due to a revolving movement between a planet gear around a corresponding journal pin. A journal pin for supporting a gear and a gas turbine engine.

Abstract: A power transmission device includes a pinion gear having a large pinion gear and a small pinion gear, a carrier that supports the pinion gear, a ring gear that engages with the small pinion gear, an oil supply unit positioned above a horizontal line that passes through a revolution center of the pinion gear, and a downstream side wall part facing a gear surface of the large pinion gear. The downstream side wall part is arranged to be adjacent to the oil supply unit further downstream in a revolution direction of the pinion gear than the oil supply unit when viewed from an axial direction.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a propulsor section including a propulsor supported on a propulsor shaft, a turbine section including a turbine shaft, a compressor section, and an epicyclic gear train interconnecting the propulsor shaft and the turbine shaft. The gear train includes a sun gear coupled to the turbine shaft, intermediary gears arranged circumferentially about and meshing with the sun gear, a carrier supporting the intermediary gears, and a ring gear including first and second portions each having an inner periphery with teeth intermeshing with the intermediate gears. The first and second portions have axially opposed faces abutting one another at a radial interface. The first and second portions have grooves at the radial interface that form a hole that expels oil through the ring gear.

Abstract: A planet carrier (213) for a speed reducer (210) of a turbomachine (1), this planet carrier (213) having a main axis X and comprising: a cage carrier (222) comprising an annular row of axial fingers (282) about the axis X, which comprises first connection elements, and a cage (220) comprising at its periphery housings (280) and second connection elements which are mounted in said housings and which cooperate with the first connection elements to form connections between the cage carrier (222) and the cage (220), which allow at least one degree of freedom, characterised in that the cage (220) comprises two shells (220a, 220b) which are axially assembled to each other, said first or second connection elements comprising broaches (288) oriented radially with respect to said axis X and passing through radial orifices (220a, 220a2, 220b1, 220b2) of said shells (220a, 220b).

Abstract: A planetary gear transmission has a sun gear, a ring gear, at least one first planet gear, and at least one second planet gear. The first planet gear and the second planet gear are arranged on a planet carrier, and the sun gear, the ring gear, the first planet gear, and the second planet gear mesh with one another. The planetary gear transmission is characterized in that the planet carrier has a first planet carrier part and a second planet carrier part. The first planet carrier part and the second planet carrier part are designed such that the planet carrier parts are rotated relative to each other starting from a base position and can be fixed in their respective rotated position relative to each other, wherein the at least one first planet gear is connected to the first planet carrier part, and the at least one second planet gear is connected to the second planet carrier part.

Abstract: A method of manufacturing a planet carrier of a gearbox comprises manufacturing a plurality of preforms. Each preform comprises a base portion, a first end portion connected to a first end of the base portion, a second end portion connected to a second end of the base portion, a first side portion connected to a first side of the base portion, a second side portion connected to a second side of the base portion and a top portion. The first and second end portions and the first and second side portions are folded relative to the base portion and the top portion is folded and the adjacent edges of the portions of each preform are secured together to form a support structure. A first ring and a second ring are manufactured. The first and second end portions of each support structure are secured to the first and second rings respectively.

Abstract: An epicyclic gear train of an aircraft powerplant is provided. The epicyclic gear train includes a sun gear having a rotation axis, a ring gear, a plurality of intermediate gears circumscribed by the ring gear and being meshed with the sun gear and with the ring gear, a carrier supporting the intermediate gears, and a torque frame attaching the carrier to a stationary structure of the aircraft powerplant to prevent rotation of the carrier and of the intermediate gears about the rotation axis of the sun gear. The torque frame is attached to the carrier at a connection. The torque frame and the carrier cooperatively define a lubricant passage extending through the connection and supplying lubricant to at least one of the intermediate gears.

Abstract: An apparatus and method for reducing edge contact stress concentrations in a press-fit. The apparatus and method of the present disclosure specifically provide for a press-fit collar having a channel circumscribing a collar axis. The channel having an asymmetrical cross-sectional profile in a radial face. The asymmetrical cross-sectional profile being configured to reduce an edge contact pressure.

Abstract: A universal driving device includes a sun gear rotatably provided, a ring gear, wherein a rotation axis of the ring gear is moved relative to a rotation axis of the sun gear in a plane of rotation parallel to a plane of rotation of the sun gear, at least one gear train configured to allow relative motion between the rotation axes of the sun gear and the ring gear and to form a continuous power transmission state between the sun gear and the ring gear, and at least one balance gear engaged with the ring gear.

Abstract: An interdigitated turbine assembly for a gas turbine engine, the interdigitated turbine assembly including a first turbine rotor assembly interdigitated with a second turbine rotor assembly. A first static frame is positioned forward of the first turbine rotor assembly and the second turbine rotor assembly. The first turbine rotor assembly is operably coupled to an inner rotatable component of a gear assembly. The second turbine rotor assembly is operably coupled to an outer rotatable component of the gear assembly. The static structure is connected to the first static frame. A driveshaft is operably coupled to the outer rotatable component. A first bearing assembly is operably coupled to the driveshaft and the first static frame. A second bearing assembly is operably coupled to the first static frame and first turbine rotor assembly. A third bearing assembly is operably coupled to the first turbine rotor assembly and the second turbine rotor assembly.

Abstract: An engine for an aircraft includes an engine core having a turbine, a compressor, and a core shaft connecting the turbine to the compressor; a fan located upstream of the engine core, the fan having a plurality of fan blades; and a gearbox. The gearbox is an epicyclic gearbox and comprises a sun gear, a plurality of planet gears, a ring gear, and a planet carrier on which the planet gears are mounted. The radial bending stiffness of the planet carrier is equal to or greater than 1.20×109 N/m, and/or the tilt stiffness of the planet carrier is greater than or equal to 6.00×108 Nm/rad. A method of operation of such an engine is also disclosed.

Abstract: A planetary gear is disclosed that provides at least a first hollow wheel with a helical gearing and a second hollow wheel with a helical gearing are adapted to rotate in a first rotational direction and a second opposite rotational direction, and a first double planet having a first wheel with a helical gearing meshing with the helical gearing of the first hollow wheel and having a second wheel with a helical gearing meshing with the helical gearing of the second hollow wheel. The disclosed configuration minimizes backlash between the helical gearings.

Abstract: An aircraft turbomachine with a reduction gear has a first shaft and a second shaft having one same axis of rotation, the second shaft being rotationally driven by the first shaft via the reduction gear, the first shaft having elastically deformable means having bellows section(s) and being connected to the reduction gear by a connecting system likewise having elastically deformable means involving a hairpin or bellows section(s).

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a propulsor section including a propulsor supported on a propulsor shaft, a turbine section including a turbine shaft, and an epicyclic gear train interconnecting the propulsor shaft and the turbine shaft. The epicyclic gear train includes a sun gear coupled to the turbine shaft, intermediary gears arranged circumferentially about and meshing with the sun gear, a carrier supporting the intermediary gears, and a ring gear including first and second portions each having an inner periphery with teeth intermeshing with the intermediate gears. The first and second portions have axially opposed faces abutting one another at a radial interface and respective flanges extending along the radial interface radially outward from the teeth. The first and second portions define a trough axially between and separating the teeth of the first portion from the teeth of the second portion.

Abstract: A gas turbine engine includes a turbine section that includes a fan drive turbine. A geared architecture includes a sun gear in driving engagement with the fan drive turbine. A plurality of planet gears surrounds the sun gear. A ring gear surrounds the plurality of planet gears. A deflection limiter mechanically attaches the ring gear to an engine static structure. The deflection limiter includes a first support fixed to the ring gear that has a first interlocking feature and a second support fixed to the engine static structure that has a second interlocking feature. The first and second interlocking features define at least one of a radial clearance of between 0.005 inches (0.127 mm) and 0.080 inches (2.032 mm) or a circumferential clearance of between 0.005 inches (0.127 mm) and 0.250 inches (2.032 mm). A fan section includes a plurality of fan blades in driving engagement with the geared architecture through a fan drive shaft.

Abstract: A turbofan engine includes a fan section. A turbine section is in driving engagement with the fan section through a geared architecture. A flexible support supports the geared architecture relative to an engine static structure. A deflection limiter includes at least one of an axially extending branch or a radially extending branch. A flexible output shaft is in driving engagement with the fan section and driven by the geared architecture. A speed change mechanism for a gas turbine engine is also disclosed.

Abstract: A gas turbine engine includes a bypass ratio greater than about ten (10). A fan is supported on a fan shaft and has a plurality of fan blades. A gear system is connected to the fan shaft. A plurality of planetary gears and a first set of opposed angled ring gear teeth are separated from a second set of opposed angled ring gear teeth. A lubricant flow path is located axially between the first set of opposed angled ring gear teeth and the second set of opposed angled ring gear teeth. A gear system support is relative to a fixed housing facilitating segregation of vibrations. An annular channel is axially aligned with the lubricant flow path. A low pressure turbine has an inlet, an outlet, and a low pressure turbine pressure ratio greater than 5:1.

Abstract: A planetary gear box, which has a sun gear, a plurality of planet gears, a ring gear, a plurality of planet pins an axially front carrier plate and an axially rear carrier plate, wherein the planet pins are connected to the carrier plates. Provision is made whereby the planet pins, at their axial ends, have in each case one platform, radially oriented slots are formed on the carrier plates, and the platforms are pushed via guide grooves into the radially oriented slots. The invention furthermore relates to a method for the assembly of a planetary gear box.

Abstract: A one-way clutch includes a first rotator including an inner gear and configured to rotate on a first axis, a planetary gear configured to mesh with the inner gear and configured to rotate on a second axis that revolves around the first axis, a second rotator configured to rotate on the first axis and including a stopper configured to stop rotation of the planetary gear by engaging with the planetary gear, and an urging member configured to urge the planetary gear not to be brought in contact with the stopper in a state where the first rotator and the second rotator relatively rotate.

Abstract: A sun gear for a mechanical reduction gear of a turbine engine, in particular for aircraft, the sun gear having a general annular shape about an axis and comprising at the outer periphery thereof, a meshing gearing with planet gears of the reduction gear, and at the inner periphery thereof, splines for coupling with an input shaft of the reduction gear, characterised in that the sun gear has a staged profile in axial cross-section, and preferably comprises an annular recess opening radially inwards and configured to receive at least one oil jet.

Abstract: A planetary gearbox, a splined sleeve, a gas turbine engine with a planetary gearbox and a method for producing a torque-proof connection between a planetary carrier and a support element. The splined sleeve is formed with an outer substantially cylindrical shell surface area and an inner conical shell surface area, and is inserted between the planetary carrier and the support element for creating the torque-proof connection. The diameter of the inner conical shell surface area decreases in the axial direction, starting from an end of the splined sleeve in the direction of a second end of the splined sleeve. The outer cylindrical shell surface area is formed in a stepped manner. The outer cylindrical shell surface area comprises a first cylindrical section and a second cylindrical section which has a diameter larger than the diameter of the first cylindrical section. Between the sections, a conical area is provided.

Abstract: A gas turbine engine includes a fan shaft that drives a fan that has fan blades. An outer housing surrounds the fan. A bypass flow path is within the outer housing. A fan shaft support that supports the fan shaft defines a fan shaft support transverse stiffness. A gear system is connected to the fan shaft. The gear system includes a gear mesh that defines a gear mesh transverse stiffness. A flexible support which supports the gear system relative to a static structure defines a flexible support transverse stiffness. The flexible support transverse stiffness is less than 11% of the fan shaft support transverse stiffness. The flexible support transverse stiffness is less than 8% of the gear mesh transverse stiffness.

Abstract: An engine includes a static frame member; a spool configured to rotate relative to the static frame member during operation of the engine; a gearbox coupled to the spool; and a gearbox coupling assembly mounting the gearbox to the static frame member using a plurality of moveable connection members, each moveable connection member including a sliding connection allowing for movement of the gearbox relative to the static frame member in a plane perpendicular to an axial direction of the engine.

Abstract: A method of assembling an epicyclic gear train includes providing a unitary carrier that includes spaced apart walls and circumferentially spaced mounts interconnecting the walls, spaced apart apertures provided between the mounts at an outer circumference of the carrier, gear pockets provided between the walls and mounts extending to the apertures, and a central opening in at least one of the walls, inserting an intermediate gear through the central opening and moving the intermediate gear radially into the gear pocket to extend through the aperture, inserting a baffle into the carrier, and inserting a sun gear through the central opening to intermesh with the intermediate gear.

Abstract: A planetary gearset (6) has a sun gear (10) connected rotationally fixedly to an input shaft (8), a carrier (15) that carries planetary gears (11) and is connected rotationally fixedly to an output shaft (16), and a ring gear (14) fixedly connected to a housing (4) that encloses the planetary gearset (6). To reduce the noise emission from the planetary gearset with as little structural complexity as possible without reducing its efficiency due to pressure rings that are guided and slide against the planetary gears and the carrier, the sun gear (10), the planetary gears (11) and the ring gear (14) are provided with helical teeth and the input shaft (8) is at least indirectly supported on the housing (4), in both axial directions, by way of a single roller bearing (20).

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan shaft configured to drive a fan, a support configured to support at least a portion of the fan shaft, the support defining a support transverse stiffness and a support lateral stiffness, a gear system coupled to the fan shaft, and a flexible support configured to at least partially support the gear system. The flexible support defines a flexible support transverse stiffness with respect to the support transverse stiffness and a flexible support lateral stiffness with respect to the support lateral stiffness. The input defines an input transverse stiffness with respect to the support transverse stiffness and an input lateral stiffness with respect to the support lateral stiffness.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan shaft driving a fan having fan blades. The fan delivers airflow to a bypass duct. A fan shaft support supports the fan shaft and defines a support transverse stiffness. A gear system is connected to the fan shaft and includes a gear mesh defining a gear mesh transverse stiffness and a reduction ratio greater than 2.3. A gear system input is connected to the gear system and defines a gear system input lateral stiffness. A flexible support supports the gear system and defines a flexible support transverse stiffness. The gear system input lateral stiffness is less than 5% of the gear mesh lateral stiffness and the flexible support transverse stiffness is less than 20% of the fan shaft support transverse stiffness.

Abstract: The gear is used for driving pneumatic turbomachinery while providing insignificant impact of the tolerances on the performance parameters leading to extended service life. It comprises a sun shaft (1) supported and driven by at least three planet wheels (2) rotating around their axes, on each side of which in axial direction there is an identical radially-elastic flat frame (7) in the shape of a flat planar closed-contour element having at least three annular bearing slots (7.1) with a cylindrical hole accepting the respective bearings (4) of the planet wheels (2). The bearing slots (7.1) are equidistant from the center of the frame (7) and each two adjacent bearing slots (7.1) are connected to one another via a respective curvilinear bridge (7.2) whose inner bend, towards the center, has an ear formed thereon (7.4) accepting the respective support pillar (6) fixed to the rear housing (5).

Abstract: A torsional vibration damper includes a planetary rotary unit and an elastic body that couples two rotary elements of three rotary elements so that the two rotary elements can rotate relatively to each other. The torsional vibration damper includes a shaft supporting member by which a rotation center axis of at least any one rotary element of the two rotary elements and a rotation center axis of the rotary element other than the planetary rotary unit and the two rotary elements are held on the same axis. The shaft supporting member has a holding section that is disposed in a position between fellow planetary rotary elements and not making contact with the planetary rotary elements and that fits with and thereby suppresses movement of the rotary element other than the planetary rotary unit and the two rotary elements in the axial direction.

Abstract: A gear assembly support for a gas turbine engine includes a spline ring configured to fit into a case of the gas turbine engine and a flex support. The flex support includes splines for engaging the spline ring and an inner portion attachable to a portion the gear assembly.

Abstract: A planetary gear system for a turbomachine includes a forward planetary gear assembly including a plurality of forward planet gears meshed to a forward sun gear disposed on a power shaft and a forward ring gear meshed to the forward planet gears and an aft planetary gear assembly aft of the forward planetary assembly including a plurality of aft planet gears meshed to an aft sun gear disposed on the power shaft and an aft ring gear meshed to the aft planet gears. The system also includes a gear housing disposed between the forward planetary gear assembly and the aft planetary gear assembly. The gear housing includes a stationary carrier, wherein the forward and aft planet gears are rotatably mounted to the stationary carrier, and a mount extending radially from the stationary carrier that is connectable to a stationary portion of the turbomachine.

Abstract: A planetary transmission for transmitting drive power to a work machine, comprising a plurality of planetary gearwheels, a plurality of planetary shafts and at least one planetary carrier, the planetary gearwheels being arranged in each case rotatably on one of the planetary shafts, and the planetary shafts being fastened in each case to the planetary carrier, characterized in that the planetary carrier is configured for a releasable connection to a work machine shaft.

Abstract: The invention relates to a method for assembling (S) a planet carrier (16), comprising the following steps: separately producing (S1) the cage (20) and the cage carrier (30), providing a machining allowance at one element from among the through-holes (23, 25) in at least one upright (21) of the cage (20) or the through-hole (32) in a finger bar (31) of the cage carrier (30), and/or at one element from among a bearing seat (26) or a rolling bearing seat (41, 42); assembling (S2) the cage (20) and the cage carrier (30) and securing (S3) same to produce a one-piece assembly; determining (S4) the position of a reference axis (Y1, Y2) linked to the cage (20), to the cage carrier (30) and/or to the shaft (40); and, taking account of the position of the reference axis (Y1, Y2), machining (S5) all or part of the machining allowances.

Abstract: A gas turbine engine includes a fan, a fan shaft coupled with the fan and arranged along an engine central axis, a gear system rotatably coupled to the fan shaft, and first and second flexible couplings supporting the gear system. The first flexible coupling and the second flexible coupling are subject to, with respect to the engine central axis, torsional motion and lateral motion. The first and second flexible couplings individually having a torsional stiffness under the torsional motion and a lateral stiffness under the lateral motion, and a ratio, of each of the first and second flexible couplings, of the torsional stiffness to the lateral stiffness is greater than or equal to 2.

Abstract: An input coupling for a fan drive gear system includes features for maintaining lubricant within a splined interface. The fan drive gear system includes a gear rotatable about an axis that includes an inner spline. The input coupling includes an outer spline engaged to the inner spline of the gear. The input coupling includes an aft oil dam for maintaining lubricant within an interface between the outer spline and the inner spline.

Abstract: A gas turbine engine includes a fan shaft that drives a fan that has fan blades. A fan shaft support that supports the fan shaft defines a fan shaft support transverse stiffness. A gear system is connected to the fan shaft and includes a gear mesh that defines a gear mesh transverse stiffness. A flexible support supports the gear system and defines a flexible support transverse stiffness. The flexible support transverse stiffness is less than 11% of the fan shaft support transverse stiffness and less than 8% of the gear mesh transverse stiffness.

Abstract: A compound planet gear arrangement (100, 200, 300, 400) having a ring gear (110, 210, 310, 410), at least two planet gear units (120, 220, 329, 429) and a sun wheel (130, 230, 330, 430). Each planet gear unit comprise a primary planet gear (121, 221, 321, 421) with primary planet teeth meshing with the ring gear and a secondary planet gear (122,222, 322, 422) with secondary planet teeth meshing with the sun wheel. The secondary planet gear is axially connected with the primary planet gear and has a diameter which is larger than the diameter of the primary planet gear Each planet gear unit (120, 220, 320,420) comprises a shock absorbing transmission arrangement (20) which is arranged to allow a limited elastic rotation of the secondary planet teeth relative to the primary planet teeth. A drive train arrangement comprising such a compound planet gear arrangement is also disclosed.

Abstract: A geared turbofan engine with a sun shaft driving a sun gear of planetary gearbox. The sun shaft having a front section proximal to the gearbox and a rear section distal from the gearbox. The outer diameter of the front section of the sun shaft is smaller than the outer diameter of the rear section of the sun shaft. The front section of the sun shaft having between two and four undulant sections, wherein each undulant section having at least one axial part extending in axial direction of the sun shaft and two diaphragm parts on either side of the at least one axial part extending in radial direction outward, the at least one axial part of the undulant section having an inner diameter smaller than the outer diameter of the front section of the sun shaft.

Abstract: An apparatus for an air turbine starter for an engine. The air turbine starter includes a housing defining an inlet, an outlet, and a flow path extending between the inlet and the outlet for communicating a flow of gas there through. A turbine member is journaled within the housing and disposed within the flow path for rotatably extracting mechanical power from the flow of gas and having a turbine output shaft. The air turbine starter further includes a planetary gear system drivingly coupled with the turbine output shaft and including a sun gear, a ring gear mounted to the housing, and a set of planetary gears operably coupling the sun gear and the ring gear with the sun gear is coupled to the turbine output shaft.

Abstract: A gas turbine engine includes a fan, an engine static structure, a geared architecture to drive the fan and supported relative to the static structure, a fan drive turbine to drive the geared architecture, a first member secured to the geared architecture, and a second member secured to the engine static structure and configured to cooperate with the first member to limit movement of the geared architecture relative to the static structure. A fan drive gear system and method are also disclosed.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan shaft configured to drive a fan, a support configured to support at least a portion of the fan shaft, the support defining a support transverse stiffness and a support lateral stiffness, a gear system coupled to the fan shaft, and a flexible support configured to at least partially support the gear system. The flexible support defines a flexible support transverse stiffness with respect to the support transverse stiffness and a flexible support lateral stiffness with respect to the support lateral stiffness. The input defines an input transverse stiffness with respect to the support transverse stiffness and an input lateral stiffness with respect to the support lateral stiffness.

Abstract: According to various embodiments, disclosed is a fixed support and gutter system for a ring gear of a turbine engine gear train, the fixed support and gutter system comprising a support structure having an undulating path which forms at least a portion of a gutter structure for capturing oil shed off the gear train.

Abstract: A planetary gear arrangement includes a planet carrier assembly defining a sun gear rotation axis for rotatably supporting a plurality of planetary gears about the sun gear rotation axis and a positioning element coupling a first of the planetary gears to the planet carrier. The planetary gear is movable between first and second positions for displacing a rotation axis of the first of the planetary gears relative to the sun gear rotation axis to change load share among the plurality of planetary gears.

Abstract: A gas turbine engine according to an example of the present disclosure includes, among other things, a fan shaft driving a fan having fan blades. A fan shaft support supports the fan shaft and defines a support transverse stiffness. A gear system is connected to the fan shaft and includes a gear mesh defining a gear mesh transverse stiffness and a reduction ratio greater than 2.3. A gear system input is connected to the gear system and defines a gear system input lateral stiffness. A flexible support supports the gear system and defines a flexible support transverse stiffness. The gear system input lateral stiffness is less than 5% of the gear mesh lateral stiffness and the flexible support transverse stiffness is less than 20% of the fan shaft support transverse stiffness.

Abstract: A geared architecture for a gas turbine comprising an output shaft for connection with a fan, an input shaft and a gearbox connecting the input shaft with the output shaft. The gearbox has a forward planet carrier plate supported by a forward radially fixed bearing structure and a rearward planet carrier plate supported by a rearward radially fixed bearing structure. By supporting the carrier plates on radially fixed bearing structures the planet carriers can rotate about their own axis to lower vibration and mesh forces within the gearbox.

Abstract: An epicyclic gear train includes a carrier that supports star gears that mesh with a sun gear. A ring gear surrounds and meshes with the star gears. The star gears are supported on respective journal bearings. Each of the journal bearings includes a peripheral journal surface and each of the star gears includes a radially inner journal surface that is in contact with the peripheral journal surface of the respective journal bearing.

Abstract: 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.