Oil scavenge system for a gearbox

A gearbox including a gear and a gutter. The gear is rotatable about a rotational axis in a rotational direction. The gear has a radial direction and an axial direction, and the gear expels oil radially outward when the gear rotates. The gutter is positioned radially outward of the gear in the radial direction of the gear to collect oil expelled by the gear when the gear rotates. The gutter includes an axial surface, a plurality of radial surfaces including a first radial surface and a second radial surface, and at least one opening to allow the oil collected in the gutter to flow therethrough. Each of the first radial surface and the second radial surface is oriented in a direction intersecting the axial surface, and the at least one opening is formed on both the axial surface and one of the first radial surface and the second radial surface.

TECHNICAL FIELD

The present disclosure relates to a gearbox and, more particularly, to an oil scavenge system for an epicyclical gear train, such as epicyclical gear trains used in gas turbine engines for aircraft.

BACKGROUND

Oil is used in power gearboxes, including gearboxes having an epicyclical gear train, to lubricate gears and bearings in the gearbox. In an epicyclical gear train, oil may be supplied to lubricate the mesh between the gears. As the gears of the epicyclical gear train rotate during operation, the oil is expelled outwardly by inertial (or centrifugal) forces. The oil may be collected by a gutter located radially outward of the gears.

DETAILED DESCRIPTION

Features, advantages, and embodiments of the present disclosure are set forth or apparent from a consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that the following detailed description is exemplary and intended to provide further explanation without limiting the scope of the disclosure as claimed.

As noted above, oil used to lubricate the gears of an epicyclical gear train may be expelled radially outward. The epicyclical gear may include a sun gear and planet gears. In some embodiments, the planet gears rotate individually about an axis and collectively about the sun gear. As discussed further below, the planet gears may be bihelical gears that expel the oil in an axial direction of the planet gear. A local oil gutter is positioned in the carrier of the planet gears to collect the oil expelled from the planet gears. This local gutter includes openings that are positioned in a way that accounts for the axial movement of the oil from the bihelical planet gears to efficiently remove the oil to avoid oil accumulation which may result in higher windage loss or oil churning in extreme cases. A global gutter that circumscribes the gears of the epicyclical gear train may have similarly designed openings as the local gutter to collect oil expelled from the collective rotation of the planet gears.

The gutter designs discussed herein are suitable for use in gearboxes used in the engines of aircraft and, in particular, gas turbine engines.FIGS.1and2illustrate two gas turbine engines that may be used for propulsion of an aircraft. The gas turbine engine shown inFIG.1is a high-bypass turbofan engine100. The gas turbine engine shown inFIG.2is a turboprop engine102. Both of the turbofan engine100and the turboprop engine102include a gearbox200having gutter arrangements according to the present disclosure, as will be discussed further below. Although the description below refers to the turbofan engine100and/or the turboprop engine102, the present disclosure is also applicable to wind turbines and turbo-machinery, in general, including, e.g., propfan gas turbine engines, turbojet gas turbine engines, and turboshaft gas turbine engines, including marine turbine engines, industrial turbine engines, and auxiliary power units. Moreover, the gutter arrangements discussed herein may be used in any suitable gearbox, including those having an epicyclical gear train.

As shown inFIG.1, the turbofan engine100has an axial direction A (extending parallel to a longitudinal centerline104), a radial direction R, and a circumferential direction. The circumferential direction (not depicted inFIG.1) extends in a direction rotating about the longitudinal centerline104. The turbofan engine100may include an engine core106(also referred to as a turbomachine) and a fan assembly140. The engine core106may generally include, in serial flow arrangement, a compressor section110, a combustion section120, and a turbine section130. The compressor section110may define one or more compressors, such as, for example, a low-pressure compressor112and a high-pressure compressor114. The turbine section130may define one or more turbines, such as, e.g., a high-pressure turbine132and a low-pressure turbine134. In various embodiments, the compressor section110may further include an intermediate pressure compressor. In still other embodiments, the turbine section130may further include an intermediate pressure turbine. In wind turbine applications, the engine core106may generally be defined as one or more generators.

The low-pressure compressor112and the high-pressure compressor114in the compressor section110and the high-pressure turbine132, and the low-pressure turbine134in the turbine section130, may each include one or more rotors. In one embodiment, the rotors include one or more shafts of the turbofan engine100connecting the compressor section110to the turbine section130. In other embodiments, the rotors generally define a disk extended at least partially in the radial direction R and a plurality of airfoils connected in a circumferentially adjacent arrangement and extended outward in the radial direction R from the disk. In one embodiment, the one or more rotors may each be connected together. For example, each rotor of the turbine section130or the compressor section110may be connected by mechanical fasteners, such as, e.g., bolts, nuts, screws, and/or rivets, or by a bonding process, such as, e.g., welding, friction bonding, diffusion bonding, etc. In various embodiments, one or more compressors of the compressor section110may be drivingly connected and rotatable with one or more turbines of the turbine section130, by way of the one or more shafts. For example, the rotors of the low-pressure compressor112may be connected to and driven by the rotors of the low-pressure turbine134, by a low-pressure shaft122, and the rotors of the high-pressure compressor114may be connected to and driven by the rotors of the high-pressure turbine132, by a high-pressure shaft124.

The fan assembly140generally includes a fan rotor142. The fan rotor142includes a plurality of blades144that are coupled to and extend outwardly from the fan rotor142in the radial direction R. In the embodiment shown inFIG.1, the fan rotor142may extend in the axial direction A toward a forward end from a reduction gearbox or a power gearbox200(herein referred to as “gearbox200”). The fan assembly140further includes a coupling shaft126coupled to the gearbox200and extended toward an aft end of the turbofan engine100. The coupling shaft126may couple the engine core106to the gearbox200. InFIG.1, an outer casing of the gearbox200is omitted for clarity.

As shown inFIGS.1and3, the gearbox200of this embodiment includes an epicyclical gear train202, including a sun gear210and a plurality of planet gears222. The sun gear210is axially installed onto and concentric to the coupling shaft126, such that the sun gear210is attached to, or integral to, the coupling shaft126. As will be discussed further below, the sun gear210is driven by the engine core106(receives a torque from the engine core106) to rotate about a rotational axis212, which, in this embodiment, is coincident with the longitudinal centerline104. The sun gear210includes a plurality of teeth that engage (or mesh with) a plurality of teeth formed on each of the plurality of planet gears222. A ring gear230(or annular gear) engages with the plurality of planet gears222and surrounds the plurality of planet gears222. More specifically, the ring gear230includes a plurality of teeth that engage (or mesh with) a plurality of teeth formed on each of the plurality of planet gears222.

In this embodiment, the ring gear230is stationary. The plurality of planet gears222rotate, not only about a rotational axis224for each planet gear222, but the plurality of planet gears222also collectively rotate about the rotational axis212of the sun gear210. The planet gears222are rotatably connected to a carrier226, and the carrier226rotates about the rotational axis212of the sun gear210as the plurality of planet gears222collectively rotate. The plurality of planet gears222may be rotatably connected to the carrier226by various bearings (e.g., rollers, balls, or other bearing types, e.g., a journal bearing). The carrier226further connects to an output element227to allow for rotation, and the transfer of power and torque from the sun gear210through the plurality of planet gears222. For example, the carrier226may be coupled to or otherwise integral with the fan rotor142. Each planet gear222of the plurality of planet gears222engages with the sun gear210to be rotated by the sun gear210. Each planet gear222is configured to receive power and torque from the sun gear210.

In other embodiments, the plurality of planet gears222may each be fixed such that the rotational axis224of each planet gear222is fixed relative to the sun gear210. In such an arrangement, the ring gear230rotates about the rotational axis212of the sun gear210, and the ring gear230connects to the output element227, such as the fan rotor142, to allow for rotation, and transfer of power and torque from the sun gear210through the plurality of planet gears222. The ring gear230engages with each planet gear222of the plurality of planet gears222to be rotated by the plurality of planet gears222. The ring gear230is configured to receive power and torque from the plurality of planet gears222. In various embodiments, the gearbox200may further include additional planet gears disposed radially between the plurality of planet gears222and the sun gear210, or between the plurality of planet gears222and the ring gear230. The various gears may be various suitable gear designs, such as helical gears and, in the case of the planet gears222, may include step gears.

As shown inFIG.1, the coupling shaft126is connected to the engine core106to transmit torque and power from the engine core106to the sun gear210, and through the epicyclical gear train202to the fan rotor142. The fan rotor142may be connected to carrier226or the ring gear230to receive torque from the sun gear210, and to transfer torque to drive the fan assembly140. As power is transmitted from the engine core106, the gearbox200provides torque at an output speed to the fan rotor142that is more suitably adjusted for the fan assembly140. For example, the gearbox200may reduce the speed of the fan rotor142relative to the engine core106by a factor of two or more. According to one embodiment, the gearbox200reduces the rotational speed from the engine core106(e.g., the compressor section110or the turbine section130) and provides a desired amount of torque and rotational speed to the fan assembly140.

During operation of the turbofan engine100, a volume of air (inlet air12), as indicated schematically by arrow12, enters the turbofan engine100. As the inlet air12passes across the fan blades144, a portion of the air (bypass air14), as indicated schematically by arrow14, is directed or routed outside the engine core106to provide propulsion. Additionally, another portion of air, as indicated schematically by arrow22and referred to as core air22, is directed or routed through an associated inlet108into the compressor section110. The core air22is progressively compressed as it flows through the compressor section110, such as through the low-pressure compressor112and the high-pressure compressor114, toward the combustion section120. The now-compressed air24(as indicated schematically by arrows24) flows into the combustion section120where a fuel is introduced, mixed with at least a portion of the compressed air24, and ignited to form combustion gases26. The combustion gases26flow into the turbine section130, causing rotary members of the turbine section130to rotate, and to support operation of respectively coupled rotary members in the compressor section110and/or the fan assembly140, as discussed above.

As noted above,FIG.2shows a turboprop engine102that may be equipped with the gearbox200having the gutter arrangements discussed herein. The discussion of the turbofan engine100shown inFIG.1also applies to the turboprop engine102shown inFIG.2. The same reference numerals are used for the same or similar components between the turbofan engine100and the turboprop engine102, and a detailed description of these components is omitted. In the arrangement shown inFIG.2, the inlet108is located on the aft end of the turboprop engine102, and the core air22flows in a forward direction, but other arrangements of turboprop engine102may be used where the inlet108is located on the forward end of the turboprop engine102. Instead of a fan assembly140as described inFIG.1, the turboprop engine102includes a propeller assembly150. The propeller assembly150includes a plurality of propeller blades152that are coupled to and extend outwardly from a propeller shaft154in the radial direction R. As with the fan rotor142ofFIG.1, the propeller shaft154is connected to the gearbox200to receive torque and power from the engine core106through the epicyclical gear train202. The propeller shaft154may be connected to the epicyclical gear train202in a manner similar to the fan rotor142, as discussed above. InFIG.2, the outer casing of the gearbox200and a global gutter are omitted for clarity.

FIG.3is a perspective, cross-sectional view of the gearbox200according to an embodiment. The cross-sectional view ofFIG.3is taken along line3-3shown inFIG.1. As discussed above, the gearbox200includes the epicyclical gear train202including the sun gear210, the plurality of planet gears222rotatably connected to the carrier226, and the ring gear230. Oil may be used to lubricate the rotating parts of the gearbox200, including the sun gear210, the planet gears222, and the ring gear230. An oil system240is configured to supply oil to the gearbox200. In this embodiment, the oil system240includes an oil pump241that draws oil from a reservoir243(or sump). The oil pump241pressurizes and drives the flow of oil to be injected by at least one oil nozzle245. Oil may be injected downstream (in the rotation direction) of a nip formed between meshing (engaging) gears. As shown inFIG.3, for example, the oil nozzle245is fluidly connected to the reservoir244and configured to inject oil in a nip formed between one of the planet gears222and the ring gear230. In this embodiment, the nip is where the teeth of the planet gear222meshes with the teeth of the ring gear230. A plurality of oil nozzles245may be used, such as, for example, at each of the nips formed between the planet gears222and the ring gear230.

FIG.4is a detail view of detail4inFIG.3showing the oil nozzle245injecting oil on the converging side of the nip between one of the planet gears222and the ring gear230. The oil nozzle245is preferably located upstream of the nip and injects oil in a direction toward the nip as indicated by the arrows labeled246. Oil may be supplied to the epicyclical gear train202using other suitable supply devices and at other locations, including, for example, nips formed between the planet gears222and the sun gear210.

FIG.5is a table schematically illustrating the axial flow of oil for different apex directions of the sun gear210and the planet gears222. The sun gear210, the plurality of planet gears222, and the ring gear230may be bihelical gears. The following discussion of one of the planet gears222applies equally to the other planet gears222, the sun gear210, and the ring gear230. The planet gear222has an axial direction (a direction of the rotational axis224), a radial direction, and a circumferential direction (a direction of rotation). The width of the gear is in the axial direction. The planet gear222includes a plurality of teeth250, with each tooth250on the bihelical gear having a first portion252and a second portion254. Each of the first portion252and the second portion254is angled relative to the axial direction of the gear. The angle of the first portion252and the second portion254intersects such that the first portion252and the second portion254converge at an apex256. In some embodiments, the apex256may be in the center of the width of the gear. In some embodiments, the bihelical planet gear222may be formed by two separate helical gears that are coupled together to operate as the planet gear222. The first portion252and the second portion254are shown as being in phase in these embodiments, but other arrangements of the bihelical gear may be used, such as the second portion254being angularly displaced by, for example, a half tooth circular pitch or a quarter tooth circular pitch, from the first portion252. As the planet gear222rotates about the rotational axis224, the oil is expelled radially outward by inertial (or centrifugal) forces and collected by a local gutter260connected to the carrier226. In this embodiment, the local gutter260is integrally formed in the carrier226(seeFIG.8).

Because of the helical nature of these gears, the oil has an axial component, in addition to a circumferential component of travel. The table inFIG.5identifies the axial component of the expelled oil direction from the rotational effect of the gears, as well as the force direction acting on the two halves of the gear. The center line represents the location of the apex, which in this embodiment is the center of the bihelical gear. For example, in the oil direction column, arrows pointing towards the center line means the axial component of the expelled oil from the two halves of the bihelical gear is towards the center, while the arrows pointing away from the center line means the axial component of the expelled oil from the two halves of the bihelical gear is away from the center. The same applies to the force column—arrows pointing to the center line indicates forces on the two halves of bihelical gear act towards the middle, while arrows pointing away from the center line indicates the forces on the two halves of bihelical gear drive the two halves away. The table lists oil and force directions for the sun gear210, the planet gears222, and the ring gear230depending on the position of the apex relative to the rotational direction of the gear. As shown inFIG.5, the oil will travel toward the apex256in the axial and circumferential directions of the planet gear222when the apex256is trailing the rotational direction of the planet gear222, and the oil will travel away from the apex256in the axial and circumferential directions of the planet gear222when the apex256is leading the rotational direction of the planet gear222.

FIGS.6A and6Bshow a configuration of the local gutter260when the apex256is trailing the rotational direction of the planet gear222.FIG.6Ais a perspective view of the local gutter260with the planet gears222and sun gear210shown in broken lines.FIG.6Bshows the position of the local gutter260in the epicyclical gear train202. The local gutter260is mounted on the carrier226in close proximity to the planet gears222and the sun gear210. The local gutter260rotates with the carrier226. The local gutter260is positioned between adjacent planet gears222such that the local gutter260collects oil from each of the adjacent planet gears222.

The local gutter260of this embodiment has a trapezoidal cross section, having an axial surface262and a plurality of radial surfaces264. In this embodiment, the local gutter260includes two radial surfaces, a first radial surface and a second radial surface. The local gutter260may have other shapes, such as a U-shape. Although shown as a generally planar surface, the axial surface262and the plurality of radial surfaces264may have other suitable shapes, such as curved shapes, or be divided into multiple sections. The axial surface262of this embodiment is oriented in a direction parallel to the rotational axis224of the planet gear222. Each of the radial surfaces264is oriented in a direction intersecting the axial surface262. In this embodiment, each of the radial surfaces264forms an oblique angle with the axial surface262and extends outward from the axial surface262in the axial direction, but, in some embodiments, each of the radial surfaces264may be perpendicular to the axial surface262. A plurality of openings266is formed on the local gutter260to allow the oil collected in the local gutter260to flow from the local gutter260at the openings and flow into a cavity268(see alsoFIG.8). The shape of the local gutter260and the position of the openings266are placed for efficient removal and utilization of the oil. As noted above, the oil travels toward the apex256in the axial direction of the planet gear222when the apex256is trailing the rotational direction of the planet gear222, such as in the configuration shown inFIGS.6A and6B. The oil has both a radial component of travel and an axial component of travel, and each opening266is formed both on the axial surface262and one of the radial surfaces264.

FIG.6Cis a schematic of the local gutter260positioned over the planet gear222in the arrangement shown inFIGS.6A and6B. Because the oil travels toward the apex256, the width of the local gutter260in the axial direction does not need to be greater than the width of the planet gear222. The bihelical planet gear222may have a gap258(or a groove) formed between the first portion252and the second portion254. The edges of the local gutter260are positioned such that the local gutter260at least covers the gap258. In this embodiment, the width of the local gutter260is the width of the gap258or greater. The axial surface262may also have a width that is at least the width of the gap258and, in some embodiments less than the width of the planet gear222.

FIGS.7A,7B, and7Cshow a configuration of the local gutter260when the apex256is leading the rotational direction of the planet gear222.FIG.7Ais a perspective view of the local gutter260with the planet gears222and sun gear210shown in broken lines.FIG.7Bshows the position of the local gutter260in the epicyclical gear train202.FIG.7Cis a schematic of the local gutter260positioned over the planet gear222in the arrangement shown inFIGS.7A and7B. The local gutter260has the same general shape and components as the local gutter260discussed above with reference toFIGS.6A and6B, but the sizing of the local gutter260is different. As noted above, the oil travels away from the apex256in the axial direction of the planet gear222when the apex256is leading the rotational direction of the planet gear222. In this case, oil tends to be sprayed out axially away from the apex256. Therefore, catching oil on both sides of the planet gear222is needed. In order to catch the oil spun out, the axial surface262covers the width of the planet gear222, and the radial surfaces264extend outwardly beyond the width of the planet gear222to cover at least a portion of the sides. The edges of the local gutter260are positioned at least at the outer edges of the teeth250and preferably beyond the outer edges of the teeth250. In this embodiment, the width of the local gutter260is at least the width of the planet gear222and is preferably greater than the width of the planet gear222. In some embodiments, the width of the axial surface262is the same width as the planet gear222.

FIG.8is a cross-sectional view of the carrier226, taken along line3-3inFIG.1, andFIG.9is a perspective, cross-sectional view, showing detail9inFIG.8.FIGS.8and9show the local gutter260in the carrier226. As noted above, oil collected by the local gutter260flows out of the local gutter260and into a cavity268formed in the local gutter260. Here, a first portion of the local gutter260collects oil from one planet gear222(seeFIG.3), and a second portion of the local gutter260collects oil from an adjacent planet gear222. The cavity268is formed therebetween. The cavity268includes local gutter exits269(openings) formed on a surface228of the carrier226that faces the ring gear230(seeFIG.3). As the carrier226rotates, the oil is expelled outwardly through the local gutter exit269by inertial (or centrifugal) forces and is collected by a global gutter247(FIG.3).

As shown inFIG.3, in some embodiments, the global gutter247circumscribes the gears of the epicyclical gear train202, such that the global gutter247is located radially outward of the carrier226. The global gutter247is shown as having a U-shape in this embodiment, but the global gutter247may have any shape suitable for collecting the oil therein. The global gutter247includes a scavenge port249. The oil collected in the global gutter247may be removed at the scavenge port249. The scavenge port249is located on a bottom portion of the global gutter247so that gravity may assist in the flow of oil to the scavenge port249. The scavenge port249is fluidly connected to the reservoir243, and the oil is scavenged from the global gutter247through the scavenge port249and returned to the reservoir243. The reservoir243, thus, is configured to receive oil from the scavenge port249.

FIG.10is a perspective, cross-sectional view of an upper portion of the gearbox200, taken along line10-10inFIG.2, andFIG.11is a perspective view of one half of the ring gear230shown inFIG.10. As noted above, the ring gear230may be stationary and, in this embodiment, has an integrated global gutter290. The integrated global gutter290is integrally formed in the ring gear230. The ring gear230of this embodiment is formed by two halves in the axial direction. Each half includes a flange232, and the flanges232of each half are fastened to each other by a suitable fastener, such as a bolt.

Each half also includes a plurality of teeth234. As shown inFIG.10, the integrated global gutter290is formed between the teeth234of each half when the ring gear230is assembled. The integrated global gutter290of this embodiment has a U-shape with an axial surface292and two radial surfaces294. A plurality of openings296is also formed in the integrated global gutter290. As with the openings266of the local gutter260discussed above, the openings296of the integrated global gutter290are strategically placed, and each opening296is formed both on the axial surface292and one of the radial surfaces294. The openings296allow the oil collected in the integrated global gutter290to flow from the integrated global gutter290at the openings and into a cavity298formed between the ring gear230and an outer casing204of the gearbox200. In such a configuration, a scavenge port (not shown), generally similar to the scavenge port249ofFIG.3, may be formed in the outer casing204. The scavenge port is located on a bottom portion of the outer casing204so that gravity may assist in the flow of oil to the scavenge port249.

A gearbox including an oil system, at least one gear, and at least one gutter. The oil system is configured to supply oil to the gearbox. The gear rotates about a rotational axis in a rotational direction. The gear has a radial direction and an axial direction. The gear expels oil radially outward when the gear rotates. The gutter is positioned radially outward of the gear in the radial direction of the gear to collect oil expelled by the gear when the gear rotates. The gutter includes an axial surface, a plurality of radial surfaces, and at least one opening. The plurality of radial surfaces includes a first radial surface and a second radial surface. Each of the first radial surface and the second radial surface is oriented in a direction intersecting the axial surface. The at least one opening allows the oil collected in the gutter to flow therethrough. The at least one opening is formed on both the axial surface and one of the first radial surface and the second radial surface.

The gearbox of the preceding clause, further including a plurality of openings. Each of the openings is formed on both the axial surface and one of the first radial surface and the second radial surface.

The gearbox of any preceding clause, wherein the gutter has a trapezoidal shape. Each of the first radial surface and the second radial surface forms an oblique angle with the axial surface.

The gearbox of any preceding clause, wherein the first radial surface and the second radial surface extend outward from the axial surface in the axial direction.

The gearbox of any preceding clause, wherein the gear is a bihelical gear having a plurality of teeth. Each tooth of the plurality of teeth includes a first portion and a second portion. The first portion and the second portion are angled relative to the axial direction of the gear to converge at an apex.

The gearbox of any preceding clause, wherein the gear includes a gap between the first portion and the second portion. The apex trails the rotational direction of the gear. The axial surface of the at least one gutter has a width that is greater than the gap in between the first portion and the second portion.

The gearbox of any preceding clause, wherein the apex is leading the rotational direction of the gear. The width of the gutter is greater than the width of the gear.

The gearbox of any preceding clause, further including an epicyclical gear train and a plurality of the at least one gutter. The epicyclical gear train includes a plurality of the at least one gear and a sun gear. The plurality of the at least one gear is a plurality of planet gears. The sun gear is configured to receive a torque and rotate about an axis of rotation. The sun gear engages with each planet gear of the plurality of planet gears to rotate each planet gear. The ring gear engages with each planet gear of the plurality of planet gears. Each gutter of the plurality of the at least one gutter is a local gutter.

The gearbox of any preceding clause, wherein each local gutter is positioned between adjacent planet gears such that the local gutter collects oil from each of the adjacent planet gears. The first portion of the local gutter collects oil from one planet gear. The second portion of the local gutter collects oil from an adjacent planet gear.

The gearbox of any preceding clause, wherein each local gutter further includes a cavity formed between the first portion of the local gutter and the second portion of the local gutter. The opening is fluidly connected to the cavity.

The gearbox of any preceding clause, further including a carrier. The planet gears are rotatably connected to the carrier, wherein the plurality of planet gears is collectively rotatable about the rotational axis of the sun gear. The carrier rotates about the rotational axis of the sun gear as the plurality of planet gears collectively rotate.

A gearbox including an epicyclical gear train, a plurality of local gutters, and a global gutter. The epicyclical gear train includes a sun gear, a plurality of planet gears, a carrier, and a ring gear. The sun gear is configured to receive a torque and rotate about a rotational axis. Each planet gear engages with the sun gear to be rotated by the sun gear. The plurality of planet gears is collectively rotatable about the rotational axis of the sun gear. The planet gears are rotatably connected to the carrier. The carrier rotates about the rotational axis of the sun gear as the plurality of planet gears collectively rotate. The ring gear engages with each planet gear of the plurality of planet gears. The oil system is configured to supply oil to the gearbox. Each local gutter is positioned radially outward of a planet gear in the radial direction of the planet gear to collect oil expelled by the planet gear when the planet gear rotates. The plurality of local gutters are connected to the carrier to collectively rotate with the carrier. The global gutter circumscribes the plurality of planet gears, such that the global gutter is located radially outward of the plurality of planet gears to collect oil expelled by the plurality of local gutters when the plurality of local gutters rotate.

The gearbox of any preceding clause, wherein each local gutter is formed in the carrier.

The gearbox of any preceding clause, wherein each local gutter further includes a cavity and at least one local gutter exit fluidly connected to the cavity. The oil is expelled outwardly through the local gutter exit when the carrier rotates.

The gearbox of any preceding clause, wherein the global gutter is integrally formed in the ring gear.

The gearbox of any preceding clause, wherein each local gutter is positioned between adjacent planet gears such that the local gutter collects oil from each of the adjacent planet gears. The first portion of the local gutter collects oil from one planet gear. The second portion of the local gutter collects oil from an adjacent planet gear.

The gearbox of any preceding clause, wherein each local gutter further includes at least one opening and a cavity. At least one opening to allow the oil collected in the local gutter to flow therethrough. The cavity is formed between the first portion of the local gutter and the second portion of the local gutter. The opening is fluidly connected to the cavity.

A gas turbine engine includes a core, an output element, and the gearbox of any preceding clause. The core includes a compression section, a combustion section, and a turbine section. The gearbox is coupled to the core to transmit torque and power from the core to the output element.

The gas turbine engine of any preceding clause, further including a fan. The fan includes a fan rotor and a plurality of fan blades extending radially outward from the fan rotor. The fan rotor is the output element.

The gas turbine engine of any preceding clause, further including a propeller assembly. The propeller assembly includes a propeller shaft and a plurality of propeller blades extending outwardly from the propeller shaft. The propeller shaft is the output element.

Although the foregoing description is directed to the preferred embodiments, other variations and modifications will be apparent to those skilled in the art and may be made without departing from the spirit or the scope of the disclosure. Moreover, features described in connection with one embodiment may be used in conjunction with other embodiments, even if not explicitly stated above.