Gear assembly for aeronautical engine with lubricant storing pockets

A gear assembly for an aeronautical engine includes a first gear disposed at a centerline axis of the gear assembly, a second gear coupled to the first gear in adjacent radial arrangement to form a first mesh between the first gear and the second gear, a static portion coupled to the second gear in adjacent circumferential arrangement, the static portion defining a pocket, and a spraybar disposed within the static portion such that a supply opening of the spraybar is directed at the first mesh between the first gear and the second gear. The supply opening provides a flow of lubricant to the first mesh between the first gear and the second gear and at least a portion of the flow of lubricant is collected by the pocket. The flow of lubricant is continuously released from the pocket to the gear system.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to Italian Application No. 102020000015064 filed Jun. 23, 2020, which is hereby incorporated by reference in its entirety.

FIELD

The present subject matter relates generally to a gear drive system, or more particularly to a gear drive system including a gear assembly with a lubricant storing pocket.

BACKGROUND

A gas turbine engine generally includes a fan and a core arranged in flow communication with one another. Additionally, the core of the gas turbine engine generally includes, in serial flow order, a compressor section, a combustion section, a turbine section, and an exhaust section. In operation, air is provided from the fan to an inlet of the compressor section where one or more axial compressors progressively compress the air until it reaches the combustion section. Fuel is mixed with the compressed air and burned within the combustion section to provide combustion gases. The combustion gases are routed from the combustion section to the turbine section. The flow of combustion gases through the turbine section drives the turbine section and is then routed through the exhaust section, e.g., to atmosphere.

Mechanical and electro-mechanical systems, such as gas turbine engines or other engines, include gear assemblies to change an input or output rotational speed between two or more shafts such as to optimize turbine engine efficiency and performance. Gear assemblies are also used to move accessories and/or propellers or rotors. For example, gear assemblies are used to decouple turbine and fan shafts in turbofan engines and are used to decouple a gas turbine from a propeller in turboprop engines.

Lubricant systems for such gear assemblies are designed to supply lubricant injected into gear meshes. However, a primary lubrication system may be interrupted from providing a lubricant to the gear assembly for several seconds, e.g., an oil interruption event, or longer times, e.g., an oil off event. To avoid gear and bearing failure or damage, additional parts are needed such as auxiliary systems to provide lubricant during such interruption periods. Conventional systems to provide lubrication during interruption periods require additional parts, such as auxiliary systems, and require dedicated hardware and pre-flight filling/discharging activities to operate.

BRIEF DESCRIPTION

In one exemplary embodiment of the present disclosure, a gear assembly is provided. The gear assembly includes a first gear disposed at a centerline axis of the gear assembly; a second gear coupled to the first gear in adjacent radial arrangement to form a first mesh between the first gear and the second gear; a static portion coupled to the second gear in adjacent circumferential arrangement, the static portion defining a pocket; and a spraybar disposed within the static portion such that a supply opening of the spraybar is directed at the first mesh between the first gear and the second gear, wherein the supply opening is configured to provide a flow of lubricant to the first mesh between the first gear and the second gear and at least a portion of the flow of lubricant is collected by the pocket.

In certain exemplary embodiments the gear assembly includes a third gear coupled to the second gear in adjacent radial arrangement to form a second mesh between the second gear and the third gear, wherein the flow of lubricant is released from the pocket to the second mesh between the second gear and the third gear during an interruption condition of a primary lubrication system in which the flow of lubricant is interrupted from being provided to the supply opening, and wherein the primary lubrication system provides the flow of lubricant to the supply opening during a working condition.

In certain exemplary embodiments the static portion defines a flow aperture spaced from the pocket, and wherein the flow of lubricant released from the pocket flows through the flow aperture to the second mesh between the second gear and the third gear also during the interruption condition.

In certain exemplary embodiments the pocket includes an inlet and an outlet, and wherein the inlet of the pocket is larger than the flow aperture so that the flow of lubricant from the supply opening is first collected by the pocket.

In certain exemplary embodiments the flow of lubricant flows into the pocket via centrifugal force and windage effects between the first gear and the second gear.

In certain exemplary embodiments the flow of lubricant is released from the pocket to the second mesh between the second gear and the third gear also during the interruption condition via a pumping effect of the second gear.

In certain exemplary embodiments the first gear is a sun gear rotatable around the centerline axis of the gear assembly, the second gear is a star gear coupled to the sun gear, and the third gear is a ring gear coupled to the star gear.

In another exemplary embodiment of the present disclosure, a mechanical or electro-mechanical system including an aeronautical engine having a gear assembly is provided. The gear assembly includes a first gear disposed at a centerline axis of the gear assembly; a second gear coupled to the first gear in adjacent radial arrangement to form a first mesh between the first gear and the second gear; a static portion coupled to the second gear in adjacent circumferential arrangement, the static portion defining a pocket; and a spraybar disposed within the static portion such that a supply opening of the spraybar is directed at the first mesh between the first gear and the second gear, wherein the supply opening is configured to provide a flow of lubricant to the first mesh between the first gear and the second gear and at least a portion of the flow of lubricant is collected by the pocket.

In certain exemplary embodiments the system includes a primary lubrication system in communication with the gear assembly, the primary lubrication system transitionable between a working condition in which the flow of lubricant is provided to the supply opening and an interruption condition in which the flow of lubricant is interrupted from being provided to the supply opening.

In certain exemplary embodiments the system includes a third gear coupled to the second gear in adjacent radial arrangement to form a second mesh between the second gear and the third gear, wherein the flow of lubricant is released from the pocket to the second mesh between the second gear and the third gear also when the primary lubrication system is in the interruption condition.

In certain exemplary embodiments the static portion defines a flow aperture spaced from the pocket, and wherein the flow of lubricant released from the pocket flows through the flow aperture to the second mesh between the second gear and the third gear when the primary lubrication system is in the interruption condition.

In certain exemplary embodiments the pocket includes an inlet and an outlet, and wherein the inlet of the pocket is larger than the flow aperture so that the flow of lubricant from the supply opening is first collected by the pocket.

In certain exemplary embodiments the flow of lubricant flows into the pocket via centrifugal force and windage effects between the first gear and the second gear.

In certain exemplary embodiments the flow of lubricant is released from the pocket to the second mesh between the second gear and the third gear also during the interruption condition via a pumping effect of the second gear.

In certain exemplary embodiments the first gear is a sun gear rotatable around the centerline axis of the gear assembly, the second gear is a planet gear coupled to the sun gear, and the third gear is a ring gear coupled to the planet gear.

DETAILED DESCRIPTION

Epicyclic gearboxes integrated in modern aeroengines require continuous lubrication to transmit power. In special off-design or interruption conditions, a lubrication supply may be interrupted for several seconds or more. To avoid gear and bearing failure or damage, conventional systems use additional auxiliary systems. However, such additional systems require dedicated hardware and/or pre-flight filling/discharging activities to operate. A gear assembly of the present disclosure utilizes structure integrated into a static portion of the gear assembly to provide lubrication to the gear assembly, e.g., an epicyclic gearbox, for a few seconds during interruption conditions. In this manner, a gear assembly of the present disclosure does not require any external connections or additional parts as are needed in conventional systems.

A gear assembly of the present disclosure provides a system for collecting and storing a lubricant during a working condition of a primary lubrication system in which a flow of lubricant is provided to a supply opening of a spraybar. For example, during a working condition of the primary lubrication system, a flow of lubricant travels through a supply channel and out a supply opening of a spraybar to a first mesh between a first gear and a second gear. Next, the flow of lubricant flows into a pocket of a gear assembly of the present disclosure via centrifugal force and windage effects between the first gear and the second gear. In this manner, a gear assembly of the present disclosure is capable of storing a portion of the flow of lubricant during a working condition of the primary lubrication system within the pocket of the static portion for later use to lubricate the system during an interruption condition.

A gear assembly of the present disclosure is able to release the flow of lubricant stored within a pocket of a static portion of the gear assembly during an interruption condition of the primary lubrication system. During an interruption condition, the flow of lubricant is interrupted from being provided to the supply opening of the spraybar by the primary lubrication system.

The flow of lubricant is released from the pocket of the gear assembly of the present disclosure to a second mesh between a second gear and a third gear of the present disclosure during an interruption condition of the primary lubrication system via a pumping effect of the second gear and gravity (when acting). In this manner, a gear assembly of the present disclosure is able to continuously lubricate the gears and meshes of a gear system during an interruption condition of the primary lubrication system without requiring additional parts, auxiliary systems, and/or tanks. In other words, a gear assembly of the present disclosure utilizes a pocket within a static portion of the gear assembly to store residual lubricant and take advantage of a fluid dynamic field generated by the gears of the present disclosure to allow lubrication of the system during an interruption condition through the gears pumping effect and gravity (when acting).

Referring now to the drawings, wherein identical numerals indicate the same elements throughout the figures,FIG.1is a schematic cross-sectional view of a gas turbine engine in accordance with an exemplary embodiment of the present disclosure. More particularly, for the embodiment ofFIG.1, the gas turbine engine is a high-bypass turbofan jet engine10, referred to herein as “turbofan engine10.” AlthoughFIG.1illustrates a turbofan configuration, a gear assembly of the present disclosure is compatible with other configurations, such as a turboprop or other configurations, as described below. As shown inFIG.1, the turbofan engine10defines an axial direction A (extending parallel to a longitudinal centerline12provided for reference) and a radial direction R. In general, the turbofan10includes a fan section14and a turbomachine16disposed downstream from the fan section14. In an exemplary embodiment, the engine10includes a gear assembly or power gear box46having a plurality of gears for decoupling a gas turbine shaft from a fan shaft. The position of the power gear box46is not limited to that as shown in the exemplary embodiment of turbofan10. For example, the position of the power gear box46may vary along the axial direction A.

In other exemplary embodiments, a gear assembly of the present disclosure may be included in a turboprop configuration, wherein a gear box decouples a gas turbine from a propeller.

It is also contemplated that a gear assembly of the present disclosure is able to be utilized in any mechanical or electro-mechanical system, such as gas turbine engines, piston engines, turbofan engines, turboprop engines, other gear drive systems, and/or rotor drive systems.

The exemplary turbomachine16depicted generally includes a substantially tubular outer casing18that defines an annular inlet20. The outer casing18encases, in serial flow relationship, a compressor section including a booster or low pressure (LP) compressor22and a high pressure (HP) compressor24; a combustion section26; a turbine section including a high pressure (HP) turbine28and a low pressure (LP) turbine30; and a jet exhaust nozzle section32. A high pressure (HP) shaft or spool34drivingly connects the HP turbine28to the HP compressor24. A low pressure (LP) shaft or spool36drivingly connects the LP turbine30to the LP compressor22. Other embodiments may feature different turbomachine configurations. For example, an LP turbine that is not directly connected to an LP compressor, e.g., in a decoupling gear box configuration. Additionally, the compressor section, combustion section26, and turbine section together define at least in part a core air flowpath37extending therethrough.

A gear assembly of the present disclosure is compatible with standard fans, variable pitch fans, or other configurations. For the embodiment depicted, the fan section14may include a variable pitch fan38having a plurality of fan blades40coupled to a disk42in a spaced apart manner. As depicted, the fan blades40extend outwardly from disk42generally along the radial direction R. Each fan blade40is rotatable relative to the disk42about a pitch axis P by virtue of the fan blades40being operatively coupled to a suitable actuation member44configured to collectively vary the pitch of the fan blades40in unison. The fan blades40, disk42, and actuation member44are together rotatable about the longitudinal axis12by LP shaft36across a gear assembly or power gear box46. A gear assembly46may enable a speed change between a first shaft, e.g., LP shaft36, and a second shaft, e.g., LP compressor shaft and/or fan shaft. For example, in one embodiment, the gear assembly46may be disposed in an arrangement between a first shaft and a second shaft such as to reduce an output speed from one shaft to another shaft.

More generally, the gear assembly46can be placed anywhere along the axial direction A to decouple the speed of two shafts, whenever it is convenient to do so from a component efficiency point of view, e.g., faster LP turbine and slower fan and LP compressor or faster LP turbine and LP compressor and slower fan, or it is required to do so due to technology limits, e.g., propeller tip speed in turboprops require much lower speed with respect to gas turbine shafts speed.

Referring still to the exemplary embodiment ofFIG.1, the disk42is covered by rotatable front nacelle48aerodynamically contoured to promote an airflow through the plurality of fan blades40. Additionally, the exemplary fan section14includes an annular fan casing or outer nacelle50that circumferentially surrounds the fan38and/or at least a portion of the turbomachine16. The nacelle50is, for the embodiment depicted, supported relative to the turbomachine16by a plurality of circumferentially-spaced outlet guide vanes52. Additionally, a downstream section54of the nacelle50extends over an outer portion of the turbomachine16so as to define a bypass airflow passage56therebetween.

It should be appreciated, however, that the exemplary turbofan engine10depicted inFIG.1is by way of example only, and that in other exemplary embodiments, the turbofan engine10may have any other suitable configuration. For example, in other exemplary embodiments, an engine of the present disclosure may be part of an airplane engine or a helicopter engine. In other exemplary embodiments, any other suitable engine may be utilized with a gear assembly of the present disclosure. For example, in other embodiments, the engine may be any other suitable gas turbine engine, such as a turbofan engine, turboprop engine, turbojet engine, any other suitable turboshaft engine, etc. In such a manner, it will further be appreciated that in other embodiments the gas turbine engine may have any other suitable configuration, such as any other suitable number or arrangement of shafts, compressors, turbines, fans, etc. Further, although not depicted herein, in other embodiments the gas turbine engine may be any other suitable type of gas turbine engine, such as an industrial gas turbine engine incorporated into a power generation system, a nautical gas turbine engine, etc. Further, still, in alternative embodiments, aspects of the present disclosure may be incorporated into, or otherwise utilized with, any other type of combustion engine, such as reciprocating engines.

Referring now toFIGS.2-5, a schematic drawing of a gear assembly100for an aeronautical engine, e.g., a gas turbine engine, in accordance with an exemplary aspect of the present disclosure is provided. In at least certain exemplary embodiments, the exemplary gear assembly100depicted inFIGS.2-5may be incorporated into, e.g., the exemplary engine10described above with reference toFIG.1(e.g., may be incorporated into the gear assembly46depicted inFIG.1and described above, or in other positions along the axial direction A depending on the turbofan engine architecture, or in other configurations such as turboprop engines, or other gear drive systems).

Referring toFIGS.2-5, an exemplary embodiment of a gear assembly100according to an aspect of the present disclosure is provided.FIG.2provides a longitudinal side view of a gear assembly100of the present disclosure andFIGS.3-5provide a circumferential view of the gear assembly100of the present disclosure. The gear assembly100defines a longitudinal direction L co-directional to a reference longitudinal centerline axis12extended through the gear assembly100. A reference radial direction R is extended from the centerline axis12. A reference circumferential direction C is extended relative to the centerline axis12.FIGS.2-5schematically show a portion of a gear assembly100of the present disclosure.

Referring toFIGS.2-5, in an exemplary embodiment, a gear assembly100of the present disclosure generally includes a first gear102, a second gear104, a third gear106, a static portion108, and a spraybar110. In one embodiment, the static portion108may be a static structure of the gear assembly100that is used as a support for lubrication. In other embodiments, the portion108may have other configurations.

In one embodiment, the first gear102is disposed at the centerline axis12of the gear assembly100. The second gear104is coupled to the first gear102in adjacent arrangement along the radial direction R to form a first mesh112between the first gear102and the second gear104. The third gear106is coupled to the second gear104in adjacent arrangement along the radial direction R to form a second mesh114between the second gear104and the third gear106.

Referring toFIGS.3-5, in one embodiment, a static portion108is coupled to the second gear104in adjacent arrangement along the circumferential direction C. For example, a static portion108may be disposed between adjacent second gears104as shown inFIGS.3-4. In an exemplary embodiment, the static portion108defines a pocket116and a flow aperture118spaced away from the pocket116. The pocket116disposed within the static portion108includes an inlet120and an outlet122.

Referring toFIG.5, in an exemplary embodiment, the pocket116includes flow guiding sidewalls150, flow guiding bottom wall152, and curved flow guiding connecting walls154. The curved flow guiding connecting walls154are located between respective flow guiding sidewalls150and flow guiding bottom wall152. The flow guiding sidewalls150, flow guiding bottom wall152, and curved flow guiding connecting wall154are shaped to direct a flow of lubricant to and out outlet122of pocket116. In one embodiment, the inlet120of pocket116includes an inlet hole or aperture120. In one embodiment, the outlet122of pocket116includes an outlet hole or aperture122. Referring toFIGS.3and4, in one exemplary embodiment, the pocket116includes two opposing outlet apertures122. Referring toFIG.5, in another exemplary embodiment, the pocket116includes one outlet aperture122. In one embodiment, an outlet aperture122is located within the curved flow guiding connecting wall154. In another embodiment, an outlet aperture122is located within the flow guiding sidewall150. In yet another embodiment, an outlet aperture122is located within the flow guiding bottom wall152. In other exemplary embodiments, the pocket116may include any number of outlet apertures122for a variety of different applications. Referring toFIG.5, in one exemplary embodiment, the pocket116includes two inlet apertures120. Referring toFIGS.3and4, in one exemplary embodiment, the pocket116includes one inlet aperture120. In other exemplary embodiments, the pocket116may include any number of inlet apertures120for a variety of different applications. In one embodiment, an inlet aperture120is located within a portion of flow guiding sidewall150. In one embodiment, the inlet apertures120and the outlet apertures122of pocket116have a diameter of approximately 10 mm or less. In other embodiments, the inlet apertures120and the outlet apertures122of pocket116may have other sizes for a variety of different applications.

Referring toFIG.5, in an exemplary embodiment, the pocket116has a triangular cross-sectional shape, though it is contemplated that the pocket116may have other shapes and sizes. For example, the pocket116can have other multi-sided polygon cross-sectional shapes. Referring toFIGS.3-5, it is contemplated that a pocket116of a static portion108of the present disclosure can be sized, e.g., have a desired volume, to store a specific amount of lubricant for a desired application depending on a requirement of a lubricant interruption time requirement. In other words, a pocket116of the present disclosure can be sized, e.g., have a desired volume, for a variety of different applications and is sized to allow a sufficient percentage of the supply flow of lubricant132from the spraybar110therein.

Referring toFIGS.2-5, in an exemplary embodiment, the gear assembly100includes a spraybar110within the static portion108. In one embodiment, the spraybar110includes a supply opening126in communication with a supply channel128. The supply channel128forms a primary lubrication system130that supplies a flow of lubricant132, i.e., an inlet flow of lubricant indicated by arrows132, through the supply channel128to the supply opening126during a working condition of the primary lubrication system130as described in more detail below. In an exemplary embodiment, the lubricant132is an oil or similar lubricant.

Referring toFIGS.2-4, in an exemplary embodiment, the spraybar110is in communication with the first gear102and the second gear104such that a supply opening126of the spraybar110is directed at the first mesh112between the first gear102and the second gear104.

Referring toFIGS.2-4, a flow of lubricant132being provided to the gear assembly100will now be discussed. In an exemplary embodiment, the supply opening126of the spraybar110provides a flow of lubricant132, i.e., an inlet flow of lubricant indicated by arrows132, to the first mesh112between the first gear102and the second gear104. Next, a portion of the lubricant after contacting the first mesh112between the first gear102and the second gear104flows to and is collected by the pocket116within the static portion108, e.g., a flow of lubricant indicated by arrows140to the pocket116. For example, during a working condition of the primary lubrication system130, a flow of lubricant132travels through the supply channel128and out the supply opening126of the spraybar110to the first mesh112between the first gear102and the second gear104. Next, a portion of the flow of lubricant140flows into the pocket116, e.g., through inlet120and into pocket116, via centrifugal force and windage effects between the first gear102and the second gear104. In one embodiment, the filling of lubricant into a pocket116of the present disclosure corresponds to utilizing a region where a portion of the lubricant is injected. In this manner, the gear assembly100of the present disclosure is capable of storing a portion of the flow of lubricant140during a working condition of the primary lubrication system130within the pocket116of the static portion108for later use to lubricate the system during an interruption condition. In an exemplary embodiment, the inlet120of the pocket116is larger than the flow aperture118so that a flow of lubricant132from the supply opening126contacts the first mesh112between the first gear102and the second gear104and then the flow of lubricant indicated by arrows140is first collected by the pocket116. It is contemplated that a pocket116of a static portion108of the present disclosure can be sized, e.g., have a desired volume, to store a specific amount of lubricant for a desired application depending on a requirement of a lubricant interruption time requirement. In other words, a pocket116of the present disclosure can be sized, e.g., have a desired volume, for a variety of different applications. In an exemplary embodiment, the flow aperture118allows the lubricant to be injected towards the second mesh114between the second gear104and the third gear106during an interruption condition.

A gear assembly100of the present disclosure is able to release the stored flow of lubricant140within the pocket116of the static portion108during an interruption condition of the primary lubrication system130. During an interruption condition, the flow of lubricant132is interrupted from being provided to the supply opening126of the spraybar110by the primary lubrication system130. In other words, the primary lubrication system130is in communication with the gear assembly100and the primary lubrication system130is transitionable between a working condition in which the flow of lubricant132is provided to the supply opening126and an interruption condition in which the flow of lubricant132is interrupted from being provided to the supply opening126.

In an exemplary embodiment, the flow of lubricant indicated by arrows142is continuously released from the pocket116, e.g., released through outlet122, to the second mesh114between the second gear104and the third gear106during all conditions. As the flow of lubricant132is interrupted from being provided to the supply opening126, the pockets116are still filled with lubrication and they continue to provide a flow of lubricant142to the gear system for a few seconds, depending on the size of the pocket116. In other words, the flow of lubricant indicated by arrows142is released from the pocket116to the second mesh114between the second gear104and the third gear106during an interruption condition. In an exemplary embodiment, the flow of lubricant142is released from the pocket116to the second mesh114between the second gear104and the third gear106during an interruption condition of the primary lubrication system130via a pumping effect of the second gear104and gravity (when acting). In this manner, a gear assembly100of the present disclosure is able to continuously lubricate the gears102,104,106and meshes112,114during an interruption condition of the primary lubrication system130without requiring additional parts, auxiliary systems, and/or tanks. In other words, a gear assembly100of the present disclosure utilizes a pocket116within static portion108to store residual lubricant and takes advantage of a fluid dynamic field generated by the gears102,104,106to allow lubrication of the system during an interruption condition through the gears104pumping effect and gravity (when acting). In one embodiment, the flow of lubricant142that is released from the pocket116may flow through a flow aperture118to the second mesh114between the second gear104and the third gear106during an interruption condition of the primary lubrication system130.

In one embodiment, the flow of lubricant142that is released from the pocket116to a second mesh114between the second gear104and the third gear106during an interruption condition is facilitated by the second gear104and third gear106coupling having a lower amount of lubrication with respect to the first gear102and second gear104coupling. Furthermore, in such conditions, a gear assembly100of the present disclosure is able to lubricate, at least partially, the first mesh112between the first gear102and the second gear104, in addition to the second mesh114between the second gear104and the third gear106, by utilizing the rotational effects of the gear system.

Referring toFIGS.3-4, in an exemplary embodiment, a gear assembly100of the present disclosure may include a plurality of second gears104coupled to the first gear102. In such an embodiment, a gear assembly100of the present disclosure may include multiple static portions108. For example, in one embodiment, a static portion108may be between each pair of adjacent second gears104. In this manner, a gear assembly100of the present disclosure is able to utilize multiple pockets116within respective static portions108to store residual lubricant and take advantage of a fluid dynamic field generated by the gears102,104to allow lubrication of the system during an interruption condition through the gears104pumping effect and gravity (when acting). In such an embodiment, the flow of lubricant142that is released from each pocket116flows to the second mesh114between the second gear104and the third gear106during an interruption condition of the primary lubrication system130. The rotation of each of the second gears104and the third gear106allows lubrication to be provided to several meshes between the gears104,106.

Referring toFIG.2, in an exemplary embodiment, the gear assembly100further includes a first shaft134coupled to the first gear102. The first shaft134may be defined substantially concentric to the centerline axis12. The gear assembly100further includes a second shaft136. In one embodiment, the first shaft134is an input shaft and the second shaft136is an output shaft.

In one exemplary embodiment, the plurality of second gears104may be coupled to the second shaft102via a carrier. For example, in an exemplary embodiment, each second gear104is rotatably mounted on a portion of a carrier, e.g., a roller bearing or pin146. As such, rotation of the first shaft134and the first gear102enables rotation of each second gear104around a respective second gear axis138. Referring toFIGS.2-4, the schematic views illustrated for a gear assembly of the present disclosure do not show the entirety of a carrier portion of the gear assembly. The gear assembly of the present disclosure is compatible with and utilize standard carrier configurations known in the art. Furthermore, in one embodiment, rotation of the second gear axis138around the first gear102, i.e., around the centerline axis12, may be enabled. In one embodiment, the second shaft136coupled to the second gear104may rotate around the centerline axis12along with the second gear104. In other exemplary embodiments, the second shaft136may be coupled to the third gear106. The second gear104may transfer energy between the first gear102and the third gear106. As such, the second gear104may rotate about its second gear axis138while the second gear axis138remains stationary relative to the centerline axis12, i.e., the second gear axis138does not rotate around the centerline axis12.

In one exemplary embodiment, the first gear102is a sun gear rotatable around the centerline axis12of the gear assembly100, the second gear104is a planet gear coupled to the sun gear, and the third gear106is a ring gear coupled to the planet gear. In one embodiment, the gear assembly100forms a part of a star gear system.

In such an embodiment, a gear carrier of the gear assembly100is mechanically grounded, the ring gear or third gear106is rotatable and the output shaft extends from the ring gear or third gear106. Because the carrier is grounded, the planet gears or second gears104cannot orbit the sun gear or first gear102and therefore are referred to as star gears104. In operation, the input shaft134rotatably drives the sun gear or first gear102, compelling each star gear or second gear104to rotate about its own axis, i.e., a respective second gear axis138. In an exemplary embodiment, each second gear104is rotatably mounted on a portion of a carrier, e.g., a roller bearing or pin146. The rotary motion of the star gears or second gears104turn the ring gear or third gear106, and hence the output shaft136, in a direction opposite that of the input shaft134.

It is contemplated that a gear assembly100of the present disclosed may be used with aeronautical engines, e.g., such as airplane engines or helicopter engines, and also may be applied to other mechanical or electro-mechanical systems not shown herein. In some exemplary embodiments, a gear assembly100generally shown and described herein may be produced using one or more manufacturing methods known in the art. For example, the gear assembly100, including, but not limited to, the gears102,104,106, a static portion108, and/or a spraybar110may be manufactured via one or more processes known such as additive manufacturing or 3D printing, machining processes, forgings, castings, etc., or combinations thereof. Still further, a spraybar110may be formed into the gear assembly100, such as via one or more of the processes described herein, or via a bonding process, e.g., welding, brazing, adhesive, bonding, etc., or mechanical fasteners, e.g., bolts, nuts, screws, rivets, tie rods, etc., or otherwise adhering a spraybar110such as shown and described in the exemplary embodiments herein. Alternatively, or additionally, various components of the gear assembly100may be formed via a material removal process, such as, but not limited to, a machining process, e.g., cutting, milling, grinding, boring, etc.

1. A gear assembly (100), comprising: a first gear (102) disposed at a centerline axis (12) of the gear assembly (100); a second gear (104) coupled to the first gear (102) in adjacent radial arrangement to form a first mesh (112) between the first gear (102) and the second gear (104); a static portion (108) coupled to the second gear (104) in adjacent circumferential arrangement, the static portion (108) defining a pocket (116); and a spraybar (110) disposed within the static portion (108) such that a supply opening (126) of the spraybar (110) is directed at the first mesh (112) between the first gear (102) and the second gear (104), wherein the supply opening (126) is configured to provide a flow of lubricant to the first mesh (112) between the first gear (102) and the second gear (104) and at least a portion of the flow of lubricant is collected by the pocket (116).

2. The gear assembly (100) of any preceding clause, further comprising: a third gear (106) coupled to the second gear (104) in adjacent radial arrangement to form a second mesh (114) between the second gear (104) and the third gear (106), wherein the flow of lubricant is released from the pocket (116) to the second mesh (114) between the second gear (104) and the third gear (106) during an interruption condition of a primary lubrication system (130) in which the flow of lubricant is interrupted from being provided to the supply opening (126), and wherein the primary lubrication system (130) provides the flow of lubricant to the supply opening (126) during a working condition.

3. The gear assembly (100) of any preceding clause, wherein the static portion (108) defines a flow aperture (118) spaced from the pocket (116), and wherein the flow of lubricant released from the pocket (116) flows through the flow aperture (118) to the second mesh (114) between the second gear (104) and the third gear (106) also during the interruption condition.

4. The gear assembly (100) of any preceding clause, wherein the pocket (116) includes an inlet (120) and an outlet (122), and wherein the inlet (120) of the pocket (116) is larger than the flow aperture (118) so that the flow of lubricant from the supply opening (126) is first collected by the pocket (116).

5. The gear assembly (100) of any preceding clause, wherein the flow of lubricant flows into the pocket (116) via centrifugal force and windage effects between the first gear (102) and the second gear (104).

6. The gear assembly (100) of any preceding clause, wherein the flow of lubricant is released from the pocket (116) to the second mesh (114) between the second gear (104) and the third gear (106) also during the interruption condition via a pumping effect of the second gear (104).

7. The gear assembly (100) of any preceding clause, wherein the first gear (102) comprises a sun gear rotatable around the centerline axis (12) of the gear assembly (100), the second gear (104) comprises a star gear coupled to the sun gear, and wherein the third gear (106) comprises a ring gear coupled to the star gear.

8. A mechanical or electro-mechanical system, comprising: an aeronautical engine (10) including a gear assembly (100), the gear assembly (100) comprising: a first gear (102) disposed at a centerline axis (12) of the gear assembly (100); a second gear (104) coupled to the first gear (102) in adjacent radial arrangement to form a first mesh (112) between the first gear (102) and the second gear (104); a static portion (108) coupled to the second gear (104) in adjacent circumferential arrangement, the static portion (108) defining a pocket (116); and a spraybar (110) disposed within the static portion (108) such that a supply opening (126) of the spraybar (110) is directed at the first mesh (112) between the first gear (102) and the second gear (104), wherein the supply opening (126) is configured to provide a flow of lubricant to the first mesh (112) between the first gear (102) and the second gear (104) and at least a portion of the flow of lubricant is collected by the pocket (116).

9. The system of any preceding clause, further comprising: a primary lubrication system (130) in communication with the gear assembly (100), the primary lubrication system (130) transitionable between a working condition in which the flow of lubricant is provided to the supply opening (126) and an interruption condition in which the flow of lubricant is interrupted from being provided to the supply opening (126).

10. The system of any preceding clause, further comprising: a third gear (106) coupled to the second gear (104) in adjacent radial arrangement to form a second mesh (114) between the second gear (104) and the third gear (106), wherein the flow of lubricant is released from the pocket (116) to the second mesh (114) between the second gear (104) and the third gear (106) also when the primary lubrication system (130) is in the interruption condition.

11. The system of any preceding clause, wherein the static portion (108) defines a flow aperture (118) spaced from the pocket (116), and wherein the flow of lubricant released from the pocket (116) flows through the flow aperture (118) to the second mesh (114) between the second gear (104) and the third gear (106) when the primary lubrication system (130) is in the interruption condition.

12. The system of any preceding clause, wherein the pocket (116) includes an inlet (120) and an outlet (122), and wherein the inlet (120) of the pocket (116) is larger than the flow aperture (118) so that the flow of lubricant from the supply opening (126) is first collected by the pocket (116).

13. The system of any preceding clause, wherein the flow of lubricant flows into the pocket (116) via centrifugal force and windage effects between the first gear (102) and the second gear (104).

14. The system of any preceding clause, wherein the flow of lubricant is released from the pocket (116) to the second mesh (114) between the second gear (104) and the third gear (106) also during the interruption condition via a pumping effect of the second gear (104).

15. The system of any preceding clause, wherein the first gear (102) comprises a sun gear rotatable around the centerline axis (12) of the gear assembly (100), the second gear (104) comprises a planet gear coupled to the sun gear, and wherein the third gear (106) comprises a ring gear coupled to the planet gear.