Turbine and epicyclic gear assembly with lubrication passages

Abstract

A gear assembly for use with a turbine includes a sun gear, a plurality of planetary gear layshafts each supporting first-stage and second-stage planetary gears, and a ring gear. The sun gear is configured to rotate about a longitudinal centerline of the gear assembly, and the plurality of planetary gear layshafts include internal passages that receive one or more lubrication supply lines.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Italian Patent Application No. 102021000015386, filed on June 11, 2021. The entire contents of that prior application are incorporated herein by reference. Technical Field

[0003] The present subject matter generally relates to turbomachines including gear assemblies, and, in particular, to gear assembly arrangements specific to certain turbomachine configurations.

[0004] Confirm government support

[0005] The project presented in this application has received funding from the Clean Sky 2 Joint Undertaking (JU) under grant agreement No. 945541. JU receives support from the EU Horizon 2020 research and innovation programme and from Clean Sky 2 JU members outside the EU. Background Art

[0006] Gearboxes used in modern aircraft engines require constant lubrication to transmit power. Space constraints within gearboxes present technical challenges related to lubricating fluid supply and / or collection. Consequently, there is a need for gear assemblies that provide improved lubricating fluid distribution and / or collection systems, including improvements that can reduce the radial and / or axial footprint of the gearbox and lubrication system and / or otherwise provide improved management of the lubricating fluid within the gearbox. Summary of the Invention

[0007] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the techniques disclosed in the description.

[0008] Various turbomachine engines and gear assemblies are disclosed herein, including various lubrication supply and / or collection systems and methods associated with the gear assemblies.

[0009] For example, in one embodiment, a gear assembly for use with a turbine engine includes a sun gear, a plurality of planetary gear layshafts each supporting first-stage planetary gears and second-stage planetary gears, and a ring gear, the sun gear rotating about a longitudinal centerline of the gear assembly; and a lubrication system including a plurality of lubrication fluid supply lines. The plurality of planetary gear layshafts each include an internal passage extending between a rear side of the layshaft and a front side of the layshaft, and the plurality of lubrication fluid supply lines include one or more layshaft supply lines extending through corresponding internal passages of the internal passages of the planetary gear layshafts.

[0010] These and other features, aspects and advantages of the present disclosure will become better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosed technology and, together with the description, serve to explain the principles of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A complete and effective disclosure of the present invention to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0012] Figure 1 is a schematic cross-sectional view of an exemplary embodiment of an open rotor propulsion system;

[0013] Figure 2 is a schematic cross-sectional view of an exemplary embodiment of a ducted propulsion system;

[0014] Figure 3 is a schematic diagram of an exemplary gear assembly;

[0015] Figure 4 is a cross-sectional view of an exemplary planetary gear layshaft;

[0016] Figure 5 is a schematic diagram of an exemplary planetary gear layshaft having a first stage planetary gear and a second stage planetary gear;

[0017] Figure 6 is a schematic diagram of an exemplary lubricating fluid supply system for a gearbox;

[0018] Figure 7 yes Figure 6 A schematic diagram of a portion of an exemplary lubrication fluid supply system is shown;

[0019] Figure 8 is a schematic diagram of an exemplary lubricating fluid supply system for a gearbox;

[0020] Figure 9A 、 9B and 9C is Figure 8 a cross-sectional view of the gearbox shown;

[0021] Figure 10 is a schematic diagram of an exemplary lubrication collection system for a gearbox;

[0022] Figure 11 is a schematic diagram of an exemplary gearbox;

[0023] Figure 12 yes Figure 11 A cross-sectional view of an exemplary gearbox is shown, illustrating an exemplary lubrication collection system. DETAILED DESCRIPTION

[0024] Reference will now be made in detail to embodiments of the present invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided to illustrate the present invention, not to limit the present invention. Indeed, it will be apparent to those skilled in the art that various modifications and variations may be made to the present invention without departing from the scope or spirit of the present invention. For example, features shown or described as part of one embodiment may be used in conjunction with another embodiment to produce yet another embodiment. Therefore, the present invention is intended to encompass such modifications and variations as come within the scope of the appended claims and their equivalents.

[0025] The word “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations.

[0026] As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to indicate the position or importance of each component.

[0027] The terms "fore" and "aft" refer to relative positions within a gas turbine engine or vehicle and refer to the normal operating attitude of the gas turbine engine or vehicle. For example, for a gas turbine engine, the front position refers to the position closer to the engine inlet, while the aft position refers to the position closer to the engine nozzle or exhaust.

[0028] The terms "upstream" and "downstream" refer to relative directions of fluid flow in a fluid path. For example, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction toward which the fluid is flowing.

[0029] The terms “coupled,” “fixed,” “attached,” and the like refer to both direct coupling, fixing, or attachment as well as indirect coupling, fixing, or attachment through one or more intermediate components or features, unless otherwise indicated herein.

[0030] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0031] As used throughout the specification and claims herein, approximating language is applied to modify any quantitative representation that can be permitted to vary without resulting in a change in the basic function to which it is related. Thus, a value modified by one or more terms (e.g., "about," "approximately," and "substantially") is not limited to the precise value specified. In at least some cases, approximating language can correspond to the precision of an instrument used to measure the value, or the precision of a method or machine used to construct or manufacture a component and / or system. For example, approximating language can mean within a margin of 1%, 2%, 4%, 10%, 15%, or 20%.

[0032] Here and throughout the specification and claims, range limitations are combined and interchanged, and unless context or language indicates otherwise, such ranges are identified and include all sub-ranges contained therein. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.

[0033] Referring now to the accompanying drawings, Figure 1 is an exemplary embodiment of an engine 100 including a gear assembly 102 according to aspects of the present disclosure. The engine 100 includes a fan assembly 104 driven by a core engine 106. In various embodiments, the core engine 106 is a Brayton cycle system configured to drive the fan assembly 104. The core engine 106 is at least partially covered by an outer casing 114. The fan assembly 104 includes a plurality of fan blades 108. A blade assembly 110 extends from the outer casing 114. The blade assembly 110, including a plurality of blades 112, is positioned in an operative arrangement with the fan blades 108 to provide thrust, control thrust vectoring, attenuate or redirect undesirable acoustic noise, and / or otherwise desirably alter air flow relative to the fan blades 108. In certain embodiments, the fan assembly 104 includes three (3) to twenty (20) fan blades 108. In a particular embodiment, the fan assembly 104 includes ten (10) to sixteen (16) fan blades 108. In some embodiments, fan assembly 104 includes twelve (12) fan blades 108. In some embodiments, blade assembly 110 includes the same number of blades 112 as fan blades 108 or a fewer number.

[0034] In some embodiments, the fan blade tip speed at cruise flight conditions may be 650 fps to 900 fps, or 700 fps to 800 fps. The fan pressure ratio (FPR) of fan assembly 104 may be 1.04 to 1.10, or in some embodiments, 1.05 to 1.08 as measured across the fan blades at cruise flight conditions.

[0035] In some embodiments, for example Figure 1As shown, the blade assembly 110 is located downstream or rearward of the fan assembly 104. However, it should be understood that in certain embodiments, the blade assembly 110 may be located upstream or forward of the fan assembly 104. In various other embodiments, the engine 100 may include a first blade assembly located in front of the fan assembly 104 and a second blade assembly located behind the fan assembly 104. The fan assembly 104 may be configured to adjust the pitch at one or more fan blades 108 as desired, such as to control thrust vectoring, reduce or redirect noise, and / or change thrust output. The blade assembly 110 may be configured to adjust the pitch at one or more blades 112 as desired, such as to control thrust vectoring, reduce or redirect noise, and / or change thrust output. The pitch control mechanisms at one or both of the fan assembly 104 or the blade assembly 110 may cooperate to produce one or more desired effects described above.

[0036] The core engine 106 is generally enclosed in an outer casing 114 that defines a maximum diameter. In certain embodiments, the engine 100 includes a length from a longitudinal forward end 116 to a longitudinal rearward end 118. In various embodiments, the engine 100 defines a length (L) and a maximum diameter (D max ) ratio, which provides reduced installation resistance. In one embodiment, L / D max At least 2. In another embodiment, L / D max At least 2.5. In certain embodiments, L / D max Less than 5, less than 4 and less than 3. In various embodiments, it should be understood that L / D max For use with a single, unducted rotor engine.

[0037] Reduced installed drag can further provide improved efficiency, such as improved fuel consumption. Additionally or alternatively, reduced drag can provide engine and aircraft operation at cruising altitudes of Mach 0.5 or above. In some embodiments, L / D max , fan assembly 104 , and / or bucket assembly 110 , individually or together, at least partially configure engine 100 to operate at a maximum cruise altitude operating speed between approximately Mach 0.55 and approximately Mach 0.85.

[0038] Reference again Figure 1 , the core engine 106 extends in a radial direction R relative to the engine axis centerline 120. The gear assembly 102 receives power or torque from the core engine 106 via a power input source 122 and provides power or torque to drive the fan assembly 104 in a circumferential direction C about the engine axis centerline 120 via a power output source 124.

[0039] In some embodiments, for example Figure 1As shown, engine 100 is an unducted thrust generating system, such that a plurality of fan blades 108 are not covered by a nacelle or fan case. Thus, in various embodiments, engine 100 may be configured as an unshrouded turbofan engine, an open rotor engine, or a propfan engine. In certain embodiments, engine 100 is a single unducted rotor engine including a single row of fan blades 108. An open rotor engine configuration, including a fan assembly 104 with large-diameter fan blades 108, may be suitable, for example, for high bypass ratios, high cruise speeds (e.g., compared to aircraft equipped with turbofan engines, or generally higher cruise speeds than aircraft equipped with turboprop engines), high cruise altitudes (e.g., compared to aircraft equipped with turbofan engines, or generally higher cruise speeds than aircraft equipped with turboprop engines), and / or relatively low rotational speeds. Cruise altitude is typically the altitude at which an aircraft reaches level after climbing and before descending to the approach phase of flight. In various embodiments, the engine is used in vehicles having a cruise altitude of up to approximately 65,000 feet. In certain embodiments, the cruising altitude is between about 28,000 feet and about 45,000 feet. In certain embodiments, the cruising altitude is expressed in flight altitude (FL) based on standard atmospheric pressure at sea level, with the cruising flight condition being between FL280 and FL650. In another embodiment, the cruising flight condition is between FL280 and FL450. In certain embodiments, the cruising altitude is defined at least based on atmospheric pressure, wherein the cruising altitude is between about 4.85 psia and about 0.82 psia based on a sea level pressure of about 14.70 psia and a sea level temperature of about 59 degrees Fahrenheit. In another embodiment, the cruising altitude is between about 4.85 psia and about 2.14 psia. It should be understood that in certain embodiments, the cruising altitude range defined by pressure can be adjusted based on different reference sea level pressures and / or sea level temperatures.

[0040] Although described above as Figure 1 It should be understood that the gear assemblies disclosed herein may be applied to shrouded or ducted engines, partially ducted engines, rear fan engines, or other turbine configurations, including those used in marine, industrial, or aerospace propulsion systems. Furthermore, the gear assemblies disclosed herein may also be applied to turbofan, turboprop, or turboshaft engines.

[0041] For example, Figure 2 is a schematic cross-sectional view of an exemplary embodiment of an engine 200 including a gear assembly 202 in conjunction with a ducted fan propulsion system. Figure 2Unlike the open rotor configuration of FIG, fan assembly 204 and its fan blades 208 are contained within an annular fan case 230, and blade assembly 210 and blades 212 extend radially between fan case 230 and an inner surface of fan case 230. As described above, the gear assemblies disclosed herein can provide increased gear ratios for a fixed gear envelope (e.g., a ring gear of the same size), or alternatively, a smaller diameter ring gear can be used to achieve the same gear ratio.

[0042] like Figure 2 As shown, the core engine 206 is generally enclosed in an outer casing 214 and has a length extending from a longitudinal forward end 216 to a longitudinal aft end 218. An exemplary core engine (for a ducted or non-ducted engine) may include a compressor section 240, a heat addition system 242 (e.g., a combustor), and an expansion section 244 arranged in series flow. The core engine 206 extends circumferentially relative to the engine central axis 220. The core engine 206 includes a high-speed spool comprising a high-speed compressor and a high-speed turbine operably and rotatably coupled together by the high-speed shaft. The heat addition system 232 is located between the high-speed compressor and the high-speed turbine. Various embodiments of the heat addition system 232 include a combustion section. The combustion section can be configured as a deflagration combustion section, a rotating detonation combustion section, a pulse detonation combustion section, or other suitable heat addition system. The heat addition system 242 can be configured as one or more of a rich burn system or a lean burn system or a combination thereof. In various embodiments, the heat addition system 242 includes an annular combustor, a can combustor, a tubular combustor, a trapped vortex combustor (TVC), or other suitable combustion systems, or combinations thereof.

[0043] The core engine 206 may also include a supercharger or low-speed compressor positioned in flow relationship with the high-speed compressor. The low-speed compressor is rotatably coupled to a low-speed turbine via a low-speed shaft 246 so that the low-speed turbine can drive the low-speed compressor. The low-speed shaft 246 is also operatively connected to the gear assembly 202 to provide power to the fan assembly 204 via a power input source 222, such as described further herein.

[0044] It should be understood that the terms "low" and "high," or their respective degrees of comparison (e.g., comparatives, where applicable), when used with compressor, turbine, shaft, or spool components, each refer to relative speeds within the engine, unless otherwise specified. For example, a "low turbine" or "low-speed turbine" defines a component that is configured to operate at a speed lower than a "high turbine" or "high-speed turbine," such as a maximum allowable speed. Alternatively, the above terms may be understood as superlatives, unless otherwise specified. For example, a "low turbine" or "low-speed turbine" may refer to the lowest maximum speed turbine within a turbine section, a "low compressor" or "low-speed compressor" may refer to the lowest maximum speed turbine within a compressor section, a "high turbine" or "high-speed turbine" may refer to the highest maximum speed turbine within a turbine section, and a "high compressor" or "high-speed compressor" may refer to the highest maximum speed compressor within a compressor section. Similarly, a low-speed spool refers to a lower maximum speed than a high-speed spool. It will also be understood that the terms "low" or "high" in these aspects may additionally or alternatively be understood as relative to a minimum allowable speed, or relative to a minimum or maximum allowable speed for normal, desired, steady state, etc. operation of the engine.

[0045] As discussed in more detail below, the core engine includes a gear assembly configured to transfer power from the expansion section and reduce the output speed at the fan assembly relative to the low-speed turbine. The embodiments of the gear assembly depicted and described herein may allow for application to large diameter unducted fans (e.g., Figure 1 ) or certain turbofans (e.g. Figure 2 ) gear ratio. In addition, embodiments of the gear assemblies provided herein may be adapted for radial or diametrical constraints of a core engine within an outer casing.

[0046] The gear assembly described herein includes a gear set for reducing the rotational speed of the fan assembly relative to the low-speed (pressure) turbine. In operation, the rotating fan blades are driven by the low-speed (pressure) turbine via the gear assembly, causing the fan blades to rotate about the engine axis centerline and generate thrust to propel the engine, thereby propelling the aircraft in which the engine is installed in a forward direction.

[0047] Figure 1 and Figure 2 A case in which the fan assembly is located forward of the engine core is shown in what may be referred to as a "pull" configuration. Other configurations are possible and are considered within the scope of the present disclosure, such as embodiments in which the engine core is located forward of the fan assembly in what may be referred to as a "push" configuration. The choice of a "pull" or "push" configuration may be consistent with the choice of mounting orientation relative to the fuselage for the intended aircraft application, and some may be structurally or operationally advantageous depending on whether the mounting location and orientation is wing-mounted, fuselage-mounted, or tail-mounted.

[0048] exist Figure 1 In the exemplary embodiment, air enters core engine 106 through openings behind the fan blades. Figure 2 Such an opening is shown in more detail. Figure 2 As shown, air A entering the fan assembly is divided into air A1 entering the core engine and air A2 bypassing the core engine.

[0049] The embodiments of the gear assembly depicted and described herein can provide an L / D suitable for an engine. max Gear Ratios and Arrangements Within Constraints. In certain embodiments, the depicted and described gear assemblies allow for gear ratios and arrangements that provide fan assembly rotational speeds corresponding to one or more ranges of cruise altitudes and / or cruise speeds provided above.

[0050] Various embodiments of the gear assemblies provided herein may allow for gear ratios up to 14:1. Various embodiments of the gear assemblies may allow for gear ratios of at least 6:1. Still other embodiments of the gear assemblies provided herein allow for gear ratios between 6:1 and 12:1, between 7:1 and 11:1, and between 8:1 and 10:1. It should be understood that the embodiments of the gear assemblies provided herein may allow for large gear ratios and may be used in applications such as, but not limited to, the length (L) of the engine 10, the maximum diameter (D) of the engine, and the like. max ), a cruise altitude of up to 65,000 feet, and / or an operational cruise speed of up to Mach 0.85, or a combination thereof.

[0051] Various exemplary gear assemblies are shown and described herein. These gear assemblies can be used with any exemplary engine and / or any other suitable engine that may require such a gear assembly. In this manner, it should be understood that the gear assemblies disclosed herein can generally operate with an engine and a turbine, the engine having a rotating element having a plurality of rotor blades, the turbine having a turbine and a shaft that can rotate with the turbine. For such an engine, the rotating element (e.g., a fan assembly) can be driven by a shaft (e.g., a low-speed shaft) of the turbine through the gear assembly.

[0052] Figure 3 An exemplary gear assembly 302 having a compound symmetric arrangement is shown. The gear assembly 302 includes a s The sun gear 304 has a diameter D p1 The plurality of first stage planetary gears 306 have a diameter D p2 The plurality of second stage planetary gears 308 and having a diameter D rEach of the sun gear 304, planetary gears 306 and 308, and ring gear 310 is a double helical gear having first and second sets of helical teeth inclined at an acute angle relative to one another. Specifically, sun gear 304 includes a first sun gear set 312 and a second sun gear set 314. Each of the first-stage planetary gears includes a first planetary gear set 316 and a second planetary gear set 318, and each of the second-stage planetary gears includes a third planetary gear set 321 and a fourth planetary gear set 322. Ring gear 310 includes a first ring gear set 324 and a second ring gear set 326. Figure 3 The ring gear shown comprises two halves having interconnected flange portions.

[0053] The compound planet gears 306, 308 are supported by a layshaft 330 having a tubular configuration. As used herein, "tubular" refers to a longitudinally extending structure that is at least partially hollow to define an interior passage 331, such as Figure 4 As shown. The tubular layshaft 330 may include an inner surface 333. The tubular layshaft 330 also supports and / or carries the first and second stage planetary gears on its outer surface, such as Figure 3 and Figure 4 shown.

[0054] The tubular layshaft may include a middle portion 332 that supports the first stage planet gears 306 between two outer portions 334. Figure 4 (and elsewhere) as shown, the first stage planetary gear D p1 The diameter can be larger than the second stage planetary gear D p2 In some embodiments, D p1 :D p2 The ratio can vary from 1.0 to 2.0, or in certain embodiments, from 1.2 to 1.7, or from 1.3 to 1.6, or from 1.4 to 1.5.

[0055] Since the diameters of the first and second stage planetary gears are different, the tubular layshaft 330 can be similarly varied to support these gears. Figure 4 As shown, the middle portion 332 has a larger diameter than the outer portion 334 , with the angled portion of the secondary shaft extending between the middle portion 332 and the outer portion 334 .

[0056] In some embodiments, the countershaft 330 may include a plurality of holes 338 to remove lubricating oil from the gear assembly. Figure 4 As shown, a plurality of apertures 338 may extend circumferentially about the layshaft 330 at an intermediate portion 332 (eg, an enlarged portion) between the first and second outer portions 334 .

[0057] For clarity, Figure 5 A planet carrier 328 is shown with a single compound planet gear (306, 308). The layshaft 330 extends through openings 337 in the front and rear sides of the planet carrier 328. Figure 5 Only one planetary gear is shown in FIG, and only one layshaft 330 is depicted. However, it should be understood that each opening 337 will include a corresponding layshaft 330. In certain embodiments, the bracket can be connected to the engine frame via a flexible support system that is configured to collect oil and remove oil via holes at a lower portion.

[0058] exist Figure 3 In the illustrated embodiment, the gear assembly 302 is a planetary gear configuration in which the planet carrier is typically fixed (e.g., stationary) to a support structure within the engine. The sun gear 304 is driven by an input shaft (e.g., a low-speed shaft). The planet carrier 328 is rotatably coupled to the layshafts of the compound planetary gears 306, 308, and the ring gear 310 is configured to rotate circumferentially about the longitudinal engine axis centerline, which in turn drives a power output source (e.g., a fan shaft) that is coupled to the ring gear and configured to rotate with the ring gear to drive the fan assembly. In this embodiment, the low-speed shaft rotates in a circumferential direction opposite to the direction of rotation of the fan shaft.

[0059] In certain embodiments, the distribution of gear ratios between the first stage and the second stage may range from 40% to 60% for each stage (ie, 40% to 60% for the first stage and 60% to 40% for the second stage).

[0060] As described above, in certain embodiments, the sun gear 304 , the planet gears 306 , 308 , and the ring gear 310 may be double helical gears having first and second sets of helical teeth that are canted at an acute angle relative to one another.

[0061] Refer again Figure 3 , the ring gear 310 is coupled to the fan drive shaft 340 to drive the fan section. The sun gear 304 is coupled to an input power source (e.g., input shaft 342). In some embodiments, the input shaft can be formed integrally with the sun gear. The double helical meshing of the planetary gears axially balances the load on the four (phased) gear sets of each compound planetary gear. The second stage planetary gears 308 can be supported by two rows of cylindrical roller bearings 344 at the planetary bores. In addition, the fan drive shaft 340 can be supported by tapered roller bearings 350, which support the fan drive shaft in an axially compact manner. In some embodiments, the roller bearings can be formed of a ceramic material. In some embodiments, such as Figure 3 As shown, the inner support element of the two rows of roller bearings 344 can be a solid unique element.

[0062] like Figure 6 As shown, the layshaft 330 disclosed herein can provide the additional benefit of improved lubrication distribution. As described above, the layshaft 330 is a tubular structure that defines an internal passage 331. The internal passage 331 can facilitate lubrication distribution by allowing the lubrication fluid supply line 352 to pass through the layshaft 330. Figure 6 As shown, lubrication fluid (eg, oil) is delivered to flow from a remote location (eg, an oil reservoir) through one or more lubrication fluid supply lines 352 extending through the layshaft 330 .

[0063] The lubrication fluid may flow into the layshaft (as indicated by arrow 354), through the layshaft (arrow 356), and out the other side of the layshaft (arrow 358) into the main manifold 360. From the main manifold 360, the lubrication fluid may be passed to a first lubrication distribution system 362 configured to distribute the lubrication fluid to the sun gear mesh area where the sun gear 304 is configured to contact the first stage planet gears 306. The first lubrication distribution system 362 may include a plurality of spray bars that distribute the lubrication fluid to the sun gear mesh area.

[0064] Lubrication fluid is also directed through a plurality of lubrication passages 363 within the bracket 328. Figure 6 As shown, lubrication fluid is directed from the main manifold 360 through lubrication passages (in the direction indicated by arrows 364) to the ring gear mesh area where the forward second stage planetary gears 308 engage the ring gear 310. A secondary lubrication distribution system 366 (e.g., one or more spray bars) directs lubrication fluid to the ring gear mesh area of ​​the forward second stage planetary gears 308.

[0065] Lubrication fluid is also directed from the main manifold 360 to a second-stage manifold 368, which directs the lubrication fluid (in the direction indicated by arrows 370) through one or more lubrication passages 363 in the carrier to the ring gear mesh area where the aft second-stage planetary gears 308 engage the ring gear 310. A third lubrication distribution system 372 (e.g., one or more spray bars) directs the lubrication fluid to the ring gear mesh area of ​​the aft second-stage planetary gears 308.

[0066] like Figure 6 As shown, lubricating fluid can overflow within the layshaft to provide lubricating fluid to the lower race passage of the layshaft bearing 344. In particular, the roller bearing 344 can be lubricated by directing lubricating fluid overflowing within the layshaft (e.g., through one or more openings 361 in the lubricating fluid supply line 352 passing through the layshaft), which is in turn directed under the inner race and squeezed out through a plurality of holes in the inner race.

[0067] The internal passage 331 can vary depending on the structural and / or functional requirements of the secondary shaft. In some embodiments, for example, the internal passage can have a diameter 335 that varies along the length of the secondary shaft. Figure 4 An exemplary embodiment is shown in which a first portion of the layshaft (eg, middle portion 332 ) has a larger diameter 335 than a second portion of the layshaft (eg, outer portion 334 ).

[0068] As used herein, a manifold refers to any structure that holds a volume of lubricating fluid. The manifolds 360, 368 described herein can be formed of any suitable shape and / or volume to facilitate the distribution of lubricating fluid in the systems disclosed herein. Similarly, the lubricating fluid supply lines disclosed herein can be formed of any suitable size and / or shape (e.g., straight, curved, etc.). As described above, the lubricating fluid supply lines can extend to one or more remote locations where the lubricating fluid is accessible, such as a gearbox tank or other reservoir of lubricating fluid. In Figure 6 In the embodiment shown, the lubrication fluid supply line also passes through one or more engine struts 374 .

[0069] In some embodiments, the lubrication fluid directed through the layshaft 330 can also be directed to other locations. For example, an oil transfer bearing for the pitch control mechanism can be located on the front side of the gear assembly, and a gear assembly / pitch control oil supply line can be provided through the stationary planet carrier, as schematically indicated by arrow 376.

[0070] Figure 7 Shown Figure 6 A front view of a portion of the system shown. Figure 7 As shown, the lubrication fluid is directed through one or more supply lines 352, through the internal passage 331 of the layshaft 330 to the front side of the layshaft 330. The lubrication fluid is further directed to the main manifold 360 and then to the lubrication distribution systems 362, 366, 372. The lubrication fluid directed to the ring gear meshing area is directed through one or more lubrication passages 363 in the carrier 328. For example, Figure 6 As shown, for each layshaft 330 , at least two lubrication passages 363 (one forward and one rearward) are provided in the carrier 328 to supply the second and third lubrication distribution systems 366 , 372 .

[0071] Figure 8 Figure 2 shows the distribution of lubricating fluid to different gear mesh areas of the system. Figure 8As shown, lubrication fluid is delivered through lubrication fluid supply line 352, which is delivered through layshaft 330 to main manifold 360 for distribution to various gear meshes. For example, as described elsewhere, lubrication fluid can be distributed to a first lubrication distribution system 362 at the sun gear mesh area where sun gear 304 is configured to contact first stage planet gears 306. Lubrication fluid is also directed through a plurality of lubrication passages 363 within carrier 328. Figure 8 As shown, lubrication fluid is directed from the main manifold 360 through lubrication passages 363 to a second lubrication distribution system 366 at the ring gear mesh area where the forward second stage planetary gears 308 engage the ring gear 310 .

[0072] Figure 9A yes Figure 8 , showing the passage of the lubricating fluid supply line 352 through the internal passage 331 of the layshaft 330. Figure 9A As shown, lubrication fluid may overflow into the layshaft 330 through an opening 361 in the lubrication fluid supply line 352 to provide lubrication fluid to the lower race passage of the layshaft bearing 344 .

[0073] Figure 9B yes Figure 8 , a cross-sectional view illustrating an exemplary path of lubrication fluid from the main manifold 360 to the first lubrication distribution system 362 at the sun gear mesh area where the sun gear 304 is configured to contact the first stage planet gears 306 .

[0074] Figure 9C yes Figure 8 , shows an exemplary path of lubrication from the main manifold 360 through the lubrication passage 363 to the second lubrication system 366 and the third distribution system 372 at the ring gear mesh area where the front and rear second stage planetary gears 308 mesh with the ring gear 310.

[0075] Figure 10 A scavenging system involves collecting lubricating fluid and redirecting it to a scavenging port in the lubrication system. The ring gear 310 may include a plurality of radial drain holes 378 at the outermost radius of the ring gear 310. As the ring gear rotates, lubricating fluid within the ring gear 310 is pushed toward the inner wall of the ring gear and directed to the radial drain holes 378 as indicated by arrows 380. In addition, one or more openings 382 between the leading first-stage planetary gears and the trailing first-stage planetary gears allow lubricating fluid from the lower race bearing 344 to be directed toward the inner wall of the ring gear and, in turn, to the plurality of radial drain holes 378 as indicated by arrows 384.

[0076] like Figure 10 As shown, the static support structure 386 of the bracket 328 surrounds at least a portion of the ring gear 310 and can direct lubricating fluid from the ring gear drain hole 378 toward the main collector area 387, as indicated by arrows 388. In addition, the static support structure 386 can include one or more grooved windows 390 spaced from the main collector area to account for pitch and roll attitude conditions. Thus, during flight cruise conditions, the majority of the lubricating fluid can be directed toward the main collector area below the main opening 392 in the static support structure 386, while pitch and roll attitude conditions can cause more lubricating fluid (relative to flight cruise conditions) to be directed to one or more off-center grooved windows 390.

[0077] Sloped trough walls 394 can extend along and beneath the static support structure 386 to collect lubricating fluid and direct it toward a primary collector area, as indicated by arrows 396. In addition to lubricating fluid from the gearbox, lubricating fluid from other components can bypass the trough windows 390 of the bracket's static support structure, as indicated by arrows 398, and be directed to the primary collector area by gravity. Furthermore, the static support structure with its trough windows provides a shield for other lubricating fluid flows, protecting the trough walls 394 from the rotating gears and the lubrication distribution system.

[0078] In operation, all lubricating fluid from the gearbox is directed toward the static support structure and its grooved windows 390 and / or main openings 292. This lubricating fluid, along with lubricating fluid from other components of the engine, is directed downward by gravity to the main collector before ultimately reaching the purge port 400. In some embodiments, the purge port may also be integrated into the engine's struts 402, such as Figure 10 shown.

[0079] Figure 11 shows a side view of an exemplary epicyclic gear system, and Figure 12 A cross-sectional view of the gear system is shown taken along line 12 - 12 . Figure 12 The exemplary location of the lubricating fluid and the direction of flow of the lubricating fluid within the system are shown. Figure 12As shown, lubrication fluid is delivered to the sun gear mesh area 402 where the sun gear 304 is configured to contact the first stage planet gears 306, and is directed through the ring gear drain hole and through the main opening 392 in the static support structure 386 toward the main collector area 387, as indicated by arrow 388. Angled slot walls 394 extend along and beneath the static support structure 386 to collect the lubrication fluid and direct it toward the main collector area, as indicated by arrow 396. As described above, lubrication fluid from other components can bypass the opening in the static support structure, as indicated by arrow 398, and be directed to the main collector area by gravity.

[0080] Thus, in certain embodiments, the lubrication fluid collection system described herein provides a three-stage scavenging configuration. First, the lubrication fluid is radially ejected through a series of radial discharge holes located at the outermost radius of the rotating ring gear. Second, the bracket-supported static frame provides circumferential grooves that serve as a first collector for the ejected lubrication fluid, significantly reducing the kinetic energy of the lubrication fluid. Third, the bracket-supported static frame has multiple dedicated groove windows to allow gravity drainage to a primary collector derived from the groove wall, collecting the oil from the entire groove into a scavenging port. As a result, the reduction in the hydrodynamic effects associated with the momentum of the rotating lubrication fluid is significantly improved, which can improve the efficiency of the scavenging system.

[0081] Furthermore, the integration of the scavenging system with the bracket's static support reduces and / or eliminates the need for any additional static collector parts. In other words, the bracket itself can function as the oil scavenging system, reducing system weight and cost. The scavenging windows are also configured to handle the entire flight envelope (including pitch and roll attitude conditions), providing full scavenging capability under all operating conditions. This reduces the risk of additional drag losses associated with oil churning and foaming, maintaining gearbox efficiency at nominal values ​​throughout operation. As a secondary function, the intermediate scavenging system also protects additional oil paths from other components in the sump. Thus, while the bracket's scavenging only collects oil from the gearbox, the sump collector collects all oil in the sump, optimizing oil flow management and scavenging efficiency. The scavenging ports can also be integrated within the engine's struts, saving significant radial space and keeping the entire scavenging system quite compact relative to the gearbox's radial envelope. Due to its integration with the bracket's static structure, the scavenging system has little impact on the gearbox assembly sequence.

[0082] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. If such other examples include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims, they are intended to be within the scope of the claims.

[0083] Further aspects of the invention are provided by the subject matter of the following clauses:

[0084] 1. A turbine engine (100, 200) comprising a fan assembly (104, 204) comprising a plurality of fan blades (108, 208); a core engine (106, 206) comprising a turbine and an input shaft (122, 222) rotatable with the turbine; and a gear assembly (102, 202, 302) receiving the input shaft (122, 222) at a first speed and driving an output shaft (124, 224) coupled to the fan assembly (104, 204) at a second speed, the second speed being slower than the first speed, the gear assembly (102, 202, 302) comprising a sun gear (304). , a plurality of planetary gear layshafts (330) each supporting a first stage planetary gear (306) and a second stage planetary gear (308), and a ring gear (310), the sun gear rotating about a longitudinal centerline (120, 220, 320) of the gear assembly; and a lubrication system comprising a plurality of lubrication fluid supply lines (352), wherein the plurality of planetary gear layshafts each include an internal passage (331) extending between a rear side of the layshaft and a front side of the layshaft, and the plurality of lubrication fluid supply lines include one or more layshaft supply lines (353) extending through corresponding ones of the internal passages (331) of the planetary gear layshafts (330).

[0085] 2. A turbine engine according to clause 1, further comprising one or more openings (361) along the length of the one or more layshaft supply lines (353) to direct fluid from within the layshaft supply lines to the internal passage of the planetary gear layshaft (330).

[0086] 3. The turbine engine according to any preceding clause, further comprising a planet carrier (328), the planet carrier (328) comprising a plurality of lubrication passages (363), the plurality of lubrication passages (363) receiving one or more of the lubrication fluid supply lines (353).

[0087] 4. The turbine engine of clause 3, wherein the planet carrier (328) comprises a front portion and an aft portion, and wherein both the front portion and the aft portion comprise one or more lubrication passages.

[0088] 5. A turbine engine according to item 4, wherein the one or more lubrication fluid supply pipelines (353) received in the plurality of lubrication passages (363) are fluidly connected to a first lubrication fluid distribution system (366) and a second lubrication fluid distribution system (372), wherein the first lubrication fluid distribution system (366) directs the lubrication fluid to the front ring gear meshing area and the second lubrication fluid distribution system (372) directs the lubrication fluid to the front ring gear meshing area.

[0089] 6. A turbine according to any preceding clause, further comprising a main lubrication fluid manifold in fluid communication with a third lubrication distribution system (362) at the sun gear mesh area.

[0090] 7. The turbine of any of clauses 5 and 6, wherein one or more of the first lubrication system, the second lubrication system and the third lubrication system comprises a spray bar.

[0091] 8. A turbine according to any preceding clause, wherein the first stage planetary gears (306) include forward first stage planetary gears and aft first stage planetary gears, and further comprising one or more openings between the forward first stage planetary gears and the aft first stage planetary gears to clear oil from the internal passages (331) of the plurality of planetary gear layshafts (330).

[0092] 9. The turbine of any preceding clause, wherein the ring gear comprises a plurality of radial discharge holes between the rear side and the front side of the ring gear (310).

[0093] 10. A turbine according to any preceding clause, wherein the planet carrier includes an axially extending portion extending around at least a portion of the ring gear (310), wherein the axially extending portion includes one or more grooves (390, 392) that direct lubrication fluid to a main collector area (387).

[0094] 11. The turbine according to clause 10, wherein the one or more grooves include a main groove located at the axial center of the ring gear (310) and one or more grooves offset from the axial direction.

[0095] 12. The turbine engine of any preceding clause, wherein the sun gear (304), the first and second stage planetary gears (306, 308), and the ring gear (310) comprise double helical gears.

[0096] 13. A turbine engine according to any preceding clause, wherein the ring gear (310) comprises a first ring gear set (324) meshed with the third gear set (321) and a second ring gear set (326) meshed with the fourth gear set (322).

[0097] 14. A turbine according to any preceding clause, wherein the gear ratio of the gear assembly is in the range of 6:1 to 14:1, 6.1 to 12:1, 7:1 to 11:1, or 8:1 to 10:1.

[0098] 15. A turbomachine engine according to any preceding clause, wherein the fan assembly is a single stage unducted fan blade.

[0099] 16. A turbine engine according to any preceding clause, wherein the first stage planetary gear has a first diameter and the second stage planetary gear has a second diameter, wherein a ratio of the first diameter to the second diameter is in the range of 1.0 to 2.0, 1.2 to 1.7, 1.3 to 1.6, or 1.4 to 1.5.

[0100] 17. A turbine engine according to any preceding clause, wherein there are three planetary gear layshafts (330).

[0101] 18. A gear assembly for use with a turbine engine (100, 200), comprising: a sun gear (304), a plurality of planetary gear layshafts (330) each supporting a first stage planetary gear (306) and a second stage planetary gear (308), and a ring gear (310), the sun gear rotating about a longitudinal centerline (120, 220, 320) of the gear assembly; and a lubrication system comprising a plurality of lubrication fluid supply lines (352), wherein the plurality of planetary gear layshafts each include an internal passage (331) extending between a rear side of the layshaft and a front side of the layshaft, and the plurality of lubrication fluid supply lines include one or more layshaft supply lines (353) extending through corresponding ones of the internal passages (331) of the planetary gear layshafts (330).

[0102] 19. The gear assembly of clause 18, further comprising one or more openings (361) along the length of the one or more layshaft supply lines (353) to direct fluid from within the layshaft supply lines to the internal passages of the planetary gear layshafts (330).

[0103] 20. The gear assembly of any one of claims 18 or 19, further comprising a planet carrier (328) comprising a plurality of lubrication passages (363) receiving one or more of the lubrication fluid supply lines (353).

[0104] 21. The gear assembly of clause 20, wherein the planet carrier (328) includes a front portion and a rear portion, and wherein the front portion and the rear portion each include one or more lubrication passages.

[0105] 22. A gear assembly according to any one of items 20 or 21, wherein the one or more lubrication fluid supply lines (353) received in the multiple lubrication passages (363) are fluidly connected to a first lubrication fluid distribution system (366) and a second lubrication fluid distribution system (372), wherein the first lubrication fluid distribution system (366) directs the lubrication fluid to the front ring gear meshing area and the second lubrication fluid distribution system (372) directs the lubrication fluid to the front ring gear meshing area.

[0106] 23. The gear assembly of any of clauses 18-22, further comprising a main lubrication fluid manifold in fluid communication with a third lubrication distribution system (362) at the sun gear mesh area.

[0107] 24. A gear assembly according to any one of clauses 18-23, wherein the first stage planetary gears (306) include forward first stage planetary gears and aft first stage planetary gears, and further including one or more openings between the forward first stage planetary gears and the aft first stage planetary gears to clear oil from the internal passages (331) of the plurality of planetary gear countershafts (330).

[0108] 25. The gear assembly of any one of clauses 18 to 24, wherein the ring gear comprises a plurality of radial drain holes between the rear side and the front side of the ring gear (310).

[0109] 26. A gear assembly according to any of clauses 18-25, wherein the planet carrier includes an axially extending portion extending around at least a portion of the ring gear (310), wherein the axially extending portion includes one or more grooves (390, 392) for directing lubricating fluid to a main collector area (387).

Claims

1. A turbine engine, characterized in that: include: a fan assembly, the fan assembly comprising a plurality of fan blades; a core engine comprising a turbine and an input shaft rotatable with the turbine; a gear assembly receiving the input shaft at a first speed and drivingly coupled to an output shaft of the fan assembly at a second speed, the second speed being slower than the first speed, the gear assembly including a sun gear, a plurality of planet gear layshafts each supporting a first stage planet gear and a second stage planet gear, and a ring gear, the sun gear rotating about a longitudinal centerline of the gear assembly, the gear assembly having a rear side and a front side; as well as a lubrication system comprising a plurality of lubrication fluid supply lines, including at least one first lubrication supply line, wherein each of the plurality of planetary gear layshafts includes an internal passage extending between a rear side of the planetary gear layshaft and a front side of the layshaft, the first lubrication supply line extending along the rear side of the gear assembly, through the internal passage of a corresponding one of the plurality of planetary gear countershafts, and extending along the front side of the gear assembly to a main lubrication fluid manifold, The main lubrication fluid manifold is in fluid communication with the first lubrication distribution system in the sun gear mesh area, and The first lubrication supply line has one or more openings along a portion extending through the internal passage of a corresponding one of the plurality of planetary gear countershafts to direct fluid from within the first lubrication supply line to the internal passage of the planetary gear countershaft.

2. The turbine engine according to claim 1, characterized in that Further included is a planet carrier comprising a plurality of lubrication passages receiving one or more of the lubrication fluid supply lines, and the first lubrication supply line further extends through a corresponding lubrication passage of the plurality of lubrication passages.

3. The turbine engine according to claim 2, characterized in that in, The planet carrier includes a front portion and a rear portion, and both the front portion and the rear portion include one or more lubrication passages.

4. The turbine engine according to claim 3, characterized in that in, The first lubrication supply line is in fluid communication with a second lubrication fluid distribution system through one or more lubrication passages of the plurality of lubrication passages to direct lubrication fluid to the front ring gear mesh area.

5. The turbine engine according to claim 3, characterized in that in, The first lubrication supply line is in fluid communication with a third lubrication fluid distribution system through one or more of the plurality of lubrication passages to direct lubrication fluid to the rear ring gear mesh area.

6. The turbine engine according to claim 4, characterized in that in, At least one of the first lubrication system and the second lubrication system includes a spray boom.

7. The turbine engine according to claim 2, characterized in that in, The planet carrier includes an axially extending portion extending around at least a portion of the ring gear, wherein the axially extending portion includes one or more grooves that direct lubrication fluid to a main collector area.

8. The turbine engine according to claim 7, characterized in that in, The one or more grooves include a main groove located at the axial center of the ring gear and one or more grooves offset from the axial direction.

9. The turbine engine according to claim 1, wherein: in, The first stage planetary gears include forward first stage planetary gears and aft first stage planetary gears, and further include one or more openings between the forward first stage planetary gears and the aft first stage planetary gears to clear oil from the internal passages of the plurality of planetary gear layshafts.

10. The turbine engine according to claim 1, wherein in, The ring gear includes a plurality of radial drain holes between a rear side and a front side of the ring gear.

11. The turbine engine according to claim 1, wherein: in, The sun gear, the first and second stage planetary gears, and the ring gear include double helical gears.

12. The turbine engine according to claim 1, wherein: in, The ring gear includes a first ring gear set meshing with the third gear set and a second ring gear set meshing with the fourth gear set.

13. The turbine engine according to claim 1, wherein: in, The gear ratio of the gear assembly is in the range of 6:1 to 14:

1.

14. The turbine engine according to claim 1, wherein: in, The fan assembly is a single-stage ductless fan blade.

15. The turbine engine according to claim 1, wherein in, The first stage planet gear has a first diameter and the second stage planet gear has a second diameter, wherein a ratio of the first diameter to the second diameter is in a range of 1.0 to 2.

0.

16. The turbine engine according to claim 1, wherein in, There are three planetary gear countershafts.

17. A gear assembly for use with a turbine engine, characterized in that include: Sun gear; a plurality of planetary gear layshafts each supporting a first stage planetary gear and a second stage planetary gear; Ring gear; a lubrication system comprising a plurality of lubrication fluid supply lines; as well as a first lubrication distribution system at the sun gear meshing area; wherein the sun gear rotates about the longitudinal centerline of the gear assembly, wherein each of the plurality of planetary gear layshafts includes an internal passage extending between a rear side of the layshaft and a front side of the layshaft, and wherein respective ones of the plurality of lubrication fluid supply lines extend through respective ones of the internal passages of the planetary gear layshaft from the rear side of the gear assembly to the front side of the gear assembly to direct the lubrication fluid to the first lubrication distribution system, the second lubrication distribution system, and the third lubrication distribution system.

18. The gear assembly according to claim 17, wherein: Further included is one or more openings along the length of corresponding ones of the plurality of lubrication fluid supply lines to direct fluid to the internal passage of the planetary gear layshaft.

19. The gear assembly according to claim 17, wherein: in, The second lubrication distribution system is located in the front ring gear meshing area, and the third lubrication distribution system is located in the rear ring gear meshing area, and the gear assembly further comprises: A planet carrier includes a plurality of lubrication passages receiving corresponding ones of the plurality of lubrication fluid supply lines to direct the lubrication fluid between the first lubrication system and at least one of the second and third lubrication systems.

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