CN114382593A - Turbine and gear assembly - Google Patents

Abstract

A turbine engine and gear assembly is provided. The engine includes a first power input member rotatable in a first direction relative to the engine centerline axis, a second power input member rotatable in a second direction relative to the engine centerline axis, a power output member rotatable relative to the engine centerline axis, a static member fixed relative to a circumferential direction relative to the gear assembly centerline axis, and a gear assembly. The gear assembly includes a first rotatable gear operably coupled to the first power input component at a first interface. The first rotatable gear is operably coupled to the static component at a static component interface. The static component interface is configured to act against the first rotatable gear to rotate the first rotatable gear relative to the gear assembly centerline axis. The power output member is operably coupled to the first rotatable gear.

Description

Turbine and gear assembly

PRIORITY INFORMATION

This application claims priority to indian patent application No. 202011046038 filed on 22/10/2020.

Technical Field

The present subject matter generally relates to turbomachines including gear assemblies. The present subject matter is particularly concerned with gear assembly arrangements and gear assembly arrangements specific to certain turbine configurations.

Background

Turbofan engines operate on the principle that a central gas turbine core drives a bypass fan located at a radial location between the nacelle and the engine core of the engine. With this configuration, the engine is typically limited by the allowable size of the bypass fan, as an increase in the size of the fan correspondingly increases the size and weight of the nacelle.

In contrast, open rotor engines operate on the principle of having a bypass fan located outside the engine compartment. This allows the use of larger rotor blades capable of acting on a larger volume of air than conventional turbofan engines, potentially improving propulsion efficiency compared to conventional turbofan engine designs.

Turbines such as open rotor engines may require a large gear ratio between the low speed spool and the fan rotor to allow larger rotor blades to act on a larger volume of air and/or to do so at certain desired operating speeds of the engine or aircraft. One challenge is that known gear assemblies may provide insufficient gear ratios for desired open rotor engine operation. For example, known gear assemblies may not sufficiently reduce the output rotational speed relative to the turbine such that the fan rotor operates too fast and inefficiently and/or the turbine operates too slow and inefficiently. Another challenge is that known gear assemblies that may be scaled to provide sufficient gear ratios may be too large for the desired length and/or diameter of the engine. Another challenge is that known gear assemblies may not be sufficient to receive multiple input shafts and/or counter-rotating input shafts. As a result, the interdigitated compressor and/or turbine configuration may not be compatible with certain known gear assemblies.

Accordingly, there is a need for a gear assembly that can receive multiple input shafts, counter-rotating input shafts, and/or provide multiple output shafts providing a desired gear ratio, and/or be arranged within desired diameter or length constraints, which may be applicable to turbomachines in general, or to open rotor engines in particular.

Disclosure of Invention

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 invention disclosed herein.

One aspect of the present disclosure relates to a turbine engine and gear assembly. An engine centerline axis is defined through the engine. The engine includes: a first power input member rotatable in a first direction relative to the engine centerline axis; a second power input member, the first power input member being rotatable in a second direction relative to the engine centerline axis; a power output member rotatable relative to the engine centerline axis; a static component fixed relative to a circumferential direction relative to a gear assembly centerline axis; and a gear assembly. The gear assembly includes: a first rotatable gear operably coupled to the first power input component at a first interface. The first rotatable gear is operably coupled to the static component at a static component interface. The static component interface is configured to act against the first rotatable gear to rotate the first rotatable gear relative to the gear assembly centerline axis. The power output member is operably coupled to the first rotatable gear. The first power input component and the second power input component together are configured to be transmitted to the power output component through a second interface at the first power input component. The first interface and the second interface are axially separated relative to the gear assembly centerline axis.

These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings incorporated in and forming a part of the specification illustrate various aspects of the present invention, and together with the description serve to explain the principles of the invention

Drawings

A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: FIG. 1 is a schematic cross-sectional view of an exemplary embodiment of a turbomachine including a core engine having a gear assembly, according to one aspect of the present disclosure;

FIG. 2 is a schematic cross-sectional view of an exemplary embodiment of a turbine engine having a core engine of a gear assembly according to one aspect of the present disclosure;

FIG. 3 is an exemplary schematic embodiment of the engine of FIGS. 1-2, according to one aspect of the present disclosure;

FIG. 4 is an exemplary schematic embodiment of the engine of FIGS. 1-2, according to one aspect of the present disclosure;

FIG. 5 is an exemplary schematic embodiment of the engine of FIGS. 1-2, according to one aspect of the present disclosure;

FIG. 6 is an exemplary schematic embodiment of a turbine section of the core engine of FIG. 5 including a gear assembly according to aspects of the present disclosure;

FIG. 7 is an exemplary layout of a gear assembly of the core engine of FIGS. 3-4, according to one aspect of the present disclosure; and

fig. 8 is a schematic layout of the gear assembly of fig. 6, according to one aspect of the present disclosure.

Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention.

Detailed Description

Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. . In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

As used herein, the terms "first," "second," and "third" are used interchangeably to distinguish one component from another component, and are not intended to denote the position or importance of a single component.

The terms "forward" and "aft" refer to relative positions within the gas turbine engine or aircraft, and to the normal operating attitude of the gas turbine engine or aircraft. For example, with respect to a gas turbine engine, the forward refers to a location closer to the engine inlet and the aft refers to a location closer to the engine nozzle or exhaust.

The terms "upstream" and "downstream" refer to relative directions with respect to fluid flow in a fluid path. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction to which the fluid flows.

Unless otherwise indicated herein, the terms "coupled," "fixed," "attached," and the like, refer to both a direct coupling, fixing, or attachment, and an indirect coupling, fixing, or attachment through one or more intermediate components or features.

The singular forms "a", "an" and "the" include plural references unless the context clearly dictates otherwise.

Approximating language, as used herein throughout the specification and claims, is intended to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as "about", "approximately" and "substantially", are not to be limited to the precise value specified. In at least some examples, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of a method or machine for constructing or manufacturing the component and/or system. For example, approximate language may refer to within a margin of 1%, 2%, 4%, 10%, 15%, or 20%.

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

One or more components of the turbine engine or gear assembly described below may be manufactured or formed using any suitable process, such as an additive manufacturing process, for example, a 3D printing process. The use of such processes may allow such components to be integrally formed, as a single unitary component, or as any suitable number of sub-components. In particular, the additive manufacturing process may allow such components to be formed integrally and include various features not possible when using existing manufacturing methods. For example, the additive manufacturing methods described herein may allow for the manufacture of gears, housings, pipes, heat exchangers, gear assemblies, or other components having unique features, configurations, thicknesses, materials, densities, fluid passages, headers, and mounting structures that are not possible or practical when using existing manufacturing methods. Some of these features are described herein.

Suitable additive manufacturing techniques according to the present disclosure include, for example, Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), 3D printing (such as by inkjet, laser jet, and binder jet), Stereolithography (SLA), Direct Selective Laser Sintering (DSLS), Electron Beam Sintering (EBS), Electron Beam Melting (EBM), Laser Engineered Net Shape (LENS), laser net shape fabrication (LNSM), Direct Metal Deposition (DMD), Digital Light Processing (DLP), Direct Selective Laser Melting (DSLM), Selective Laser Melting (SLM), Direct Metal Laser Melting (DMLM), and other known processes.

Referring now to the drawings, fig. 1-2 are exemplary embodiments of an engine 10 including a gear assembly according to aspects of the present disclosure. The engine 10 includes a fan assembly 14 driven by a core engine 16. In various embodiments, core engine 16 is generally a Brayton (Brayton) cycle system configured to drive fan assembly 14. Core engine 16 is at least partially covered by an outer casing 18. The fan assembly 14 includes a plurality of fan blades 13. Bucket assemblies 20 extend from the outer casing 18. A bucket assembly 20 including a plurality of buckets 15 is positioned in operable arrangement with the fan blades 13. The bucket assembly 20 may provide thrust, control thrust vectors, attenuate or redirect undesirable noise, or otherwise desirably alter airflow relative to the fan blades 13.

In certain embodiments, as shown in FIGS. 1-2, the vane assembly 20 is positioned downstream or aft of the fan assembly 14. However, it should be understood that in some embodiments, the vane assembly 20 may be located upstream or forward of the fan assembly 14. In various embodiments, engine 10 may include a first vane assembly positioned forward of fan assembly 14 and a second vane assembly positioned aft of fan assembly 14. The fan assembly 14 may be configured to desirably adjust the pitch at one or more fan blades 13, such as to control the thrust vector, attenuate or redirect noise, or alter thrust output. The bucket assembly 20 may be configured to desirably adjust the pitch at one or more of the buckets 15, such as to control the thrust vector, attenuate or redirect noise, or alter thrust output. The pitch control mechanisms at one or both of the fan assembly 14 or the bucket assembly 20 may cooperate to produce one or more of the desired effects described above.

In various embodiments, such as shown in FIG. 1, engine 10 is a turbofan gas turbine engine that includes a nacelle or fan casing 54 that houses fan assembly 14. In other embodiments, such as shown in FIG. 2, the engine 10 is a non-ducted thrust producing system such that the plurality of fan blades 13 are not shrouded by the nacelle or fan casing. As such, in various embodiments, engine 10 may be configured as a shroudless turbofan engine, an open rotor engine, or a turbofan engine. In a particular embodiment, the engine 10 is a single non-ducted rotary engine including a single row of fan blades 13. The engine 10 may include a fan assembly 14 having large diameter fan blades 13, such as may be suitable for high bypass ratios, high cruise speeds, high cruise altitudes, and/or relatively low rotational speeds. Cruise altitude is generally the altitude at which the aircraft is level after climbing and before descending to near flight phase. In various embodiments, the engine is employed in an aircraft that is cruising at an altitude of up to about 65,000 feet. In some embodiments, the cruising height is between about 28,000 feet and about 45,000 feet. In certain embodiments, cruise altitude is expressed in flight altitude based on standard air pressure at sea level, with cruise flight conditions between FL280 and FL 650. In another embodiment, the cruise flight condition is between FL280 and FL 450. In some embodiments, the cruise altitude is defined based at least on atmospheric pressure, wherein the cruise altitude is between about 4.85psia and about 0.82psia based on a sea level pressure of about 14.70psia and a sea level temperature of about 59 degrees Fahrenheit. In another embodiment, the cruising height is between about 4.85psia and about 2.14 psia. It should be appreciated that in some embodiments, the cruise altitude range defined by the pressure may be adjusted based on different reference sea level pressures and/or sea level temperatures.

Core engine 16 is generally enclosed in an outer casing 18 defining a maximum diameter. In certain embodiments, engine 10 includes a length from a longitudinally forward end 98 to a longitudinally rearward end 99. In various embodiments, the engine 10 defines a ratio of length (L) to maximum diameter (Dmax) that provides reduced installation resistance. In one embodiment, L/Dmax is at least 2. In another embodiment, L/Dmax is at least 2.5. In various embodiments, it should be understood that L/Dmax is used for a single non-duct rotary engine.

The reduced installation resistance may further provide improved efficiency, such as improved specific fuel consumption. Additionally, or alternatively, the reduced drag may provide operation of the cruise altitude engine and aircraft at or above mach 0.5. In certain embodiments, L/Dmax, fan assembly 14, and/or bucket assembly 20, individually or collectively, at least partially configure engine 10 to operate at a maximum cruise altitude operating speed between approximately Mach 0.55 and approximately Mach 0.85.

Referring now to fig. 3-5, an exemplary embodiment of core engine 16 is provided. Core engine 16 includes a compressor section 21, a heat addition system 26, and an expansion section 33 in a series flow arrangement. The core engine 16 extends circumferentially relative to the engine centerline axis 12. Core engine 16 includes a high-speed spool that includes a high-speed compressor 24 and a high-speed turbine 28 operatively rotationally coupled together by a high-speed shaft 22. The heat addition system 26 is positioned between the high speed compressor 24 and the high speed turbine 28. Various embodiments of heater system 26 include a combustion section. The combustion section may be configured as a deflagration combustion section, a rotary detonation combustion section, a pulse detonation combustion section, or other suitable heat addition system. The heat addition system 26 may be configured as one or more of a rich combustion system or a lean combustion system, or a combination thereof. In various embodiments, the heat addition system 26 includes an annular combustor, a can combustor, a sleeve combustor, a Trapped Vortex Combustor (TVC), or other suitable combustion system, or a combination thereof.

Still referring to fig. 3-5, the core engine 16 includes a booster or low speed compressor 22 positioned in flow relationship with a high speed compressor 24. The low speed compressor 22 is rotatably coupled with a first turbine 30 via a first shaft 29. Various embodiments of the expansion section 33 further include a second turbine 32 rotatably coupled to the second shaft 31. First turbine 30 and second turbine 32 are each operably connected to a gear assembly 100, as further described herein, to provide power to fan assembly 14.

It should be understood that unless otherwise specified, the terms "low" and "high" or their respective degrees of comparison (e.g., lower, higher, if applicable) when used with compressor, turbine, shaft or spool components, respectively, refer to the relative speeds within the engine. For example, "low turbine" or "low speed turbine" defines a component configured to operate at a lower rotational speed (such as a maximum allowable rotational speed) than a "high turbine" or "high speed turbine" at the engine. Alternatively, the above terms are to be understood to their fullest extent, unless otherwise specified. For example, "low turbine" or "low speed turbine" may refer to the lowest maximum rotational speed turbine within the turbine section, "low compressor" or "low speed compressor" may refer to the lowest maximum rotational speed turbine within the compressor section, "high turbine" or "high speed turbine" may refer to the highest maximum rotational speed turbine within the turbine section, and "high compressor" or "high speed compressor" may refer to the highest maximum rotational speed compressor within the compressor section. Similarly, a low speed spool refers to a lower maximum rotational speed than a high speed spool. It should further be appreciated that the terms "low" or "high" in such aforementioned aspects may additionally or alternatively be understood as a minimum or maximum allowable speed relative to a minimum allowable speed, or relative to normal, desired, steady state, etc. operation of the engine.

In certain embodiments, such as shown in fig. 3-6, core engine 16 includes one or more staggered structures at compressor section 21 and/or expansion section 33. In one embodiment, the expansion section 33 includes a second turbine 32 interleaved with the first turbine 30, such as via a rotating nacelle, drum, casing, or rotor. Although not shown, it should be understood that embodiments of the expansion section 33 may include the first and/or second turbines 30, 32 interleaved with one or more stages of the high speed turbine 28. In another embodiment, the compressor section 21 includes a low speed compressor 22 interleaved with a high speed compressor 24. For example, a high speed compressor (such as the high speed compressor 24) may be the first compressor interleaved with a low speed compressor (such as the low speed compressor 22).

Referring now to fig. 2 and 3-5, the core engine includes a gear assembly 100 (fig. 3-5) configured to transfer power from the expansion section 33 and reduce an output rotational speed at the fan assembly 14 relative to one or both of the turbines 30, 32 (fig. 3-5). The embodiment of the gear assembly 100 depicted and described with respect to fig. 6-8 may allow the gear ratio to be adapted for use with large diameter non-ducted fans and relatively small diameter and/or relatively high speed turbines, such as turbines 30, 32 (fig. 3-5). Additionally, embodiments of the gear assembly 100 provided herein may be adapted to be within the radial or diametric constraints of the core engine within the outer casing 18.

The embodiment of the gear assembly 100 depicted and described with respect to fig. 6-8 may provide gear ratios and arrangements that are suitable within the L/Dmax constraints of the engine 10. In certain embodiments, the gear assembly 100 depicted and described with respect to fig. 6-8 allows for providing a gear ratio and arrangement of rotational speeds of the fan assembly 14 corresponding to one or more of the cruise altitude and/or cruise speed ranges provided above. Various embodiments of the gear assembly 100 provided herein may allow for gear ratios as high as 14: 1. Various embodiments of the gear assembly 100 provided herein may also allow for a gear ratio of at least 4: 1. The various embodiments of the gear assembly 100 provided herein allow for a gear ratio of a two-stage planetary or compound gear assembly between 4:1 and 12: 1. It should be appreciated that embodiments of the gear assembly 100 provided herein may allow for large gear ratios, such as between the expansion section 33 and the fan assembly 14, or particularly between the first turbine 30 (fig. 3-5) and the fan assembly 14 and/or between the second turbine 32 (fig. 3-5) and the fan assembly 14 provided herein, and within constraints such as, but not limited to, the length (L) of the engine, the maximum diameter (Dmax) of the engine, cruise altitudes up to 65,000 feet, and/or operating cruise speeds up to mach 0.85, or combinations thereof.

Although depicted as a turbofan engine and an unshrouded or open rotor engine, it should be understood that aspects of the present disclosure provided herein may be applied to turbine configurations that are shrouded or ducted engines, partially ducted engines, tail fan engines, or other turbine configurations, including those used in marine, industrial, or aviation propulsion systems. Certain aspects of the present invention may be applicable to a turbofan, turboprop or turboshaft engine, such as a turbofan, turboprop or turboshaft engine having a reduction gear assembly. However, it should be understood that certain aspects of the present disclosure may address issues that may be particular to shroudless or open rotor engines. Aspects of the present disclosure may provide a gear assembly that allows for a particular gear ratio, fan diameter, fan speed, length (L) of engine 10, maximum diameter (Dmax) of engine 10, L/Dmax of engine 10, desired cruise altitude, and/or desired operating cruise speed, or a combination thereof.

Referring to fig. 6-8, an exemplary embodiment of a gear assembly 100, 500, 600 operatively connected to a first power input member 101 and a second power input member 102 is provided. Embodiments of the gear assembly 100 receive power or torque from the first and second power input members 101, 102. In one embodiment, the first power input member 101 is the first shaft 29 (fig. 3-5) and the second power input member 102 is the second shaft 31 (fig. 3-5). Accordingly, in certain embodiments, the gear assembly 100 is configured to receive power or torque from a first turbine (e.g., the first turbine 30 in fig. 3-5) and a second turbine (e.g., the second turbine 32 in fig. 3-5). In some embodiments, the second turbine 32 is connected to the gear assembly 100 via a ring gear, as described herein. Further, in certain embodiments, the first and second turbines are rotatably independent of the other turbine such that rotation of one turbine does not necessarily cause rotation of the other turbine.

The first power input component 101 and the second power input component 102 may generally include coaxial counter-rotating shafts opposite each other, such as represented by "+" and "-" in fig. 7-8. The first power input component 101 may generally be coupled to a higher speed spool than the second power input component 102. Thus, the first power input member 101 is generally capable of rotating at a higher speed than the second power input member 102. Further, the gear assembly 100 is configured to receive the first power input component 101 at a higher rotational speed than the second power input component 102.

Still referring to fig. 7-8, the gear assembly 100 includes a static component assembly 140 that is fixed relative to the gear assembly centerline axis 104, such as fixed in a circumferential direction C relative to the gear assembly centerline axis 104. The reference radial direction R extends from the gear assembly centerline axis 104. In various embodiments, the first power input component 101 is configured to rotate in a first direction relative to the gear assembly centerline axis 104, and the second power input component 102 is configured to rotate in a second direction opposite the first direction. In various embodiments, the power output component 103 is configured to rotate in the same direction as the first power input component 101.

The static component assembly 140 is operably coupled to the first power input component 101 to allow the gear assembly to be statically determined such that the static component assembly 140 allows a load to be transferred from the first power input component 101 to the power output component 103. The static component assembly 140 is further operatively connected to the second power input component 102 to allow the gear assembly to be statically determined such that the static component assembly 140 allows a load to be transferred from the second power input component 102 to the power output component 103. In various embodiments, such as depicted and described with reference to fig. 7-8, the static component assembly 140 includes one or more gears, such as the first gear 141 and the second gear 142 depicted and described herein. The first gear 141 is fixed relative to the gear assembly centerline axis 104.

In certain embodiments, the power output component 103 comprises a first rotatable gear that is rotatable circumferentially about the gear assembly centerline axis 104. The first rotatable gear 131 includes a component centerline axis relative to each gear. In certain embodiments, each gear of the power output component 103 may rotate about its respective component centerline axis while also being rotatable in the circumferential direction C relative to the gear assembly centerline axis 104.

In various embodiments, the static component assembly 140 includes a mounting structure 146. In certain embodiments, the mounting structure 146 comprises a frame, housing, mount, static shaft, or other substantially fixed or grounded structure. Although not described in further detail, it should be appreciated that the mounting structure 146 may generally include any one or more stationary structures of the engine 10 or turbine. In various embodiments, the mounting structure 146 is an inlet housing at the fan assembly 14 or forward of the compressor section 21 (fig. 3-5), an intermediate housing positioned between the low speed compressor 22 and the high speed compressor, or other fixed structure at the fan assembly 14, the compressor section 21, or the heat addition system 26. In other various embodiments, the mounting structure 146 is a turbine casing, a turbine center frame, an intermediate turbine frame, or a turbine aft frame positioned at the expansion section 33, or other fixed structure positioned aft or downstream of the expansion section 33, or other suitable fixed structure at the turbine, such as shown in fig. 6. In yet another embodiment, mounting structure 146 is a conical or frustoconical arm connected to ring gear 141.

The gear assembly 100 is operatively connected to transfer power or torque from the first and second power input members 101, 102 to the power output member 103. In various embodiments, the power output component 103 is connected to a load device. In certain embodiments, the load device is a fan or propeller assembly (e.g., fan assembly 14 in fig. 1-5), a motor, a rotor assembly (e.g., a helicopter rotor), or other power take-off or propulsion device. In certain embodiments, the power output component 103 includes a shaft that is driven at least partially by power received from the first and second turbines 30, 32 through the gear assembly 100. In various embodiments, the power output component 103 is configured to rotate in the same direction as the first power input component 101 or the second power input component 102, such as indicated by "+" or "-" in the 7-8 figures.

Still referring to fig. 7-8, various embodiments of the gear assembly 100 include bearings connected to certain components described herein to allow rotation of the component centerline axis, the gear assembly centerline axis, or both (such as further described herein). It should be understood that certain embodiments depicted and described herein may omit depiction of bearing placement and/or static structures to which bearings may be secured for clarity. In certain embodiments, the bearing is placed between the static component assembly 140 and one or more structures that are rotatable about the gear assembly centerline axis 104, including, but not limited to, the first power input component 101, the second power input component 102, the power output component 103, or a gear. In certain embodiments, the bearings are placed between the static component assembly 140 and one or more structures that are rotatable relative to the component centerline axis, including but not limited to the gears of the static component 140. The bearings may comprise any suitable bearing type or combination thereof. It should be understood that one skilled in the art may, without undue experimentation, reasonably determine a bearing assembly type (e.g., roller bearing, thrust bearing, journal bearing, fluid film bearing, etc.) that may be used to receive or transmit power, rotate certain structures relative to a desired axis, fix or mount certain structures relative to a desired axis, or otherwise arrange or operate embodiments of the gear assembly 100 provided herein.

Still referring to fig. 7-8, it should be understood that some of the illustrative embodiments provided herein are partially exploded such that a surface or interface may appear to be separated from adjacent structures. However, unless otherwise specified, the interfaces or engagements depicted or described herein may be operably coupled together, such as to desirably transfer power or torque between the components or features described herein. The interface between the rotating and/or stationary structures described and depicted herein may include any suitable gear type, gear mesh, spline, or other interface. It should be understood that one skilled in the art may reasonably determine without undue experimentation the gear spline type (e.g., helical splines, serrations, crowned splines, parallel spline, etc.) or gear type (e.g., helical, double helix, spur gear, etc.) that may be used to receive or transmit power, limit undesirable vibration or resonance, mitigate undesirable wear or degradation, or other considerations of gear interfaces known in the art.

Referring now to fig. 7, an illustrative embodiment of a gear assembly 500 is provided. The embodiment of the gear assembly 500 provided with respect to fig. 7 may be configured substantially similarly to that described with respect to the gear assembly 100 and engine 10 of fig. 1-5. The gear assembly 500 provided herein includes a first power input component 101 operably coupled to a first rotatable gear 131 at a first interface 111. The gear assembly 500 further includes a first power input member 101, the first power input member 101 being operably coupled to the second rotatable gear 132 at the second interface 121. Each of the first and second rotatable gears 131, 132 is rotatable in a circumferential direction about the gear assembly centerline axis 104. The second power input member 102 is operatively coupled to the second rotatable gear 132.

The power output component 103 is coupled to each of the first and second rotatable gears 131, 132 to receive power or torque from the first and second power input components 101, 102. In particular, power output member 103 is operably coupled to receive power or torque from first power input member 101 via first rotatable gear 131. Further, the power output member 103 is operatively coupled to receive power or torque from the first and second power input members 101 and 102 via the second rotatable gear 132. Various embodiments may include a carrier structure 102A, 103A that couples each respective gear to either an input or output member. The load bearing structure may generally be coupled to a central portion of the respective gear, such as at component centerline axis 105 (e.g., 105A, 105B, 105C), proximate to or about component centerline axis 105 (e.g., 105A, 105B, 105C).

The rotatable gears 131, 132 may generally be configured as a plurality of gears arranged in a circumferential arrangement relative to the gear assembly centerline axis 104. As described above, the first power input component 101 is coupled to the respective rotatable gear 131, 132 via the respective interface 111, 121. In certain embodiments, the first interface 111 defines a gear mesh or spline interface where power is transferred from the first power input component 101 to rotate the first rotatable gear 131 about the gear assembly centerline axis 104. The power output component 103 is operably coupled to each of the first rotatable gears 131, such as via a carrier structure 103A.

In certain embodiments, the power output component 103 is operably coupled to each second rotatable gear 132 at the output interface 113. The second power input member 102 is operatively coupled to the second rotatable gear 132, such as via the carrier structure 102A. The interfaces may allow torque to be transferred between the second power input member 102, the second rotatable gear 132, and the power output member 103. In certain embodiments, the power output component 103 comprises a ring gear at the output interface 113 around the plurality of second rotatable gears 132.

The gear assembly 500 further includes a static component 140 positioned at the static component interface 134 with the first rotatable gear 131. As described herein, the static component interface 134 may generally define a geared or splined interface. In a particular embodiment, the static component includes a ring gear 141 at the static component interface 134, the ring gear 141 being operable to mesh with or contact the plurality of first rotatable gears 131. The static component 140 may generally allow the gear assembly to be statically determined such that the static component assembly 140 allows a load to be transferred from the first power input component 101 to the power output component 103. As described herein, the static component interface 134 may define an interface that provides a surface against which the first rotatable gear 131 acts against a stationary surface to allow torque transfer and rotation of the power output component 103.

In certain embodiments, the first power input component 101 comprises a sun gear at the first interface 111. In certain embodiments, the first power input component 101 comprises a gear engagement interface at the second interface 121. In various embodiments, the first power input component 101 is coupled to the respective first and second rotatable gears 131, 132 at an inner radius relative to the static component interface 134 and the output interface 113.

Still referring to fig. 7, in further conjunction with fig. 3-4, in various embodiments, a gear assembly 500 is operatively coupled to the medium or high speed turbine assembly via the first power input member 101. In certain embodiments, first power input member 101 is further coupled to a medium or high speed compressor assembly. Referring to fig. 7 and 4, in another embodiment, one or more of the compressors or turbines may include rotors that are interleaved with one or more other respective compressors or turbines.

Referring now to fig. 8, an illustrative embodiment of a gear assembly 600 is provided. The embodiment of the gear assembly 600 provided with respect to fig. 8 may be configured substantially similar to that described with respect to the gear assembly 100 and the engine 10 of fig. 1-6. In certain embodiments, the gear assembly 600 is particularly relevant to the schematic engine configuration of fig. 5. The gear assembly 600 provided herein includes a first power input component 101 operably coupled to a second gear 142 at a second interface 121. The gear assembly 600 further includes a first power input component 101 operably coupled to the first rotatable gear 131 at the first interface 111. The first rotatable gear 131 is rotatable circumferentially about the gear assembly centerline axis 104. The second gear 142 is stationary relative to the gear assembly centerline axis 104. However, the second gear 142 is generally rotatable relative to its respective component centerline axis 105B. In certain embodiments, the second gear 142 is a planetary gear that is configured to rotate relative to the component centerline axis 105B and remain stationary relative to the gear assembly centerline axis 104.

The second power input member 102 is operatively coupled to the second gear 142 at the second power input member interface 122. In certain embodiments, the second power input component 102 comprises a ring gear coupled with a plurality of second gears 142 at the second power input component interface 122. The second gear 142 is coupled to the static component 140, such as fixing the second gear 142 relative to the gear assembly centerline axis 104. The second gear 142 provides a surface on which a force from the second power input component 102 can act to transfer energy to the first power input component 101. In various embodiments, static component 140 is coupled to second gear 142 and first rotatable gear 131, for example, via a load bearing or coupling structure 140A extending axially between second gear 142 and first rotatable gear 131.

The power output component 103 is coupled to each second gear 142 to receive power or torque from the first power input component 101 via the second interface 121. The power received by the power output component 103 from the first power input component 101 also includes power transmitted from the second power input component 102 via the second gear 142 and the second interface 121. In particular, power output component 103 is operably coupled to receive power or torque from the first plurality of rotatable gears 131 via first interface 111.

Various embodiments may include a carrier structure 103A coupling each respective first rotatable gear 131 to the power output component 103. The load bearing structure may generally be coupled to a central portion of the respective plurality of first rotatable gears 131, such as at, proximate to, or about the respective component centerline axis 105A of the first rotatable gears 131, for example, at the respective component centerline axis 105A of the first rotatable gears 131. In one embodiment, such as shown in fig. 7, the load bearing structure 103A further couples the power output component 103 to the first and second rotatable gears 131, 132 across an axial span relative to the gear assembly centerline axis 104.

The first rotatable gear 131 may generally be configured as a plurality of gears arranged circumferentially relative to the gear assembly centerline axis 104. As described above, the first power input component 101 is coupled to the respective first rotatable gear 131 via the respective first interface 111. In certain embodiments, the first interface 111 defines a gear mesh or spline interface at which power is transferred from the first power input component 101 to rotate the first rotatable gear 131 and the power output component 103 attached to the first rotatable gear 131 about the gear assembly centerline axis 104. The power output component 103 is operatively coupled to each of the first rotatable gears 131, for example, via a carrier structure 103A.

The gear assembly 600 also includes a static component 140 positioned with the first rotatable gear 131 at the static component interface 134. As described herein, the static component interface 134 may generally define a geared or splined interface. In a particular embodiment, the static component includes a ring gear 141 at the static component interface 134, the ring gear 141 being operable to mesh with or contact the plurality of first rotatable gears 131. The static member 140 may generally allow power or torque to be transferred from the first power input member 101 through the first rotatable gear 131 to the power output member 103. As described herein, the static component interface 134 may define an interface that provides a surface at which the first rotatable gear 131 acts against a stationary surface to allow torque transfer and rotation of the power output component 103.

In certain embodiments, the first power input component 101 comprises a first sun gear at the first interface 111. In certain embodiments, the first power input component 101 comprises a second sun gear at the second interface 121. In various embodiments, the first power input component 101 is coupled to the respective first and second rotatable gears 131, 142 at an inner radius relative to the static component interface 134 and the output interface 113.

Still referring to fig. 8, in further conjunction with fig. 5-6, in various embodiments, a gear assembly 600 is operatively coupled to the medium or high speed turbine assembly via the first power input member 101. In any embodiment, one or more turbines may include a rotor that is interleaved with one or more other respective turbines. In certain embodiments, the second power input component 102 comprises a low speed turbine assembly. As such, in various embodiments, the first power input component 101 generally defines a greater rotational speed during operation than the second power input component 102. In certain embodiments, the rotational speed of the second power input component 102 is approximately equal to the rotational speed of the power output component 103.

Referring to fig. 7-8, embodiments of the gear assembly 500, 600 generally include a first interface 111 that is axially separated from a second interface 121 (i.e., along the direction of extension of the engine centerline axis 12 or the gear assembly centerline axis 104).

The embodiments of the gear assemblies 500, 600 depicted and described with reference to fig. 7-8 may provide gear ratios and arrangements within the L/Dmax constraints suitable for engines 10 such as shown and described with reference to fig. 1-5. It should be appreciated that the gear assembly 100 generally provided in fig. 1-5 may include one or more embodiments of the gear assemblies 500, 600 depicted and described with reference to fig. 7-8. In certain embodiments, the gear assemblies 500, 600 depicted and described with reference to fig. 7-8 allow for providing gear ratios and arrangements of rotational speeds of the fan assembly 14 (fig. 2, 3-5) corresponding to one or more ranges of cruise altitude and/or cruise speed provided above. It should be appreciated that embodiments of the gear assemblies 500, 600 provided herein may allow for a gear ratio such as provided herein (e.g., up to about 12:1 or greater). Embodiments of the gear assemblies 500, 600 may provide a desired gear ratio within constraints such as, but not limited to, a length (L) of the engine (fig. 2), a maximum diameter (Dmax) of the engine 10, an L/Dmax of the engine 10 (fig. 2), a cruising altitude of up to 65,000 feet, and/or an operating cruising speed of up to mach 0.85, or combinations thereof.

Embodiments of the gear assemblies provided herein may allow decoupling of the second power input component 102 from the power output component 103. The embodiments depicted and described herein may improve gear assembly maintenance of known configurations, e.g., allowing gear assemblies to be removed without removing one or more shafts. The second power input component 102, such as a low-pressure turbine, is decoupled from the power output component 103, such as a fan shaft or a low-pressure turbine shaft. Furthermore, the arrangement provided herein may improve dynamic closure between rotatable components, such as improving the specific fuel consumption of the engine. Additionally or alternatively, embodiments of the gear assemblies 100, 500, 600 provided herein may provide improvements to planetary gear assemblies, such as simply or otherwise improving lubricant supply and/or reducing weight. For example, the axial separation of the gears and the structure coupled to the first and second interfaces 111, 121 may reduce the number of parts, increase the strength of the gear assembly and allow greater loads to pass therethrough, improve lubrication, and allow the fan assembly 14 to operate at lower rotational speeds than known gear assemblies.

This written description uses examples to disclose aspects of the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, 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. Such other examples are intended to be within the scope of the claims if they have 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 languages of the claims.

Other aspects of the invention are provided by the subject matter of the following clauses:

1. a turbine engine with which an engine centerline axis is defined, the engine comprising: a first power input member rotatable in a first direction relative to the engine centerline axis; a second power input member rotatable in a second direction relative to the engine centerline axis; a power output member rotatable relative to the engine centerline axis; a static component fixed relative to a circumference relative to a gear assembly centerline axis; and a gear assembly, the gear assembly comprising: a first rotatable gear operably coupled to the first power input component at a first interface, wherein the first rotatable gear is operably coupled to the static component at a static component interface, wherein the static component interface is configured to react to the first rotatable gear to rotate the first rotatable gear relative to the gear assembly centerline axis, and wherein the power output component is operably coupled to the first rotatable gear; wherein the first power input component and the second power input component together are configured to be transmitted at the first power input component to the power output component through a second interface; and wherein the first interface and the second interface are separated along an axial direction relative to a centerline axis of the gear assembly.

2. The engine of any one or more of the clauses herein, wherein the static component at the static component interface is a ring gear.

3. The engine of any one or more of the clauses herein, wherein the first interface is a first sun gear at the first power input component.

4. The engine of any one or more of the clauses herein, wherein the first interface is a second sun gear at the first power input component.

5. The engine of any one or more of the clauses herein, wherein the second interface is a gear mesh interface at the first power input component.

6. The engine of any one or more of the clauses herein, wherein the static component comprises a second gear operably coupled to the second power input component and the first power input component.

7. The engine of any one or more of the clauses herein, wherein the second power input component comprises a ring gear at a second power input component interface at which the second power input component is operably coupled to the second gear.

8. The engine of any one or more of the clauses herein, wherein the stationary component is operatively coupled to the second gear and the first rotatable gear.

9. The engine of any one or more of the clauses herein, wherein the power output component comprises a carrier structure coupled to each of the plurality of first rotatable gears.

10. The engine of any one or more of the clauses herein, wherein the second power input component comprises a second rotatable gear operably coupled to the power output component and the first power input component.

11. The engine of any one or more of the clauses herein, wherein the power output component comprises a ring gear at an output interface at which the second power input component is operably coupled to the power output component.

12. The engine of any one or more of the clauses herein, wherein the power output component is coupled to the first and second rotatable gears.

13. The engine of any one or more of the clauses herein, wherein the second power input component comprises a carrier structure coupled to each of the plurality of second rotatable gears.

14. The engine of any one or more of the clauses herein, wherein the first direction is opposite the second direction, and wherein the power output component rotates in the same direction as the first direction.

15. The engine of any one or more of the clauses herein, wherein the first interface and the second interface are each positioned radially inward of the first rotatable gear relative to the gear assembly centerline axis.

16. The engine of any one or more of the clauses herein, wherein the first power input member includes a first shaft defining a higher speed rotor relative to the second power input member, and the second power input member includes a second shaft defining a lower speed rotor relative to the first power input member.

17. The engine of any one or more of the clauses herein, wherein the first power input component comprises a first turbine, and wherein the second power input component comprises a second turbine, and wherein the first turbine and the second turbine are in a staggered arrangement.

18. The engine of any one or more of the clauses herein, wherein the first power input component comprises a first compressor, and wherein the second power input component comprises a second compressor, and wherein the first and second compressors are in a staggered arrangement.

19. The engine of any one or more of the clauses herein, wherein the engine comprises: a fan assembly operably coupled to the power output component.

20. The engine of any one or more of the clauses herein, wherein the fan assembly is configured as a shroudless open rotor.

21. The engine of any one or more of the clauses herein, wherein the fan assembly is configured as a shrouded turbofan engine.

22. The engine of any one or more of the clauses herein, wherein the engine is configured to have a ratio of length to maximum diameter between 2 and 10.

23. The engine of any one or more of the clauses herein, wherein the engine is configured such that a ratio of length to maximum diameter is between 2.5 and 9.

24. The engine of any one or more of the clauses herein, wherein the engine is configured to have a length to maximum diameter ratio of at least 2.

25. The engine of any one or more of the clauses herein, wherein the engine is configured as an open rotor engine comprising an equal or lesser number of vanes as fan blades.

Claims (10)

1. A turbine engine characterized by an engine centerline axis defined therethrough, said engine comprising:

a first power input member rotatable in a first direction relative to the engine centerline axis;

a second power input member rotatable in a second direction relative to the engine centerline axis;

a power output member rotatable relative to the engine centerline axis;

a static component fixed relative to a circumference relative to a gear assembly centerline axis; and

a gear assembly, the gear assembly comprising:

a first rotatable gear operably coupled to the first power input component at a first interface, wherein the first rotatable gear is operably coupled to the static component at a static component interface, wherein the static component interface is configured to react to the first rotatable gear to rotate the first rotatable gear relative to the gear assembly centerline axis, and wherein the power output component is operably coupled to the first rotatable gear;

wherein the first power input component and the second power input component together are configured to be transmitted at the first power input component to the power output component over a second interface; and

wherein the first interface and the second interface are axially separated relative to the gear assembly centerline axis.

2. The engine of claim 1, wherein the static component at the static component interface is a ring gear.

3. The engine of claim 2, wherein the first interface is a first sun gear at the first power input component.

4. The engine of claim 3, wherein the second interface is a second sun gear at the first power input component.

5. The engine of claim 3, wherein the second interface is a gear mesh interface at the first power input member.

6. The engine of claim 1, wherein the static component includes a second gear operatively coupled to the second power input component and the first power input component.

7. The engine of claim 6, wherein the second power input component includes a ring gear at a second power input component interface at which the second power input component is operatively coupled to the second gear.

8. The engine of claim 7, wherein the static component is operably coupled to the second gear and the first rotatable gear.

9. The engine of claim 6, wherein the power output component comprises a carrier structure coupled to each of the plurality of first rotatable gears.

10. The engine of claim 1, wherein the second power input member includes a second rotatable gear operably coupled to the power output member and the first power input member.

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