Turbomachine and epicyclic gear assembly with axially offset sun gear and ring gear

Abstract

A turbomachine engine is provided that includes a fan assembly and a core engine including a turbine and an input shaft rotatable with the turbine. A single stage epicyclic gear assembly receives the input shaft at a first speed and drives an output shaft coupled to the fan assembly at a second speed. A sun gear rotates about a longitudinal centerline of the gear assembly and has a sun gear meshing region along the longitudinal centerline of the gear assembly, the sun gear configured to contact a plurality of planet gears at the sun gear meshing region. An annular gear meshing region is disposed along the longitudinal centerline of the gear assembly, the annular gear configured to contact the plurality of planet gears at the annular gear meshing region. The sun gear meshing region is axially offset from the annular gear meshing region along the longitudinal centerline.

Description

[0001] This application is a divisional application of the invention patent application filed on May 6, 2021, with application number 202110491160.0 and invention title "Turbine and a rotary gear assembly having an axially offset sun gear and a ring gear". Technical Field

[0002] This topic generally relates to turbines that include gear assemblies, and more particularly to gear assembly arrangements specific to certain turbine structures.

[0003] Thank you for the government's support

[0004] The project that led to this application has been funded by CleanSky2JointUndertaking (JU) under grant agreement No. 945541. JU received support from the EU Horizon 2020 Research and Innovation Programme and CleanSky2JU members outside the EU. Background Technology

[0005] A turbofan engine works by having a central gas turbine core drive a bypass fan located radially between the engine nacelle and the engine core. This configuration, by increasing the size of the fan, correspondingly increases the size and weight of the engine nacelle, thus typically limiting the permissible size of the bypass fan.

[0006] In contrast, open-rotor engines operate by placing the bypass fan outside the engine nacelle. This allows for the use of larger rotor blades capable of handling a greater volume of air compared to conventional turbofan engines, potentially improving propulsive efficiency.

[0007] Turbine engine designs, including turbofans and open rotor engines, may require a large gear ratio between the low-speed spool and the fan rotor to allow the larger rotor blades to act on a larger volume of air and / or do so at certain desired operating speeds of the engine or aircraft. One challenge is that known gear assemblies may not provide a sufficient gear ratio for the desired operation. For example, known gear assemblies may not be sufficient to reduce the output speed relative to the input speed, causing the fan rotor to operate too fast and inefficiently and / or the turbine to operate too slowly and inefficiently.

[0008] Therefore, it is necessary to provide gear assemblies that can be adapted to the desired gear ratios of certain turbine structures. Summary of the Invention

[0009] Aspects and advantages of the invention will be set forth in part in the description which follows, or may be apparent from the description, or may be learned by practice of the techniques disclosed in the description.

[0010] This document discloses various turbine engines and gear assemblies. In some embodiments, a turbine engine is provided, comprising a fan assembly and a core engine including a turbine and an input shaft rotatable with the turbine. A single-stage planetary gear assembly receives the input shaft at a first speed and drives an output shaft coupled to the fan assembly at a second speed slower than the first speed. The gear assembly includes a sun gear, a plurality of planetary gears, and a ring gear. The sun gear rotates about a longitudinal centerline of the gear assembly and has a sun gear engagement region along the longitudinal centerline of the gear assembly, the sun gear being configured to contact the plurality of planetary gears in the sun gear engagement region. The ring gear engagement region is disposed along the longitudinal centerline of the gear assembly, the ring gear being configured to contact the plurality of planetary gears in the ring gear engagement region. The sun gear engagement region is axially offset from the ring gear engagement region along an axial centerline.

[0011] These and other features, aspects, and advantages of this disclosure will be better understood with reference to the following description and the appended claims. Embodiments of the disclosed technology are illustrated in conjunction with the accompanying drawings, which are incorporated in and constitute a part of this specification, and serve to explain the principles of this disclosure. Attached Figure Description

[0012] The complete and practical disclosure of the invention for those skilled in the art is set forth in the specification, with reference to the accompanying drawings, wherein:

[0013] Figure 1 This is a cross-sectional schematic diagram of an exemplary embodiment of an open rotor propulsion system;

[0014] Figure 2 This is a cross-sectional schematic diagram of an exemplary embodiment of an open rotor propulsion system;

[0015] Figure 3 This is an illustration of an alternative embodiment of an exemplary blade assembly for an open rotor propulsion system;

[0016] Figure 4 This is a schematic diagram of an exemplary gear assembly with an axially offset gear meshing region;

[0017] Figure 5 This is a schematic diagram of an exemplary gear assembly with an axially offset gear meshing region;

[0018] Figure 6A and 6B This is a schematic diagram of a gear assembly with three planetary gears;

[0019] Figure 7A and 7BThis is a schematic diagram of a gear assembly with two planetary gears;

[0020] Figure 8 This is a schematic diagram of an exemplary gear assembly with an axially offset gear meshing region;

[0021] Figure 9 This is a schematic diagram of an exemplary gear assembly with an axially offset gear meshing region;

[0022] Figure 10 This is a schematic diagram of an exemplary gear assembly having non-overlapping axial offset gear meshing areas;

[0023] Figure 11 This is a schematic diagram of an exemplary gear assembly having overlapping axially offset gear meshing areas; and

[0024] Figure 12 This is a cross-sectional schematic diagram of an exemplary embodiment of a pipeline propulsion system. Detailed Implementation

[0025] Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation rather than limitation. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made to the invention without departing from the scope or spirit thereof. For example, features shown or described as part of one embodiment may be used with another embodiment to produce yet another embodiment. Therefore, the invention is intended to cover such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0026] 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.

[0027] As used herein, the terms “first,” “second,” and “third” are used interchangeably to distinguish one component from another and are not intended to indicate the location or importance of the individual components.

[0028] The terms "forward" and "rearward" refer to relative positions within a gas turbine engine or vehicle, and specifically to the normal operating posture of the gas turbine engine or vehicle. For example, for a gas turbine engine, "forward" refers to a position closer to the engine inlet, while "rearward" refers to a position closer to the engine nozzle or exhaust port.

[0029] The terms "upstream" and "downstream" refer to the relative directions of fluid flow within a fluid path. For example, "upstream" refers to the direction from which the fluid flows, while "downstream" refers to the direction from which the fluid flows.

[0030] Unless otherwise stated, the terms “connection,” “fixed,” “attached to,” etc., refer to direct connection, fixation, or attachment, as well as indirect connection, fixation, or attachment via one or more intermediate parts or features.

[0031] Unless the context clearly indicates otherwise, the singular forms “a,” “a,” and “the” include plural references.

[0032] As used throughout this specification and claims, approximate language is used to modify any quantitative representation that allows for variation without altering its underlying function. Therefore, values ​​modified by terms such as “about,” “approximately,” and “substantially” are not limited to the specified precise values. In at least some cases, approximate language may correspond to the precision of the instrument used to measure the value, or the precision of the method or machine used to construct or manufacture the component and / or system. For example, approximate language may refer to a margin of 1%, 2%, 4%, 10%, 15%, or 20% at the endpoints of a single value, a range of values, and / or a defined range of values.

[0033] Throughout this specification and claims, scope limitations are combined and interchanged, and unless the context or language otherwise indicates otherwise, such scope is identified and includes all subscopes contained herein. For example, all scopes disclosed herein include endpoints, and endpoints may be combined independently of each other.

[0034] One or more components of the turbine engine or gear assembly described below can be manufactured or formed using any suitable process, such as additive manufacturing or 3D printing. Using such a process can allow such components to be integrally formed into a single monolithic part, or any suitable number of sub-parts. In particular, additive manufacturing processes can allow such components to be integrally formed and include a variety of features that would be impossible to achieve using existing manufacturing methods. For example, the additive manufacturing methods described herein enable the manufacture of heat exchangers with unique features, construction, thickness, material, density, fluid channels, manifolds, and mounting structures that would be impossible or impractical using existing manufacturing methods. Some of these features are described herein.

[0035] Now refer to the attached diagram, Figure 1This is an exemplary embodiment of an engine 100 including a gear assembly 102 according to aspects of this 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 enclosed by a housing 114. The fan assembly 104 includes a plurality of fan blades 108. A blade assembly 110 extends from the housing 114. The blade assembly 110, including a plurality of blades 112, is operatively positioned with respect to the fan blades 108 to provide thrust relative to the fan blades 108, control the thrust vector, reduce or redirect unwanted acoustic noise, and / or otherwise desirously alter airflow. In some embodiments, the fan assembly 104 includes between three (3) and twenty (20) fan blades 108. In a particular embodiment, the fan assembly 104 includes between ten (10) and sixteen (16) fan blades 108. In some embodiments, fan assembly 104 includes twelve (12) fan blades 108. In some embodiments, blade assembly 110 includes a number of blades 112 equal to or fewer than the number of fan blades 108.

[0036] In some embodiments, the fan blade tip speed can reach 650 to 900 fps, or 700 to 800 fps, under cruise flight conditions. The fan pressure ratio (FPR) of the fan assembly 104, as measured across the fan blades under cruise flight conditions, can be 1.04 to 1.10, or in some embodiments 1.05 to 1.08. In some embodiments, the output torque provided by the gear assembly can be in the range of 20 kNm to 200 kNm, or in other embodiments in the range of 40 kNm to 150 kNm.

[0037] In some embodiments, for example Figure 1 As shown, the blade assembly 110 is positioned downstream or rearward of the fan assembly 104. However, it should be understood that in some embodiments, the blade assembly 110 may be positioned upstream or forward of the fan assembly 104. Still in various embodiments, the engine 100 may include a first blade assembly positioned forward of the fan assembly 104 and a second blade assembly positioned rearward of the fan assembly 104. The fan assembly 104 may be configured to desirably adjust the pitch at one or more fan blades 108, for example, to control the thrust vector, reduce or redirect noise, and / or change the thrust output. The blade assembly 110 may be configured to desirably adjust the pitch at one or more blades 112, for example, to control the thrust vector, reduce or redirect noise, and / or change the thrust output. Pitch control mechanisms at one or both of the fan assembly 104 or the blade assembly 110 may cooperate to produce one or more of the aforementioned desired effects.

[0038] In some embodiments, for example Figure 1 As shown, engine 100 is a non-ducted thrust generation system, such that the multiple fan blades 108 are not enclosed by a nacelle or fan casing. Thus, in various embodiments, engine 100 can be configured as an unshrouded turbofan engine, an open rotor engine, or a propfan engine. In a particular embodiment, engine 100 is a single non-ducted rotor engine comprising a single row of fan blades 108. Engine 100 configured as an open rotor engine includes a fan assembly 104 with large-diameter fan blades 108, which may be suitable for high bypass ratios, high cruise speeds (e.g., comparable to, or generally higher than, those of aircraft with turbofan engines), high cruise altitudes (e.g., comparable to, or generally higher than, those of aircraft with turboprop engines), and / or relatively low speeds. Cruise altitude generally refers to the level at which an aircraft is after climb and before descending into the approach phase. In various embodiments, the engine is used in vehicles with cruise altitudes up to approximately 65,000 ft. In some embodiments, the cruising altitude is between approximately 28,000 ft and approximately 45,000 ft. Still in some embodiments, the cruising altitude is expressed in flight level (FL) based on standard atmospheric pressure at sea level, where cruising flight conditions are between FL280 and FL650. In another embodiment, cruising flight conditions are between FL280 and FL450. Still in some embodiments, the cruising altitude is defined at least based on atmospheric pressure, where the cruising altitude is between approximately 4.85 psia and approximately 0.82 psia based on a sea level pressure of approximately 14.70 psia and a sea level temperature of approximately 59 degrees Fahrenheit. In another embodiment, the cruising altitude is between approximately 4.85 psia and approximately 2.14 psia. It should be understood that in some embodiments, the range of pressure-defined cruising altitude can be adjusted based on different reference sea level pressures and / or sea level temperatures.

[0039] The core engine 106 is typically encapsulated within a housing 114 that defines a maximum diameter. In some embodiments, the engine 100 includes a length from a longitudinal front end 116 to a longitudinal rear end 118. In various embodiments, the engine 100 defines a length (L) and a maximum diameter (D). max The ratio of L / D is used to provide reduced installation resistance. In one embodiment, L / D max For at least 2. In another embodiment, L / D max It is at least 2.5. In some embodiments, L / D max Less than 5, less than 4, and less than 3. In various embodiments, it should be understood that L / D maxFor use in a single non-pipeline rotary engine.

[0040] Reduced installation drag can further provide improved efficiency, such as improved specific fuel consumption. Additionally or alternatively, reduced drag can provide cruise altitudes of Mach 0.5 or higher for engine and aircraft operation. In some embodiments, L / D max The fan assembly 104 and / or the blade assembly 110, respectively or together, at least partially construct the engine 100 to operate at a maximum cruise altitude operating speed between approximately Mach 0.55 and approximately Mach 0.85.

[0041] Refer again Figure 1 The core engine 106 extends in the radial direction R relative to the engine axis centerline 120. The gear assembly 102 receives power or torque from the core engine 106 via the power input source 122 and provides power or torque in the circumferential direction C around the engine axis centerline 120 via the power output source 124 to drive the fan assembly 104.

[0042] Figure 2 A front cross-sectional view of an exemplary embodiment of an open rotor propulsion engine 100 is shown. The engine 100 has a fan assembly 104, which includes a plurality of fan blades 108 surrounding a central longitudinal axis 120 of the engine 100. The fan blades 108 are arranged circumferentially at equal intervals around the centerline 120, and each fan blade 108 has a root 125, a tip 126, an axial span defined therebetween, and a central blade axis 128.

[0043] The core engine 16 includes a compressor section 130, a heat addition system 132 (e.g., a burner), and an extension section 134 arranged together in a series flow configuration. The core engine 106 extends circumferentially relative to an engine centerline axis 120. The core engine 106 includes a high-speed spool comprising a high-speed compressor 136 and a high-speed turbine 138 operably and rotatably coupled together via a high-speed shaft 140. The heat addition system 132 is positioned between the high-speed compressor 136 and the high-speed turbine 138. Various embodiments of the heat addition system 132 include a combustion section. The combustion section may be configured as a detonation combustion section, a rotary detonation combustion section, a pulse detonation combustion section, or other suitable heat addition systems. The heat addition system 132 may be configured as a rich-burner system or a lean-burner system, or a combination thereof. Still in various embodiments, the heat addition system 132 includes an annular burner, a canister burner, a coaxial burner, a trap vortex burner (TVC), or other suitable combustion systems or combinations thereof.

[0044] The core engine 106 also includes a turbocharger or low-speed compressor, which is positioned in a flow relationship with the high-speed compressor 136. The low-speed compressor 142 is rotatably coupled to a low-speed turbine 144 via a low-speed shaft 146, enabling the low-speed turbine 144 to drive the low-speed compressor 142. The low-speed shaft 146 is also operatively connected to a gear assembly 102 to power the fan assembly 104, as further described herein.

[0045] It should be understood that, unless otherwise stated, when used with compressors, turbines, shafts, or spool components, the terms "low" and "high," or their respective comparatives (e.g., lower, higher, if applicable), refer to relative speeds within the engine. For example, "low turbine" or "low-speed turbine" defines a component configured to operate at a speed (e.g., maximum permissible speed) lower than that of the engine's "high turbine" or "high-speed turbine." Alternatively, unless otherwise stated, the foregoing terms may be understood in their superlative sense. For example, "low turbine" or "low-speed turbine" may refer to the turbine with the lowest maximum speed within the turbine section, "low compressor" or "low-speed compressor" may refer to the turbine with the lowest maximum speed within the compressor section, "high turbine" or "high-speed turbine" may refer to the turbine with the highest maximum speed within the turbine section, and "high compressor" or "high-speed compressor" may refer to the compressor with the highest maximum speed within the compressor section. Similarly, a low-speed spool refers to a maximum speed lower than that of a high-speed spool. It should also be understood that the terms “low” or “high” in the foregoing may additionally or alternatively be understood as relative to the minimum permissible speed, or relative to the minimum or maximum permissible speed of the engine’s normal, desired, stable operation, etc.

[0046] As discussed in more detail below, the core engine 106 includes a gear assembly 102 configured to transmit power from the extension section 140 and reduce the output speed at the fan assembly 104 relative to the low-speed turbine 144. Embodiments of the gear assembly 104 depicted and described herein can allow gear ratios suitable for large-diameter non-ducted fans. Furthermore, embodiments of the gear assembly 102 provided herein can be suitable within the radial or diametrical constraints of the core engine 106 within the housing 114.

[0047] exist Figure 2 In an exemplary embodiment, the engine 100 further includes a blade assembly 110 comprising a plurality of blades 112 disposed around a central axis 120. Each blade 112 has a root 148 and a tip 150, and a span defined therebetween. The blades 112 may be arranged in various ways. For example, in some embodiments, they are not all equidistant from the rotating components.

[0048] In some embodiments, the blades 112 are mounted to a fixed frame and do not rotate relative to the central axis 120, but may include mechanisms for adjusting their orientation relative to their axis 154 and / or relative to the blade 108. For reference purposes, Figure 2 The forward direction, indicated by arrow F, is depicted, which in turn defines the forward and backward portions of the system. For example... Figure 1 and Figure 2 As shown, the fan assembly 104 can be located in front of the gas core engine 106 in a "puller" configuration, while the exhaust port 156 is located behind the core engine 106.

[0049] Left-hand or right-hand drive engine configurations can be achieved by using mirrored airfoil elements (e.g., 108, 112) to allow fan assembly 104 to rotate clockwise for one propulsion system and counterclockwise for another. This configuration is useful for certain facilities in reducing the impact of multi-engine torque on the aircraft. Alternatively, an optional reversing gearbox can be provided to allow the use of a common gas turbine core and a low-pressure turbine to rotate the fan blades clockwise or counterclockwise, i.e., to provide left-hand or right-hand drive configurations as needed. For example, a pair of counter-rotating engine assemblies can be provided for certain aircraft facilities without having internal engine parts designed for counter-rotation.

[0050] The engine 100 also includes a gear assembly 102, which comprises a set of gears for reducing the rotational speed of the fan assembly 104 relative to the low-speed (pressure) turbine 144. In operation, rotating fan blades 108 are driven by the low-speed (pressure) turbine 144 via the gear assembly 102, causing the fan blades 108 to rotate about axis 120 and generate thrust to propel the engine 100, thereby propelling the aircraft on which the engine 100 is mounted in the forward direction F.

[0051] It is likely desirable that one or both of the fan blades 104 or the rotor blades 112 include a pitch mechanism, allowing the blades to rotate independently or in combination with each other relative to the pitch rotation axis (labeled 128 or 154, respectively). This pitch variation can be used to alter thrust and / or vortex effects under a variety of operating conditions, including providing thrust reversal characteristics, which may be useful under certain operating conditions, such as during aircraft landing.

[0052] The impeller 112 can be sized, shaped, and configured to impart counteracting vortices to the fluid, thereby significantly reducing the vorticity of the fluid in the downstream direction behind the fan blades 104 and impeller 112, which translates into an improved level of induced efficiency. For example... Figure 1 and Figure 2As shown, the impeller blade 112 may have a shorter span than the fan blade 104. For example, the span of the impeller blade 112 is at least 50% of the span of the fan blade 104. In some embodiments, the span of the impeller blade may be the same as or longer than the span of the fan blade 104, if desired. Figure 1 As shown, the blades 112 can be attached to an aircraft structure associated with the engine 100, or to another aircraft structure such as a wing, pylon, or fuselage. The number of blades 112 can be less than, greater than, or equal to the number of fan blades 104. In some embodiments, the number of blades 112 is greater than two or greater than four. The fan blades 104 can be sized, shaped, and profiled to account for desired blade loads.

[0053] exist Figure 2 In the illustrated embodiment, an annular 360-degree inlet 158 ​​is located between the fan assembly 104 and the blade assembly 110, and provides a path for incoming atmosphere to enter the engine core 106 radially inward from at least a portion of the blade assembly 110. Such a location may be advantageous for various reasons, including managing icing performance and protecting the inlet 158 ​​from various objects and materials that may be encountered during operation.

[0054] Figure 1 and Figure 2 A so-called "pull" configuration is shown, in which the fan assembly 104 is located in front of the engine core 106. Other configurations are also possible and are contemplated within the scope of this disclosure, such as a so-called "push" configuration embodiment in which the engine core 106 is located in front of the fan assembly 104.

[0055] The choice between a "pull" or "push" configuration can be consistent with the choice of the fuselage mounting orientation relative to the intended application of the aircraft, and depending on the mounting location and orientation—wing-mounted, fuselage-mounted, or tail-mounted—some choices may be structurally or operationally advantageous.

[0056] exist Figure 2In an exemplary embodiment, in addition to the open rotor or non-ducted fan assembly 104 having multiple fan blades 104, an optional ducted fan 160 is included behind the fan assembly 104, such that the engine 100 includes both ducted and non-ducted fans, both used to generate thrust by moving air at atmospheric temperature without passing through the engine core 106. The ducted fan 160 shown is located at approximately the same axial position as the impeller 112 and radially inside the impeller root 148. Alternatively, the ducted fan 160 may be located between the impeller 112 and the core duct 162, or further ahead of the impeller 112. The ducted fan 160 may be driven by a low-pressure turbine or any other suitable rotating source and may be used as the first stage of the supercharger 142 or may be operated independently. Air entering the inlet 158 ​​flows through the inlet duct 164 and is then split, such that a portion flows through the core duct 162 and a portion flows through the fan duct 166. The fan duct 166 may be integrated with a heat exchanger 168 and exhausts air to the atmosphere through a separate fixed or variable nozzle 170 located behind the impeller assembly 110, outside the fan shroud 152 and the engine core shroud 172. Thus, the air flowing through the fan duct 166 "bypasses" the engine core without passing through it.

[0057] Therefore, in an exemplary embodiment, engine 100 includes a non-ducted fan formed by fan blades 108, followed by a ducted fan 160 that directs airflow into two concentric or non-concentric ducts 162 and 166, thereby forming a three-flow engine architecture with three paths for air to pass through fan assembly 104.

[0058] exist Figure 2 In the exemplary embodiments shown, a slidable, movable, and / or translational plug nozzle 172 with an actuator may be included to change the outlet area of ​​nozzle 170. The plug nozzle is typically an annular, symmetrical device that adjusts the opening area of ​​the outlet (e.g., fan flow or core flow) by axial movement of the nozzle, such that the clearance between the nozzle surface and a fixed structure (e.g., adjacent walls of a duct) varies in a predetermined manner, thereby reducing or increasing the space for airflow through the duct. Other suitable nozzle designs may also be employed, including those incorporating thrust reversing functionality. This adjustable, movable nozzle may be designed to operate cooperatively with other systems (e.g., VBV, VSV, or blade pitch mechanism) and may be designed to have failure modes (e.g., fully open, fully closed, or intermediate position) so that nozzle 170 has a consistent “original” position to return to in the event of any system failure, which may prevent commands from reaching nozzle 170 and / or its actuator.

[0059] In some embodiments, the mixing device 174 may be included in a region behind the core nozzle 176 to help mix the fan flow and the core flow in order to improve acoustic performance by directing the core flow outward and the fan flow inward.

[0060] because Figure 2 The illustrated engine 100 includes an open rotor fan assembly 104 and a ducted fan assembly 160, so that the thrust output of both and the power distribution between them can be customized to achieve specific thrust, fuel combustion, thermal management, and / or acoustic characteristics targets that are superior to those of typical ducted fan gas turbine propulsion assemblies with comparable thrust levels. By reducing the proportion of thrust required to be provided by the non-ducted fan assembly 104, the ducted fan assembly 160 allows for a reduction in the overall fan diameter of the non-ducted fan assembly, thereby providing installation flexibility and reduced weight.

[0061] Operationally, engine 100 may include a control system that manages the loads of the respective open and ducted fans, and potentially, the exit area of ​​the fan nozzles, to provide different thrust, noise, cooling capacity, and other performance characteristics for various parts of the flight envelope and various operating conditions associated with aircraft operation. For example, in climb mode, the ducted fan can operate at its maximum pressure ratio to maximize the thrust of the flow, while in cruise mode, the ducted fan can operate at a lower pressure ratio to improve overall efficiency by relying on thrust from the non-ducted fans. Nozzle actuation can adjust the operating lines of the ducted fans and the overall engine fan pressure ratio, independent of the overall engine airflow.

[0062] The ducted fan flow passing through fan duct 166 may include one or more heat exchangers 168 for removing heat from various fluids used in engine operation, such as air-cooled oil coolers (ACOC), cooled air coolers (CCA), etc. Compared to conventional ducted fan architectures, heat exchangers 168 can take advantage of integration with fan duct 166, resulting in reduced performance losses (e.g., fuel efficiency and thrust) because they do not affect the primary thrust source, which in this case is the non-ducted fan flow. The heat exchangers can cool fluids such as gearbox oil, engine oil pan oil, heat transfer fluids (e.g., supercritical fluids) or commercially available single-phase or two-phase fluids (supercritical CO2, EGV, Slither 800, liquid metal, etc.), engine bleed air, etc. The heat exchangers may also consist of different sections or channels cooling different working fluids (e.g., ACOC paired with a fuel cooler). The heat exchanger 168 can be integrated into a thermal management system that provides heat transfer via a heat exchange fluid flowing through the network to remove heat from the source and transfer heat to the heat exchanger.

[0063] Because ducted fans have a higher fan pressure ratio than ductless fans, fan ducts provide an environment in which a more compact heat exchanger can be utilized compared to the exterior of a core shroud installed in a ductless fan flow. The fan pressure ratio (FPR) of the fan bypass air is very low (1.05 to 1.08), making it difficult to drive air through the heat exchanger. In the absence of fan ducts as described herein, scoops or boosters may be required to bleed air to provide cooling air to and through the heat exchanger. A set of parameters can be developed around the heat exchanger in the fan duct based on heat load, heat exchanger size, ducted fan flow correction flow, and ducted fan flow temperature.

[0064] The fan duct 166 offers additional advantages in terms of reduced nacelle drag, enabling more aggressive nacelle closure, improved core flow particle separation, and operation in adverse weather conditions. By discharging the fan duct flow over the core cowling, this helps to excite the boundary layer and allows for a steeper nacelle closure angle selection between the maximum dimensions of the core cowling 172 and the exhaust vents 156. Closure angles are typically limited by airflow separation, but boundary layer excitation through the air discharged from the fan duct 166 over the core cowling reduces airflow separation. This results in a shorter, lighter structure with lower frictional surface drag.

[0065] Fan assembly 104 and / or blade assembly can be shrouded or unshrouded (e.g.) Figure 1 and 2 (As shown). Figure 3An optional annular shroud or duct 178 is shown on the blade assembly 110 located at the distal end of axis 120. In addition to the benefit of noise reduction, Figure 3 The duct 178 shown can also provide improved vibration response and structural integrity of the fixed impeller 112 by connecting the fixed impeller 112 to an assembly forming an annular ring or one or more circumferential sectors (i.e., a segment forming the portion of the annular ring linking two or more impellers 112). The duct 178 also allows for easier variation of the impeller pitch. This will be discussed in more detail below. Figure 12 Another embodiment is disclosed in which both the fan assembly and the impeller assembly are covered.

[0066] The embodiments of the gear assembly 102 described herein can provide an L / D suitable for engine 10. max Gear ratios and arrangement within constraints. In some embodiments, regarding... Figure 4-11 The gear assembly described and illustrated allows for gear ratios and arrangements that correspond to one or more ranges of fan assembly rotational speeds provided above, for cruise altitudes and / or cruise speeds.

[0067] Various embodiments of the gear assembly 102 provided herein allow gear ratios up to 14:1. Further various embodiments of the gear assembly 102 provided herein allow gear ratios of at least 6:1. For single-stage planetary gear assemblies, further various embodiments of the gear assembly 102 provided herein allow gear ratios between 6:1 and 12:1. It should be understood that embodiments of the gear assembly 102 provided herein can allow large gear ratios and are subject to constraints (e.g., but not limited to, the length (L) of engine 100, the maximum diameter (D) of engine 100). max ( ), with a cruising altitude of up to 65,000 ft and / or an operating cruise speed of up to Mach 0.85, or a combination thereof.

[0068] This document illustrates and describes various exemplary gear assemblies. 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 way, it will be understood that the gear assemblies disclosed herein are generally operable with an engine and a turbine having a rotating element with multiple rotor blades, and a turbine having a turbine and a shaft that rotates with the turbine. For such an engine, the rotating element (e.g., fan assembly 104) can be driven by the turbine shaft (e.g., low-speed shaft 146) via the gear assembly.

[0069] Figure 4 An exemplary gear assembly 202 with an axially offset surface width is shown. The gear assembly 202 includes gears with a diameter D. s The sun gear 204 has a diameter of D. pMultiple planetary gears 206 and a diameter of D r The ring gear 208. Each of the sun gear 204, planet gears 206, and ring gear 208 is a double helical gear having a first set of helical teeth and a second set of helical teeth, which are inclined at an acute angle relative to each other. Specifically, the sun gear 204 includes a first sun gear set 210 and a second sun gear set 212. Each planet gear 206 includes a first planet gear set 214 and a second planet gear set 216. The ring gear 208 includes a first ring gear set 218 and a second ring gear set 220.

[0070] As discussed in more detail below, the number of planetary gears can vary. In one embodiment, there are three planetary gears 206. In another embodiment, there are two planetary gears 206.

[0071] exist Figure 4 In the illustrated embodiment, gear assembly 202 is a planetary gear configuration, wherein the ring gear 208 is substantially fixed (e.g., statically) within the engine by a support structure 236. The sun gear 204 is driven by an input shaft (i.e., the low-speed shaft 146). A planetary gear carrier 222 is rotatably coupled to a plurality of planetary gears 206 and is configured to rotate about a longitudinal centerline 120 in a circumferential direction 224, which in turn drives a power output source 124 (e.g., a fan shaft), which is coupled to the planetary gear carrier 222 and configured to rotate therewith to drive the fan assembly. In this embodiment, the low-speed shaft 146 rotates in the same circumferential direction 226 as the direction of rotation 224 of the fan shaft 124.

[0072] like Figure 4 As shown, the sun gear 204 meshes with the planet gear 206 in the first contact areas (i.e., the sun gear meshing areas) 228 and 230, and the ring gear 208 meshes with the planet gear 206 in the second contact areas 232 and 234 (i.e., the ring gear meshing areas). The first contact areas 228 and 230 are axially offset from the first contact areas 232 and 234, such that the gear teeth of the sun gear are not axially aligned with the gear teeth of the ring gear relative to the longitudinal axis 120.

[0073] Refer again Figure 4The first ring gear set 218 and the second ring gear set 220 are axially spaced apart from each other, and the first sun gear set 210 and the second sun gear set 212 are positioned between the first ring gear set 218 and the second ring gear set 220. As discussed in more detail below, the first contact area may not overlap with the second contact area, or there may be a relatively small overlap. Therefore, in this embodiment, the ring gear 208 meshes with the planet gear 206 with an outward offset, and the sun gear 204 meshes with the planet gear 206 with an inward offset.

[0074] The sun gear and ring gear can be axially offset such that at least 50% of the width of the sun gear meshing area does not axially overlap with the ring gear meshing area. In other embodiments, the axial offset can prevent at least 25% of the width of the sun gear meshing area from axially overlapping with the ring gear meshing area. Depending on the amount of offset, the axial offset of the first and second contact areas described herein can reduce and / or eliminate reverse bending of the planetary teeth. That is, due to the axial offset described herein, some or all of the planetary teeth do not alternately mesh with the sun gear and ring gear, causing the teeth to experience reverse bending stress due to the reverse load. Compared to conventional single-stage planetary gear assemblies designed to address reverse bending limitations, the axial offset provided by this arrangement can provide a gear assembly with a higher gear ratio.

[0075] By reducing and / or eliminating some or all of the reverse bending stress on the planetary gear teeth, the face width of the sun gear teeth can be reduced, which in turn reduces the diameter of the sun gear. Since the gear ratio is related to the relative diameters of the ring gear and the sun gear, reducing the diameter of the sun gear while maintaining the diameter of the ring gear will result in a corresponding increase in the gear ratio.

[0076] In some embodiments, the axial offset described herein can reduce the diameter of the sun gear by approximately 0.6 to 0.8 while maintaining the same diameter of the ring gear. Thus, for example, for a gear assembly with a planetary gear configuration having three planetary gears, reducing the sun gear diameter by 0.7 can increase the gear ratio from 6:1 to 8.2:1, or from 6.5:1 to 8.8:1. This allows a single-stage gear assembly with a planetary gear configuration to achieve a gear ratio greater than or equal to 6:1, and in some embodiments, the gear ratio is greater than or equal to 6.6:1, greater than or equal to 7:1, or greater than or equal to 8:1. In other embodiments, the upper limit range of the above-described gear assembly can be 14:1, or in some cases, 12:1.

[0077] Figure 5 An exemplary gear assembly 302 with an axially offset surface width is shown. The gear assembly 302 includes gears with a diameter D. s The sun gear 304 has a diameter of D. pMultiple planetary gears 306 and a diameter of D r The ring gear 308. Each of the sun gear 304, planet gear 306 and ring gear 308 is a bihelical gear having a first set of helical teeth and a second set of helical teeth, which are inclined at an acute angle relative to each other.

[0078] The double helical sun gear 304 includes a first sun gear set 310 and a second sun gear set 312. Each double helical planetary gear 306 includes a first planetary gear set 314 and a second planetary gear set 316. The double helical ring gear 308 includes a first ring gear set 318 and a second ring gear set 320. In some embodiments, the gear assembly has two or three planetary gears.

[0079] exist Figure 5 In the illustrated embodiment, the gear assembly has a star gear configuration, wherein the planetary carrier 322 is fixed (e.g., statically) within the engine by a support structure 336. The sun gear 304 is driven by an input shaft (i.e., low-speed shaft 146). The ring gear 308 is configured to rotate in a direction 324 opposite to the rotational direction 326 of the low-speed shaft 146 to drive the power output source 124 (e.g., fan shaft) and the fan assembly 104.

[0080] With Figure 4 Similarly, the sun gear 304 meshes with the planetary gear 306 in the first contact areas 328 and 330, and the ring gear 308 meshes with the planetary gear 306 in the second contact areas 332 and 334, with the first contact areas 328 and 330 axially offset from the second contact areas 332 and 334. As described above, the axial offset provided by this arrangement can provide a gear assembly with a higher gear ratio compared to a conventional single-stage planetary gear assembly required to address reverse bending stress.

[0081] As described above, depending on the offset, the axial offset of the first and second contact areas significantly reduces and / or eliminates the reverse bending of the planetary teeth, which in turn allows for a smaller diameter sun gear and a gear assembly with a high gear ratio. For example, for a gear assembly with a star gear configuration with three planetary gears, reducing the diameter of the sun gear by 0.7 can increase the gear ratio from 5:1 to 7.2:1, and from 5.5:1 to 7.8:1. This allows single-stage gear assemblies with a star gear configuration (such as single-stage gear assemblies with a planetary gear configuration) to achieve gear ratios greater than or equal to 6:1, and in some embodiments greater than or equal to 6.6:1, greater than or equal to 7:1, and in some embodiments greater than or equal to 8:1. In other embodiments, the upper limit range of the above-described gear assembly can be 14:1, or in some cases, 12:1.

[0082] Figure 6A 6B, 7A and 7B are Figure 4 and 5 A schematic diagram of an exemplary gear assembly of the type shown. For clarity, details are omitted. Figures 6A-7B The diagram shows the structure of some gear components (e.g., planet carrier, support structure). Although it should be understood that... Figure 6A and 6B The gear assembly shown can be used with a planetary gear configuration ( Figure 4 ) or star gear construction ( Figure 5 They can be used together, but for convenience, Figures 6A-7B Use and Figure 4 The same reference numerals are used for planetary gear construction.

[0083] Figure 6A and 6B A gear assembly with three planetary gears 206 is shown, while Figure 7A and 7B A gear assembly with two planetary gears 206 is shown. Figure 6B and Figure 7B They are shown respectively Figure 6A and Figure 7A For clarity, one of the double helical gears in the gear assembly has been removed. As shown in these figures, the contact area of ​​the sun gear and planetary gear meshing is axially offset from the contact area of ​​the ring gear and planetary gear meshing to avoid and / or reduce the effect of reverse bending stress on the planetary gear teeth.

[0084] Figure 8 Another exemplary gear assembly 402 with an axially offset surface width is shown. Figure 8 It has a planetary gear structure and is similar to Figure 4 The gear assembly 202 shown; however, in this embodiment, the ring gear meshes with the planetary gear in an inward offset, and the sun gear meshes with the planetary gear in an outward offset.

[0085] refer to Figure 8 Gear assembly 402 includes gears with a diameter of D S The sun gear is 404, with a diameter of D. p Multiple planetary gears 406 and a diameter of D rThe ring gear 408. Each of the sun gear 404, planet gear 406, and ring gear 408 is a bihelical gear having a first set of helical teeth and a second set of helical teeth, which are inclined at an acute angle relative to each other. The sun gear 404 includes a first sun gear set 410 and a second sun gear set 412, the planet gear 406 includes a first planet gear set 414 and a second planet gear set 416, and the ring gear 408 includes a first ring gear set 418 and a second ring gear set 420. The number of planet gears can vary as described elsewhere herein.

[0086] Figure 8 The embodiments shown are in accordance with the above regarding Figure 4 The same method is used, but with different axial offset arrangements. For example... Figure 8 As shown, the sun gear 404 meshes with the planet gear 406 in the first contact areas 428 and 430, and the ring gear 408 meshes with the planet gear 406 in the second contact areas 432 and 434, with the first contact areas 428 and 430 axially offset from the second contact areas 432 and 434. The axial offset provided by this arrangement can provide a gear assembly with a higher gear ratio.

[0087] As in Figure 4 In the embodiments described herein, depending on the offset, the axial offset of the first and second contact areas significantly reduces and / or eliminates the reverse bending of the planetary teeth, and, as described above, provides a reduction in the sun gear diameter and an increase in the gear ratio compared to a conventional single-stage gear assembly.

[0088] Figure 9 An exemplary gear assembly 502 with an axially offset surface width is shown. Figure 9 It is similar to Figure 5 The gear assembly 302 shown has a star gear configuration; however, in this embodiment, the ring gear meshes with the planetary gear in an inward offset, and the sun gear meshes with the planetary gear in an outward offset.

[0089] Gear assembly 502 includes gears with a diameter of D S The sun gear 504 has a diameter of D. p Multiple planetary gears 506 and a diameter of D rThe ring gear 508. Each of the sun gear 504, planet gears 506, and ring gear 508 is a bihelical gear having a first set of helical teeth and a second set of helical teeth, which are inclined at an acute angle relative to each other. Specifically, the sun gear 504 includes a first sun gear set 510 and a second sun gear set 512. Each planet gear 506 includes a first planet gear set 514 and a second planet gear set 516. The ring gear 508 includes a first ring gear set 518 and a second ring gear set 520. The number of planet gears can be two or three.

[0090] In this embodiment, similar to Figure 5 As shown, the gear assembly has a star gear configuration, wherein the planet carrier 522 is fixed (e.g., statically) within the engine by a support structure 536. The sun gear 504 is driven by the input shaft (i.e., the low-speed shaft 146). The ring gear 508 is configured to rotate in a direction 524 opposite to the rotational direction 526 of the low-speed shaft 146 to drive the power output source 124 (e.g., the fan shaft) to drive the fan assembly.

[0091] With similar Figure 5 As shown, the sun gear 504 meshes with the planet gear 506 in the first contact areas 528, 530, and the ring gear 508 meshes with the planet gear 506 in the second contact areas 532, 534. The first contact areas 528, 530 and the second contact areas 532, 534 are axially offset to provide a gear assembly with a higher gear ratio by reducing and / or eliminating the reverse bending stress on the planet gear teeth.

[0092] Figure 10 Provided Figure 5 A magnified view of a portion. For example... Figure 10 As shown, the first contact area 330 and the second contact area 334 of the gear assembly 302 are axially spaced apart, such that there is no overlap between the first and second contact areas. An axial clearance 340 is provided between the first contact area 330 and the second contact area 334. A similar clearance is provided between the other contact areas (i.e., the first contact area 328 and the second contact area 332). The clearance 340 may be less than 25%, 20%, or 15% of the width 342 of the corresponding planetary gear set (e.g., planetary gear set 316). In some embodiments, the clearance 340 between the first and second contact areas may be less than 10%, 5%, or 2% of the width 342 of the corresponding planetary gear set.

[0093] In a non-overlapping embodiment, the width of the planetary gear set can be greater than the combined width of the corresponding sun gear set and ring gear set meshing with the planetary gear set. Therefore, for example, the combined width of the first contact area 330 (i.e., the width of the second sun gear set 312) and the second contact area 334 (i.e., the width of the second ring gear set 320) is less than the width of the planetary gear 342.

[0094] In other embodiments, the contact areas of the respective ring gear set and sun gear set may overlap. For example, Figure 11 An enlarged view of a portion of a gear assembly is shown, which resembles... Figure 5 As shown, however, there is an overlapping contact area.

[0095] refer to Figure 11 The first contact area 330 and the second contact area 334 of the gear assembly 302 are axially spaced apart; however, there is a relatively small overlap 344 between the first contact area 330 and the second contact area 334. Similar overlap can be provided for other contact areas (i.e., the first contact area 328 and the second contact area 332). The amount of overlap between the first and second contact areas (e.g., 330, 334) is preferably less than 15% of the width 342 of the corresponding planetary gear set (e.g., planetary gear set 316). More preferably, the amount of overlap 344 between the first and second contact areas is less than 10%, 5%, or 2% of the width 342 of the corresponding planetary gear set.

[0096] In overlapping embodiments, the width of the planetary gear set can be smaller than the combined width of the corresponding sun gear set and ring gear set meshing with the planetary gear set. Therefore, for example, in... Figure 11 In the process, the combined width of the first contact area 330 (i.e., the width of the second sun gear set 312) and the second contact area 334 (i.e., the width of the second ring gear set 320) is greater than the width of the planetary gear 342.

[0097] Although the embodiments described above are described as unshrouded or open-type rotary engines, it should be understood that the aspects disclosed herein can be applied to shrouded or ducted engines, partially ducted engines, rear-fan engines, or other turbine structures, including those for marine, industrial, or aerospace propulsion systems. Certain aspects of this disclosure can be applied to turbofan engines, turboprop engines, or turboshaft engines. However, it should be appreciated that certain aspects of this disclosure can address problems that may be specific to unshrouded or open-type rotary engines, such as, but not limited to, issues related to gear ratios, fan diameter, fan speed, engine length (L), and maximum engine diameter (D). max L / D of the engine maxQuestions related to the desired cruise altitude and / or the desired operational cruise speed, or a combination thereof.

[0098] For example, Figure 12 This is a cross-sectional schematic diagram of an exemplary embodiment of an engine 600, which includes a gear assembly 102 coupled with a ducted fan propulsion system. However, with Figure 2 Unlike the open rotor configuration, the fan assembly 104 and its fan blades 108 are contained within an annular fan housing 180, and the blade assembly 110 and blades 112 extend radially between the fan shroud 152 and the inner surface of the fan housing 180. As described above, the gear assembly disclosed herein can provide an increased gear ratio for a fixed gear envelope (e.g., ring gears of the same size), or alternatively, a smaller diameter ring gear can be used to achieve the same gear ratio. Although Figure 12 The optional ducted fan and optional fan duct (similar to) are shown. Figure 2 (as shown), but it should be understood that this gear assembly can be used with other turbofan engines (and other open rotary engines) that do not have any of this structure.

[0099] This written description uses examples to disclose the invention, including the best mode, and also enables any person skilled in the art to practice the invention, including making and using any device or system and any method of combination. The patentable scope of the invention is defined by the claims, but may include other examples that would occur to a person skilled in the art. Such other examples are intended to fall within the scope of the claims if they comprise structural elements that are not different from the literal language of the claims, or if they comprise equivalent structural elements that are not substantially different from the literal language of the claims.

[0100] Further aspects of the invention are provided by the subject matter of the following clauses:

[0101] 1. A turbine engine comprising: a fan assembly including a plurality of fan blades; a core engine including a turbine and an input shaft rotatable with the turbine; and a single-stage planetary gear assembly receiving the input shaft at a first speed and driving an output shaft coupled to the fan assembly at a second speed slower than the first speed. The gear assembly includes: a sun gear, a plurality of planetary gears, and a ring gear, the sun gear rotating about a longitudinal centerline of the gear assembly; a sun gear meshing region along the longitudinal centerline of the gear assembly, the sun gear being configured to contact the plurality of planetary gears in the sun gear meshing region; and a ring gear meshing region along the longitudinal centerline of the gear assembly, the ring gear being configured to contact the plurality of planetary gears in the ring gear meshing region, wherein the sun gear meshing region is axially offset from the ring gear meshing region along the longitudinal centerline such that at least 50% of the width of the sun gear meshing region does not axially overlap with the ring gear meshing region.

[0102] 2. The turbine engine according to any clause of this document, wherein the sun gear, the plurality of planetary gears and the ring gear include double helical gears, and the sun gear includes a first sun gear set and a second sun gear set, each of the plurality of planetary gears includes a first planetary gear set and a second planetary gear set, and the ring gear includes a first ring gear set and a second ring gear set.

[0103] 3. The turbine engine according to any clause of this document, wherein the first ring gear set and the second ring gear set are axially spaced apart from each other along a longitudinal centerline, and the first sun gear set and the second sun gear set are positioned between the first ring gear set and the second ring gear set.

[0104] 4. The turbine engine according to any clause of this document, wherein the first sun gear set and the second sun gear set are axially spaced apart from each other along a longitudinal centerline, and the first ring gear set and the second ring gear set are positioned between the first sun gear set and the second sun gear set.

[0105] 5. The turbine engine according to any clause of this document, wherein the sun gear meshing region includes a first sun gear meshing region and a second sun gear meshing region, the first sun gear set meshes with a first planetary gear set in the first sun gear meshing region, the second sun gear set meshes with a second planetary gear set in the second sun gear meshing region, and the ring gear meshing region includes a first ring gear meshing region and a second ring gear meshing region, the first ring gear set meshes with the first planetary gear set in the first ring gear meshing region, and the second ring gear set meshes with the second planetary gear set in the second ring gear meshing region.

[0106] 6. The turbine engine according to any clause of this document, wherein the first sun gear meshing region and the first ring gear meshing region do not overlap axially along the longitudinal centerline.

[0107] 7. The turbine engine according to any clause of this document, wherein there is an axial clearance between the first sun gear meshing region and the first ring gear meshing region.

[0108] 8. The turbine engine according to any clause of this document, wherein the axial clearance width is less than 15% of the width of the first planetary gear set, less than 10% of the width of the first planetary gear set, less than 5% of the width of the first planetary gear set, or less than 2% of the width of the first planetary gear set.

[0109] 9. The turbine engine according to any clause of this document, wherein there is an axial overlap between the first sun gear meshing region and the first ring gear meshing region, and the amount of axial overlap is less than 15% of the width of the first planetary gear set, less than 10% of the width of the first planetary gear set, less than 5% of the width of the first planetary gear set, or less than 2% of the width of the first planetary gear set.

[0110] 10. The turbine described in any clause of this document, wherein the gear ratio of the gear assembly ranges from 6:1 to 14:1, from 6.6 to 12:1, from 7:1 to 12:1, or from 8:1 to 12:1.

[0111] 11. The turbine according to any clause of this document, wherein the gear assembly is a planetary gear configuration in which the ring gear is fixed relative to the engine and does not rotate.

[0112] 12. The turbine according to any clause of this document, wherein the gear assembly is a planetary gear configuration in which the planetary gears are fixed relative to the engine and do not rotate.

[0113] 13. The turbine described in any clause of this document, wherein the fan assembly is a single-stage non-ducted fan blade.

[0114] 14. The turbine according to any clause of this document, wherein the width of the first planetary gear set is greater than the combined width of the first sun gear set and the first ring gear set.

[0115] 15. The turbine according to any clause of this document, wherein the width of the first planetary gear set is less than the combined width of the first sun gear set and the first ring gear set.

[0116] 16. The turbine described in any clause of this document, wherein the fan assembly has ten to sixteen blades, or ten to fourteen blades, or twelve blades.

[0117] 17. The turbine described in any clause of this document, wherein the fan blade tip speed under cruise flight conditions is 650 to 900 fps, or 700 to 800 fps.

[0118] 18. The turbine described in any clause of this document, wherein the fan pressure ratio (FPR) of the fan assembly may be from 1.04 to 1.10, or in some embodiments from 1.05 to 1.08, as measured across the fan blades under cruise flight conditions.

[0119] 19. A gear assembly that configures an input shaft at a first speed and drives an output shaft at a second speed slower than the first speed, the gear assembly comprising: a sun gear, a plurality of planetary gears, and a ring gear, the sun gear rotating about a longitudinal centerline of the gear assembly; a sun gear meshing region along the longitudinal centerline of the gear assembly, the sun gear being configured to contact the plurality of planetary gears in the sun gear meshing region; and a ring gear meshing region along the longitudinal centerline of the gear assembly, the ring gear being configured to contact the plurality of planetary gears in the ring gear meshing region, wherein the sun gear meshing region is axially offset from the ring gear meshing region along the longitudinal centerline such that at least 50% of the width of the sun gear meshing region does not axially overlap with the ring gear meshing region.

[0120] 20. The gear assembly according to any clause of this document, wherein the sun gear, the plurality of planetary gears and the ring gear include double helical gears, and the sun gear includes a first sun gear set and a second sun gear set, each of the plurality of planetary gears includes a first planetary gear set and a second planetary gear set, and the ring gear includes a first ring gear set and a second ring gear set.

[0121] 21. The gear assembly according to any clause of this document, wherein the first ring gear set and the second ring gear set are axially spaced apart from each other along a longitudinal centerline, and the first sun gear set and the second sun gear set are positioned between the first ring gear set and the second ring gear set.

[0122] 22. The gear assembly according to any clause of this document, wherein the first sun gear set and the second sun gear set are axially spaced apart from each other along a longitudinal centerline, and the first ring gear set and the second ring gear set are positioned between the first sun gear set and the second sun gear set.

[0123] 23. The gear assembly according to any provision of this document, wherein the sun gear meshing region includes a first sun gear meshing region and a second sun gear meshing region, the first sun gear set meshes with a first planetary gear set in the first sun gear meshing region, the second sun gear set meshes with a second planetary gear set in the second sun gear meshing region, and the ring gear meshing region includes a first ring gear meshing region and a second ring gear meshing region, the first ring gear set meshes with the first planetary gear set in the first ring gear meshing region, and the second ring gear set meshes with the second planetary gear set in the second ring gear meshing region.

[0124] 24. The gear assembly according to any clause of this document, wherein the first sun gear meshing region and the first ring gear meshing region do not overlap axially along the longitudinal centerline.

[0125] 25. The gear assembly according to any clause of this document, wherein there is an axial clearance between the first sun gear meshing region and the first ring gear meshing region.

[0126] 26. The gear assembly according to any clause herein, wherein the axial clearance is less than 15% of the width of the first planetary gear set, less than 10% of the width of the first planetary gear set, less than 5% of the width of the first planetary gear set, or less than 2% of the width of the first planetary gear set.

[0127] 27. The gear assembly according to any clause of this document, wherein there is an axial overlap between the first sun gear meshing area and the first ring gear meshing area, and the amount of axial overlap is less than 15% of the width of the first planetary gear set, less than 10% of the width of the first planetary gear set, less than 5% of the width of the first planetary gear set, or less than 2% of the width of the first planetary gear set.

[0128] 28. The gear assembly according to any clause of this document, wherein the gear ratio of the gear assembly ranges from 6:1 to 14:1, from 6.6 to 12:1, from 7:1 to 12:1 or from 8:1 to 12:1.

[0129] 29. The gear assembly described in any clause of this document, wherein the gear assembly is a planetary gear configuration or a star gear configuration.

[0130] 30. The turbine according to any clause of this document, wherein the width of the first planetary gear set is greater than the combined width of the first sun gear set and the first ring gear set, or wherein the width of the first planetary gear set is less than the combined width of the first sun gear set and the first ring gear set.

[0131] 31. The turbine or gear assembly described in any clause of this document, wherein the gear assembly is configured to provide an output torque ranging from 20 kNm to 200 kNm, or in other embodiments from 40 kNm to 150 kNm.

Claims

1. A turbine engine, characterized in that, include: Fan assembly, the fan assembly including a plurality of fan blades; A core engine, the core engine including a turbine and an input shaft capable of rotating with the turbine; as well as A single-stage planetary gear assembly, wherein the single-stage planetary gear assembly receives the input shaft at a first speed and drives the output shaft connected to the fan assembly at a second speed, the second speed being slower than the first speed, the gear assembly comprising: A sun gear, multiple planetary gears, and a ring gear, the sun gear rotating about the longitudinal centerline of the gear assembly; A sun gear meshing area, the sun gear meshing area being along the longitudinal centerline of the gear assembly, wherein the sun gear is configured to contact the plurality of planetary gears; A ring gear meshing region, the ring gear meshing region being along the longitudinal centerline of the gear assembly, wherein the ring gear is configured to contact the plurality of planetary gears. The sun gear meshing region is axially offset from the ring gear meshing region along the longitudinal centerline, such that at least 50% of the width of the sun gear meshing region does not axially overlap with the ring gear meshing region. The sun gear, the plurality of planetary gears, and the ring gear include double helical gears, and the sun gear includes a first sun gear set and a second sun gear set; each of the plurality of planetary gears includes a first planetary gear set and a second planetary gear set; and the ring gear includes a first ring gear set and a second ring gear set. The first and second ring gear sets are axially spaced apart from each other along the longitudinal centerline, and the first and second sun gear sets are positioned between the first and second ring gear sets. The sun gear meshing regions include a first sun gear meshing region and a second sun gear meshing region. The first sun gear set meshes with the first planetary gear set in the first sun gear meshing region, and the second sun gear set meshes with the second planetary gear set in the second sun gear meshing region. The ring gear meshing area includes a first ring gear meshing area and a second ring gear meshing area. The first ring gear set meshes with the first planetary gear set in the first ring gear meshing area, and the second ring gear set meshes with the second planetary gear set in the second ring gear meshing area. The width of the first planetary gear set is less than the combined width of the first sun gear set and the first ring gear set.

2. The turbine engine according to claim 1, characterized in that, The first sun gear meshing area and the first ring gear meshing area do not overlap axially along the longitudinal centerline.

3. The turbine engine according to claim 1, characterized in that, An axial clearance exists between the first sun gear meshing area and the first ring gear meshing area.

4. The turbine engine according to claim 3, characterized in that, The axial clearance width is less than 15% of the width of the first planetary gear set, less than 10% of the width of the first planetary gear set, less than 5% of the width of the first planetary gear set, or less than 2% of the width of the first planetary gear set.

5. The turbine engine according to claim 1, characterized in that, Wherein there is an axial overlap between the first sun gear meshing area and the first ring gear meshing area, and the amount of the axial overlap is less than 15% of the width of the first planetary gear set, less than 10% of the width of the first planetary gear set, less than 5% of the width of the first planetary gear set, or less than 2% of the width of the first planetary gear set.

6. The turbine engine according to any one of claims 1-5, characterized in that, The gear ratio of the single-stage planetary gear assembly is in the range of 6:1 to 14:

1.

7. The turbine engine according to any one of claims 1-5, characterized in that, The single-stage planetary gear assembly is a planetary gear configuration in which the ring gear is fixed relative to the core engine and does not rotate.

8. The turbine engine according to any one of claims 1-5, characterized in that, The single-stage planetary gear assembly is a star gear configuration in which the plurality of planetary gears are fixed relative to the core engine and do not rotate.

9. The turbine engine according to any one of claims 1-5, characterized in that, The fan assembly described therein is a single-stage non-ducted fan blade.

10. The turbine engine according to any one of claims 1-5, characterized in that, The fan assembly described herein has ten to sixteen blades, or ten to fourteen blades, or twelve blades.

11. The turbine engine according to any one of claims 1-5, characterized in that, The fan blade tip speed under cruise flight conditions is 650 to 900 fps, or 700 to 800 fps.

12. The turbine engine according to any one of claims 1-5, characterized in that, The fan pressure ratio (FPR) of the fan assembly is 1.04 to 1.10, as measured across the fan blades under cruise flight conditions.

13. A turbine engine, characterized in that, include: Fan assembly, the fan assembly including a plurality of fan blades; A core engine, the core engine including a turbine and an input shaft capable of rotating with the turbine; as well as Gear assembly configured to drive an input shaft at a first speed and an output shaft at a second speed slower than the first speed, the gear assembly comprising: Sun gear, which rotates about the longitudinal centerline of the gear assembly; Multiple planetary gears; Ring gear; A sun gear meshing area, the sun gear meshing area being along the longitudinal centerline of the gear assembly, wherein the sun gear is configured to contact the plurality of planetary gears; A ring gear meshing region, the ring gear meshing region being along the longitudinal centerline of the gear assembly, wherein the ring gear is configured to contact the plurality of planetary gears. The sun gear meshing region is axially offset from the ring gear meshing region along the longitudinal centerline, such that at least 50% of the width of the sun gear meshing region does not axially overlap with the ring gear meshing region. The sun gear, the plurality of planetary gears, and the ring gear include double helical gears, and the sun gear includes a first sun gear set and a second sun gear set; each of the plurality of planetary gears includes a first planetary gear set and a second planetary gear set; and the ring gear includes a first ring gear set and a second ring gear set. The first sun gear set and the second sun gear set are axially spaced apart from each other along the longitudinal centerline, and the first sun gear set and the second sun gear set are positioned between the first ring gear set and the second ring gear set. The fan pressure ratio (FPR) of the fan assembly is 1.04 to 1.10, as measured across the fan blades under cruise flight conditions.

14. The turbine engine according to claim 13, characterized in that, The sun gear meshing region includes a first sun gear meshing region and a second sun gear meshing region. The first sun gear set meshes with the first planetary gear set in the first sun gear meshing region, and the second sun gear set meshes with the second planetary gear set in the second sun gear meshing region. The ring gear meshing region includes a first ring gear meshing region and a second ring gear meshing region. The first ring gear set meshes with the first planetary gear set in the first ring gear meshing region, and the second ring gear set meshes with the second planetary gear set in the second ring gear meshing region.

15. The turbine engine according to claim 14, characterized in that, The first sun gear meshing area and the first ring gear meshing area do not overlap axially along the longitudinal centerline.

16. The turbine engine according to claim 14, characterized in that, There is an axial clearance between the first sun gear meshing area and the first ring gear meshing area, and The axial clearance width is less than 15% of the width of the first planetary gear set, less than 10% of the width of the first planetary gear set, less than 5% of the width of the first planetary gear set, or less than 2% of the width of the first planetary gear set.

17. The turbine engine according to any one of claims 13-16, characterized in that, The gear ratio of the gear assembly is in the range of 6:1 to 14:

1.

18. A turbine engine, characterized in that, include: Fan assembly, the fan assembly including a plurality of fan blades; A core engine, the core engine including a turbine and an input shaft capable of rotating with the turbine; as well as A single-stage planetary gear assembly, wherein the single-stage planetary gear assembly receives the input shaft at a first speed and drives the output shaft connected to the fan assembly at a second speed, the second speed being slower than the first speed, the gear assembly comprising: A sun gear, multiple planetary gears, and a ring gear, the sun gear rotating about the longitudinal centerline of the gear assembly; A sun gear meshing area, the sun gear meshing area being along the longitudinal centerline of the gear assembly, wherein the sun gear is configured to contact the plurality of planetary gears; A ring gear meshing region, the ring gear meshing region being along the longitudinal centerline of the gear assembly, wherein the ring gear is configured to contact the plurality of planetary gears. The sun gear meshing region is axially offset from the ring gear meshing region along the longitudinal centerline, such that at least 50% of the width of the sun gear meshing region does not axially overlap with the ring gear meshing region. The sun gear, the plurality of planetary gears, and the ring gear include double helical gears, and the sun gear includes a first sun gear set and a second sun gear set; each of the plurality of planetary gears includes a first planetary gear set and a second planetary gear set; and the ring gear includes a first ring gear set and a second ring gear set. The first ring gear set and the second ring gear set are axially spaced apart from each other along the longitudinal centerline, and the first sun gear set and the second sun gear set are positioned between the first ring gear set and the second ring gear set. The sun gear meshing region includes a first sun gear meshing region and a second sun gear meshing region. The first sun gear set meshes with the first planetary gear set in the first sun gear meshing region, and the second sun gear set meshes with the second planetary gear set in the second sun gear meshing region. The ring gear meshing area includes a first ring gear meshing area and a second ring gear meshing area. The first ring gear set meshes with the first planetary gear set in the first ring gear meshing area, and the second ring gear set meshes with the second planetary gear set in the second ring gear meshing area. There is an axial overlap between the first sun gear meshing area and the first ring gear meshing area, and the amount of the axial overlap is less than 15% of the width of the first planetary gear set.

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