Turbine engine gearbox assembly

Abstract

A turbine engine has a turbocharged engine coupled to an input shaft, a fan coupled to an output shaft, and a gearbox assembly. Torque can be transmitted from the input shaft to the output shaft through the gearbox assembly. The gearbox assembly has a split sun gear rotationally coupled to the input shaft, a plurality of planetary gears located radially outward of and intermeshing with the split sun gear, and a one-piece ring gear located radially outward of and intermeshing with the plurality of planetary gears. The split sun gear includes a front sun gear and a rear sun gear separate from the front sun gear, and the front sun gear and the rear sun gear are each rotationally coupled to the input shaft.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Italian Patent Application No. 102024000007375, filed April 4, 2024, which is incorporated herein in its entirety by this reference. TECHNICAL FIELD

[0003] The present disclosure relates generally to a gearbox assembly, for example, for a turbine engine. BACKGROUND

[0004] Turbine engines generally include a fan and a core section arranged in flow communication with one another. A gearbox assembly is coupled between the fan and the core section. BRIEF DESCRIPTION OF DRAWINGS

[0005] The above-described and other features and advantages will become more apparent by reference to the following more particular description of various exemplary embodiments, as illustrated in the accompanying drawings in which like reference numerals generally represent like structures similar or analogous elements and functions throughout the several views.

[0006] Figure 1 A schematic cross-sectional view of a turbine engine taken along a longitudinal centerline axis of the engine is shown in accordance with the present disclosure.

[0007] Figure 2 A schematic cross-sectional view of a gearbox assembly for a turbine engine taken along a longitudinal centerline axis of the gearbox assembly is shown in accordance with the present disclosure.

[0008] Figure 3A A partial cross-sectional schematic view of a working spline connection of a connection device for coupling a sun gear of the gearbox assembly of Figure 2 to an input shaft is shown in accordance with the present disclosure.

[0009] Figure 3B A partial cross-sectional schematic view of a fixed spline connection of a connection device for coupling a sun gear of the gearbox assembly of Figure 2 to an input shaft is shown in accordance with the present disclosure.

[0010] Figure 4 A schematic cross-sectional view of a gearbox assembly for a turbine engine taken along a longitudinal centerline axis of the gearbox assembly is shown in accordance with the present disclosure.

[0011] Figure 5A A schematic cross-sectional view of a gearbox assembly for a turbine engine taken along a longitudinal centerline axis of the gearbox assembly is shown in accordance with the present disclosure.

[0012] Figure 5BA schematic cross-sectional view of a gearbox assembly for a turbine engine is shown taken along a longitudinal centerline axis of the gearbox assembly according to the present disclosure.

[0013] Figure 6 A partial schematic view of a curve connector of a connection device coupling a sun gear of a gearbox assembly to an input shaft is shown according to the present disclosure. Figure 5A and Figure 5B A partial schematic view of a curve connector of a connection device coupling a sun gear of a gearbox assembly to an input shaft is shown according to the present disclosure.

[0014] Figure 7 A schematic cross-sectional view of a gearbox assembly for a turbine engine is shown taken along a longitudinal centerline axis of the gearbox assembly according to the present disclosure.

[0015] Figure 8 A schematic cross-sectional view of a gearbox assembly for a turbine engine is shown taken along a longitudinal centerline axis of the gearbox assembly according to the present disclosure.

[0016] Figure 9 A schematic cross-sectional view of a gearbox assembly for a turbine engine is shown taken along a longitudinal centerline axis of the gearbox assembly according to the present disclosure.

[0017] Figure 10 A method of installing a split sun gear on an input shaft is shown according to the present disclosure.

[0018] Figure 11 A method of installing a split sun gear on an input shaft is shown according to the present disclosure.

[0019] Figure 12 A method of installing a split sun gear on an input shaft is shown according to the present disclosure.

[0020] Figure 13 A method of installing a split sun gear on an input shaft is shown according to the present disclosure.

[0021] Figure 14 A schematic cross-sectional view of a gearbox assembly for a turbine engine is shown taken along a longitudinal centerline axis of the gearbox assembly according to the present disclosure. DETAILED DESCRIPTION

[0022] The features, advantages, and embodiments of the present disclosure are set forth in or apparent from the detailed description, drawings, and claims. Moreover, the following detailed description is exemplary and intended to provide further explanation of the disclosure, rather than limitation thereof.

[0023] Various embodiments of the present disclosure are discussed in detail below. Although specific embodiments are discussed, this is for illustrative purposes only. One skilled in the relevant art will recognize that other components and configurations can be used without departing from the present disclosure.

[0024] As used herein, the terms “first” and “second” and the like can be used interchangeably to distinguish one component from another and are not intended to signify location or importance of individual components.

[0025] The terms “upstream” and “downstream” refer to the relative direction with respect to the flow of fluid in a fluid path. For example, “upstream” refers to the direction from which fluid flows, and “downstream” refers to the direction to which fluid flows.

[0026] The terms “forward” and “aft” refer to relative positions within a turbine engine or vehicle and refer to the normal operating attitude of the turbine engine or vehicle. For example, for a turbine engine, forward refers to a position closer to the engine inlet, and aft refers to a position closer to the engine nozzle or exhaust.

[0027] As used herein, the terms “low,” “medium” (or “mid”), and “high,” or their respective comparative forms (e.g., “lower” and “higher,” if applicable), when used in conjunction with a compressor, turbine, shaft, fan, or turbine engine component, each refer to relative pressure, relative speed, relative temperature, and / or relative power output within the engine, unless otherwise specified. For example, a “low power” setting defines an engine configured to operate at a power output lower than a “high power” setting of the engine, while a “mid power” setting defines an engine configured to operate at a power output higher than the “low power” setting and lower than the “high power” setting. The terms “low,” “medium” (or “mid”), or “high” in such aforementioned terms can additionally or alternatively be understood with respect to a minimum allowable speed, pressure, or temperature, or with respect to a minimum or maximum allowable speed, pressure, or temperature of normal, expected, steady state, or the like operation of the engine.

[0028] Unless otherwise specified herein, the terms “coupled,” “fixed,” “attached,” “connected,” and the like, refer both direct and indirect coupling, fixation, attachment, or connection, through one or more intermediate components or features. These terms include integral and unitary constructions (e.g., a blisk rotor blade system).

[0029] The singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.

[0030] As used herein, the terms "axial" and "axially" refer to a direction and orientation that extends substantially parallel to a centerline of the turbine engine. Further, the terms "radial" and "radially" refer to a direction and orientation that extends substantially perpendicular to the centerline of the turbine engine. Additionally, as used herein, the terms "circumferential" and "circumferentially" refer to a direction and orientation that extends arcuately about the centerline of the turbine engine.

[0031] Throughout this document and in the claims, range limits are combined and interchanged. Such ranges are identified and include all sub-ranges therein unless context or language indicates otherwise. For example, all ranges disclosed herein include the endpoints, and the endpoints can be combined independently of one another.

[0032] The present disclosure provides a gearbox assembly for use in an indirect drive turbine engine that includes a sun gear, a plurality of planet gears, and a ring gear. The gear train of the gearbox assembly is composed of double helical gears. The double helical gears include two rows of helical teeth that are opposite in helix angle. For example, the sun gear, each of the plurality of planet gears, and the ring gear each include a double helical gear having gear teeth that mesh with the gear teeth of an adjacent double helical gear, as described in more detail below. To enable assembly of the gear train with double helical gears, the ring gear can be formed by joining two separate pieces during assembly.

[0033] The present disclosure provides a double helical gear with a single piece / single ring gear (e.g., not a split ring gear) by providing a split sun gear. The split sun gear, in combination with the single piece ring gear, provides a small radial envelope for the gearbox assembly (as compared to examples with a split ring gear). The small radial envelope reduces the weight of the gearbox, as compared to a gearbox with a split ring gear, and provides a lower profile, thus providing a higher performance flow path, which provides enhanced performance and lower fuel burn of the turbine engine.

[0034] In examples of the present disclosure, the sun gear is a split sun gear such that the sun gear is formed from two separate pieces that are coupled to an input shaft, and in some examples, the two separate pieces can be coupled to one another. The split sun gear can be rotationally coupled to the input shaft by a spline coupling. In some examples, the two separate pieces of the sun gear can be coupled to one another by a curvilinear coupling. The present disclosure provides examples of a split sun gear in combination with a single piece ring gear. The present disclosure provides a gearbox assembly that prevents relative axial slippage of two meshing gears (e.g., by preventing relative axial slippage of the sun gear).

[0035] The one-piece ring gear allows for a reduced radial envelope by eliminating the bolted connection between the two separate pieces of the one-piece ring gear. For the one-piece ring gear, the sun gear should then be split into two separate pieces. The combination of a split sun gear and one-piece ring gear allows for a lower radial envelope, ease of packaging in a sump, flow path optimization (e.g., due to the low profile gearbox assembly), enhanced efficiency, and higher reliability with lighter weight as compared to a gearbox assembly with a split ring gear. The one-piece ring gear also allows for a more flexible structure (as compared to a split bolted ring gear) due to the lack of constraints on the radial deflection typically associated with a split bolted ring gear. (In a split ring gear, the radial deflection is controlled and minimized to mitigate fretting risk at the bolted connection.) The more flexible structure thus allows for a more even load distribution among the multiple planetary gears, which in turn provides a higher power density of the gearbox assembly.

[0036] Referring now to the drawings, Figure 1 is a schematic cross-sectional view of a turbine engine 10 taken along a longitudinal centerline axis 12 of the turbine engine 10 in accordance with an embodiment of the present disclosure. As Figure 1 shown, the turbine engine 10 defines an axial direction A (extending parallel to the longitudinal centerline axis 12 for reference), a radial direction R that is perpendicular to the axial direction A, and a circumferential direction C that extends about the longitudinal centerline axis 12. Generally, the turbine engine 10 includes a fan section 14 and a turbocharger engine 16 disposed downstream of the fan section 14.

[0037] The turbocharger engine 16 includes, in serial flow relationship, a compressor section 22, a combustion section 28, and a turbine section 30. The turbocharger engine 16 is substantially enclosed within a casing 18 that is substantially tubular and defines an annular inlet 20. As Figure 1 schematically shown in

[0038] For the Figure 1In the embodiment depicted in FIG, fan section 14 includes a fan 42 (eg, a variable pitch fan) having a plurality of fan blades 44 coupled to a disk 46 in a spaced-apart manner. Figure 1 As depicted in FIG, fan blades 44 extend generally outwardly from disk 46 in a radial direction R. Each fan blade 44 is rotatable relative to disk 46 about pitch axis P by virtue of fan blades 44 being operably coupled to an actuation member 48 that is configured to collectively and in unison change the pitch of fan blades 44. Fan blades 44, disk 46, and actuation member 48 are rotatable together about longitudinal centerline axis 12 via fan shaft 50, which is powered by LP shaft 40 across a power gearbox (also referred to as a gearbox assembly 52). Gearbox assembly 52 is Figure 1 The gearbox assembly 52 includes a plurality of gears for adjusting the rotational speed of the fan shaft 50 and, therefore, the rotational speed of the fan 42 relative to the LP shaft 40 .

[0039] Still refer to Figure 1 In the exemplary embodiment of the present invention, disk 46 is covered by a rotatable fan hub 54 that is aerodynamically shaped to facilitate airflow through a plurality of fan blades 44. In addition, fan section 14 includes an annular fan casing or nacelle 56 that circumferentially surrounds fan 42 and at least a portion of turbocharger engine 16. Nacelle 56 is supported relative to turbocharger engine 16 by a plurality of circumferentially spaced outlet guide vanes 58. Furthermore, a downstream section 60 of nacelle 56 extends over an outer portion of turbocharger engine 16 to define a bypass airflow passage 62 therebetween.

[0040] During operation of turbine engine 10, a volume of air 64 enters turbine engine 10 through nacelle 56 or an inlet 66 of fan section 14. As volume of air 64 passes through fan blades 44, a first portion of air 68 is directed or channeled into bypass airflow passage 62, and a second portion of air 70 is directed or channeled into an upstream section of the core air flow path, or more specifically, into annular inlet 20 of LP compressor 24. The ratio between first portion of air 68 and second portion of air 70 is generally referred to as the bypass ratio. The pressure of second portion of air 70 is then increased, generating compressed air 72, which is then directed through HP compressor 26 and into combustion section 28. Combustors of combustion section 28 are positioned in the core air flow path, where compressed air 72 is mixed with a fuel stream and ignited to generate combustion gases 74. As described in more detail below, the fuel stream may be a primary fuel stream provided to the combustor.

[0041] The combustion gases 74 are directed into and expanded through the HP turbine 32, with a portion of the thermal and kinetic energy from the combustion gases 74 being extracted via sequential stages of HP turbine stator vanes 76 coupled to the outer casing 18 and HP turbine rotor blades 78 coupled to the HP shaft 38, thus rotating the HP shaft 38 to thereby support operation of the HP compressor 26 (self-sustaining cycle). In this manner, the combustion gases 74 do work on the HP turbine 32. The combustion gases 74 are then directed into and expanded through the LP turbine 34. Here, a second portion of the thermal and kinetic energy from the combustion gases 74 is extracted via sequential stages of LP turbine stator vanes 80 coupled to the outer casing 18 and LP turbine rotor blades 82 coupled to the LP shaft 40, thus rotating the LP shaft 40 to thereby support operation of the LP compressor 24 (self-sustaining cycle) and rotation of the fan 42 via the gear box assembly 52. In this manner, the combustion gases 74 do work on the LP turbine 34. One or more stages can be used in each of the HP turbine 32 and the LP turbine 34.

[0042] The combustion gases 74 are then directed through the jet exhaust nozzle section 36 of the turbocharged engine 16 to provide propulsive thrust. At the same time, the pressure of the first portion of air 68 is significantly increased as it is directed through the bypass airflow passage 62 before being discharged from the fan nozzle exhaust section 84 of the turbine engine 10, also providing propulsive thrust. The HP turbine 32, the LP turbine 34, and the jet exhaust nozzle section 36 at least partially define a hot gas path 86 for directing the combustion gases 74 through the turbocharged engine 16.

[0043] Figure 2 is a schematic cross-sectional side view of a gear box assembly 200 according to an embodiment of the present disclosure, which can be used as Figure 1 the gear box assembly 52 of FIG. 1. The gear box assembly 200 includes a sun gear 202, a plurality of planet gears 204 (only one of which is visible in Figure 2 FIG. 2), and a ring gear 206. The sun gear 202 is also referred to herein as a split sun gear 202. That is, the sun gear 202 is formed from two separate components (e.g., a front sun gear 216 and a rear sun gear 218) that have a connecting device 236 to couple the two separate components together and couple the sun gear 202 to the input shaft 210 through the connecting device 236. For clarity, only a portion of the gears is shown.

[0044] The gear box assembly 200 is a planetary gear box assembly. That is, the ring gear 206 is held stationary and the carrier 208 is allowed to rotate. In this arrangement, the fan 42 Figure 1) by the planet carrier 208. In this way, the plurality of planet gears 204 are the output of the gear box assembly 200. However, other suitable types of gear box assemblies can also be employed. For example, the gear box assembly 200 can be a star or rotary ring gear type gear box assembly (e.g., the ring gear 206 rotates and the planet carrier 208 is fixed and stationary). In this arrangement, the fan 42( Figure 1 ) by the ring gear 206. In this way, the ring gear 206 is the output of the gear box assembly 200. In another non-limiting embodiment, the gear box assembly 200 can be a differential gear box, where both the ring gear 206 and the planet carrier 208 are allowed to rotate.

[0045] The gear box assembly 200 includes a gear train composed of double helical gears. Double helical gears include two rows of helical teeth with opposite helix angles. That is, the sun gear 202, each of the plurality of planet gears 204, and the ring gear 206 each include a double helical gear having gear teeth that mesh with the gear teeth of an adjacent double helical gear, as described in more detail below.

[0046] The input shaft 210 is coupled to the sun gear 202. The input shaft 210 is coupled to the turbine section 30( Figure 1 ). For example, the input shaft 210 can be coupled to the LP shaft 40( Figure 1 ). The input shaft 210 rotates the sun gear 202. Radially outward of and intermeshing with the sun gear 202 is the plurality of planet gears 204, which are coupled together and supported by the planet carrier 208. The planet carrier 208 supports and constrains the plurality of planet gears 204 such that the plurality of planet gears 204 do not rotate together about the sun gear 202, while enabling each of the plurality of planet gears 204 to rotate about its own axis 212. Radially outward of and intermeshing with the plurality of planet gears 204 is the ring gear 206, which is an annular ring gear. The ring gear 206 is a single-piece ring gear. As used herein, “single-piece” refers to a single, unitary, and one-piece component formed of only a single part, with no bolted connections in the gear drive portion of the ring gear, although bolted connections can exist in the connecting members that couple the ring gear to a static structure, such as an engine bed. The planet carrier 208 is coupled to the fan 42( Figure 1 ) via the output shaft 214 and rotates to drive the fan 42( Figure 1 ) about rotation of the longitudinal centerline axis 12. For example, the output shaft 214 is coupled to the fan shaft 50( Figure 1 ).

[0047] As described above, sun gear 202 includes a front sun gear 216 and a rear sun gear 218. Each of sun gear 202, the plurality of planet gears 204, and the ring gear 206 includes teeth around their peripheries for intermeshing with the other gears. Specifically, front sun gear 216 of sun gear 202 includes a first set of sun gear teeth 220, and rear sun gear 218 of sun gear 202 includes a second set of sun gear teeth 222. As discussed above, sun gear 202 is a double helical or double bevel gear, such that each of the first set of sun gear teeth 220 and the second set of sun gear teeth 222 are helical teeth that are angled relative to each other. Each of the plurality of planet gears 204 includes a first set of planet gear teeth 224 and a second set of planet gear teeth 226. As discussed above, each of planet gears 204 is a double helical or double bevel gear, such that each of the first set of planet gear teeth 224 and the second set of planet gear teeth 226 are helical teeth. Ring gear 206 includes a first set of ring gear teeth 228 and a second set of ring gear teeth 230. As discussed above, ring gear 206 is a double helical gear or double bevel gear such that each of first set of ring gear teeth 228 and second set of ring gear teeth 230 are helical teeth.

[0048] exist Figure 2 In the gearbox assembly 200, the first set of sun gear teeth 220 of the front sun gear 216 meshes with the first set of planet gear teeth 224 of each of the planet gears 204, and the second set of sun gear teeth 222 of the rear sun gear 218 meshes with the second set of planet gear teeth 226 of each of the planet gears. Similarly, the first set of planet gear teeth 224 and the second set of planet gear teeth 226 of each of the planet gears 204 mesh with the first set of ring gear teeth 228 and the second set of ring gear teeth 230 of the ring gear 206, respectively.

[0049] Each of the planet gears 204 includes a pin 232 about which the corresponding planet gear 204 rotates. The pin 232 is coupled to the planet carrier 208 and is disposed within a bore 234 of the corresponding planet gear 204. Lubricant (e.g., oil) is provided between the pin 232 and the corresponding planet gear 204, allowing the planet gear 204 to rotate relative to the pin 232. For simplicity, the pin 232 is shown as a single component, but may also be a subassembly including one or more of a pin, a rolling element (e.g., a journal or bearing), and a retaining feature.

[0050] As described above, the connection device 236 couples the split sun gear 202 to the input shaft 210. The connection device 236 includes a front support member 238, a rear support member 240, an input shaft coupling member 242, and a fastening device 244.

[0051] The front support member 238 includes a first portion 246 and a second portion 248. The first portion 246 extends in a radial direction and includes an opening (not visible) therethrough for receiving the fastening device 244. The second portion 248 extends at an angle between the first portion 246 and the front sun gear 216.

[0052] The rear support member 240 includes a first portion 250 and a second portion 252. The first portion 250 extends in a radial direction and includes an opening (not visible) therethrough for receiving the fastening device 244. The second portion 252 extends at an angle between the first portion 250 and the rear sun gear 218.

[0053] The input shaft coupling member 242 includes a first portion 254 and a second portion 256. The first portion 254 extends in a radial direction between and parallel to the first portion 246 of the front support member 238 and the first portion 250 of the rear support member 240. The first portion 254 includes an opening (not visible) therethrough for receiving the fastening device 244. The second portion 256 extends in an axial direction parallel to the input shaft 210 and parallel to the longitudinal centerline axis 12 Figure 1 ). The second portion 256 is rotationally coupled to the input shaft 210 such that rotation of the input shaft 210 causes rotation of the second portion 256, and thus rotation of the sun gears 202. In Figure 2 the example, the second portion 256 is rotationally coupled to the input shaft 210 by splines, such as described in more detail with reference to Figure 3A and Figure 3B .

[0054] The fastening device 244 extends through the respective openings in the first portion 246 of the front support member 238, the first portion 250 of the rear support member 240, and the first portion 254 of the input shaft coupling member 242. The fastening device 244 is secured within the openings such that the front support member 238, the rear support member 240, and the input shaft coupling member 242 are fixedly attached together. In this way, the front sun gear 216 and the rear sun gear 218 are rotationally coupled to the input shaft 210 by the connecting device 236. As described herein, the fastening device 244 can be a bolt, screw, weld, anchor, river, or other mechanical fastener.

[0055] Figure 2 The illustration of Figure 1a cross-sectional view taken along the longitudinal centerline axis 12 of the turbine engine 10, with half of the sun gear 202 omitted for simplicity. However, the sun gear 202 extends circumferentially about the longitudinal centerline axis 12 such that the front sun gear 216, the rear sun gear 218, the front support member 238, the rear support member 240, and the input shaft coupling member 242 are each annular members. Thus, although a single fastening device 244 is shown and a single opening in each of the first portions 246, 250, and 254 is described, multiple fastening devices 244 can be provided in circumferentially spaced apart fashion about the longitudinal centerline axis 12 to secure the sun gear 202 to the input shaft 210.

[0056] Figure 3A A partial cross-sectional schematic view of an exemplary spline connection 300 that can be used to couple the input shaft coupling member 242 to the input shaft 210 is shown. The spline connection 300 can be a working spline. The spline connection 300 includes a first portion 302 on a radially outer surface of the input shaft 210 that mates with a second portion 304 on a radially inner surface of the input shaft coupling member 242. The first portion 302 includes a plurality of first portion protrusions 306 and a plurality of first portion grooves 308, and the second portion 304 includes a plurality of second portion protrusions 310 and a plurality of second portion grooves 312. The plurality of first portion protrusions 306 are received within and mate with the plurality of second portion grooves 312, and the plurality of second portion protrusions 310 are received within and mate with the plurality of first portion grooves 308. In this manner, the input shaft coupling member 242 (and thus the connection device 236 and the sun gear 202) can move axially relative to the input shaft 210 while remaining rotationally coupled to the input shaft 210. While a plurality of grooves and protrusions are depicted, more or fewer grooves and protrusions can be provided than shown. In one example, a single protrusion can be provided on one of the input shaft 210 or the input shaft coupling member 242, and a single groove can be provided in the other of the input shaft 210 or the input shaft coupling member 242. The spline connection 300 is not limited to the particular structure, shape, and size shown in FIG. 3, and other structures, shapes, and sizes that allow for rotational coupling between the input shaft 210 and the sun gear 202 can be envisioned. Figure 3A

[0057] Figure 3B ​A partial cross-sectional view of another example spline connection 300' that can be used to couple the input shaft coupling member 242' to the input shaft 210' taken along the longitudinal centerline axis 12 is shown. The spline connection 300' can be a fixed spline. The spline connection 300' includes a male spline 302' on a radially outer surface of the input shaft 210' that mates with a female spline 304' on a radially inner surface of the input shaft coupling member 242'. A first press fit 243 can be located at the forward end 253 between the input shaft 210' and the input shaft coupling member 242'. A second press fit 245 can be located at the rearward end 255 between the input shaft 210' and the input shaft coupling member 242'. The input shaft coupling member 242' can abut and be proximate to a rear shoulder 251 of the input shaft 210' that limits the axial position of the input shaft coupling member 242'. A fastening device 244' is secured to the input shaft 210' at the forward end. Thus, the rear shoulder 251, the fastening device 244', the first press fit 243, and the second press fit 245' maintain the input shaft coupling member 242' and the input shaft 210' in a predetermined axial relationship. The male spline 302' and the female spline 304' are capable of transmitting rotation from the input shaft 210' to the input shaft coupling member 242', and thus to the gear, as previously described with respect to the spline connection 300. Figure 2

[0058] Figure 4 A partial cross-sectional view of an example sun gear 402 taken along the longitudinal centerline axis 12 is shown that can be used with the gear box assembly 200 of Figure 2 Thus, only features that differ between the sun gear 202 and the sun gear 402 are described. All other features are understood to be the same or substantially the same as described with respect to the sun gear 202.

[0059] The sun gear 402 is a split sun gear 402 having a forward sun gear 416 and a rearward sun gear 418 that are substantially the same as the forward sun gear 216 and the rearward sun gear 218, but with the following differences. Like the sun gear 202, the sun gear 402 is coupled to the input shaft 210 by a connection device 436. The connection device 436 couples each of the forward sun gear 416 and the rearward sun gear 418 to the input shaft 210, but does not couple the forward sun gear 416 to the rearward sun gear 418. The connection device 436 includes a forward support member 438, a rearward support member 440, an input shaft coupling member 442, and a fastening device 444.

[0060] ​The front support member 438 includes a first portion 446 extending in a radial direction between the input shaft coupling member 442 and the front sun gear 416. The rear support member 440 includes a first portion 450 extending in a radial direction between the input shaft coupling member 442 and the rear sun gear 418.

[0061] The input shaft coupling member 442 includes a first portion 454 and a second portion 456, each extending in an axial direction parallel to the input shaft 210. The first portion 454 rotationally couples the front support member 438, and thus the front sun gear 416, to the input shaft 210, and the second portion 456 couples the rear support member 440, and thus the rear sun gear 418, to the input shaft 210. The first portion 454 is integral with, connected to, or coupled to the front support member 438, and the second portion 456 is integral with, connected to, or coupled to the rear support member 440.

[0062] The first portion 254 and the second portion 256 are both rotationally coupled to the input shaft 210 such that rotation of the input shaft 210 can be coupled to the rotation of the input shaft 210. Figure 2 and Figure 3A 、 3B Rotation of the sun gear 402 is caused in the same or similar manner as described. A front fastening device 444 extends at an axial forward end 453 of the front sun gear 416 to prevent axial movement of the sun gear 402 in a forward direction relative to the input shaft 210. The shoulder 211 of the input shaft 210 is located at an axial rearward end 455 of the rear sun gear 418 to prevent axial movement of the sun gear 402 in a rearward direction relative to the input shaft 210. Thus, the fastening device 444 is fixed so that the front support member 438, the rear support member 440 and the input shaft coupling member 442 are axially fixed to the input shaft 210. In this manner, the front sun gear 416 and the rear sun gear 418 are rotationally coupled to the input shaft 210 via the coupling device 436. The fastening device 444 may be a device that is rotatable about the longitudinal centerline axis 12 ( Figure 1 ) a plurality of circumferentially spaced fastening devices, or may be a single annular fastening device extending circumferentially about the longitudinal centerline axis 12. As described herein, the fastening device 444 may be a bolt, screw, weldment, anchor, river piece, or other mechanical fastener.

[0063] Figure 4 The diagram is along the Figure 1 1. In the cross-sectional view taken about the longitudinal centerline axis 12 of the turbine engine 10, half of the sun gear 402 is omitted for simplicity. However, the sun gear 402 extends circumferentially about the longitudinal centerline axis 12 such that the forward sun gear 416, the aft sun gear 418, the forward support member 438, the aft support member 440, and the input shaft coupling member 442 are each annular members.

[0064] Figure 5A A partial cross-sectional view of an example sun gear 502 taken along the longitudinal centerline axis 12 is shown, which can be used in place of the sun gear 202 with the gear box assembly 200 of Figure 2 Thus, only the features that differ between the sun gear 202 and the sun gear 502 are described. All other features are understood to be the same or substantially the same as described with respect to the sun gear 202.

[0065] The sun gear 502 is a split sun gear 502 having a front sun gear 516 and a rear sun gear 518 that are substantially the same as the front sun gear 216 and the rear sun gear 218, but with the following differences. Like the sun gear 202, the sun gear 502 is coupled to the input shaft 510 by a connection device 536. The connection device 536 couples the two separate components (e.g., the front sun gear 516 and the rear sun gear 518) together and couples the sun gear 502 to the input shaft 510. The connection device 536 includes a front support member 538, a rear support member 540, an input shaft coupling member 542, and a fastening device 544.

[0066] The front support member 538 includes a first portion 546 and a second portion 548. The first portion 546 extends in a radial direction and includes an opening (not visible) therethrough for receiving the fastening device 544. The second portion 548 extends at an angle between the first portion 546 and the front sun gear 516.

[0067] The rear support member 540 includes a first portion 550 and a second portion 552. The first portion 550 extends in a radial direction and includes an opening (not visible) therethrough for receiving the fastening device 544. The second portion 552 extends at an angle between the first portion 550 and the rear sun gear 518. The first portion 550 of the rear sun gear 518 is rotationally coupled to the first portion 546 of the front sun gear 516 by a coupling 560 such that rotation of the input shaft 510 causes rotation of the first portion 550, which causes rotation of the first portion 546, and thus rotation of the sun gear 502. In Figure 5A In the example, the coupling 560 is a curvilinear coupling, such as described in more detail with respect to Figure 6 The rear support member 540 includes a first portion 550 and a second portion 552. The first portion 550 extends in a radial direction and includes an opening (not visible) therethrough for receiving the fastening device 544. The second portion 552 extends at an angle between the first portion 550 and the rear sun gear 518. The first portion 550 of the rear sun gear 518 is rotationally coupled to the first portion 546 of the front sun gear 516 by a coupling 560 such that rotation of the input shaft 510 causes rotation of the first portion 550, which causes rotation of the first portion 546, and thus rotation of the sun gear 502. In Figure 6 The rear support member 540 includes a first portion 550 and a second portion 552. The first portion 550 extends in a radial direction and includes an opening (not visible) therethrough for receiving the fastening device 544. The second portion 552 extends at an angle between the first portion 550 and the rear sun gear 518. The first portion 550 of the rear sun gear 518 is rotationally coupled to the first portion 546 of the front sun gear 516 by a coupling 560 such that rotation of the input shaft 510 causes rotation of the first portion 550, which causes rotation of the first portion 546, and thus rotation of the sun gear 502. In

[0068] The input shaft coupling member 542 extends in a radial direction on the rear side of the first portion 550 of the rear support member 540 and is parallel to the first portion 550 of the rear support member 540. The input shaft coupling member 542 includes an opening (not visible) therethrough for receiving a fastening device 544. The input shaft coupling member 542 can extend directly from the input shaft 510. In some examples, the input shaft coupling member 542 is formed integrally with the input shaft 510. In some examples, the input shaft coupling member 542 is coupled to the input shaft 510. The input shaft coupling member 542 is rotationally coupled to the first portion 550 of the rear sun gear 518 such that rotation of the input shaft 510 causes rotation of the first portion 550 and, therefore, rotation of the sun gear 502. Figure 5A In the example, the first portion 550 is rotationally coupled to the input shaft coupling member 542 via a connection of a fastening device 544 .

[0069] Fastening device 544 extends through corresponding openings in first portion 546 of front support member 538, first portion 550 of rear support member 540, and input shaft coupling member 542. Fastening device 544 is secured within the openings, such that front support member 538, rear support member 540, and input shaft coupling member 542 are fixedly attached together. In this manner, front sun gear 516 and rear sun gear 518 are rotationally coupled to input shaft 510 via connecting device 536. Although input shaft coupling member 542 is shown coupled to the axial rear side of rear support member 540, coupling to other locations is contemplated, such as the axial front side of rear support member 540, the axial rear side of front support member 538, or the axial front side of front support member 538.

[0070] Figure 5A The diagram is along the Figure 1 FIG5 is a cross-sectional view taken about the longitudinal centerline axis 12 of the turbine engine 10, with half of the sun gear 502 omitted for simplicity. However, the sun gear 502 extends circumferentially about the longitudinal centerline axis 12, such that the forward sun gear 516, the aft sun gear 518, the forward support member 538, the aft support member 540, and the input shaft coupling member 542 are each annular members. Therefore, although a single fastening device 544 is shown and a single opening in each of the first portions 546, 550 and the input shaft coupling member 542 is described, multiple openings may be provided in a circumferentially spaced manner about the longitudinal centerline axis 12 to secure the sun gear 502 to the input shaft 510.

[0071] Figure 5B A partial cross-sectional view of an exemplary sun gear 502' is shown, which may be used in place of the sun gear 202. Figure 2gearbox assembly 200. Except for the location of the curved link, the sun gear 502' is similar to the sun gear 502 described with respect to Figure 5A Thus, only the features that differ between the sun gear 502 and the sun gear 502' are described. All other features are understood to be the same or substantially the same as described with respect to the sun gear 502.

[0072] The sun gear 502' is a split sun gear 502 having a front sun gear 516' and a rear sun gear 518'. The sun gear 502' is coupled to the input shaft 510' by a connecting device 536'. The connecting device 536' couples the two separate components (e.g., the front sun gear 516' and the rear sun gear 518') together and couples the sun gear 502' to the input shaft 510'. The connecting device 536' includes a front support member 538', a rear support member 540', an input shaft coupling member 542', and a fastening device 544'.

[0073] In Figure 5A , the front sun gear 516 is coupled to the rear sun gear 518 by a link 560 between a rear surface 553 of the first portion 546 and a front surface 555 of the first portion 550. However, in Figure 5B , the rear surface of the first portion 546' simply abuts the front surface of the first portion 550', with no link 560 therebetween. Instead, a link 560' is provided between the rear surface 553' of the first portion 550' and the front surface 555' of the input shaft coupling member 542'. The link 560' can be a curved link such as described with respect to Figure 6 Thus, as previously described, rotation of the input shaft 510' causes rotation of the sun gear 502'.

[0074] Figure 6 A partial view of an exemplary curved link 600 is shown that can be used to couple a first portion 546 of a front support member 538 and a first portion 550 of a rear support member 540 Figure 5A . The first portion 546 and the first portion 550 are simply shown as cylinders in Figure 6 for ease of understanding the curved link 600. However, the first portion 546 and the first portion 550 are arranged as shown and described with respect to Figure 5A Likewise, when the curved link 600 is employed in the sun gear 502' of Figure 5B , Figure 6 the first portion 546 shown in Figure 5B may be the first portion 550' of Figure 6 , and Figure 5B the first portion 550 shown in Figure 5B may be the input shaft coupling member 542' shown in

[0075] Figure 6 The curved connector 600 Figure 5A and Figure 5B The operation is the same as in the embodiment except that the position of the coupling is different. Therefore, the following description is only for simplicity with reference to Figure 5A , but it will be appreciated that a similar arrangement exists between the first portion 550' and the input shaft coupling member 542'. The curvilinear connector 600 includes an axial surface of the first portion 550 (at Figure 5A In the embodiment of the present invention, the axially forward-facing surface) of the first portion 602 and the axial surface of the first portion 546 (at Figure 5A In the embodiment of the present invention, the second portion 604 is provided on the axially rearwardly facing surface). The first portion 602 includes a plurality of first portion protrusions 606 and a plurality of first portion grooves 608, and the second portion 604 includes a plurality of second portion protrusions 610 and a plurality of second portion grooves 612. The plurality of first portion protrusions 606 are received in and engage with the plurality of second portion grooves 612, and the plurality of second portion protrusions 610 are received in and engage with the plurality of first portion grooves 608. Although a plurality of grooves and protrusions are depicted, more or fewer grooves and protrusions than shown may be provided. The curvilinear connector 600 is not limited to Figure 6 Rather, other structures, shapes, and sizes that allow for a rotational coupling between the input shaft 510 and the sun gear 502 are contemplated.

[0076] Figure 7 A partial cross-sectional view of an exemplary sun gear 702 taken along the longitudinal centerline axis 12 is shown, which may be used in place of the sun gear 202. Figure 2 Therefore, only the features that differ between sun gear 202 and sun gear 702 will be described. All other features are understood to be the same or substantially the same as those described with respect to sun gear 202. Sun gear 702 is a split sun gear 702.

[0077] Sun gear 702 includes a front sun gear 716 and a rear sun gear 718. Rear sun gear 718 is integrally and monolithically formed with input shaft 710. Thus, rotation of input shaft 710 causes rear sun gear 718 to rotate. Front sun gear 716 is coupled to rear sun gear 718 via a connecting device 736. Connecting device 736 includes a front support member 738 and a rear support member 740. Front support member 738 and rear support member 740 are coupled together by a fastening device 744. Thus, rotation of rear sun gear 718 (due to rotation of the integrally formed input shaft 710) causes front sun gear 716 to rotate due to connecting device 736.

[0078] Figure 8A partial cross-sectional view of an example sun gear 802 is shown, which can be used in place of the sun gear 202 with the gear box assembly 200 of Figure 2 Thus, only features that are different between the sun gear 202 and the sun gear 802 are described. All other features are understood to be the same or substantially the same as described with respect to the sun gear 202. The sun gear 802 is a split sun gear 802.

[0079] The sun gear 802 includes a front sun gear 816 and a rear sun gear 818. The rear sun gear 818 is integral and unitarily formed with the input shaft 810. A rear support member 840 supports the rear sun gear 818 on the input shaft 810. Thus, rotation of the input shaft 810 causes the rear sun gear 818 to rotate. The input shaft 810 includes an input shaft coupling member 842. The front sun gear 816 is coupled to the input shaft coupling member 842 by a connection 836. The connection 836 includes a male spline 845 on the input shaft coupling member 842 and a female spline 854 on the front sun gear 816, and thus is a fixed spline as in Figure 3B The connection 836 allows for rotational coupling between the input shaft 810 and the front sun gear 816. A front support member 838 supports the front sun gear 816 relative to the female spline 854. A fastening device 844 secures the front sun gear 816 to the input shaft 810.

[0080] Figure 7 and Figure 8 Example sun gears are shown that incorporate various features from other embodiments. For example, Figure 8 The unitary rear sun gear of Figure 7 is combined with the fixed spline of Figure 5B Thus, any portion of the above-described embodiments can be combined with any other portion, so long as the final combination is a split sun gear that rotates with an input shaft.

[0081] Figure 9 A schematic cross-sectional view is shown that illustrates a portion of the installation process for a split sun gear, such as the split sun gears 202, 402, 502, 502', 702, or 802 described herein. During installation of any of the split sun gears described herein, the rear sun gear (e.g., the rear sun gear 218, 418, 518, 518', 718, 818) is moved longitudinally in the axial direction A over the front end 943 of the input shaft 210 (or the input shaft 510, 510', 710, or 810).

[0082] In the example of the sun gear 202, and with reference to Figure 2 and Figure 9 and Figure 10The method 1000 of the present disclosure, in an example of the sun gear 202, the rear sun gear 218 is longitudinally moved over the front end 943 of the input shaft 210 in the axial direction A at step 1002. The input shaft coupling member 242 is longitudinally moved over the front end 943 of the input shaft 210 in the axial direction A to a position adjacent to the rear sun gear 218 at step 1004. After installing the input shaft coupling member 242, the front sun gear 216 is longitudinally moved over the front end 943 of the input shaft 210 in the axial direction A at step 1006. The fastening device 244 can be secured through the respective openings at step 1008. Upon installation of the sun gear 202, the protrusions and the slots of the spline connection are aligned upon installation of the input shaft coupling member 242 to ensure proper operation and proper rotational coupling of the input shaft 210 and the sun gear 202. Figure 9 The longitudinal movement of the components in the axial direction A is shown by the movement of the front sun gear from the position 902a to the position 902b in the example of the sun gear 202. The fastening device 244 can be secured through the respective openings at step 1008. Upon installation of the sun gear 202, the protrusions and the slots of the spline connection are aligned upon installation of the input shaft coupling member 242 to ensure proper operation and proper rotational coupling of the input shaft 210 and the sun gear 202.

[0083] Referring to Figure 4 and Figure 11 The method 1100 of the present disclosure, in an example of the sun gear 402, the input shaft coupling member 442 is part of each of the front sun gear 416 and the rear sun gear 418. Accordingly, the rear sun gear 418 including the rear portion of the input shaft coupling member 442 is longitudinally moved over the input shaft 210 in the axial direction A at step 1102. After installing the rear sun gear 418, the front sun gear 416 is longitudinally moved over the front end 943 of the input shaft 210 in the axial direction A along with the front portion of the input shaft coupling member 442 at step 1104. The fastening device 444 can be installed at the front end 943 of the input shaft 210 to prevent the sun gear 402 from disengaging the longitudinal movement of the input shaft 210 at step 1106. Upon installation of the sun gear 402, the protrusions and the slots of the spline connection are aligned upon installation of each of the rear sun gear 418 and the front sun gear 416 to ensure proper operation and proper rotational coupling of the input shaft 210 and the sun gear 402.

[0084] Referring to Figure 5A and Figure 12the method 1200 of FIG. 12, in the example of the sun gear 502, the input shaft coupling member 542 is either pre-installed on the input shaft 510 prior to the installation of the rear sun gear 518 or optionally integral and unitary with the input shaft 510 such that no installation is required. In either case, at step 1202, the rear sun gear 518 is aligned with the rear end of the input shaft coupling member 542. After the rear sun gear 518 is aligned with the input shaft 510, at step 1204, the front sun gear 516 is moved longitudinally in the axial direction A to align with the rear sun gear 518. During step 1204, the openings of the rear sun gear 518 and the front sun gear 516 are aligned. At step 1206, the fastening devices 544 can then be secured through the respective openings. In installing the sun gear 502, the protrusions and slots of the curvilinear link are aligned in installing the front sun gear 516 to ensure proper operation and proper rotational coupling of the input shaft 510 and the sun gear 502. Referring to Figure 5B In installing the sun gear 502', the only difference is that the protrusions and slots of the curvilinear link are aligned in installing the rear sun gear 518' to ensure proper operation and proper rotational coupling of the input shaft 510' and the sun gear 502'.

[0085] Referring to Figure 7 and Figure 13 the method 1300 of FIG. 13, in the example of the sun gear 702, the rear sun gear 718 is integral with the input shaft 710. Thus, to install the sun gear 702, at step 1302, the front sun gear 716 is moved longitudinally in the axial direction A to mate the front support member 738 with the rear support member 740. At step 1304, the fastening devices 744 can then be secured through the respective openings.

[0086] Referring to Figure 8 In the example of the sun gear 802, the rear sun gear 818 is integral with the input shaft 810. Thus, to install the sun gear 802, Figure 13 the method 1300 of FIG. 13 applies. In the example of the sun gear 802, the front sun gear 816 is moved longitudinally in the axial direction A over the input shaft 810. The fastening devices 844 can then be secured through the respective openings. In installing the sun gear 802, the protrusions and slots of the spline link are aligned in installing the front sun gear 816 to ensure proper operation and proper rotational coupling of the input shaft 810 and the sun gear 802.

[0087] Figure 14 A partial cross-sectional view of a sun gear 1402 is shown, which can replace the sun gear 202 with Figure 2The sun gear 1402 is used with a gear box assembly 200 that is similar to the gear box assembly 200. Thus, only the features that are different between the sun gear 202 and the sun gear 1402 are described. All other features are understood to be the same or substantially the same as described with respect to the sun gear 202. The sun gear 1402 is coupled to an input shaft 1410 that has a flexible coupling 1413. The flexible coupling 1413 has stiffnesses (e.g., axial stiffness, lateral stiffness, bending stiffness, and torsional stiffness) and damping coefficients (e.g., longitudinal damping, lateral damping, bending damping, and torsional damping) that help reduce or prevent vibrations from propagating between the gear box assembly 200 and the input shaft 1410.

[0088] The sun gear 1402 is a split sun gear 1402. The sun gear 1402 includes a front sun gear 1416 and a rear sun gear 1418. Sun gear teeth are not shown in the view. The input shaft 1410 includes an input shaft coupling member 1442. The front sun gear 1416 includes a flexible sun gear portion 1417. In this way, the flexible sun gear portion 1417 functions similarly to the flexible coupling 1413. The front sun gear 1416 is coupled to the input shaft coupling member 1442 at the flexible sun gear portion 1417 by a front connection 1436a. The front connection 1436a includes a front male spline 1445a on the input shaft coupling member 1442 and a front female spline 1454a on the flexible sun gear portion 1417 of the front sun gear 1416, and thus is a fixed spline as in Figure 14 The front connection 1436a allows rotational coupling between the input shaft 1410 and the front sun gear 1416. A front support member 1438 supports the front sun gear 1416 relative to the front female spline 1454a. A front fastening device 1444a fixes the front sun gear 1416 to the input shaft 1410. Figure 3B

[0089] The rear sun gear 1418 is coupled to the front sun gear 1416 by a rear connection 1436b. The rear connection 1436b includes a rear male spline 1445b on the front sun gear 1416 and a rear female spline 1454b on the rear sun gear 1418, and thus is a fixed spline as in Figure 3B The rear connection 1436b allows rotational coupling between the front sun gear 1416 and the rear sun gear 1418. A rear support member 1440 supports the rear sun gear 1418 relative to the rear female spline 1454b. A rear fastening device 1444b fixes the rear sun gear 1418 to the front sun gear 1416.

[0090] Figure 14 The illustration of the gear box assembly 200 is along a longitudinal direction L of the gear box assembly 200. Figure 1 ​a cross-sectional view taken along a longitudinal centerline axis 12 of the turbine engine 10, with half of the sun gear 1402 omitted for simplicity. However, the sun gear 1402 extends circumferentially about the longitudinal centerline axis 12 such that the front sun gear 1416, the rear sun gear 1418, the front support member 1438, the rear support member 1440, and the input shaft coupling member 1442 are each annular members.

[0091] Further aspects are provided by the subject matter of the following clauses.

[0092] A turbine engine comprising a turbocharger engine coupled to an input shaft, a fan coupled to an output shaft, and a gearbox assembly through which torque can be transmitted from the input shaft to the output shaft. The gearbox assembly comprises a split sun gear rotatably coupled to the input shaft, a plurality of planet gears radially outward of and intermeshed with the split sun gear, and a single-piece ring gear radially outward of and intermeshed with the plurality of planet gears. The split sun gear has a front sun gear and a rear sun gear separate from the front sun gear, wherein the front sun gear and the rear sun gear are each rotatably coupled to the input shaft.

[0093] The turbine engine according to any preceding clause, wherein the split sun gear is a double helical gear.

[0094] The turbine engine according to any preceding clause, wherein the gearbox assembly further comprises a connection arrangement for rotatably coupling the split sun gear to the input shaft.

[0095] The turbine engine according to any preceding clause, wherein the connection arrangement comprises a front support member, a rear support member, and an input shaft coupling member.

[0096] The turbine engine according to any preceding clause, wherein the front support member extends between the input shaft and the front sun gear, the rear support member extends between the input shaft and the rear sun gear, and the input shaft coupling member rotatably couples the front sun gear and the rear sun gear to the input shaft.

[0097] The turbine engine according to any preceding clause, wherein the input shaft coupling member is rotatably coupled to the input shaft by a spline connection.

[0098] The turbine engine according to any preceding clause, wherein a first portion of the input shaft coupling member extends from the front support member and a second portion of the input shaft coupling member extends from the rear support member.

[0099] The turbine engine according to any preceding clause, wherein the first portion and the second portion extend axially and parallel to a longitudinal centerline axis of the input shaft.

[0100] The turbine engine according to any preceding clause, wherein the first portion is integral with the forward support member and the second portion is integral with the aft support member.

[0101] The turbine engine according to any preceding clause, further comprising a fastening device coupled to a forward side of the forward sun gear to secure the split sun gear on the input shaft in an axial direction.

[0102] The turbine engine according to any preceding clause, wherein the first portion and the second portion each comprise a spline connection with the input shaft.

[0103] The turbine engine according to any preceding clause, wherein the forward support member is rotationally coupled to the aft support member by a curvilinear connection.

[0104] The turbine engine according to any preceding clause, wherein an axially forward facing surface of the input shaft coupling member comprises a first portion of the curvilinear connection and an axially aft facing surface of the aft support member comprises a second portion of the curvilinear connection, the first portion of the curvilinear connection and the second portion of the curvilinear connection cooperating to form a rotational coupling between the input shaft coupling member and the aft support member such that rotation of the input shaft results in rotation of the input shaft coupling member and, in turn, rotation of the split sun gear.

[0105] The turbine engine according to any preceding clause, wherein the aft support member is rotationally coupled to the input shaft coupling member by a curvilinear connection.

[0106] The turbine engine according to any preceding clause, wherein the curvilinear connection comprises a plurality of protrusions and a plurality of slots on the axially forward facing surface of the input shaft coupling member that cooperate with a corresponding plurality of slots and a plurality of protrusions on the axially aft facing surface of the aft support member.

[0107] The turbine engine according to any preceding clause, wherein each of the forward support member, the aft support member, and the input shaft coupling member comprises a first portion and a second portion.

[0108] The turbine engine according to any preceding clause, further comprising a fastening device extending through the first portion of each of the forward support member, the aft support member, and the input shaft coupling member to secure the forward sun gear and the aft sun gear in an axial direction relative to the input shaft.

[0109] The turbine engine according to any preceding clause, wherein the first portion of the forward support member extends in a radial direction, and the second portion of the forward support member extends at an angle between the first portion of the forward support member and the forward sun gear, the first portion of the aft support member extends in the radial direction, and the second portion of the aft support member extends at an angle between the first portion of the aft support member and the aft sun gear, and the first portion of the input shaft coupling member extends in the radial direction, and the second portion of the input shaft coupling member extends in an axial direction parallel to a longitudinal centerline axis of the turbine engine.

[0110] The turbine engine according to any preceding clause, wherein the first portion of each of the forward support member, the aft support member, and the input shaft coupling member extends parallel to one another.

[0111] The turbine engine according to any preceding clause, wherein a radially inner surface of the second portion of the input shaft coupling member comprises a first portion of a spline connection, and a radially outer surface of the input shaft comprises a second portion of the spline connection, the first portion of the spline connection and the second portion of the spline connection cooperating to form a rotational coupling between the input shaft and the input shaft coupling member such that rotation of the input shaft causes rotation of the input shaft coupling member, and thus rotation of the split sun gear.

[0112] The turbine engine according to any preceding clause, wherein the spline connection comprises a plurality of protrusions and a plurality of slots on the radially inner surface of the second portion of the input shaft coupling member that cooperate with a corresponding plurality of slots and a plurality of protrusions on the radially outer surface of the input shaft.

[0113] The turbine engine according to any preceding clause, wherein the gear box assembly comprises a planet carrier for constraining the plurality of planetary gears, the planet carrier being coupled to the output shaft.

[0114] The turbine engine according to any preceding clause, further comprising a low pressure shaft coupled to the output shaft and the fan via the gear box assembly, wherein the low pressure shaft is drivingly coupled to the input shaft such that rotation of the low pressure shaft rotates the input shaft.

[0115] The turbine engine according to any preceding clause, further comprising a fastening device extending through each of the forward support member, the rear support member, and the input shaft coupling member to secure the forward sun gear and the rear sun gear in the axial direction.

[0116] The turbine engine according to any preceding clause, wherein the spline connection is a fixed spline.

[0117] The turbine engine according to any preceding clause, wherein the spline connection is a working spline.

[0118] The turbine engine according to any preceding clause, wherein the forward sun gear comprises a flexible sun gear portion.

[0119] The turbine engine according to any preceding clause, wherein the forward sun gear is coupled to the shaft coupling member at the flexible sun gear portion by a forward connection device.

[0120] The turbine engine according to any preceding clause, wherein the forward connection device comprises a forward male spline on the shaft coupling member and a forward female spline on the flexible sun gear portion.

[0121] The turbine engine according to any preceding clause, wherein the rear sun gear is coupled to the forward sun gear by a rear connection device.

[0122] The turbine engine according to any preceding clause, wherein the rear connection device comprises a rear male spline on the forward sun gear and a rear female spline on the rear sun gear.

[0123] A gear box assembly comprising a split sun gear, a single piece ring gear, and a plurality of planet gears. The split sun gear has a forward sun gear and a rear sun gear separate from the forward sun gear, wherein the forward sun gear and the rear sun gear are each rotationally coupled to the input shaft.

[0124] The gear box assembly according to the preceding clause, wherein the split sun gear is rotationally coupled to a shaft of a turbine engine, the plurality of planet gears are radially outward of and intermeshed with the split sun gear, and the single piece ring gear is radially outward of and intermeshed with the plurality of planet gears.

[0125] The gearbox assembly according to any preceding clause, wherein the split sun gear is a double bevel gear.

[0126] The gearbox assembly according to any preceding clause, further comprising a connection device for rotationally coupling the split sun gear to the shaft.

[0127] The gearbox assembly according to any preceding clause, the connection device comprising a front support member, a rear support member, and an input shaft coupling member.

[0128] The gearbox assembly according to any preceding clause, wherein the front support member extends between the shaft and the front sun gear, the rear support member extends between the shaft and the rear sun gear, and the input shaft coupling member rotationally couples the front sun gear and the rear sun gear to the shaft.

[0129] The gearbox assembly according to any preceding clause, wherein the input shaft coupling member is rotationally coupled to the shaft by a spline connection.

[0130] The gearbox assembly according to any preceding clause, wherein a first portion of the input shaft coupling member extends from the front support member and a second portion of the input shaft coupling member extends from the rear support member.

[0131] The gearbox assembly according to any preceding clause, wherein the first portion and the second portion extend axially and parallel to a longitudinal centerline axis of the input shaft.

[0132] The gearbox assembly according to any preceding clause, wherein the first portion is integral with the front support member and the second portion is integral with the rear support member.

[0133] The gearbox assembly according to any preceding clause, further comprising a fastening device coupled to a front side of the front sun gear to secure the split sun gear on the input shaft in an axial direction.

[0134] The turbine engine according to any preceding clause, wherein the first portion and the second portion each comprise a spline connection with the input shaft.

[0135] The gearbox assembly according to any preceding clause, wherein the front support member is rotationally coupled to the rear support member by a curved connection.

[0136] The gearbox assembly according to any preceding clause, wherein the axially forward facing surface of the input shaft coupling member comprises a first portion of the curved link and the axially rearward facing surface of the rear support member comprises a second portion of the curved link, the first portion of the curved link and the second portion of the curved link cooperating to form a rotational coupling between the input shaft coupling member and the rear support member such that rotation of the input shaft causes rotation of the input shaft coupling member and, in turn, rotation of the split sun gear.

[0137] The gearbox assembly according to any preceding clause, wherein the rear support member is rotationally coupled to the input shaft coupling member by a curved link.

[0138] The gearbox assembly according to any preceding clause, wherein the curved link comprises a plurality of protrusions and a plurality of slots on the axially forward facing surface of the input shaft coupling member that cooperate with a corresponding plurality of slots and a plurality of protrusions on the axially rearward facing surface of the rear support member.

[0139] The gearbox assembly according to any preceding clause, wherein each of the front support member, the rear support member, and the input shaft coupling member comprises a first portion and a second portion.

[0140] The gearbox assembly according to any preceding clause, further comprising a fastening device extending through the first portion of each of the front support member, the rear support member, and the input shaft coupling member to secure the front sun gear and the rear sun gear in an axial direction relative to the input shaft.

[0141] The gearbox assembly according to any preceding clause, wherein the first portion of the front support member extends in a radial direction and the second portion of the front support member extends at an angle between the first portion of the front support member and the front sun gear, the first portion of the rear support member extends in the radial direction and the second portion of the rear support member extends at an angle between the first portion of the rear support member and the rear sun gear, and the first portion of the input shaft coupling member extends in the radial direction and the second portion of the input shaft coupling member extends in an axial direction parallel to a longitudinal centerline axis of the turbine engine.

[0142] The gearbox assembly according to any preceding clause, wherein the first portion of each of the front support member, the rear support member, and the input shaft coupling member extends parallel to one another.

[0143] The gearbox assembly of any preceding clause, wherein a radially inner surface of the second portion of the input shaft coupling member comprises a first portion of a spline connection and a radially outer surface of the input shaft comprises a second portion of the spline connection, the first portion of the spline connection and the second portion of the spline connection cooperating to form a rotational coupling between the input shaft and the input shaft coupling member such that rotation of the input shaft causes rotation of the input shaft coupling member and, in turn, rotation of the split sun gear.

[0144] The gearbox assembly of any preceding clause, wherein the spline connection comprises a plurality of protrusions and a plurality of slots on the radially inner surface of the second portion of the input shaft coupling member that cooperate with a corresponding plurality of slots and a plurality of protrusions on the radially outer surface of the input shaft.

[0145] The gearbox assembly of any preceding clause, wherein the gearbox assembly comprises a planet carrier for constraining the plurality of planetary gears, the planet carrier being coupled to the output shaft.

[0146] The gearbox assembly of any preceding clause, the turbine engine further comprising a low pressure shaft coupled to the output shaft and the fan via the gearbox assembly, wherein the low pressure shaft is drivingly coupled to the input shaft such that rotation of the low pressure shaft causes rotation of the input shaft.

[0147] The gearbox assembly of any preceding clause, further comprising a fastening device extending through each of the front support member, the rear support member, and the input shaft coupling member to secure the front sun gear and the rear sun gear in the axial direction.

[0148] The gearbox assembly of any preceding clause, wherein the spline connection is a fixed spline.

[0149] The gearbox assembly of any preceding clause, wherein the spline connection is a working spline.

[0150] The gearbox assembly of any preceding clause, wherein the front sun gear comprises a flexible sun gear portion.

[0151] The gearbox assembly of any preceding clause, wherein the front sun gear is coupled to the shaft coupling member at the flexible sun gear portion by a front connection device.

[0152] The gearbox assembly of any preceding clause, wherein the front connection device comprises a front male spline on the shaft coupling member and a front female spline on the flexible sun gear portion.

[0153] The gearbox assembly according to any preceding clause, wherein the rear sun gear is coupled to the front sun gear by a rear connection.

[0154] The gearbox assembly according to any preceding clause, wherein the rear connection comprises a rear male spline on the front sun gear and a rear female spline on the rear sun gear.

[0155] A turbine engine comprising the gearbox assembly according to any preceding clause.

[0156] A method of operating the gearbox assembly according to any preceding clause.

[0157] A method of operating the turbine engine according to any preceding clause.

[0158] A method of installing a split sun gear comprising installing a rear sun gear on an input shaft, installing an input shaft coupling member on the input shaft, installing a front sun gear on the input shaft, and fastening the front sun gear to the rear sun gear.

[0159] A method of installing a split sun gear comprising installing a rear sun gear on an input shaft, installing a front sun gear on the input shaft, and fastening the front sun gear to the rear sun gear.

[0160] The method according to the preceding clause, wherein the rear sun gear and the front sun gear are each integral with an input shaft coupling member.

[0161] The method according to any preceding clause, wherein the rear sun gear is installed longitudinally above the input shaft.

[0162] The method according to any preceding clause, wherein the rear sun gear is aligned with a front face of the input shaft.

[0163] A method of installing a split sun gear comprising installing a front sun gear on an input shaft, and fastening the front sun gear to a rear sun gear that is integral with the input shaft.

[0164] While the foregoing description has been directed to the preferred embodiments of the present disclosure, other variations and modifications will be apparent to those skilled in the art and can be made without departing from the disclosure. Furthermore, features described in conjunction with one embodiment can be used in conjunction with other embodiments, even if not explicitly stated above.

Claims

1. A turbine engine, characterized in that: include: a turbocharged engine coupled to the input shaft; a fan coupled to the output shaft; as well as A gearbox assembly, wherein torque is transferable from the input shaft to the output shaft through the gearbox assembly, the gearbox assembly comprising: a split sun gear rotationally coupled to the input shaft, the split sun gear comprising a front sun gear and a rear sun gear separate from the front sun gear, wherein the front sun gear and the rear sun gear are each rotationally coupled to the input shaft; a plurality of planetary gears, the plurality of planetary gears being located radially outward of the split sun gear and meshing with the split sun gear; as well as A single-piece ring gear is located radially outside the plurality of planetary gears and meshes with the plurality of planetary gears.

2. The turbine engine according to claim 1, characterized in that in, The split sun gear is a double helical gear.

3. The turbine engine according to claim 1, characterized in that The gearbox assembly further includes a connection device for rotationally coupling the split sun gear to the input shaft.

4. The turbine engine according to claim 3, characterized in that The connecting device includes a front support member, a rear support member and an input shaft coupling member.

5. The turbine engine according to claim 4, characterized in that in, The rear support member is rotationally coupled to the input shaft coupling member via a curvilinear connection.

6. The turbine engine according to claim 4, characterized in that in, The input shaft coupling member is rotationally coupled to the input shaft through a spline connection.

7. The turbine engine according to claim 4, characterized in that in, The front support member extends between the input shaft and the front sun gear, the rear support member extends between the input shaft and the rear sun gear, and the input shaft coupling member rotationally couples the front sun gear and the rear sun gear to the input shaft.

8. The turbine engine according to claim 4, characterized in that in, The front support member is rotationally coupled to the rear support member via a curvilinear connection.

9. The turbine engine according to claim 8, characterized in that in, The axially forward-facing surface of the input shaft coupling member includes a first portion of the curvilinear connector, and the axially rearward-facing surface of the rear support member includes a second portion of the curvilinear connector, the first portion of the curvilinear connector and the second portion of the curvilinear connector cooperating to form a rotational connection between the input shaft coupling member and the rear support member, so that rotation of the input shaft causes rotation of the input shaft coupling member and thereby causes rotation of the split sun gear.

10. The turbine engine according to claim 4, characterized in that in, A first portion of the input shaft coupling member extends from the front support member, and a second portion of the input shaft coupling member extends from the rear support member.

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