Gearbox assembly

Abstract

A gear box assembly for a gas turbine engine includes a hollow gear. The hollow gear has one or more reservoirs configured to store lubricant and one or more channels configured to supply lubricant to one or more gear meshing locations in the gear box assembly. The hollow gear provides a dampening system configured to absorb vibrations and loads experienced in the gear box assembly and configured to provide impact resistance to the gear box assembly.

Description

Technical Field

[0001] This disclosure relates to a gearbox assembly. Background Technology

[0002] A gas turbine engine includes a fan driven by a turbine. A gearbox assembly connects the fan and the turbine. The gearbox assembly provides speed reduction between the turbine and the fan. Lubrication is supplied to the meshing of the gears between the relatively rotating gears of the gearbox assembly. Attached Figure Description

[0003] The features and advantages of this disclosure will be apparent from the following description of various exemplary embodiments, as shown in the accompanying drawings, wherein similar reference numerals generally denote the same, functionally similar and / or structurally similar elements.

[0004] Figure 1 A schematic cross-sectional view of a gas turbine engine taken along its centerline according to an embodiment of the present disclosure is shown.

[0005] Figure 2 An embodiment according to this disclosure is shown. Figure 1 A partial schematic cross-sectional view of a gas turbine engine.

[0006] Figure 3 A schematic cross-sectional end view of a gearbox assembly for a gas turbine engine according to an embodiment of the present disclosure is shown.

[0007] Figure 4 A schematic side view of a gearbox assembly for a gas turbine engine according to an embodiment of the present disclosure is shown.

[0008] Figure 5 A schematic side view of a gearbox assembly for a gas turbine engine according to an embodiment of the present disclosure is shown.

[0009] Figure 6 A schematic side view of a gearbox assembly for a gas turbine engine according to an embodiment of the present disclosure is shown.

[0010] Figure 7 A schematic end view of a hollow gear in a gearbox assembly for a gas turbine engine according to an embodiment of the present disclosure is shown.

[0011] Figure 8A An enlarged cross-sectional end view of a portion of a hollow gear according to an embodiment of the present disclosure is shown.

[0012] Figure 8B An enlarged cross-sectional end view of a portion of a hollow gear according to an embodiment of the present disclosure is shown.

[0013] Figure 8C An enlarged cross-sectional end view of a portion of a hollow gear according to an embodiment of the present disclosure is shown.

[0014] Figure 8D An enlarged cross-sectional end view of a portion of a hollow gear according to an embodiment of the present disclosure is shown.

[0015] Figure 8E An enlarged cross-sectional end view of a portion of a hollow gear according to an embodiment of the present disclosure is shown.

[0016] Figure 8F An enlarged cross-sectional end view of a portion of a hollow gear according to an embodiment of the present disclosure is shown.

[0017] Figure 9 A partial cross-sectional end view of a portion of a hollow gear according to an embodiment of the present disclosure is shown. Detailed Implementation

[0018] The features, advantages, and embodiments of this disclosure will be set forth or become apparent from consideration of the following detailed description, drawings, and claims. Furthermore, it should be understood that the following detailed description is exemplary and intended to provide further explanation, and does not limit the scope of the claimed disclosure.

[0019] Various embodiments are discussed in detail below. Although specific embodiments are discussed, this is for illustrative purposes only. Those skilled in the art will recognize that other components and configurations can be used without departing from the spirit and scope of this disclosure.

[0020] The gearbox assembly disclosed herein is provided with a hollow gear. The hollow gear may be a gear with an internal reservoir and flexible interconnecting members or supports. The hollow gear may be formed by electroforming or hydroforming techniques. The internal reservoir serves to provide a lubrication cavity, enabling gear compliance and / or flexibility, and providing a lightweight gearbox. The hollow gear of this disclosure may provide emergency lubrication at one or more gear meshing points of the gearbox assembly, may be lightweight, may provide damping for the gearbox assembly, and may accommodate misalignment between gears.

[0021] Figure 1 A schematic cross-sectional view of a gas turbine engine 10 taken along its central axis A, which serves as the main axis of rotation, is shown. The gas turbine engine 10 includes an air inlet 12 and a fan 14 that generates two airflows: a core airflow F... A and bypass airflow F B The gas turbine engine 10 includes a core airflow receiver F. AThe engine core 16 includes a housing 17 that surrounds, in an axial flow sequence, a low-pressure compressor 18, a high-pressure compressor 20, a combustion section 22, a high-pressure turbine 24, a low-pressure turbine 26, and a core exhaust nozzle 28. A nacelle 30 surrounds the gas turbine engine 10. The nacelle 30 defines a bypass duct 32 and a bypass exhaust nozzle 34. The bypass airflow F... B The flow passes through bypass duct 32. Fan 14 is attached to low-pressure turbine 26 and is driven by low-pressure turbine 26 via low-pressure shaft 36 and gearbox assembly 38.

[0022] In use, the core airflow F A The air is accelerated and compressed by the low-pressure compressor 18 and directed to the high-pressure compressor 20, where it is further compressed. The compressed air exiting the high-pressure compressor 20 is directed to the combustion section 22, where it mixes with the fuel and the mixture is burned. The resulting hot combustion products then expand through the high-pressure turbine 24 and the low-pressure turbine 26 before being discharged through the core exhaust nozzle 28, thereby driving the high-pressure turbine 24 and the low-pressure turbine 26. This provides propulsive thrust. The high-pressure turbine 24 drives the high-pressure compressor 20 via the high-pressure shaft 39. The fan 14 typically provides most of the propulsive thrust. The gearbox assembly 38 is a reduction gearbox.

[0023] Figure 2 It shows Figure 1 An enlarged schematic side view of the gas turbine engine 10, showing details of the gearbox assembly 38. Figure 3 A schematic axial end cross-sectional view of gearbox assembly 38 is shown. Gearbox assembly 38 includes a sun gear 40, a plurality of planetary gears 42, and a ring gear 44. Low-pressure turbine 26 ( Figure 1 A low-pressure shaft 36 drives the gearbox assembly 38, which is connected to the sun gear 40. Radially outside and meshing with the sun gear 40 are a plurality of planetary gears 42, which are connected together by a planet carrier 46. The planet carrier 46 constrains the plurality of planetary gears 42 to rotate synchronously around the sun gear 40, while allowing each of the plurality of planetary gears 42 to rotate about its own axis. The planet carrier 46 is connected to the fan 14 via a fan rotor link 48 to drive the fan 14 to rotate about axis A and within the nacelle 30. Radially outside and meshing with the plurality of planetary gears 42 is a ring gear 44, which is an annular ring gear. The ring gear 44 is connected to a stationary support structure 50 via a link 49. The stationary support structure 50 connects the gearbox assembly 38 to the housing 17.

[0024] Although Figure 2 Not described in the text and for clarity in Figure 3It is only partially depicted, but each of the sun gear 40, the plurality of planetary gears 42 and the ring gear 44 includes teeth around their periphery for meshing with other gears. Figure 2 and 3 The gearbox assembly 38 is illustrated as a planetary gearbox, wherein the planet carrier 46 is connected to the output shaft via a fan rotor connecting rod 48, while the ring gear 44 is fixed. However, other suitable types of gearbox assemblies 38 may be used. In one non-limiting example, the gearbox assembly 38 may be a star arrangement, wherein the planet carrier 46 remains fixed, while the ring gear 44 is allowed to rotate. In this arrangement, the fan 14 is driven by the ring gear 44. In another non-limiting example, the gearbox assembly 38 may be a differential gearbox, wherein both the ring gear 44 and the planet carrier 46 are allowed to rotate.

[0025] Figure 4 A schematic cross-sectional view of an exemplary gearbox assembly 100 is shown. The gearbox assembly 100 can be used as... Figures 1 to 3 The gearbox assembly 38. That is, the gearbox assembly 100 can connect the low-pressure shaft 36 to the fan 14 ( Figure 1 The gearbox assembly 100 includes a sun gear 140 and a plurality of planetary gears 142 (in...). Figure 4 Only one gear is visible in the image (and a ring gear 144). A housing 164 may surround the gearbox assembly 100. For clarity, only a portion of the gear is shown. However, the gear configuration can vary with other gears. Figure 3 The gearbox assembly 100 is similar to or the same as described. It is a fixed ring gear type (e.g., the ring gear 144 is stationary and fixed, while the planet carrier 146 and the plurality of planet gears 142 are rotating). The planet carrier 146 constrains the plurality of planet gears 142 to rotate synchronously about the sun gear 140, while causing each of the plurality of planet gears 142 to rotate about its own axis A. P Rotation. The planetary carrier 146 is connected to the fan 14 (via rotor connecting rod 148). Figure 2 ) and rotate together with multiple planetary gears 142 to drive fan 14 ( Figure 2 The planetary gears 142 rotate about axis A. A ring gear 144 is located radially outside and meshes with the planetary gears 142. The ring gear 144 is connected to the stationary support structure 50 via a connecting rod 149. Figure 2 ).exist Figure 4 In the example, the ring gear 144 is stationary and fixed to the connecting rod 149. Each of the plurality of planetary gears 142 includes a pin 150, about which the corresponding planetary gear rotates.

[0026] The ring gear 144 of the gearbox assembly 100 includes a cavity or reservoir 152, such that the ring gear 144 is a hollow ring gear 144. The reservoir 152 may have one or more openings or channels 154 that allow fluid to enter the reservoir 152. The reservoir 152 may have: one or more openings or channels 156 that allow fluid to exit the reservoir 152 in an axial direction; and one or more openings or channels 162 that allow fluid to exit the reservoir 152 in a radial direction. The fluid may be a lubricant, such as, but not limited to, oil and / or grease. Although depicted as separate components, pipes, or channels, channels 154, 156, and / or 162 may take other forms, such as integrally formed channels or openings, as will be described herein.

[0027] Lubricant from reservoir 152 can be supplied to one or more gears, such as to sun gear 140, to one or more planetary gears 142, to ring gear 144, or any combination thereof, via one or more channels 156 and / or one or more channels 162. For example, lubricant can drip from reservoir 152 onto the gear teeth of the planetary gears 142 via one or more channels 156 and / or one or more channels 162. This lubricates the gear meshing 160 between the planetary gears 142 and the ring gear 144, and further lubricates the gear meshing 158 between the planetary gears 142 and the sun gear 140. In some examples, lubricant can be supplied to the gear meshing between the planetary gears 142 and the ring gear 144 via channel 162. In some examples, channel 162 and / or one or more channels 156 may be omitted.

[0028] During operation of the gearbox assembly 100, lubricant is supplied to the gears from a radially outer position toward a radially inward position. That is, lubricant can be supplied through the hollow ring gear 144 (e.g., radially outer position) and dripped onto the plurality of planetary gears 142 to lubricate them, which in turn lubricates gear meshing points 158 and 160 (e.g., radially inward positions). A continuous supply of lubricant can be provided through the gearbox assembly 100 to gear meshing points 158 and 160. This provides continuous lubrication to gear meshing points 158 and 160. Furthermore, the fluid in the reservoir 152 can provide suppression of vibrations within the gearbox assembly 100. The fluid in the reservoir 152 can suppress the rotation of the plurality of planetary gears 142 relative to the ring gear 144.

[0029] Therefore, the fluid or lubricant within the reservoir 152 of the hollow ring gear 144 provides a damping system that absorbs vibrations and loads experienced in the gearbox assembly 100 and provides shock resistance due to the loads on the gears of the gearbox assembly 100. (See also: ...) Figures 7 to 9 The structure of the ring gear 144 discussed also provides impact resistance and shock absorption for the loads experienced on the ring gear 144. Furthermore, the fluid or lubricant within the reservoir 152 can serve to cool the ring gear 144. That is, the rotation of the gears relative to each other and relative to other rotating parts causes the gears to heat up. The lubricant or fluid within the reservoir 152 can absorb the heat from the gears (e.g., act as a radiator), thereby cooling the ring gear 144.

[0030] Figure 5 A schematic cross-sectional view of an exemplary gearbox assembly 200 is shown. The gearbox assembly 200 can be used as... Figures 1 to 3 The gearbox assembly 38. That is, the gearbox assembly 200 can connect the low-pressure shaft 36 to the fan 14 ( Figure 1 The gearbox assembly 200 includes a sun gear 240 and multiple planetary gears 242 (in...). Figure 5 Only one is visible in the image (and a ring gear 244). For clarity, only a portion of the gear is shown. However, the gear's structure can be related to... Figure 3 The gearbox assembly 200 is similar to or the same as described. It is a star-shaped or rotating ring gear type gearbox assembly (e.g., the ring gear 244 is rotating, and the planet carrier 246 is fixed and stationary). The planet carrier 246 constrains a plurality of planet gears 242 such that the plurality of planet gears 242 do not rotate together about the sun gear 240, while allowing each of the plurality of planet gears 242 to rotate about its own axis A. P Rotation. The ring gear 244 is connected to the fan 14 via the rotor connecting rod 248. Figure 2 ) and rotate to drive fan 14 ( Figure 2 The ring gear 244 rotates about axis A. A plurality of planetary gears 242 mesh with and are located radially inside the ring gear 244. Each of the planetary gears 242 includes a pin 250, and the corresponding planetary gear rotates about the pin 250.

[0031] The sun gear 240 of the gearbox assembly 200 includes a cavity or reservoir 252, such that the sun gear 240 is a hollow sun gear 240. The reservoir 252 may have one or more channels or openings (not shown) allowing fluid to enter the reservoir 252, and these channels or openings may be connected to... Figure 4The one or more channels 154 are similar or identical. The reservoir 252 may have: one or more openings or channels 256 that allow fluid to exit the reservoir 252 in an axial direction; and / or one or more openings or channels 262 that allow fluid to exit the reservoir 252 in a radial direction. The fluid may be a lubricant, such as, but not limited to, oil and / or grease. Although depicted as separate components, pipes, or channels, the inlet opening (not shown), channel 256, and / or channel 262 may take other forms, such as integrally formed channels or openings, as will be described herein.

[0032] Lubricant from reservoir 252 can be supplied to one or more gears via one or more channels 256 and / or one or more channels 262, for example, to the sun gear 240, to one or more of the planetary gears 242, to the ring gear 244, or any combination thereof. For example, lubricant can drip from reservoir 252 onto the gear teeth of the planetary gears 242 and the sun gear 240. This lubricates the gear meshing point 258 between the planetary gears 242 and the sun gear 240. The gear meshing point 258 can be the space between the gear teeth of the sun gear 240 and the planetary gears 242. Figure 5 The diagram shows two exemplary gear teeth and the space between them (e.g., the space into which channel 262 enters). Lubrication of gear mesh 258 further lubricates gear mesh 260 between the plurality of planetary gears 142 and the ring gear 244. That is, the plurality of planetary gears 242 can transfer (e.g., due to the rotation of the planetary gears) lubricant to gear mesh 260 between the plurality of planetary gears 242 and the ring gear 244. In some examples, channel 262 and / or one or more channels 256 may be omitted.

[0033] In some examples, one or more channels 256 may be used to supply lubricant to and / or fill the reservoir 252 with lubricant. In these examples, once the lubricant has been filled into the reservoir 252, one or more channels 256 may be sealed to prevent lubricant loss from the reservoir 252. The seal may be selectively opened and closed, allowing one or more channels 256 to be filled multiple times.

[0034] Lubricant can be supplied to the pins 250 of each of the plurality of planetary gears 242 through channel 264. The channel may extend radially or axially, or may include both radial and axial channels. In some examples, channel 264 may be omitted. Although regarding... Figure 4 Gear assembly 100 and / or Figure 6 The gear assembly 300 is not shown or described, but may include a similar channel leading to the pin.

[0035] During operation of the gearbox assembly 200, lubricant is supplied to the gears from a radially inward position toward a radially outward position. That is, lubricant can be supplied through the hollow sun gear 240 (e.g., radially inward position) and dripped onto the plurality of planetary gears 242 to lubricate them, which in turn lubricates gear engagement points 258 and 260 (e.g., radially outward positions). A continuous supply of lubricant can be provided to gear engagement points 258 and 260 through the gearbox assembly 200. This provides continuous lubrication to gear engagement points 258 and 260. Furthermore, the fluid in the reservoir 252 can provide shock-absorbing resistance within the gearbox assembly 200. The fluid in the reservoir 252 can suppress the shocks caused by the rotation of the plurality of planetary gears 242 and the ring gear 244.

[0036] Therefore, the fluid or lubricant within the reservoir 252 of the hollow sun gear 240 provides a damping system that absorbs vibrations and loads experienced in the gearbox assembly 200 and provides shock resistance due to the loads on the gears of the gearbox assembly 200. (See also:) Figures 7 to 9 The structure of the sun gear 240 discussed provides shock resistance and shock absorption for the loads experienced on the sun gear 240. Furthermore, the fluid or lubricant within the reservoir 252 serves to cool the sun gear 240. That is, the rotation of the gears relative to each other and relative to other rotating parts causes the gears to heat up. The lubricant or fluid within the reservoir 252 absorbs the heat from the gears (e.g., acting as a radiator), thereby cooling the sun gear 240.

[0037] In some examples, reservoir 252 may be a backup reservoir, allowing channels 256 and / or 262 to be selectively opened based on predetermined conditions. When channels 256 and / or 262 are open, lubricant can be supplied to gear engagement 258, and subsequently to gear engagement 260. Predetermined conditions may include engine operating conditions, temperature, load, etc. In examples where channels 256 and / or 262 are selectively opened and closed based on predetermined conditions, lubricant can be continuously supplied only when channels 256 and / or 262 are open.

[0038] Figure 6 A schematic cross-sectional view of an exemplary gearbox assembly 300 is shown. The gearbox assembly 300 can be used as... Figures 1 to 3 The gearbox assembly 38. That is, the gearbox assembly 300 can connect the low-pressure shaft 36 to the fan 14 ( Figure 1 The gearbox assembly 300 includes a sun gear 340 and multiple planetary gears 342 (in...). Figure 6Only one is visible in the image (and a ring gear 344). For clarity, only a portion of the gear is shown. However, the gear's structure can be related to... Figure 3 The gearbox assembly 300 is similar to or the same as the one shown and described. The gearbox assembly 300 is a star-shaped or rotating ring gear type gearbox assembly (e.g., the ring gear 344 is rotating, and the planet carrier 346 is fixed and stationary). The planet carrier 346 constrains a plurality of planet gears 342 such that the plurality of planet gears 342 do not rotate together about the sun gear 340, while allowing each of the plurality of planet gears 342 to rotate about its own axis A. P Rotation. The ring gear 344 is connected to the fan 14 via the rotor connecting rod 348. Figure 2 ) to drive fan 14 ( Figure 2 The ring gear 344 rotates about axis A. A plurality of planetary gears 342 mesh with and are located radially inside the ring gear 344. Each of the planetary gears 342 includes a pin 350, and the corresponding planetary gear rotates about the pin 350.

[0039] Each of the plurality of planetary gears 342 in the gearbox assembly 300 includes a cavity 352, also referred to as a reservoir 352, such that each of the plurality of planetary gears 342 is a hollow planetary gear 342. Figure 6 The storage device 352 shown may be about axis A P A circumferentially extending annular reservoir. Reservoir 352 may have one or more channels or openings (not shown) that allow fluid to enter reservoir 352, and these channels or openings may be connected to... Figure 4 One or more channels 154 are described as similar or identical. Reservoir 352 may have: one or more openings or channels 356 that allow fluid to exit reservoir 352 in an axial direction; and / or one or more openings or channels 362 that allow fluid to exit reservoir 352 in a radial direction. The fluid may be a lubricant, such as, but not limited to, oil and / or grease. Although depicted as separate components, pipes, or channels, the inlet opening (not shown), channel 356, and / or channel 362 may take other forms, such as integrally formed channels or openings, as will be described herein.

[0040] Lubricant from reservoir 352 can be supplied to one or more gears via one or more channels 356 and / or one or more channels 362, for example, to the sun gear 340, to one or more of the planetary gears 342, to the ring gear 344, or any combination thereof. For example, lubricant can drip from reservoir 352 onto the gear teeth of the planetary gears 342 and the ring gear 344. This lubricates the gear mesh 360 between the planetary gears 342 and the ring gear 344. The planetary gears 342 can then pass (e.g., due to rotation of the planetary gears) lubricant to the gear mesh 358 between the planetary gears 342 and the sun gear 340. Lubricant can be supplied through channel 364 to the pin 350 of each of the planetary gears 342. In some examples, channels 362, 364, and / or 356 may be omitted.

[0041] In some examples, one or more channels 356 may be used to supply lubricant to and / or fill the reservoir 352 with lubricant. In these examples, once the lubricant has been filled into the reservoir 352, one or more channels 356 may be sealed to prevent lubricant loss from the reservoir 352. The seal may be selectively opened and closed, allowing one or more channels 356 to be filled multiple times.

[0042] During operation of the gearbox assembly 300, lubricant can be supplied through the hollow planetary gears 342 and dripped onto the plurality of planetary gears 342 to provide lubrication, which in turn lubricates the gear meshing points 360 and then the gear meshing points 358. Therefore, the gearbox assembly 300 provides lubrication in both the radially outward direction (towards the gear meshing points 360) and the radially inward direction (towards the gear meshing points 358). A continuous supply of lubricant can be provided to the gear meshing points 358 and 360 through the gearbox assembly 300. This provides continuous lubrication to the gear meshing points 358 and 360. Furthermore, the fluid in the reservoir 352 can provide shock-absorbing resistance within the gearbox assembly 300. The fluid in the reservoir 352 can suppress the impact of the rotation of the plurality of planetary gears 342 and the ring gear 344.

[0043] Therefore, the fluid or lubricant within the reservoir 352 of the hollow planetary gear 342 provides a damping system that absorbs vibrations and loads experienced in the gearbox assembly 300 and provides shock resistance due to the loads on the gears of the gearbox assembly 300. (See also: ...) Figures 7 to 9The structure of the planetary gear 342 also provides impact resistance and shock absorption for the loads experienced on the planetary gear 342. Furthermore, the fluid or lubricant within the reservoir 352 serves to cool the planetary gear 342. That is, the rotation of the gears relative to each other and relative to other rotating parts causes the gears to heat up. The lubricant or fluid within the reservoir 352 absorbs the heat from the gears (e.g., acting as a radiator), thereby cooling the planetary gear 342.

[0044] In some examples, reservoir 352 may be a backup reservoir, allowing channels 356 and / or 362 to be selectively opened based on predetermined conditions. When channels 356 and / or 362 are open, lubricant can be supplied to gear engagement 360, and subsequently to gear engagement 358. Predetermined conditions may include engine operating conditions, temperature, load, etc. In examples where channels 356 and / or 362 are selectively opened and closed based on predetermined conditions, lubricant can be continuously supplied only when channels 356 and / or 362 are open.

[0045] Although each of gearbox assemblies 100, 200, and 300 shows a single hollow gear (e.g., ring gear 144, sun gear 240, and / or planetary gear 342), the other gears in the gearbox assembly may be hollow gears. In this way, more than one lubricant reservoir may be present in the gearbox assembly. The passageways for entering and exiting the reservoir may be circumferentially, radially, and / or axially aligned.

[0046] Figures 7 to 9 A schematic diagram of a hollow gear that can be used for any of the aforementioned hollow gears (e.g., ring gear 144, sun gear 240, and / or planet gear 342) is shown. Figures 7 to 9 Hollow gears may include, for example, those related to... Figures 4 to 6 The described storage and channels. Figures 7 to 9 Hollow gears can be used as follows: Figures 4 to 6 The described gear meshing area is provided with lubricant.

[0047] about Figures 7 to 9 The hollow gear described can be formed by electroforming, hydroforming, additive manufacturing, or any combination thereof. In some examples, the hollow gear is formed as a single integral gear, such that there is no engagement and / or fastening. Figures 7 to 9 The hollow gear may include one or more supports forming a passage for lubricant flow. The hollow gear may also include one or more cavities or reservoirs for storing lubricant. In emergency situations (e.g., loss of lubricant supply and / or lubricant interruption), the cavities can store lubricant. The hollow gear can provide a continuous drip or supply of lubricant to the gear meshing points of the gear assembly.

[0048] Figure 7 An axial end view of the hollow gear 400 is shown. As described, the hollow gear 400 can be used as any of the hollow gears previously described, such as the ring gear 244. Figure 4 Sun Gear 240 ( Figure 5 ) and / or planetary gear 342 ( Figure 6 The hollow gear 400 may include multiple cavities 452 and multiple passages 480. A portion 490 of the hollow gear 400 is in... Figures 8A to 8F The image is magnified. Although the passageway into and out of the hollow gear 400 may not be visible in all views due to perspective, it is shown in reference images. Figures 4 to 6 The described channel may be included in the hollow gear 400.

[0049] exist Figure 8A middle, Figure 7 Part 490 may be a first exemplary part 490a. The first exemplary part 490a may include a plurality of supports 478. One or more of the plurality of supports 478 may include passages 480, such that the first exemplary part 490a includes a plurality of passages 480. The plurality of passages 480 and / or cavities 452 may be directed to one or more channels extending through the gear teeth (in... Figure 8A (Not visible in the cross-sectional view). One or more channels may extend through the gear teeth through the tooth root, tooth tip, or any part in between. Figure 8A One or more channels that are not visible in the middle can be similar to channels 156 and 162 ( Figure 4 ), channels 256 and 262 ( Figure 5 ) and / or channels 356 and 362 ( Figure 6 This allows fluid stored in cavity 452 and / or through multiple passages 480 to drip and / or flow out to the gear meshing. Although shown as generally "X-shaped," the multiple supports 478 can take other shapes and arrangements. One such alternative is... Figure 8C As shown in the diagram, lubricant can be supplied to the gear teeth and / or gear meshing points via multiple cavities 452 and / or multiple passages 480.

[0050] exist Figure 8B middle, Figure 7Part 490 can be a second exemplary part 490b. The second exemplary part 490b can be the same as the first exemplary part 490a. Furthermore, the second exemplary part 490b can include material 482 in the cavity 452. Material 482 can be a foam filling the cavity 452, such as a metal foam. Material 482 can be porous, such as a porous foam or a porous metal foam, allowing lubricant to be stored in the cavity 452. Material 482 can serve as a limiter; that is, the material can be selected to allow a predetermined amount of compression or bending of the hollow gear, thus allowing a predetermined amount of impact absorption.

[0051] exist Figure 8C middle, Figure 7 Part 490 may be a third exemplary part 490c. The third exemplary part 490c may include a plurality of pillars 476. One or more of the plurality of pillars 476 may include a passage 480, such that the third exemplary part 490c includes a plurality of passages 480. Figure 8A As shown, multiple passages 480 and / or cavities 452 can be directed to one or more channels extending through the gear teeth (in... Figure 8C (Not visible in the cross-sectional view). One or more channels may extend through the gear teeth via the tooth root, tooth tip, or any portion in between. Figure 8C One or more channels that are not visible in the middle can be similar to channels 156 and 162 ( Figure 4 ), channels 256 and 262 ( Figure 5 ) and / or channels 356 and 362 ( Figure 6 This allows fluid stored in cavity 452 and / or through multiple passages 480 to drip and / or flow out to the gear meshing. Although shown as generally curved and / or angled struts, the multiple struts 476 can take other shapes and arrangements. As in the previous example, lubricant can be supplied to the gear teeth and / or gear meshing via multiple cavities 452 and / or multiple passages 480.

[0052] exist Figure 8D middle, Figure 7 Part 490 may be a fourth exemplary part 490d. The fourth exemplary part 490d may be the same as the third exemplary part 490c. Furthermore, the fourth exemplary part 490d may include material 482 in the cavity 452. Material 482 may be a foam filling the cavity 452, such as a metal foam. Material 482 may be porous, such as a porous foam or a porous metal foam, allowing lubricant to be stored in the cavity 452.

[0053] Figure 8EA fifth exemplary portion 490e is shown. The fifth exemplary portion 490e may include a plurality of cavities 452. The plurality of cavities 452 may include a first plurality of recesses 470 and a second plurality of recesses 472. As in the previous example, lubricant may be supplied to the gear teeth and / or gear meshing points via the first plurality of recesses 470 and / or the second plurality of recesses 472. As described with respect to the previous figures, due to... Figure 8E The view is an axial end view of the gear, so the channels for entering and exiting the multiple recesses are not visible, although they may exist in any of the forms previously described herein.

[0054] Figure 8F A sixth exemplary portion 490f is shown. The sixth exemplary portion 490f may include an oil circuit 492. The oil circuit 492 can function as a reservoir. The oil circuit 492 allows lubricant to flow in the direction of the arrow. As in the previous example, lubricant can be supplied to gear teeth and / or gear meshing points via the oil circuit 492.

[0055] Figure 9 An exemplary hollow gear 500 is shown along the radial extension axis of the gear (e.g., perpendicular to). Figure 4 A cross-sectional view taken from the radial extension axis of axis A. As described, hollow gear 500 can be used as any hollow gear previously described, such as ring gear 244. Figure 4 Sun Gear 240 ( Figure 5 ) and / or planetary gear 342 ( Figure 6 The hollow gear 500 may include a cavity 552, also referred to as a reservoir 552. The reservoir 552 may be a circumferentially extending reservoir. That is, the reservoir 552 extends circumferentially around the hollow gear 500, such that the reservoir 552 forms an annular cavity. This is consistent with... Figure 7 The exemplary hollow gear 400 differs from the hollow gear 400, which includes a cavity 452 extending axially from the front end of the gear to the rear end of the gear to form an axially extending cavity. As described with respect to the previous figures, the passages for entering and exiting the reservoir 552 are not visible, although they may exist in any of the forms previously described herein.

[0056] Refer again Figure 9 The hollow gear 500 includes multiple supports 578 and cavities 552. The cavities 552 may be larger than the supports 578. This facilitates the transport of lubricant in a 360-degree circumferential direction around the hollow gear 500. The supports 578 may include gaps between them to absorb shocks under load.

[0057] Any channel or opening described herein can be a controlled orifice or channel. A channel or opening can be actively actuated to open and / or close, or it can be passively actuated to open and / or close. In the example where a channel from a cavity to gear engagement is passively actuated, the channel can be a source-controlled channel. That is, the channel can be opened and / or closed based on the load experienced on the corresponding gear to which the cavity is located (e.g., in…). Figure 5 In this case, the load control channels 256 and / or 262 on the sun gear 240 are opened and / or closed. In some examples, the gearbox assembly may include springs and / or shape memory alloys to enable the opening and closing of the channels.

[0058] The gear assembly disclosed herein may include gears formed or assembled from hollow portions using electroforming and / or hydroforming. The gears may be lightweight and have bending connection features such as flexible members or struts to allow the gears to conform to and accommodate gear misalignment caused by thermal effects, loads, and vibrations of the relative rotating shafts coupled to the gearbox assembly. That is, the struts may be flexible to allow gear deformation to accommodate and correct misalignment between meshing gears. In some examples, the gear includes a cavity with features allowing continuous oil supply and dripping. These features may include channels allowing lubricant to flow from the cavity to the gear meshing point (e.g., through one or more portions of the gear teeth, through the sides of the gear, and / or through the roots of the gear teeth). Lubricant may be stored in the cavity for emergencies (e.g., switching from primary to secondary oil supply). In some examples, metal foam may be included in the cavity of the electroformed gear. Metal foam may be formed to store oil or lubricant and provide flexural strength. Gear rims may be designed for oil-carrying channels.

[0059] The gear assembly disclosed herein includes a hollow gear providing a damping system that absorbs vibrations and loads experienced in the gearbox assembly and provides shock resistance due to the loads on the gears of the gearbox assembly. The structure of the hollow gear (e.g., struts, components, materials, etc.) also provides shock resistance and shock absorption for the loads experienced on the gears. Furthermore, a fluid or lubricant within a reservoir acts to cool the hollow gear. That is, rotation of the gears relative to each other and relative to other rotating parts causes the gears to heat up. The lubricant or fluid within the reservoir of the hollow gear absorbs the heat of the gear (e.g., acting as a radiator), thereby cooling the ring gear.

[0060] In the example where the hollow gear is electroformed, the inner core can be removable and / or can be metal sponge or foam. In the example where the hollow gear is hydroformed, the gear may need to be welded to close the volume.

[0061] The gearbox assembly disclosed herein provides gears that allow suppression of loads caused by relative rotation of the gears, allow continuous and / or emergency lubrication at the gear meshing points, and accommodate or resolve misalignment at the gear meshing points during rotation.

[0062] The lubricant disclosed herein may be an oil, grease, soft lubricant, or any combination thereof. The lubricant disclosed herein may be energy-absorbing to enhance the damping of gearbox components. The lubricant may be present in the cavity or reservoir of the hollow gear and may drip through the side of the gear and / or through the tooth root to be supplied to the gear meshing point in an emergency.

[0063] The gearbox assembly disclosed herein includes a compliant gear that allows for misalignment, is lightweight to produce a lightweight gearbox assembly, and is a reliable gearbox assembly.

[0064] The gearbox assembly disclosed herein can provide suppression of the load experienced by the rotating gears and internal cooling of the hollow gears. For example, as Figures 7 to 9 As illustrated in the example, the hollow gear includes both a reservoir (e.g., cavity 452) and a flow chamber (e.g., passage 480). Therefore, a support (e.g., support 476) can provide damping, but this damping is enhanced when oil or lubricant is added to both the reservoir and flow chambers. Furthermore, the reservoir and flow oil provide cooling from within the hollow gear. Heat is generated at the gear meshing point during rotation and meshing with adjacent gears. The oil supplied to the gear meshing point provides cooling. The internal static and flowing lubricant within the hollow gear also serves a cooling function. Thus, the gear can be cooled both on its surface (e.g., at the gear meshing point) and internally (e.g., due to the cavities therein).

[0065] Other aspects of this disclosure are provided by the subject matter of the following clauses.

[0066] According to one aspect of this disclosure, a gearbox assembly for a gas turbine engine includes: a hollow gear having: one or more reservoirs configured to store lubricant; and one or more channels configured to supply lubricant to one or more gear meshing points in the gearbox assembly. The hollow gear provides a damping system configured to absorb vibrations and loads experienced in the gearbox assembly, provide shock resistance to the gearbox assembly, and provide internal cooling to the hollow gear.

[0067] According to the gearbox assembly described in the foregoing clause, the hollow gear is configured to accommodate the misalignment of one or more gears within the gearbox assembly.

[0068] According to any of the preceding clauses, in a gearbox assembly, one or more reservoirs extend axially from the front end of the hollow gear to the rear end of the hollow gear, thereby forming an axially extending cavity.

[0069] The gearbox assembly according to any of the foregoing clauses, wherein one or more reservoirs extend circumferentially around the hollow gear, such that the one or more reservoirs form an annular cavity.

[0070] The gearbox assembly according to any of the foregoing clauses further includes a metal foam in one or more reservoirs, the metal foam being configured to store lubricant and provide bending strength to the hollow gear.

[0071] According to any of the foregoing clauses, in a gearbox assembly, one or more channels are passively controlled to open and close based on the load experienced by the hollow gear.

[0072] According to any of the foregoing clauses, in a gearbox assembly, one or more channels are formed in one or more struts of a hollow gear, the one or more struts being curved members configured to allow deflection of the hollow gear.

[0073] The gearbox assembly according to any of the foregoing clauses, wherein the hollow gear is formed by electroforming, hydroforming, additive manufacturing or a combination thereof.

[0074] The gearbox assembly according to any of the foregoing clauses, wherein the gearbox assembly is configured to connect the low-pressure shaft of the gas turbine engine and the fan rotor connecting rod of the gas turbine engine.

[0075] According to any of the foregoing clauses, in a gearbox assembly, lubricant is supplied to the gear meshing between adjacent opposing rotating gears of the gearbox assembly via the side of the hollow gear or via the tooth root of the hollow gear.

[0076] The gearbox assembly according to any of the foregoing clauses further includes a sun gear, a plurality of planetary gears, and a ring gear.

[0077] The gearbox assembly according to any of the foregoing clauses, wherein the hollow gear is the sun gear and the plurality of planetary gears are fixed to a stationary planet carrier.

[0078] In any of the preceding clauses, the gearbox assembly wherein the hollow gear is a ring gear, the ring gear being fixedly connected to a stationary support structure via a connecting rod.

[0079] The gearbox assembly according to any of the foregoing clauses, wherein the hollow gear is at least one of a plurality of planetary gears fixed to a stationary planet carrier.

[0080] According to one aspect of this disclosure, a hollow gear for a gearbox assembly of a gas turbine engine includes: one or more reservoirs configured to store lubricant; one or more channels configured to supply lubricant to one or more gear meshing points in the gearbox assembly; and a damping system configured to absorb vibrations and loads experienced in the gearbox assembly and to provide shock resistance to the gearbox assembly.

[0081] According to the hollow gear described in the preceding clause, one or more reservoirs extend axially from the front end of the hollow gear to the rear end of the hollow gear, thereby forming an axially extending cavity.

[0082] A hollow gear according to any of the foregoing clauses, wherein one or more reservoirs extend circumferentially around the hollow gear such that one or more reservoirs form an annular cavity.

[0083] The hollow gear according to any of the foregoing clauses further includes a metal foam in one or more reservoirs, the metal foam being configured to store lubricant and provide bending strength to the hollow gear.

[0084] A hollow gear according to any of the foregoing clauses, wherein one or more channels are formed in one or more pillars of the hollow gear, and the one or more pillars are curved members configured to allow the hollow gear to deflect.

[0085] A hollow gear as described in any of the foregoing clauses, wherein the hollow gear is a sun gear, one or more planetary gears among a plurality of planetary gears, or a ring gear.

[0086] While the foregoing description pertains to preferred embodiments, it should be noted that other variations and modifications will be apparent to those skilled in the art and can be made without departing from the spirit or scope of this disclosure. Furthermore, features described in connection with one embodiment may be used in conjunction with other embodiments, even if not explicitly stated above.

Claims

1. A gearbox assembly for a gas turbine engine, characterized in that, The gearbox assembly includes: Hollow gear, the hollow gear having: (a) One or more reservoirs configured to store lubricant; and (b) One or more channels configured to supply the lubricant to one or more gear meshing points in the gearbox assembly. The hollow gear is configured to absorb vibrations and loads experienced in the gearbox assembly, providing impact resistance to the gearbox assembly and providing internal cooling for the hollow gear. The one or more channels are formed in one or more supports of the hollow gear, and the one or more supports are curved members configured to allow the hollow gear to deflect.

2. The gearbox assembly according to claim 1, characterized in that, in, The hollow gear is configured to accommodate the misalignment of one or more gears within the gearbox assembly.

3. The gearbox assembly according to claim 1, characterized in that, in, The one or more reservoirs extend axially from the front end of the hollow gear to the rear end of the hollow gear, thereby forming an axially extending cavity.

4. The gearbox assembly according to claim 1, characterized in that, in, The one or more storage units extend circumferentially around the hollow gear, such that the one or more storage units form an annular cavity.

5. The gearbox assembly according to claim 1, characterized in that, It further includes a metal foam in one or more of the reservoirs, the metal foam being configured to store the lubricant and provide bending strength to the hollow gear.

6. The gearbox assembly according to claim 1, characterized in that, in, The one or more channels are passively controlled to open and close based on the load experienced by the hollow gear.

7. The gearbox assembly according to claim 1, characterized in that, in, The hollow gear is formed by electroforming, hydroforming, additive manufacturing, or a combination thereof.

8. The gearbox assembly according to claim 1, characterized in that, in, The gearbox assembly is configured to connect the low-pressure shaft of the gas turbine engine and the fan rotor connecting rod of the gas turbine engine.

9. The gearbox assembly according to claim 1, characterized in that, in, The lubricant is supplied to the gear meshing point between adjacent opposing rotating gears of the gearbox assembly via the side of the hollow gear or via the tooth root of the hollow gear.

10. The gearbox assembly according to claim 1, characterized in that, It further includes a sun gear, multiple planetary gears, and a ring gear.

11. The gearbox assembly according to claim 10, characterized in that, in, The hollow gear is the sun gear, and the plurality of planetary gears are fixed to a stationary planet carrier.

12. The gearbox assembly according to claim 10, characterized in that, in, The hollow gear is the ring gear, which is fixedly connected to the stationary support structure via a connecting rod.

13. The gearbox assembly according to claim 10, characterized in that, in, The hollow gear is at least one of the plurality of planetary gears, which are fixed to a stationary planet carrier.

14. A hollow gear for a gearbox assembly in a gas turbine engine, characterized in that, The hollow gear includes: (a) One or more reservoirs configured to store lubricant; and (b) One or more channels configured to supply the lubricant to one or more gear meshing points in the gearbox assembly. The hollow gear is configured to absorb vibrations and loads experienced in the gearbox assembly and is configured to provide impact resistance to the gearbox assembly. The one or more channels are formed in one or more supports of the hollow gear, and the one or more supports are curved members configured to allow the hollow gear to deflect.

15. The hollow gear according to claim 14, characterized in that, in, The one or more reservoirs extend axially from the front end of the hollow gear to the rear end of the hollow gear, thereby forming an axially extending cavity.

16. The hollow gear according to claim 14, characterized in that, in, The one or more reservoirs extend circumferentially around the hollow gear, such that the one or more reservoirs form an annular cavity.

17. The hollow gear according to claim 14, characterized in that, It further includes a metal foam in one or more of the reservoirs, the metal foam being configured to store the lubricant and provide bending strength to the hollow gear.

18. The hollow gear according to claim 14, characterized in that, in, The hollow gear is a sun gear, one or more planetary gears among a plurality of planetary gears, or a ring gear.

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