CN218094134U - Fan drive gear box and aeroengine - Google Patents

Abstract

The application relates to the technical field of aero-engines, in particular to a fan drive gear box and an aero-engine. The fan driving gear box includes: the input shaft is used for being in driving connection with a low-pressure rotor of the aircraft engine; the output shaft is used for being in driving connection with a fan rotor of the aircraft engine; and the gear system comprises a sun wheel, a planet wheel, a gear ring and a planet carrier, wherein the planet wheel is arranged on the planet carrier and is meshed with the sun wheel and the gear ring, the sun wheel is in driving connection with the input shaft through a fixed spline, and the gear ring is in driving connection with the output shaft through a floating spline. Based on this, can effectively improve the performance of fan drive gear box.

Description

Fan drive gear box and aeroengine

Technical Field

The application relates to the technical field of aero-engines, in particular to a fan drive gear box and an aero-engine.

Background

The fan driving gear box is arranged between a low-pressure rotor and a fan rotor of the aircraft engine to realize a transmission mechanism in driving connection between the low-pressure rotor and the fan rotor, and has the advantages of high transmission power, high transmission efficiency, long service life and the like. The performance of the fan-driven gearbox directly affects the performance of the aircraft engine.

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the application is as follows: the performance of the fan drive gear box is improved.

In order to solve the above technical problem, the present application provides a fan driving gear box, which includes:

the input shaft is used for being in driving connection with a low-pressure rotor of the aircraft engine;

the output shaft is used for being in driving connection with a fan rotor of the aircraft engine; and

the gear system comprises a sun wheel, a planet wheel, a gear ring and a planet carrier, wherein the planet wheel is arranged on the planet carrier and is meshed with the sun wheel and the gear ring, the sun wheel is in driving connection with the input shaft through a fixed spline, and the gear ring is in driving connection with the output shaft through a floating spline.

In some embodiments, the floating splines are crowned floating splines.

In some embodiments, the ring gear includes two ring gear portions connected axially side-by-side.

In some embodiments, an oil hole is provided between the two ring gear portions, and the oil hole extends to the floating spline in the radial direction.

In some embodiments, the gear system comprises a planet wheel bearing supported between the planet wheel and the planet carrier, the inner bore of the planet wheel acting as the outer raceway for the planet wheel bearing.

In some embodiments, the input shaft includes a shaft body having ends drivingly connected to the low pressure rotor and the sun gear, respectively, and a flexible section disposed between the ends of the shaft body and projecting radially outwardly relative to the shaft body.

In some embodiments, the fan drive gearbox includes a flexible carrier connecting the carrier and the casing of the aircraft engine to adjust the radial position of the gear system.

In some embodiments, the fan drive gearbox includes a torque transmission bracket, and the flexible bracket is connected to the planet carrier by the torque transmission bracket.

In some embodiments, the fan drive gearbox includes ball bearings, the input shaft being drivingly connected to the low pressure spool via the ball bearings; and/or the fan drive gearbox comprises a cone bearing, and the output shaft is in driving connection with the fan rotor through the cone bearing.

The application still provides an aeroengine in addition, including low-pressure rotor and fan rotor to still including the fan drive gear box of this application embodiment, low-pressure rotor and fan rotor are connected in the drive of fan drive gear box.

In this application, through fixed spline drive connection between fan drive gear box's the input shaft and the sun gear, and through floating spline drive connection between output shaft and the ring gear, not only can reduce the influence of the decentraction of fan rotor and gear system to fan drive gear box, improve the load distribution of gear system, can make fan drive gear box's overall structure compacter moreover, reduce fan drive gear box's overall dimension and weight, consequently, can effectively improve fan drive gear box's performance.

Further features of the present application and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which is to be read in connection with the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

FIG. 1 is a schematic view of a fan drive gear box according to an embodiment of the present invention.

Description of reference numerals:

10. a fan drive gear box;

1. an input shaft; 11. a shaft body; 12. a flexible section;

2. a gear system; 21. a sun gear; 22. a planet wheel; 23. a planet carrier; 24. a planet wheel bearing; 25. a planet shaft; 26. a ring gear; 27. a rim portion; 28. an oil hole; 29. pressing a plate;

3. an output shaft;

4. a ball bearing;

5. a conical bearing;

6. fixing the spline;

7. a floating spline; 71. a drum-shaped floating spline;

8. a torque transmission bracket;

9. a flexible stent.

Detailed Description

The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the application, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without any inventive step, are within the scope of the present disclosure.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In the description of the present application, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are used for convenience of description and simplicity of description only, and in the case of not making a reverse description, these directional terms do not indicate and imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the scope of the present application; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.

In the description of the present application, it should be understood that the terms "first", "second", etc. are used to define the components, and are used only for the convenience of distinguishing the corresponding components, and if not otherwise stated, the terms have no special meaning, and thus, should not be construed as limiting the scope of the present application.

In addition, the technical features mentioned in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

The gear transmission Turbofan engine (GTF) is a typical aircraft engine structure, a fan driving gear box is arranged between a low-pressure rotor (including a low-pressure compressor and a low-pressure turbine) and a fan rotor, and an input shaft and an output shaft of the fan driving gear box are respectively in driving connection with the low-pressure rotor and the fan rotor, so that the fan rotor can work at a low rotating speed and the low-pressure rotor works at a high rotating speed, the number of stages of the compressor is reduced, the overall weight of the engine is reduced, and the overall efficiency of the engine is improved.

The fan driving gear box is used as a component for connecting the fan rotor and the low-pressure rotor in the gear transmission turbofan engine, and has the characteristics of high transmission power, high transmission efficiency, long service life and the like. The performance of the fan drive gearbox remains to be improved. For example, the size of the fan drive gearbox is still to be further reduced and the weight is still to be further reduced. For another example, the performance and life of the fan drive gearbox may still be improved.

In the operation process of the aero-engine, the aero-engine vibrates and deforms, the corresponding vibration and deformation can cause the non-concentricity of the input end and the output end of the fan driving gear box, the non-concentricity can cause the unbalance loading phenomenon between the planet wheels of the fan driving gear box due to uneven load distribution, one or more gears bear excessive load, the vibration is increased, the noise is strengthened, and the working performance and the service life of the fan driving gear box and the aero-engine are influenced.

In the related art, the input shaft of the fan drive gearbox is usually in driving connection with the sun gear by using floating splines, and the output shaft of the fan drive gearbox is usually in fixed connection with the fan rotor by using bolts. In this case, on the one hand, the floating spline between the input shaft and the sun gear is large in size in order to meet the strength requirements, resulting in a large size and heavy weight of the sun gear, and even the entire fan drive gearbox; on the other hand, the bolt fixed connection mode between the output shaft and the fan rotor can not reduce the influence of the non-concentricity of the fan rotor and the aero-engine support structure on the fan drive gear box, so that the load distribution of the fan drive gear box is uneven, and the working performance and the service life of the fan drive gear box are influenced.

In view of the above, the present application provides a fan drive gearbox and an aircraft engine, which improve the performance of the fan drive gearbox and the aircraft engine by improving the structure of the fan drive gearbox.

Fig. 1 schematically shows the structure of the fan drive gear box of the present application.

Referring to fig. 1, in the present application, a fan drive gearbox 10 includes an input shaft 1, an output shaft 3, and a gear system 2. The input shaft 1 is intended for driving connection with the low-pressure spool of an aircraft engine. The output shaft 3 is intended for driving connection with the fan rotor of an aircraft engine. The gear system 2 comprises a sun wheel 21, a planet wheel 22, a ring gear 26 and a planet carrier 23, the planet wheel 22 is arranged on the planet carrier 23 and is meshed with the sun wheel 21 and the ring gear 26, the sun wheel 21 is in driving connection with the input shaft 1 through a fixed spline 6, and the ring gear 26 is in driving connection with the output shaft 3 through a floating spline 7.

Because the sun gear 21 and the input shaft 1 are connected by the fixed spline 6, the sun gear 21 and the input shaft 1 can be normally fixed and transmit torque, and according to a spline strength calculation formula, when the same torque is transmitted, if the same service life is reached, the size of the fixed spline is smaller than that of the floating spline, so that compared with the case of connecting the sun gear 21 and the input shaft 1 by the floating spline, when the sun gear 21 and the input shaft 1 are connected by the fixed spline 6, the size of the spline can be smaller, so that the fan driving gear box 10 is more compact in structure, smaller in overall size and lighter in overall weight.

Because the gear ring 26 is not connected with the output shaft 3 by bolts any more, but connected by the floating spline 7 with certain radial misalignment compensation capability, the influence of the misalignment between the fan rotor and the gear system 2 on the fan drive gearbox 10 can be reduced, the load distribution uniformity of the gear system 2 can be improved, the vibration and noise can be reduced, the working performance of the fan drive gearbox 10 can be improved, and the service life of the fan drive gearbox 10 can be prolonged.

Meanwhile, the floating spline 7 can not only generate radial displacement but also axial displacement, so when the gear ring 26 is connected with the output shaft 3 through the floating spline 7, the floating spline 7 can not only reduce the influence of the non-concentricity of the fan rotor and the gear system 2 on the fan drive gear box 10, improve the load distribution uniformity of the gear system 2, but also enable the gear ring 26 and the output shaft 3 to relatively move along the axial direction, thereby effectively preventing over-positioning.

It can be seen that, by connecting the input shaft 1 and the sun gear 21 through the fixed spline 6 and connecting the output shaft 3 and the gear ring 26 through the floating spline 7, the stress condition of the fan drive gear box 10 can be effectively optimized, the service life of the fan drive gear box 10 can be prolonged, the size and the weight of the fan drive gear box 10 can be reduced, and thus the performance of the fan drive gear box 10 can be effectively improved.

Wherein the floating splines 7 are drum-shaped floating splines 71 as an example. The floating splines may be roughly classified into general straight floating splines and special drum-shaped floating splines. Compared with a common straight floating spline, the drum-shaped floating spline has stronger angular adaptability, so when the floating spline 7 between the gear ring 26 and the output shaft 3 is specifically the drum-shaped floating spline 71, radial misalignment compensation can be better performed, so that even when the axes of the output shaft 3 and the gear ring 26 are not collinear and have included angles, the drum-shaped floating spline 71 can effectively reduce the influence of the misalignment of the fan rotor and the gear system 2 on the fan driving gearbox 10, thereby more effectively improving the working performance and prolonging the service life.

In addition, in order to further reduce the influence of deformation and vibration of the aircraft engine on the fan drive gearbox 10, the embodiment of the present application makes other improvements to the structure of the fan drive gearbox 10.

For example, referring to fig. 1, in some embodiments, the input shaft 1 includes a shaft body 11 and a flexible section 12, wherein two ends of the shaft body 11 are respectively connected to the low-pressure rotor and the sun gear 21 in a driving manner, and the flexible section 12 is disposed between the two ends of the shaft body 11 and protrudes toward the radial outer side with respect to the shaft body 11.

The flexible section 12 arranged between the two ends of the input shaft 1 can reduce the radial and axial rigidity of the input shaft 1, so that the input shaft 1 becomes a flexible shaft, and the sun gear 21 is supported by the flexible input shaft 1, so that the sun gear 21 is conveniently kept at an ideal working position, and therefore, the influence of the non-concentricity of the low-pressure rotor and the gear system 2 on the fan driving gear box 10 can be reduced, the load distribution of the gear system 2 can be further improved, the service life is prolonged, and the working performance is improved.

Moreover, under the combined action of the input shaft 1 with the flexible section 12 and the floating spline 7 positioned between the output shaft 3 and the gear ring 26, the non-concentric influence of the low-pressure rotor on the input side is reduced, and the non-concentric influence of the fan rotor on the output side is also reduced, namely, the non-concentric influence of the input end and the output end of the fan driving gear box 10 is reduced, so that the deformation and vibration influence of an aeroengine can be effectively isolated on the premise of considering the structural compactness of the fan driving gear box 10, the stress condition of the gear system 2 is improved, the working performance is improved, and the service life is prolonged.

For another example, referring to fig. 1, in some embodiments, the fan drive gearbox 10 includes a flexible carrier 9, the flexible carrier 9 connecting the planet carrier 23 and the casing of the aircraft engine to adjust the radial position of the gear system 2.

The radial rigidity of the flexible support 9 is low, so that when the aircraft engine vibrates or deforms, the radial position of the gear system 2 can be adjusted, the risk of non-concentricity between the gear system 2 and the low-pressure rotor and the fan rotor can be reduced, the load distribution uniformity of the gear system 2 is improved, the stress condition of the gear system 2 can be further improved, the working performance is improved, and the service life is prolonged.

Exemplarily, referring to fig. 1, the fan drive gearbox 10 comprises a torque transmission bracket 8, and the flexible bracket 9 is connected with the planet carrier 23 through the torque transmission bracket 8. The torque transmission bracket 8 is arranged, so that the connection and the force transmission between the planet carrier 23 and the flexible bracket 9 can be facilitated.

In the foregoing embodiments, referring to fig. 1, the ring gear 26 may include two ring gear portions 27, and the two ring gear portions 27 are connected side by side in the axial direction. At this time, the gear ring 26 is not in an integrated structure, but in a split structure, and is formed by splicing the two gear ring portions 27, so that the advantage of the arrangement is that the assembly is convenient, and particularly, the assembly of the gear system 2 with herringbone gears is convenient.

Also, with continued reference to fig. 1, where the ring gear 26 includes two ring gear portions 27, in some embodiments, an oil hole 28 is provided between the two ring gear portions 27, the oil hole 28 extending radially to the floating spline 7. In this case, lubricating oil can be supplied to the floating spline 7 between the ring gear 26 and the output shaft 3 by the centrifugal force generated when the ring gear 26 operates, which is beneficial to reducing the abrasion of the floating spline 7, improving the operational reliability of the floating spline 7, and prolonging the service life of the floating spline 7.

In the foregoing embodiments, the planetary gears 22 are supported on the planetary carrier 23 by the planetary gear bearings 24. Referring to fig. 1, in some embodiments, the inner bore of the planet 22 serves as the outer raceway for the planet bearing 24. In this case, the planet wheel 22 and the planet wheel bearing 24 are integrated, so that the whole structure of the fan drive gear box 10 can be simpler and more compact.

The embodiment shown in fig. 1 will be further described below.

As shown in fig. 1, in this embodiment the fan drive gearbox 10 comprises an input shaft 1, a gear system 2, an output shaft 3, a torque transmission carrier 8 and a flexible carrier 9, the gear system 2 comprising a sun gear 21, planet gears 22, a planet carrier 23, planet bearings 24, a planet shaft 25, a ring gear 26 and a pressure plate 29.

Wherein, as shown in fig. 1, in this embodiment, the input shaft 1 is a flexible shaft. Specifically, the input shaft 1 includes a shaft body 11, and the shaft body 11 extends in the axial direction and is hollow inside. The first end of the shaft body 11 is in driving connection with the low-pressure rotor through the ball bearing 4 so as to provide radial support and axial limit by the ball bearing 4. The second end of the shaft body 11 is drivingly connected to the sun gear 21 via the fixed spline 6. Since the fixed spline can be smaller than the floating spline in size when the torque is the same, the structural compactness of the fan drive gear case 10 can be improved, and the overall size and weight can be reduced. A shoulder on the input shaft 1 and a pressure plate 29 form a radial and axial fixation of the input shaft 1 and the sun wheel 21. And a flexible section 12 is arranged between the first end and the second end of the shaft body 11, the wall thickness of the flexible section 12 is smaller than that of the shaft body 11, and the flexible section 12 protrudes towards the radial outer side relative to the shaft body 11, so that the flexible section 12 is a thin-wall flexible structure and has lower radial and axial heights, the supporting rigidity of the input shaft 1 on the sun wheel 21 can be reduced, and the influence of the non-concentricity of the low-pressure rotor and the gear system 2 on the fan driving gear box 10 is reduced.

The sun gear 21 meshes with the ring gear 26 via the planet gears 22 to transfer the torque transmitted by the input shaft 1 to the outside. The teeth of the sun gear 21, the planet gears 22 and the gear ring 26 are herringbone teeth. Also, in this embodiment, the number of planet wheels 22 is multiple, so that the gear system 2 is a multi-split arrangement.

The sun gear 21 meshes simultaneously with a plurality of planet gears 22. Since the sun wheel 21 is supported by the flexible input shaft 1, the sun wheel 21 can be freely adjusted in position between the planet wheels 22 to maintain a more optimal operating position, and therefore the load distribution uniformity of the gear system 2 can be improved.

The planet wheels 22 are supported in a planet carrier 23 by planet wheel bearings 24 and planet shafts 25. The carrier 23 is a stator member, which does not rotate. The planet wheels 22 rotate about their own axis. In this embodiment, as shown in fig. 1, the planet wheels 22 and the planet wheel bearings 24 are integrated, i.e. the inner bores of the planet wheels 22 are used as the outer raceways of the planet wheel bearings 24, which further improves the compactness of the fan drive gearbox 10. Also, as shown in fig. 1, in this embodiment, the carrier 23 is fixed in the casing of the aircraft engine by the torque transmission bracket 8 and the flexible bracket 9. The flexible support 9 has a relatively thin wall thickness and at least two bending sections which are connected with each other and bent relatively, so that the radial rigidity of the flexible support 9 is relatively low, and the gear system 2 can be conveniently adjusted in radial position when the aeroengine deforms or vibrates, so that the non-concentricity between the gear system 2 and the low-pressure rotor and the fan rotor is reduced, and the load distribution uniformity of the gear system 2 is improved.

The ring gear 26 meshes simultaneously with a plurality of planet gears 22. Since the teeth of the gears in the gear system 2 are herringbone teeth, for ease of assembly, in this embodiment, as shown in fig. 1, the ring gear 26 includes two ring gear portions 27, the two ring gear portions 27 being a left-hand ring gear and a right-hand ring gear, respectively, which are arranged side by side in the axial direction and fastened by bolts. Thus, the gear ring 26 is of a half-split structure, and assembly is facilitated.

The output shaft 3 drivingly connects the ring gear 26 and the fan rotor to effect a driving connection between the gear system 2 and the fan rotor such that the fan rotor can be rotated at a lower rotational speed than the low pressure rotor by the fan drive gearbox 10. As shown in fig. 1, in this embodiment the first end of the output shaft 3 is drivingly connected to the fan rotor by a cone bearing 5 to provide radial support and axial location by the cone bearing 5. The second end of the output shaft 3 is drivingly connected to the ring gear 26 by a floating drum spline 71. A floating drum spline 71 is provided on the outer race of the ring gear 26. Because of the improved radial misalignment compensation capability of the floating drum splines 71, the fan drive gearbox 10 is less affected by misalignment of the fan rotor and gear system 2, and the load distribution of the gear system 2 is improved. At the same time, the drum-shaped floating spline 71 allows the ring gear 26 and the output shaft 3 to move relatively in the axial direction, preventing over-positioning.

As shown in fig. 1, oil holes 28 are formed in the joint surface of the two ring gear portions 27 of the ring gear 26, and the oil holes 28 extend from the radially inner ring of the ring gear 26 to the radially outer floating drum spline 71, so as to conveniently supply lubricating oil to the floating drum spline 71 and reduce wear of the floating drum spline 71.

It can be seen that, in this embodiment, based on the flexible structural design of multiple places such as the flexible input shaft 1, the drum-shaped floating spline 71, and the flexible support 9, the influence of the vibration and deformation of the aircraft engine on the fan drive gearbox 10 can be effectively reduced, the load distribution is improved, the working performance is improved, and the service life is prolonged, and based on the integrated design of the fixed spline 6 between the input shaft 1 and the sun gear 21 and the integrated design between the planet gear 22 and the planet gear bearing 24, the structural compactness can be improved, the volume is reduced, and the weight is reduced, so the fan drive gearbox 10 of this embodiment has not only better mechanical properties, but also has a compact structure, a smaller volume, and a lighter weight.

Meanwhile, due to the drum-shaped floating spline 71 and other flexible designs of the embodiment, adverse effects of deformation and vibration of the aircraft engine on the fan drive gearbox 10 can be well isolated, and load distribution uniformity is improved, so that tolerance to machining and assembling errors can be improved from another perspective, which is beneficial to reducing manufacturing cost.

The above description is only exemplary of the present application and should not be taken as limiting the present application, and any modifications, equivalents, improvements and the like that are made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims (10)

1. A fan drive gearbox (10), comprising:

the input shaft (1) is used for being in driving connection with a low-pressure rotor of an aircraft engine;

an output shaft (3) for driving connection with a fan rotor of the aircraft engine; and

gear system (2), including sun gear (21), planet wheel (22), ring gear (26) and planet carrier (23), planet wheel (22) set up in on planet carrier (23), and with sun gear (21) with ring gear (26) meshing, sun gear (21) with through fixed spline (6) drive connection between input shaft (1), ring gear (26) through floating spline (7) with output shaft (3) drive connection.

2. The fan drive gearbox (10) according to claim 1, wherein the floating splines (7) are drum-shaped floating splines (71).

3. The fan drive gearbox (10) according to claim 1, characterised in that the ring gear (26) comprises two ring gear portions (27), the two ring gear portions (27) being connected axially side by side.

4. The fan drive gearbox (10) according to claim 3, wherein an oil hole (28) is provided between the two ring gear portions (27), the oil hole (28) extending in a radial direction to the floating spline (7).

5. The fan drive gearbox (10) according to claim 1, characterised in that the gear system (2) comprises a planet wheel bearing (24), which planet wheel bearing (24) is supported between the planet wheels (22) and the planet carrier (23), the inner bore of the planet wheels (22) serving as the outer raceway of the planet wheel bearing (24).

6. The fan drive gearbox (10) according to claim 1, wherein the input shaft (1) comprises a shaft body (11) and a flexible section (12), wherein both ends of the shaft body (11) are in driving connection with the low-pressure rotor and the sun gear (21), respectively, and the flexible section (12) is disposed between both ends of the shaft body (11) and protrudes radially outward with respect to the shaft body (11).

7. The fan drive gearbox (10) according to any of the preceding claims 1 to 6, characterised in that the fan drive gearbox (10) comprises a flexible carrier (9), the flexible carrier (9) connecting the planet carrier (23) and the aircraft engine case for adjusting the radial position of the gear system (2).

8. The fan drive gearbox (10) according to claim 7, characterised in that the fan drive gearbox (10) comprises a torque transmission bracket (8), the flexible bracket (9) being connected with the planet carrier (23) by means of the torque transmission bracket (8).

9. A fan drive gearbox (10) according to any one of claims 1 to 6, characterised in that the fan drive gearbox (10) comprises ball bearings (4), the input shaft (1) being in driving connection with the low pressure rotor via the ball bearings (4); and/or the fan drive gear box (10) comprises a cone bearing (5), and the output shaft (3) is in driving connection with the fan rotor through the cone bearing (5).

10. An aircraft engine comprising a low pressure spool and a fan spool, characterized in that it further comprises a fan drive gearbox (10) according to any one of claims 1 to 9, said fan drive gearbox (10) drivingly connecting said low pressure spool and said fan spool.

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