CN111648867A - Simple gear transmission turbofan engine - Google Patents

Abstract

A simple gear transmission turbofan engine comprises a fan component, a boosting stage, a low-pressure shaft, a gear reduction structure, a front support structure, a high-pressure shaft, a starting and power generation integrated motor, a gas compressor, a high-pressure turbine and a rear support structure. The high-pressure shaft is connected with the low-pressure shaft through a gear reduction mechanism. When the engine is running, the high-pressure shaft and the low-pressure shaft can rotate at different rotating speeds by designing the proper gear reduction ratio. The engine is provided with the gear reduction structure, so that the rotating speed difference between the high-pressure shaft and the low-pressure shaft is changed, each pneumatic component which is assembled conveniently works at the respective optimal rotating speed, and compared with a single-shaft turbofan or turbojet engine, the fuel economy and the noise environmental protection performance are obviously improved.

Description

Simple gear transmission turbofan engine

Technical Field

The invention relates to the technical field of aircraft power, in particular to a simple gear transmission turbofan engine.

Background

Aiming at the power design requirement of a small aircraft, a single-shaft turbojet engine structure is generally adopted by current aircraft manufacturers. The engine mainly comprises a main shaft, a gas compressor, a combustion chamber, a turbine, a casing, a supporting structure and a tail nozzle component. The gas compressor, the combustion chamber, the turbine and the tail nozzle are sequentially arranged, rotors of the gas compressor and the turbine are respectively connected to two ends of a main shaft, the main shaft is connected to an engine supporting structure through a bearing, and the supporting structure, the combustion chamber and the tail nozzle are connected to a casing. The engine has no fan component and inner and outer duct structures, and is simple in structure, but poor in fuel economy and noise environmental protection.

To this end, some aircraft manufacturers have proposed single shaft turbofan engine configurations. The engine is additionally provided with a fan component, an inner duct structure and an outer duct structure on the basis of the structure of the single-shaft turbojet engine, rotors of the fan and the air compressor are sequentially arranged at the front end (or the rear end) of the main shaft, a rotor of the turbine is arranged at the rear end of the main shaft, and the connection mode and the arrangement sequence of the main shaft and other components are the same as those of the single-shaft turbojet engine. When the engine works, after external air passes through the fan, a part of air enters the outer duct, is directly discharged from the tail nozzle after being pressurized and accelerated, and provides power for the engine; the other part of air enters an inner duct, enters a combustion chamber after being pressurized by the gas compressor to participate in combustion, and high-temperature gas after combustion pushes a turbine rotor to do work to drive a fan and the gas compressor in front to rotate at a high speed. This air is eventually expelled from the jet nozzle at a high velocity to provide thrust for the engine (newton's third law). Under the condition that the performances of all parts are approximately equivalent with the same thrust level, the single-shaft turbofan engine has lower noise and higher fuel economy compared with the single-shaft turbojet engine due to the addition of the fan parts.

In order to further improve the economy and environmental protection of the single-shaft turbofan engine, the turbofan engine is required to be matched with a large-size fan and a high-pressure-ratio compressor, and the front temperature of a turbine and the number of turbine stages are correspondingly increased, or the configuration is changed, so that the number of rotating shafts is increased, but the technical problems in the following aspects exist: (1) the diameter of the fan is limited by the maximum tip tangential speed, the large-diameter fan must work at a lower rotating speed, but the lower rotating speed of the rotor can cause the working capacity and efficiency of the coaxial turbine to be reduced, so that the fan and the turbine cannot work at the respective optimal rotating speeds; (2) the increase of the front temperature of the turbine and/or the number of stages of the gas compressor and the turbine and/or the increase of the single-stage pressure ratio brings great difficulty to the overall structure, material selection and part design and manufacture of the engine, the structural complexity is increased, the processing and manufacturing cost is increased, and the working reliability is reduced; (3) an excessive increase in the number of engine shafts would increase the weight, increase the volume, complicate the structure, decrease the operational reliability of the engine, and be disadvantageous for the miniaturization of the engine and its application in small aircraft.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: a simple geared turbofan engine capable of improving fuel economy and reducing noise pollution is provided.

The technical scheme of the invention is as follows: the simple gear transmission turbofan engine configuration design comprises a fan component, a boosting stage, a low-pressure shaft, a gear speed reduction structure, a front support structure, a high-pressure shaft, a starting and power generation integrated motor, a gas compressor, a high-pressure turbine and a rear support structure.

The rotor of the fan component and the rotor of the booster stage are arranged on the low-pressure shaft to realize synchronous rotation with the low-pressure shaft; the low-pressure shaft is connected with the front support structure through a bearing, and during operation, the low-pressure shaft transmits load to the front support structure through the bearing.

The rotor of the starting and power generation integrated motor, the rotor of the gas compressor and the rotor of the high-pressure turbine are arranged on the high-pressure shaft so as to synchronously rotate with the high-pressure shaft; the high-pressure shaft is connected with the front supporting structure and the rear supporting structure through bearings, and the high-pressure shaft transmits load to the front supporting structure and the rear supporting structure respectively during working.

The high-pressure shaft is connected with the low-pressure shaft through a gear reduction structure so as to realize the speed reduction rotation of the low-pressure shaft, and the gear reduction structure is connected with the front support structure through a gear bracket. And the gear bracket is provided with a circulating lubrication system for lubricating and cooling the gear reduction structure in the working process.

The rotor of the fan component and the rotor of the booster stage are sequentially arranged on the low-pressure shaft along the axial direction, and the rotor of the starting and power-generating integrated motor, the rotor of the gas compressor and the rotor of the high-pressure turbine are sequentially arranged on the high-pressure shaft along the axial direction. Therefore, the arrangement positions of all the components on the high-pressure shaft and the low-pressure shaft are sequentially arranged and do not interfere with each other, and all the components can normally and stably run.

The low-pressure shaft is mounted on the front bearing support through the bearing, and the front bearing support is mounted on the front support structure to realize load transfer from the low-pressure shaft to the front support structure.

The high-pressure shaft is respectively arranged on the middle bearing support and the rear bearing support through bearings, the middle bearing support is connected with the front supporting structure, and the rear bearing support is connected with the rear supporting structure, so that the high-pressure shaft can transmit loads to the front supporting structure and the rear supporting structure respectively.

The low-pressure shaft and the high-pressure shaft are hollow shafts, so that the whole weight is light, and the low-pressure shaft and the high-pressure shaft are convenient to assemble and connect with components.

The tail end of the low-pressure shaft is externally expanded with a gear reduction structure, so that the connection between the gear reduction structure and the low-pressure shaft is realized, the low-pressure shaft is convenient to accommodate the gear reduction structure by utilizing the structure of the low-pressure shaft, the whole axial length is reduced, the structure is compact, and the arrangement is reasonable.

The gear reduction structure comprises an inner gear ring, a planet gear in meshing transmission with the inner gear ring and a sun gear in meshing transmission with the planet gear, the gear reduction structure is formed by utilizing the planet gear structure, the whole size is small, the structure is compact, the bearing capacity is large, and the work is stable and reliable.

Further, the tail end of the low-pressure shaft and an inner gear ring of the gear reduction structure are designed to be of an integrated structure. Therefore, the number of parts is reduced, the structure of the engine is more compact and reasonable, and the volume is smaller.

The tail end of the low-pressure shaft is externally expanded and internally provided with sleeve teeth to be connected with the gear end sleeve teeth of the outer ring of the inner gear ring, so that the gear speed reducing structure is accommodated and synchronously rotates with the inner gear ring. Not only is convenient for assembly, but also can realize reliable synchronous rotation.

The high-pressure shaft and the gear speed reducing structure are provided with a coupler, the front end of the coupler is in gear connection with the gear end sleeve on the inner side of the sun gear, and the rear end of the coupler is connected with the high-pressure shaft. Therefore, the connection of the high-pressure shaft and the low-pressure shaft is realized, and meanwhile, through the arrangement of the coupler, the influence caused by the non-coaxial structure of the high-pressure shaft and the gear reduction mechanism can be eliminated, and the stable transmission of the high-pressure shaft and the gear reduction mechanism is ensured.

The simple gear transmission turbofan engine structure has the advantages of ingenious overall structural design and reasonable and compact arrangement of all the components.

According to the simple gear transmission turbofan engine, the high-pressure shaft, the low-pressure shaft and the gear reduction structure are matched, so that the high-pressure shaft and the low-pressure shaft can rotate at different rotating speeds through a specially designed gear reduction ratio, namely the rotating speeds of the high-pressure shaft and the low-pressure shaft are differentiated, and assembled parts can work at respective optimal rotating speeds conveniently. The following advantages are present in particular:

1. the low-pressure shaft has low rotating speed, and the bypass ratio of the engine can be increased on the premise of not influencing the working performance of the high-pressure turbine, so that the oil consumption rate of the engine is greatly reduced. Meanwhile, the low-pressure shaft works at a lower rotating speed, so that the centrifugal load of the fan component is reduced, the service life of the fan component is prolonged, and the requirement on the material performance is reduced.

2. The high-pressure shaft has lower rotating speed, the number of stages of a gas compressor on the high-pressure shaft is reduced, the turbine structure is more compact, the total length of the engine is shortened, the total weight of the engine is reduced, the working capacity of parts is improved, and meanwhile, the size of the matched starting and power generation integrated motor can be reduced due to the high rotating speed.

3. The adoption of the configuration of axially increasing a gear reduction structure and a low-pressure shaft (short shaft) on the basis of a single-shaft turbofan engine has limited increase of the volume and the weight of the engine. Compared with a double-shaft gear turbofan engine (a high-pressure shaft, a low-pressure shaft and a fan shaft) and a three-shaft turbofan engine (a high-pressure shaft, a medium-pressure shaft and a low-pressure shaft), the simple gear transmission turbofan engine is simple in structure, low in system complexity and high in reliability, and is more suitable for being used as power of a small aircraft.

Compared with a single-shaft turbojet and a single-shaft turbofan engine, the simple gear transmission turbofan engine has the advantages that the fuel economy and the noise environmental protection performance are obviously improved.

Drawings

Embodiments of the present invention will now be described in more detail and by way of non-limiting example with reference to the accompanying drawings to provide a thorough understanding of the simple geared turbofan engine configuration and principles of the present invention. It should be noted that the features and structures shown in the various figures do not necessarily represent actual shapes and sizes of the corresponding parts, but are merely used to explain the operational principles of the embodiments of the present invention.

Fig. 1 is a partial structural schematic view of a simple gear-driven turbofan engine according to the present invention.

FIG. 2 is a schematic view of a gear reduction structure of a simple geared turbofan engine according to the present invention.

1. The device comprises a fan component, 2, a booster stage, 3, a low-pressure shaft, 4, a gear reduction structure, 5, a front support structure, 6, a starting and power generation integrated motor, 7, a gas compressor, 8, a high-pressure shaft, 9, a high-pressure turbine, 10, a rear support structure, 11, a rear bearing support, 12, a bearing, 13, a middle bearing support, 14, a coupler, 15, a gear support, 16, a front bearing support, 17, a sun gear, 18, a planet gear, 19, an inner gear ring, 20 and gear end sleeve teeth.

Detailed Description

Specific embodiments of the present invention will be described in detail below by way of examples.

The figures are merely schematic and not drawn to scale, and like reference numerals are used to indicate like or similar parts throughout the figures.

Embodiments of the present invention are not limited to the examples set forth below, and those skilled in the art, utilizing the principles of the present invention, may make modifications and variations to the described embodiments, resulting in other embodiments of different forms. It will be apparent that such embodiments fall within the scope of the claimed invention.

It should be noted that the drawings referred to herein are for the purpose of illustrating and explaining embodiments of the present invention, and the shapes and sizes of each component and the connection manner between the different components shown in the drawings are merely for schematically illustrating the embodiments of the present invention and do not constitute a limitation to the scope of the present invention.

Referring now to FIGS. 1-2, a simplified geared turbofan engine embodiment of the present invention will be described. In the embodiment shown in fig. 1-2, the simple geared turbofan engine comprises: the device comprises a fan component 1, a booster stage 2, a low-pressure shaft 3, a gear reduction structure 4, a front support structure 5, a starting and power generation integrated motor 6, a gas compressor 7, a high-pressure shaft 8, a high-pressure turbine 9 and a rear support structure 10.

Wherein the rotor of the fan component 1 and the rotor of the booster stage 2 are sequentially mounted on the low-pressure shaft 3 in the axial direction and rotate synchronously with the low-pressure shaft 3. In this embodiment, the synchronous rotation is realized by adopting a set gear structure, and the synchronous rotation can be realized by adopting other assembling structures which can realize the synchronous rotation, such as a tight fit structure or a key structure.

In the present embodiment, referring to the left-right orientation in fig. 1, the fan section 1 and the pressure increasing stage 2 are fitted to the low-pressure shaft 3 in the order of front and rear, with the left being front and the right being rear.

In the present embodiment, to realize the load transmission from the low-pressure shaft 3 to the front support structure 5, the low-pressure shaft 3 is mounted on a front bearing bracket 16 through a bearing 12, and the front bearing bracket 16 is mounted on the front support structure 5, so as to realize the transmission of the radial and axial loads from the low-pressure shaft 3 to the front support structure 5. Meanwhile, in the present embodiment, the bearing 12 connected to the low pressure shaft 3 includes two bearings, which are disposed at an interval and are both connected to the front bearing support 16.

The rotor of the starting and power generating integrated motor 6 is arranged on the high-pressure shaft 8 and rotates synchronously with the high-pressure shaft 8, wherein the starting and power generating integrated motor 6 has the starting and power generating functions at the same time. It is understood that the rotor of the start-and-power-generation-integrated motor 6 is used to drive the high-pressure shaft 8 to rotate at the time of engine start, and is in turn driven to rotate by the high-pressure shaft 8 after the engine start. Of course, other integrated or separated structures capable of realizing engine starting or power generation can be adopted to realize the starting or the power generation of the engine.

And the rotor of the starting and generating integrated motor 6, the rotor of the compressor 7 and the rotor of the high-pressure turbine 9 are arranged on the high-pressure shaft 8 so as to synchronously rotate with the high-pressure shaft 8. The synchronous rotation is realized by adopting the sleeve gear structure in the embodiment, and the synchronous rotation can be realized by adopting other assembling structures such as tight fit or keys.

In the present embodiment, the rotor of the starting and power generation integrated motor 6, the rotor of the compressor 7, and the rotor of the high-pressure turbine 9 are respectively installed into the high-pressure shaft 8 from the front and rear directions in the axial direction. For example, the rotor of the starting and power generation integrated motor 6 and the rotor of the compressor 7 may be installed from the front of the high-pressure shaft, and the rotor of the high-pressure turbine 8 may be installed from the rear of the high-pressure shaft.

In the present embodiment, to realize the load transmission from the high pressure shaft 8 to the front support structure 5 and the rear support structure 10, the high pressure shaft 8 is respectively mounted on the middle bearing bracket 13 and the rear bearing bracket 11 through the bearing 12, the middle bearing bracket 13 is mounted on the front support structure 5, and the rear bearing bracket 11 is mounted on the rear support structure 10, so as to realize the load transmission from the high pressure shaft 8 to the front support structure 5 and the rear support structure 10. In the present embodiment, the bearing 12 connecting the high-pressure shaft 8 includes two bearings, which are disposed in tandem.

The high-pressure shaft 8 is matched with the low-pressure shaft 3 through the gear speed reducing structure 4 so as to realize the speed reduction rotation of the low-pressure shaft 3. The gear reduction 4 is connected to the front support 5 by means of a gear support 15.

In the present embodiment, referring to fig. 2, the gear reduction structure 4 includes an inner gear ring 19, planet gears 18 in meshing engagement with the inner gear ring 19, a sun gear 17 in meshing engagement with the planet gears 18, and a gear support 15 for supporting and maintaining the relative positional relationship between the gears. In the present embodiment, there are three planet gears 18, which are arranged around the sun gear 17. The sun wheel 17 and the planet wheels 18 are connected to the front supporting structure 5 via a gear carrier 15. And a circulating lubricating oil system is also arranged on the gear bracket 15 and used for lubricating and cooling the gear reduction structure 4 in the high-speed operation process.

Meanwhile, in the present embodiment, the low pressure shaft 3 and the high pressure shaft 8 are hollow shafts, and thus the gear reduction structure 4 is configured by using the hollow low pressure shaft 3. For configuration, the tail end of the low-pressure shaft 3 is expanded outwards and is connected with a gear end sleeve gear 20 of the outer ring of the inner ring gear 19 through a built-in sleeve gear, so as to accommodate the gear speed reducing structure 4 and realize synchronous rotation with the inner ring gear 19. Of course, besides the set of teeth, other assembling structures capable of realizing synchronous rotation or a method of integrally designing the inner gear ring 19 and the outward expansion end of the low-pressure shaft 3 can be adopted to realize synchronous rotation.

In some embodiments, a similar deceleration function as the present invention can be achieved by using an inner gear ring 19 directly connected to the front support 5 and planet gears 18 connected to the low pressure shaft 3 via the gear support 15.

In order to realize the transmission connection between the low-pressure shaft 3 and the high-pressure shaft 8 and realize that the low-pressure shaft and the high-pressure shaft rotate at different speeds, in the embodiment, after the gear reduction structure 4 is arranged, a coupler 14 is further arranged between the high-pressure shaft 8 and the gear reduction structure 4. The front end sleeve teeth of the coupler 14 are connected with the gear end sleeve teeth 20 on the inner side of the sun gear 17, and the rear end of the coupler 14 is connected with the high-pressure shaft 8. Of course, the coupling 14 mainly serves as an auxiliary mounting and transmission function, and the front end of the high-pressure shaft 8 can be directly connected with the sun gear 17.

In the invention, the rotor of the compressor 7 and the rotor of the high-pressure turbine 9 can work at high rotating speed, thereby achieving higher working capacity and efficiency. The planetary gear speed reducing structure can effectively reduce the rotating speed of the internal and external culvert combined fan (fan component and booster stage), so that the fan can work at a relatively low rotating speed, the tangential speed of the blade tips of the fan blades can be reduced, and the working reliability of the fan is improved. The design configuration (by designing a proper gear reduction ratio) can effectively solve the problem that the rotating speeds of the high-pressure turbine, the air compressor and the fan are not matched, so that the high-pressure turbine, the air compressor and the fan all work at the respective optimal rotating speeds, the pneumatic efficiency of the engine is increased, the working reliability is improved, and the fuel consumption rate and the noise influence on the environment are greatly reduced.

In the invention, because the high-pressure shaft works at a higher rotating speed, the number of stages of the compressor on the high-pressure shaft is reduced, and the structure of the high-pressure turbine is compact. The engine not only shortens the total length of the engine and lightens the total weight of the engine, but also improves the working capacity and efficiency of components such as a fan, a gas compressor, a turbine and the like, and simultaneously can reduce the size of the starting integrated motor working at high rotating speed.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, the word "comprising" does not exclude the presence of elements or methods other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The mere fact that certain features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage.

Claims (10)

1. The utility model provides a simple and easy gear drive turbofan engine which characterized in that:

the device comprises a fan component, a booster stage, a low-pressure shaft, a gear reduction structure, a front support structure, a high-pressure shaft, a starting and power generation integrated motor, a gas compressor, a high-pressure turbine and a rear support structure;

the rotor of the fan component and the rotor of the booster stage are arranged on the low-pressure shaft to realize synchronous rotation with the low-pressure shaft; the low-pressure shaft is connected with the front support structure through a bearing, and during operation, the low-pressure shaft transmits load to the front support structure through the bearing.

The rotor of the starting and power generation integrated motor, the rotor of the gas compressor and the rotor of the high-pressure turbine are arranged on the high-pressure shaft so as to synchronously rotate with the high-pressure shaft; the high-pressure shaft is connected with the front supporting structure and the rear supporting structure through bearings, and during operation, the high-pressure shaft transmits load to the front supporting structure and the rear supporting structure respectively.

The high-pressure shaft is connected with the low-pressure shaft through a gear reduction structure so as to realize the speed reduction rotation of the low-pressure shaft, and the gear reduction structure is connected with the front support structure through a gear bracket.

2. The simple geared turbofan engine of claim 1 wherein: the rotor of the fan component and the rotor of the booster stage are sequentially arranged on the low-pressure shaft along the axial direction; and the rotor of the starting and power generation integrated motor, the rotor of the gas compressor and the rotor of the high-pressure turbine are sequentially arranged on the high-pressure shaft along the axial direction.

3. The simple geared turbofan engine according to claim 1 or 2 wherein: the low-pressure shaft is mounted on the front bearing support through the bearing, and the front bearing support is mounted on the front support structure to realize load transfer from the low-pressure shaft to the front support structure.

4. The simple geared turbofan engine according to claim 1 or 2 wherein: the high-pressure shaft is respectively arranged on the middle bearing support and the rear bearing support through the bearings, the middle bearing support is connected with the front supporting structure, and the rear bearing support is connected with the rear supporting structure, so that the high-pressure shaft can transmit loads to the front supporting structure and the rear supporting structure respectively.

5. The simple geared turbofan engine according to claim 1 or 2 wherein: the low-pressure shaft and the high-pressure shaft are hollow shafts.

6. The simple geared turbofan engine of claim 5 wherein: the tail end of the low-pressure shaft is expanded to accommodate a gear reduction structure.

7. The simple geared turbofan engine of claim 6 wherein: the gear reduction structure comprises an inner gear ring, a planet gear in meshing transmission with the inner gear ring and a sun gear in meshing transmission with the planet gear.

8. The simple geared turbofan engine of claim 7 wherein: the tail end of the low-pressure shaft and the inner gear ring are of an integrated structure.

9. The simple geared turbofan engine of claim 7 wherein: the tail end of the low-pressure shaft is externally expanded and internally provided with sleeve teeth to be connected with the gear end sleeve teeth of the outer ring of the inner gear ring, so that the gear speed reducing structure is accommodated and synchronously rotates with the inner gear ring.

10. The simple geared turbofan engine of claim 7 wherein: the high-pressure shaft and the gear speed reducing structure are provided with a coupler, the front end of the coupler is in gear connection with the gear end sleeve on the inner side of the sun gear, and the rear end of the coupler is connected with the high-pressure shaft.

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