阅读说明：本技术 一种共轴双旋翼带尾推直升机传动系统及直升机 (Coaxial double-rotor tail-equipped straight-pushing helicopter transmission system and helicopter ) 是由 石前列 丁文强 胡强 孙玉飞 吴志广 梁鸿章 于 2020-07-22 设计创作，主要内容包括：本发明属于直升机领域,公开了一种共轴双旋翼带尾推直升机传动系统及直升机,传动系统包括第一锥齿轮、第一换向锥齿轮、第二锥齿轮、第二换向锥齿轮、尾推输出轴、第三锥齿轮、第三换向锥齿轮和星形齿轮系,第一锥齿轮与动力输入轴连接,第一换向锥齿轮与第一锥齿轮啮合；第二锥齿轮与第一换向锥齿轮传动连接,第二换向锥齿轮与第二锥齿轮啮合,第二换向锥齿轮与尾推输出轴连接,尾推输出轴与尾推进桨传动连接；第三锥齿轮与第二换向锥齿轮传动连接,第三换向锥齿轮与第三锥齿轮啮合；第三换向锥齿轮与星形齿轮系传动连接。本发明尾推进桨传动设置为两级传动输出,共轴双旋翼设置为四级传动输出,可同时满足尾推进桨和共轴双旋翼的功率输出需求。(The invention belongs to the field of helicopters, and discloses a coaxial double-rotor tail-belt-propelling helicopter transmission system and a helicopter, wherein the transmission system comprises a first bevel gear, a first reversing bevel gear, a second reversing bevel gear, a tail-propelling output shaft, a third bevel gear, a third reversing bevel gear and a star-shaped gear train, the first bevel gear is connected with a power input shaft, and the first reversing bevel gear is meshed with the first bevel gear; the second bevel gear is in transmission connection with the first reversing bevel gear, the second reversing bevel gear is meshed with the second bevel gear, the second reversing bevel gear is connected with the tail pushing output shaft, and the tail pushing output shaft is in transmission connection with the tail pushing paddle; the third bevel gear is in transmission connection with the second reversing bevel gear, and the third reversing bevel gear is meshed with the third bevel gear; and the third reversing bevel gear is in transmission connection with the star gear train. The tail propulsion propeller transmission is set to be two-stage transmission output, and the coaxial double rotors are set to be four-stage transmission output, so that the power output requirements of the tail propulsion propeller and the coaxial double rotors can be met simultaneously.)

1. A coaxial dual-rotor tail-thrust helicopter transmission system, comprising:

the first-stage reversing transmission mechanism comprises a first bevel gear and a first reversing bevel gear, the first bevel gear is used for being connected with the power input shaft, and the first reversing bevel gear is meshed with the first bevel gear;

the second-stage tail pushing output mechanism comprises a second bevel gear, a second reversing bevel gear and a tail pushing output shaft, the second bevel gear is in transmission connection with the first reversing bevel gear, the second reversing bevel gear is meshed with the second bevel gear, the second reversing bevel gear is connected with the tail pushing output shaft, and the tail pushing output shaft is in transmission connection with a tail pushing paddle;

the three-stage reversing transmission mechanism comprises a third bevel gear and a third reversing bevel gear, the third bevel gear is in transmission connection with the second reversing bevel gear, and the third reversing bevel gear is meshed with the third bevel gear;

and the four-stage double-rotor output mechanism comprises a star gear train which is used for being in transmission connection with the coaxial double rotors, and the third reversing bevel gear is in transmission connection with the star gear train.

2. A coaxial dual-rotor tail-thrust helicopter transmission system according to claim 1,

the number of the first-stage reversing transmission mechanisms is two, and each first-stage reversing transmission mechanism is connected with one power input shaft;

the number of the second bevel gears is two, each second bevel gear is in transmission connection with one first reversing bevel gear, and the two second bevel gears are meshed with the second reversing bevel gears.

3. A coaxial dual-rotor tail-thrust helicopter transmission system according to claim 1,

the star gear train comprises a gear ring, a sun gear, a planet gear, a first cylindrical gear and a second cylindrical gear, the sun gear is in transmission connection with a third reversing bevel gear, the planet gear is meshed with the sun gear, the gear ring is meshed with the planet gear, the gear ring is used for being in transmission connection with an outer rotor shaft, the first cylindrical gear is coaxial with the planet gear, the second cylindrical gear is meshed with the first cylindrical gear, and the second cylindrical gear is used for being in transmission connection with an inner rotor shaft.

4. A coaxial dual-rotor tail-thrust helicopter transmission system according to claim 3 wherein said planet gears and said first cylindrical gear are each a plurality of and wherein a plurality of said planet gears are in external mesh with said sun gear and a plurality of said first cylindrical gear are in external mesh with said second cylindrical gear.

5. A coaxial dual-rotor tail-thrust helicopter transmission system according to claim 4 wherein a plurality of said planets are in mesh with said ring gear.

6. A coaxial dual-rotor tail-thrust helicopter transmission system according to claim 3 wherein said first cylindrical gear and said second cylindrical gear are helical gears.

7. A coaxial dual-rotor tail-thrust helicopter transmission system according to claim 1 further comprising an accessory output mechanism;

the accessory output mechanism comprises a fourth reversing bevel gear and an accessory output shaft, the fourth reversing bevel gear is meshed with the third reversing bevel gear, and the accessory output shaft is in transmission connection with the fourth reversing bevel gear.

8. A coaxial dual-rotor tail-thrust helicopter transmission system according to claim 7,

the accessory output mechanism further comprises a third cylindrical gear and a plurality of fourth cylindrical gears, the third cylindrical gear is in transmission connection with the fourth reversing bevel gear, and the plurality of fourth cylindrical gears are meshed with the third cylindrical gear;

the number of the accessory output shafts is multiple, and the accessory output shafts are in one-to-one corresponding transmission connection with the fourth cylindrical gears.

9. A co-axial dual rotor tail-thrust helicopter transmission system according to claim 1 wherein said third bevel gear is integrated on the same shaft as said second reversing bevel gear.

10. A helicopter comprising a coaxial twin rotor tail-thrust transmission system according to any of claims 1 to 9.

Technical Field

The invention relates to the field of helicopters, in particular to a coaxial double-rotor tail-belt-propelling helicopter transmission system and a helicopter.

Background

The coaxial rigid rotor high-speed helicopter adopts a coaxial rigid rotor structure with a tail propeller, and a helicopter transmission system matched with the coaxial rigid rotor structure needs to transmit the power of an engine to a coaxial double rotor and the tail propeller. Because the high-speed helicopter has high flying speed, compared with the traditional single-rotor helicopter with a tail propeller pushing structure, the tail propeller pushing power of the coaxial double-rotor helicopter transmission system is obviously improved and basically equivalent to the output power of the coaxial double rotors. The existing transmission system cannot meet the power transmission of a high-power coaxial double-rotor-wing propelling propeller with a tail.

Disclosure of Invention

The invention aims to provide a coaxial double-rotor tail-equipped straight-pushing helicopter transmission system and a helicopter, which can meet the power output requirements of a tail-pushing propeller and a coaxial double rotor simultaneously.

The technical scheme provided by the invention is as follows:

in one aspect, a coaxial dual-rotor tail-thrust helicopter transmission system is provided, comprising:

the first-stage reversing transmission mechanism comprises a first bevel gear and a first reversing bevel gear, the first bevel gear is used for being connected with the power input shaft, and the first reversing bevel gear is meshed with the first bevel gear;

the second-stage tail pushing output mechanism comprises a second bevel gear, a second reversing bevel gear and a tail pushing output shaft, the second bevel gear is in transmission connection with the first reversing bevel gear, the second reversing bevel gear is meshed with the second bevel gear, the second reversing bevel gear is connected with the tail pushing output shaft, and the tail pushing output shaft is in transmission connection with a tail pushing paddle;

the three-stage reversing transmission mechanism comprises a third bevel gear and a third reversing bevel gear, the third bevel gear is in transmission connection with the second reversing bevel gear, and the third reversing bevel gear is meshed with the third bevel gear;

and the four-stage double-rotor output mechanism comprises a star gear train which is used for being in transmission connection with the coaxial double rotors, and the third reversing bevel gear is in transmission connection with the star gear train.

In the scheme, the high-power state of the tail propulsion propeller occupies a larger proportion, and the high-power output state of the coaxial dual rotors occupies a smaller proportion; therefore, the tail propulsion propeller transmission adopts two-stage transmission output, and the coaxial double-rotor output adopts four-stage transmission, so that the power output requirements of the tail propulsion propeller and the coaxial double-rotor can be met simultaneously; the tail propulsion paddle adopts two-stage transmission, so that the length of a power transmission link is shortened, the transmission efficiency is high, and the power loss is reduced, so that the high-power transmission requirement of the tail propulsion paddle is met; in addition, the transmission system has fewer gears, and the power of the whole transmission chain is not repeatedly transmitted among the gears, so that the sum of the total estimated power of the gears is reduced, the weight of the transmission system is obviously reduced, the structural sizes of the gears and the casing are reduced, and the manufacturability of the transmission system is improved.

Further preferably, the number of the primary reversing transmission mechanisms is two, and each primary reversing transmission mechanism is connected with one power input shaft;

the number of the second bevel gears is two, each second bevel gear is in transmission connection with one first reversing bevel gear, and the two second bevel gears are meshed with the second reversing bevel gears.

In the scheme, multiple inputs are arranged, and the high-power transmission requirement of the tail propulsion paddle can be met through the parallel operation output of the second reversing bevel gear.

Further preferably, the star gear train includes a gear ring, a sun gear, a planetary gear, a first cylindrical gear and a second cylindrical gear, the sun gear is in transmission connection with the third reversing bevel gear, the planetary gear is engaged with the sun gear, the gear ring is engaged with the planetary gear, the gear ring is used for being in transmission connection with an outer rotor shaft, the first cylindrical gear is coaxial with the planetary gear, the second cylindrical gear is engaged with the first cylindrical gear, and the second cylindrical gear is used for being in transmission connection with an inner rotor shaft.

Further preferably, the number of the planet gears and the number of the first cylindrical gears are both multiple, the plurality of the planet gears are externally meshed with the sun gear, and the plurality of the first cylindrical gears are externally meshed with the second cylindrical gear.

Further preferably, a plurality of the planet wheels are in internal mesh with the ring gear.

In the scheme, the third reversing bevel gear drives the sun gear to rotate, the sun gear drives the planet gear to rotate when rotating, the planet gear drives the gear ring to rotate when rotating, and the gear ring drives the outer rotor shaft to rotate when rotating, so that the outer rotor shaft is rotated; the planet gear also drives the first cylindrical gear to rotate when rotating, the first cylindrical gear drives the second cylindrical gear to rotate when rotating, and the second cylindrical gear drives the inner rotor shaft to rotate when rotating, so that the rotation of the inner rotor shaft is realized; the planet gear is internally meshed with the gear ring, and the first cylindrical gear is externally meshed with the second cylindrical gear, so that the rotation directions of the outer rotor shaft and the inner rotor shaft are opposite.

Further preferably, the first cylindrical gear and the second cylindrical gear are both helical gears.

Further preferably, an accessory output mechanism is also included;

the accessory output mechanism comprises a fourth reversing bevel gear and an accessory output shaft, the fourth reversing bevel gear is meshed with the third reversing bevel gear, and the accessory output shaft is in transmission connection with the fourth reversing bevel gear.

In this scheme, through setting up annex output mechanism, can give annexs such as the hydraulic pump on the helicopter with power transmission for a transmission system can solve the tail and impel the power transmission of oar, coaxial bispin wing and annex, avoids setting up a plurality of transmission systems on the helicopter.

Further preferably, the accessory output mechanism further comprises a third cylindrical gear and a plurality of fourth cylindrical gears, the third cylindrical gear is in transmission connection with the fourth reversing bevel gear, and the plurality of fourth cylindrical gears are meshed with the third cylindrical gear;

the number of the accessory output shafts is multiple, and the accessory output shafts are in one-to-one corresponding transmission connection with the fourth cylindrical gears.

In the scheme, when a plurality of accessories are arranged, power division is realized through the meshing of the fourth cylindrical gears and the third cylindrical gears, and power is transmitted to the accessories to drive the accessories to work.

Further preferably, the third bevel gear and the second reversing bevel gear are integrated on the same shaft.

In another aspect, a helicopter is also provided, comprising the coaxial double-rotor tail-pushing helicopter transmission system.

The invention has the technical effects that: the tail propulsion propeller transmission is set to be two-stage transmission output, and the coaxial double rotors are set to be four-stage transmission output, so that the power output requirements of the tail propulsion propeller and the coaxial double rotors can be met simultaneously; in addition, the transmission system has fewer gears, the power of the whole transmission chain is not repeatedly transmitted among the gears, the sum of the total estimated power of the gears is reduced, the weight of the transmission system is obviously reduced, the structural size of the gears and a casing is reduced, and the manufacturability of the transmission system is improved.

Drawings

The invention is described in further detail below with reference to the following figures and detailed description:

FIG. 1 is a schematic diagram of a coaxial dual rotor tail-thrust helicopter transmission system of the present invention;

FIG. 2 is a top view of a coaxial dual rotor tail-thrust helicopter transmission of the present invention;

figure 3 is a front view of a coaxial dual rotor tail-thrust helicopter transmission system of the present invention.

The reference numbers illustrate:

1. a power input shaft; 2. an outer rotor shaft; 3. an inner rotor shaft; 10. a first-stage reversing transmission mechanism; 11. a first bevel gear; 12. a first reversing bevel gear; 20. a secondary tail pushing output mechanism; 21. a second bevel gear; 22. a second reversing bevel gear; 23. the tail pushes the output shaft; 30. a three-stage reversing transmission mechanism; 31. a third bevel gear; 32. a third reversing bevel gear; 40. a four-stage double-rotor output mechanism; 41. a ring gear; 42. a sun gear; 43. a planet wheel; 44. a first cylindrical gear; 45. a second cylindrical gear; 50. an accessory output mechanism; 51. a fourth reversing bevel gear; 52. an accessory output shaft; 53. a third cylindrical gear; 54. and a fourth cylindrical gear.

Detailed Description

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

For the sake of simplicity, the drawings only schematically show the parts relevant to the present invention, and they do not represent the actual structure as a product. In addition, in order to make the drawings concise and understandable, components having the same structure or function in some of the drawings are only schematically illustrated or only labeled. In this document, "one" means not only "only one" but also a case of "more than one".

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

In this context, it is to be understood that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition, in the description of the present application, the terms "first", "second", and the like are used only for distinguishing the description, and are not intended to indicate or imply relative importance.

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description will be made with reference to the accompanying drawings. It is obvious that the drawings in the following description are only some examples of the invention, and that for a person skilled in the art, other drawings and embodiments can be derived from them without inventive effort.

The invention provides a specific embodiment of a coaxial double-rotor tail-push helicopter transmission system, which comprises a first-stage reversing transmission mechanism 10, a second-stage tail-push output mechanism 20, a third-stage reversing transmission mechanism 30 and a fourth-stage double-rotor output mechanism 40, as shown in fig. 1 to 3; the first-stage reversing transmission mechanism 10 comprises a first bevel gear 11 and a first reversing bevel gear 12, the first bevel gear 11 is used for being connected with the power input shaft 1, and the first reversing bevel gear 12 is meshed with the first bevel gear 11;

the two-stage tail pushing output mechanism 20 comprises a second bevel gear 21, a second reversing bevel gear 22 and a tail pushing output shaft 23, the second bevel gear 21 is in transmission connection with the first reversing bevel gear 12, the second reversing bevel gear 22 is meshed with the second bevel gear 21, the second reversing bevel gear 22 is connected with the tail pushing output shaft 23, and the tail pushing output shaft 23 is in transmission connection with a tail pushing paddle;

the three-stage reversing transmission mechanism 30 comprises a third bevel gear 31 and a third reversing bevel gear 32, the third bevel gear 31 is in transmission connection with the second reversing bevel gear 22, and the third reversing bevel gear 32 is meshed with the third bevel gear 31;

the four-stage dual-rotor output mechanism 40 comprises a star gear train for driving connection with the coaxial dual rotors, and the third reversing bevel gear 32 is in driving connection with the star gear train.

Specifically, as shown in fig. 1 to 3, the primary reversing transmission mechanism 10 includes a first bevel gear 11 and a first reversing bevel gear 12, the first bevel gear 11 is connected to the power input shaft 1, the power input shaft 1 is an output shaft of an engine, and the power input shaft 1 drives the first bevel gear 11 to rotate when rotating; the first reversing bevel gear 12 is meshed with the first bevel gear 11 to realize power input reversing.

The two-stage tail pushing output mechanism 20 comprises a second bevel gear 21, a second reversing bevel gear 22 and a tail pushing output shaft 23, the second bevel gear 21 is in transmission connection with the first reversing bevel gear 12 through a transmission shaft, the first reversing bevel gear 12 drives the second bevel gear 21 to rotate when rotating, the second reversing bevel gear 22 is meshed with the second bevel gear 21 to achieve output reversing, the second reversing bevel gear 22 is fixedly connected with the tail pushing output shaft 23, and the tail pushing output shaft 23 is connected with a tail pushing paddle to achieve power output of the tail pushing paddle.

The three-stage reversing transmission mechanism 30 comprises a third bevel gear 31 and a third reversing bevel gear 32, the third bevel gear 31 is in transmission connection with the second reversing bevel gear 22 through a transmission shaft, the second reversing bevel gear 22 drives the third bevel gear 31 to rotate when rotating, the third reversing bevel gear 32 is meshed with the third bevel gear 31, and the third bevel gear 31 drives the third reversing bevel gear 32 to rotate when rotating, so that power reversing is realized.

The four-stage double-rotor output mechanism 40 comprises a star gear train, and a third reversing bevel gear 32 drives the coaxial output of the star gear train, so that the star gear train can drive the coaxial double rotors to realize positive and negative rotation of the outer rotor shaft 2 and the inner rotor shaft 3 of the coaxial double rotors.

In the research and development process, the inventor finds that when the helicopter flies, the high-power state of the tail propulsion propeller accounts for a large proportion, and the high-power output state of the coaxial double rotors accounts for a small proportion; therefore, in the embodiment, the tail propulsion propeller is driven by two-stage transmission output, the coaxial double-rotor output is driven by four stages, and the power output requirements of the tail propulsion propeller and the coaxial double-rotor can be met simultaneously.

The first stage of tail propulsion paddle transmission adopts spiral bevel gear input reversing, the second stage adopts spiral bevel gear output, the transmission link length of the tail propulsion paddle is shortened, the transmission efficiency is high, the power loss is reduced, the high-power transmission requirement of the tail propulsion paddle is met, in addition, the transmission system reduces the number of gears, the power of the whole transmission chain is not repeatedly transmitted among the gears, the sum of the total power evaluated by the gears is reduced, the weight of the transmission system is obviously reduced, the structural size of the gears and a casing is reduced, and the manufacturability of the transmission system is improved.

Preferably, as shown in fig. 1 to 3, the number of the primary reversing transmission mechanisms 10 is two, and each primary reversing transmission mechanism 10 is connected with one power input shaft 1; the number of the second bevel gears 21 is two, the number of the second bevel gears 21 corresponds to that of the first-stage reversing mechanism 10, each second bevel gear 21 is in transmission connection with one first reversing bevel gear 12, and the two second bevel gears 21 are both meshed with the second reversing bevel gear 22. In the embodiment, double-engine power input is adopted, parallel output is realized through the second reversing bevel gear 22, power confluence is realized, and power and rotating speed are transmitted to the tail propulsion output shaft 23, so that the requirement of high-power transmission of the tail propulsion paddle is met. The third bevel gear 31 and the second reversing bevel gear 22 are integrated on the tail push output shaft 23, the second reversing bevel gear 22 can transmit the converged power to the third bevel gear 31, the third reversing bevel gear 32 realizes reversing and then drives the star gear train to coaxially output, the power is transmitted to the coaxial double rotors, and the forward and reverse rotation of the outer rotor shaft 2 and the inner rotor shaft 3 of the coaxial double rotors is realized. Similarly, the number of the power input shaft 1 and the primary reversing transmission mechanism 10 can be further increased to form more than three power inputs, and the power inputs are combined and output to the tail propulsion paddle through the second reversing bevel gear 22.

As shown in fig. 1, the star gear train includes a ring gear 41, a sun gear 42, planet gears 43, a first cylindrical gear 44 and a second cylindrical gear 45, the sun gear 42 is in transmission connection with the third reversing bevel gear 32, the planet gears 43 are in mesh with the sun gear 42, the ring gear 41 is in mesh with the planet gears 43, the ring gear 41 is used for transmission connection with the outer rotor shaft 2, the first cylindrical gear 44 is coaxially arranged with the planet gears 43, the second cylindrical gear 45 is in mesh with the first cylindrical gear 44, and the second cylindrical gear 45 is used for transmission connection with the inner rotor shaft 3. The planetary gears 43 and the first cylindrical gears 44 are both multiple, the planetary gears 43 are externally meshed with the sun gear 42, and the first cylindrical gears 44 are externally meshed with the second cylindrical gear 45.

Specifically, the ring gear 41 is an inner ring gear, the sun gear 42 is in transmission connection with the third reversing bevel gear 32 through a transmission shaft, the third reversing bevel gear 32 drives the sun gear 42 to rotate when rotating, the plurality of planet gears 43 are meshed outside the sun gear 42, the sun gear 42 drives the plurality of planet gears 43 to rotate when rotating, power division is achieved, the plurality of planet gears 43 are meshed with the ring gear 41 to achieve power convergence, the ring gear 41 is fixedly connected with the outer rotor shaft 2, and the ring gear 41 drives the outer rotor shaft 2 to rotate when rotating.

Each planet wheel 43 is in transmission connection with one first cylindrical gear 44, each first cylindrical gear 44 is a helical gear, the planet wheels 43 drive the first cylindrical gears 44 to rotate through a transmission shaft when rotating, the first cylindrical gears 44 are externally meshed with the second cylindrical gears 45, the second cylindrical gears 45 are helical gears, power confluence is achieved, the second cylindrical gears 45 are fixedly connected with the inner rotor shaft 3, the second cylindrical gears 45 drive the inner rotor shaft 3 to rotate when rotating, and the outer rotor shaft 2 and the inner rotor shaft 3 rotate around the same theoretical axis in a forward-reverse rotation mode.

Preferably, as shown in FIG. 1, an accessory output mechanism 50 is also included; the accessory output mechanism 50 comprises a fourth reversing bevel gear 51 and an accessory output shaft 52, the fourth reversing bevel gear 51 is meshed with the third reversing bevel gear 32, and the accessory output shaft 52 is in transmission connection with the fourth reversing bevel gear 51. After reversing by the fourth reversing bevel gear 51, power is transmitted to accessories such as a hydraulic pump on the helicopter through an accessory output shaft 52 so as to drive the accessories to work.

When a plurality of accessories are arranged, the accessory output mechanism 50 further comprises a third cylindrical gear 53 and a plurality of fourth cylindrical gears 54, the third cylindrical gear 53 is in transmission connection with a fourth reversing bevel gear 54, and the plurality of fourth cylindrical gears 54 are meshed with the third cylindrical gear 53; the number of the accessory output shafts 52 is multiple, the multiple accessory output shafts 52 are in one-to-one corresponding transmission connection with the multiple fourth cylindrical gears 54, and each accessory output shaft 52 is in transmission connection with one accessory so as to drive the accessories to work.

The present invention also provides a helicopter embodiment, as shown in fig. 1 to 3, comprising a power input mechanism, a tail propulsion paddle, a coaxial dual-rotor mechanism and a coaxial dual-rotor tail-thrust transmission system in the above embodiments. The power input mechanism comprises a power input shaft 1, the power input shaft 1 is in transmission connection with a first bevel gear 11, drives the first bevel gear 11 to rotate, and inputs and reverses through a first reversing bevel gear 12. The power input mechanism may be plural to form multiple inputs.

The tail propulsion paddle is in transmission connection with a tail propulsion output shaft 23 in the two-stage tail propulsion output mechanism 20, the tail propulsion output shaft 23 is connected with a second reversing bevel gear 22, the second reversing bevel gear 22 can combine multiple input powers and then transmit the power to the tail propulsion paddle through the tail propulsion output shaft 23, the tail propulsion paddle adopts two-stage transmission output, transmission efficiency is improved, power loss is reduced, and the high-power large-duty-ratio state of the tail propulsion paddle can be met.

The three-stage reversing transmission mechanism 30 reverses the power of the second reversing bevel gear 22 and then transmits the power to the star-shaped gear train, the inner rotor shaft 3 of the coaxial double rotors is in transmission connection with a second cylindrical gear 45 in the star-shaped gear train, the outer rotor shaft 2 is connected with a gear ring 41 in the star-shaped gear train, the second reversing bevel gear 22 drives the star-shaped gear train to output coaxially, so that the outer rotor shaft 2 and the inner rotor shaft 3 rotate coaxially, and the rotating directions of the outer rotor shaft 2 and the inner rotor shaft 3 are opposite. Further, the transmission system may also transmit power to accessories, such as hydraulic pumps on the helicopter, via the accessory output mechanism 50 to drive the accessories to operate.

Because the high-power output state of the tail propulsion propeller occupies a relatively large proportion and the high-power output state of the coaxial dual rotors occupies a relatively small proportion, in the embodiment, the transmission output of the tail propulsion propeller adopts two-stage transmission, and the output of the coaxial dual rotors adopts four-stage transmission, so that the power output requirements of the tail propulsion propeller and the coaxial dual rotors can be met simultaneously. In addition, the whole power flow of the transmission chain of the transmission system of the embodiment is not repeatedly transmitted among the gears, the sum of the total estimated power of the gears is reduced, the weight of the transmission system is obviously reduced, the structural sizes of the gears and the casing are reduced, and the manufacturability of the transmission system is improved.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.