Face gear-based single-engine four-rotor unmanned aerial vehicle main reducer and aircraft

Abstract

The main speed reducer comprises an input mechanism, one end of the input mechanism is externally connected with power output equipment, and the other end of the input mechanism is connected with a first-stage speed reducing mechanism; the secondary speed reducing mechanism comprises two groups of secondary speed reducing devices, and the two groups of secondary speed reducing devices are arranged at one end and the other end of the primary speed reducing mechanism and are axially vertical to the primary speed reducing mechanism; wherein the number of each group of secondary speed reduction devices is two, and the rotor mechanisms are arranged on the two secondary speed reduction devices. The second-stage speed reducing mechanisms are arranged at the two ends of the first-stage speed reducing mechanism and are axially perpendicular to the first-stage speed reducing mechanism, so that the whole speed reducer is more compact in structure, the size of the unmanned aerial vehicle is reduced, the overall weight of the unmanned aerial vehicle is reduced, the transmission ratio is increased, the transmission efficiency is improved, and the flight efficiency and cruising ability of the unmanned aerial vehicle are improved.

Description

Technical Field

[0001] The present invention belongs to the field of aviation technology, and in particular relates to a main reducer of a single-engine four-rotor unmanned aerial vehicle based on face gears and an aircraft. Background Art

[0002] The main reducer, as a key component of the power transmission system of a quadcopter UAV, mainly converts the high-speed rotational motion of a power source such as a motor or engine into a low-speed, high-torque rotational motion of the rotor shaft, thereby providing sufficient lift for the rotor and ensuring the normal flight of the UAV. It directly affects the flight performance, reliability and service life of the UAV.

[0003] However, in the prior art, since the main reducer of the quadcopter UAV adopts bevel gears for transmission, the transmission ratio of the bevel gears is small, the transmission efficiency is low, and the structure is complex during operation, which makes the entire main reducer heavy; in addition, the bevel gears are usually manufactured and used in pairs. When the main reducer is subsequently maintained, they need to be replaced in pairs, with poor interchangeability, high maintenance costs, great difficulty and long cycles; secondly, since the transmission ratio of the bevel gears is relatively small, the transmission ratio of the single-stage bevel gear transmission is generally within 3, resulting in the inability to increase the speed ratio of the whole machine under the original volume, and the power density is limited; finally, due to processing errors and installation errors, the cone top angles cannot overlap, resulting in an unstable transmission ratio, unstable transmission, and prone to fatigue problems. When multiple pairs of bevel gear pairs are engaged at the same time, the axial force on the bearing is large, and the overall installation and adjustment are difficult. Summary of the invention

[0004] The purpose of the present invention is to provide a single-engine four-rotor UAV main reducer and an aircraft based on face gears, so as to solve the technical defects in the prior art that the four-rotor UAV main reducer adopts bevel gears for transmission, and the bevel gears have a small transmission ratio and low transmission efficiency during operation, and the structure is complex, which makes the weight of the entire main reducer heavy.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, a main reducer for a single-engine quad-rotor UAV based on a face gear is provided, comprising: An input mechanism, one end of which is connected to an external power output device, and the other end is connected to a first-stage reduction mechanism; The two-stage reduction mechanism comprises two sets of two-stage reduction devices, wherein the two sets of two-stage reduction devices are arranged at one end and the other end of the one-stage reduction mechanism and are perpendicular to the axial direction of the one-stage reduction mechanism; There are two secondary reduction devices in each group, and both secondary reduction devices are provided with a rotor mechanism.

[0006] Furthermore, the first-stage reduction mechanism includes a first-stage reduction device and a second-stage reduction device, and the first-stage reduction device and the second-stage reduction device are arranged on two opposite sides of the other end of the input mechanism and are transmission-connected to the other end of the input mechanism; One set of the secondary reduction devices is arranged at the end of the first stage first reduction device, and the other set of the secondary reduction devices is arranged at the end of the first stage second reduction device, and the two sets of the secondary reduction devices are separated from each other.

[0007] Furthermore, the first stage reduction device and the second stage reduction device overlap axially.

[0008] Furthermore, the two sets of secondary reduction devices are axially parallel.

[0009] Furthermore, the first stage reduction device and the second stage reduction device have the same structure.

[0010] Furthermore, the two groups of the two-stage reduction gears have the same structure.

[0011] Furthermore, two secondary reduction devices are symmetrically arranged at the ends of the primary reduction mechanism.

[0012] Furthermore, the two secondary reduction devices rotate in opposite directions so that the two rotor mechanisms rotate in the same direction.

[0013] Furthermore, the power output device is a motor or an engine.

[0014] In a second aspect, an aircraft is provided, comprising an aircraft body, on which is mounted the above-described single-engine four-rotor UAV main reducer based on face gears.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. By setting the secondary reduction mechanism at both ends of the primary reduction mechanism and perpendicular to the axial direction of the primary reduction mechanism, the entire reducer structure is made more compact, which not only reduces the size of the drone, but also reduces the overall weight of the drone, improves the transmission ratio and transmission efficiency, thereby improving the flight efficiency and endurance of the drone.

[0016] 2. The parallel setting of the first-stage reduction gear and the second-stage reduction gear ensures the balanced distribution of power from the input mechanism to the two first-stage reduction gears, reduces the unbalanced loss during power transmission, and improves the efficiency of the entire transmission system.

[0017] 3. Since the two primary reduction devices are axially overlapped, the transmission path of power from the input mechanism to the two secondary reduction devices becomes shorter, reducing the power loss during the transmission process.

[0018] 4. The parallel-arranged secondary reduction devices support each other in structure, which enhances the stability of the entire transmission system, can resist various forces and moments that may be generated during flight, and improve the structural strength and durability of the UAV.

[0019] 5. Since the two primary reduction gears have the same structure and are highly interchangeable, the same spare parts can be used to replace damaged parts during repair or replacement, without distinguishing between left and right or up and down, thus simplifying the maintenance process.

[0020] 6. The secondary reduction gears with the same structure maintain consistent transmission performance, which helps to ensure that the power is transmitted from the primary reduction gear to the rotor mechanism in a balanced and stable manner.

[0021] 7. The symmetrical setting helps to balance the load on the two secondary reduction devices, avoiding excessive wear or failure due to uneven load.

[0022] 8. By making the two secondary reduction devices rotate in opposite directions, it can be ensured that the two rotor mechanisms rotate in the same direction, reducing the torque imbalance problem caused by the different rotation directions of the rotors. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 A bottom view of the main reducer of a single-engine quad-rotor UAV based on face gears provided by the present invention; Figure 2 A stereoscopic diagram of the main reducer of a single-engine quad-rotor UAV based on face gears provided by the present invention; Among them: 1. Input shaft; 2. Input shaft bearing; 3. Input shaft gear; 4. First-stage first reduction face gear; 5. First-stage first reduction shaft first bearing; 6. First-stage first reduction shaft; 7. First-stage first reduction shaft second bearing; 8. First-stage first reduction shaft output gear; 9. First-stage second reduction face gear; 10. First-stage second reduction shaft first bearing; 11. First-stage second reduction shaft; 12. First-stage second reduction shaft second bearing; 13. First-stage second reduction shaft output gear; 14. Second-stage first reduction face gear; 15. Second-stage first reduction shaft first bearing; 16. Second-stage first reduction shaft; 17. Second-stage first reduction shaft second bearing; 18. Second-stage first reduction shaft output gear; 19. First rotor shaft face gear; 20. Second-stage second reduction face gear; 21. Second-stage second reduction shaft first bearing; 22. Second-stage second reduction shaft; Speed ​​shaft; 23, second bearing of second-stage second reduction shaft; 24, output gear of second-stage second reduction shaft; 25, second rotor shaft face gear; 26, third reduction face gear of second stage; 27, first bearing of second-stage third reduction shaft; 28, second-stage third reduction shaft; 29, second bearing of second-stage third reduction shaft; 30, output gear of second-stage third reduction shaft; 31, third rotor shaft face gear; 32, fourth reduction face gear of second stage; 33, first bearing of second-stage fourth reduction shaft; 34, fourth reduction shaft of second stage; 35, second bearing of second-stage fourth reduction shaft; 36, output gear of second-stage fourth reduction shaft; 37, fourth rotor shaft face gear; 38, first rotor shaft; 39, first rotor; 40, second rotor shaft; 41, second rotor; 42, third rotor shaft; 43, third rotor; 44, fourth rotor shaft; 45, fourth rotor. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0026] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0028] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0029] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0030] The main reducer, as a key component of the power transmission system of a quadcopter UAV, mainly converts the high-speed rotational motion of a power source such as a motor or engine into a low-speed, high-torque rotational motion of the rotor shaft, thereby providing sufficient lift for the rotor and ensuring the normal flight of the UAV. It directly affects the flight performance, reliability and service life of the UAV.

[0031] However, in the prior art, since the main reducer of the quadcopter UAV adopts bevel gears for transmission, the transmission ratio of the bevel gears is small, the transmission efficiency is low, and the structure is complex during operation, which makes the entire main reducer heavy; in addition, the bevel gears are usually manufactured and used in pairs. When the main reducer is subsequently maintained, they need to be replaced in pairs, with poor interchangeability, high maintenance costs, great difficulty and long cycles; secondly, since the transmission ratio of the bevel gears is relatively small, the transmission ratio of the single-stage bevel gear transmission is generally within 3, resulting in the inability to increase the speed ratio of the whole machine under the original volume, and the power density is limited; finally, due to processing errors and installation errors, the cone top angles cannot overlap, resulting in an unstable transmission ratio, unstable transmission, and prone to fatigue problems. When multiple pairs of bevel gear pairs are engaged at the same time, the axial force on the bearing is large, and the overall installation and adjustment are difficult.

[0032] In order to solve the above technical defects, the inventor provides a single-engine four-rotor UAV main reducer and an aircraft based on face gears.

[0033] The present invention is further described in detail below in conjunction with the accompanying drawings: like Figure 1-Figure 2As shown, in the first aspect of the embodiment of the present invention, a main reducer for a single-engine four-rotor UAV based on a face gear is provided, comprising: an input mechanism, one end of which is externally connected to a power output device, and the other end of which is connected to a primary reduction mechanism; a secondary reduction mechanism, comprising two groups of secondary reduction devices, which are arranged at one end and the other end of the primary reduction mechanism and are axially perpendicular to the primary reduction mechanism; wherein, the number of each group of secondary reduction devices is two, and a rotor mechanism is arranged on both secondary reduction devices. By arranging the secondary reduction mechanisms at both ends of the primary reduction mechanism and axially perpendicular to the primary reduction mechanism, the entire reducer structure is made more compact, which not only reduces the volume of the UAV, but also reduces the overall weight of the UAV, improves the transmission ratio and transmission efficiency, and thus improves the flight efficiency and endurance of the UAV.

[0034] Further, the first-stage reduction mechanism includes a first-stage reduction device and a second-stage reduction device, and the first-stage reduction device and the second-stage reduction device are arranged on two opposite sides of the other end of the input mechanism and are transmission-connected to the other end of the input mechanism; one group of the secondary reduction devices is arranged at the end of the first-stage reduction device, and the other group of the secondary reduction devices is arranged at the end of the second-stage reduction device, and the two groups of the secondary reduction devices are away from each other; and the first-stage reduction device and the second-stage reduction device are axially overlapped, and the first-stage reduction device and the second-stage reduction device have the same structure, and the two groups of the secondary reduction devices are axially parallel, and the two groups of the secondary reduction devices have the same structure, and the two secondary reduction devices are symmetrically arranged at the ends of the first-stage reduction mechanism, and the two secondary reduction devices have opposite directions, so that the two rotor mechanisms rotate in the same direction. Figure 1As shown, the input mechanism includes an input shaft 1, an input shaft bearing 2 and an input shaft gear 3. One end of the input shaft 1 is connected to the power output device, and the other end is connected to the input shaft gear 3 through the support of the input shaft bearing 2; the first-stage first reduction device includes a first-stage first reduction face gear 4, a first-stage first reduction shaft first bearing 5, a first-stage first reduction shaft 6, a first-stage first reduction shaft second bearing 7 and a first-stage first reduction shaft output gear 8. One end of the first-stage first reduction face gear 4 is meshed with one side of the input shaft gear 3, and the other end is connected to the first-stage first reduction shaft 6. The first-stage first reduction shaft 6 is connected to the first-stage first reduction shaft second bearing 7 and the first-stage first reduction shaft output gear 8. A reduction shaft output gear 8 is connected; the first-stage second reduction device includes a first-stage second reduction face gear 9, a first-stage second reduction shaft first bearing 10, a first-stage second reduction shaft 11 and a first-stage second reduction shaft second bearing 12. One end of the first-stage second reduction face gear 9 is meshed with the other side of the input shaft gear 3, and the other end is connected to the first-stage second reduction shaft 11. One end of the first-stage second reduction shaft 11 is connected to the first-stage second reduction shaft first bearing 10, and the other end is connected to the first-stage second reduction shaft output gear 13 through the first-stage second reduction shaft second bearing 12. Both sides of the first-stage second reduction shaft output gear 13 are each connected to a second reduction device. In the above structure, the input shaft gear 3 is meshed with the first-stage first reduction face gear 4 and the second-stage second reduction face gear 9 at the same time, and performs coaxial reverse rotation and torque reduction, and transmits power to the first-stage first reduction shaft 6 and the second-stage second reduction shaft 11. The first-stage first reduction shaft 6 is supported by the first-stage first reduction shaft first bearing 5 and the second-stage first reduction shaft second bearing 7, and the second-stage second reduction shaft 11 is supported by the first-stage second reduction shaft first bearing 10 and the second-stage second reduction shaft second bearing 12. The first-stage first reduction shaft 6 drives the first-stage first reduction shaft output gear 8 to rotate, and the first-stage second reduction shaft 11 drives the first-stage second reduction shaft output gear 13 to rotate; the meshing transmission ratio of the face gear and the cylindrical gear is large, the number of reduction transmission stages is small, the support is simple, the structure is compact, the mass of the main reduction mechanism is greatly reduced, and the power density is reduced accordingly; when the face gear and the cylindrical gear are meshed, the tooth surface overlap is large, the tooth width is large, the operation is smooth, and the gear contact stress and bending stress are significantly reduced.

[0035] Furthermore, if Figure 1As shown, one group of two-stage reduction gears includes a two-stage first reduction assembly and a two-stage second reduction assembly, and the other group of two-stage reduction gears includes a two-stage third reduction assembly and a two-stage fourth reduction assembly; specifically, the two-stage first reduction assembly includes a two-stage first reduction face gear 14, a two-stage first reduction shaft first bearing 15, a two-stage first reduction shaft 16, a two-stage first reduction shaft second bearing 17 and a two-stage first reduction shaft output gear 18, wherein one end of the two-stage first reduction face gear 14 is meshedly connected with one side of the one-stage second reduction shaft output gear 13, and two ends of the two-stage first reduction shaft 16 are provided with a two-stage first reduction shaft first bearing 15 and a two-stage first reduction shaft second bearing 17 The secondary first reduction shaft 16 is connected to the secondary first reduction shaft output gear 18 through the secondary first reduction shaft second bearing 17; the secondary second reduction assembly includes a secondary second reduction face gear 20, a secondary second reduction shaft first bearing 21, a secondary second reduction shaft 22 and a secondary second reduction shaft second bearing 23, wherein the secondary second reduction face gear 20 is meshedly connected with the other side of the primary second reduction shaft output gear 13, one end and the other end of the secondary second reduction shaft 22 are provided with a secondary second reduction shaft first bearing 21 and a secondary second reduction shaft second bearing 23, and the other end of the secondary second reduction shaft 22 is connected to the secondary second reduction shaft output gear 18 through the secondary second reduction shaft second bearing 23. The output gear 24 is connected; the secondary third reduction assembly includes a secondary third reduction face gear 26, a secondary third reduction shaft first bearing 27, a secondary third reduction shaft 28, a secondary third reduction shaft second bearing 29 and a secondary third reduction shaft output gear 30, wherein one end of the secondary third reduction face gear 26 is meshed and connected with one side of the primary first reduction shaft output gear 8, the other end of the secondary third reduction face gear 26 is connected to the secondary third reduction shaft 28, one end and the other end of the secondary third reduction shaft 28 are connected to the secondary third reduction shaft first bearing 27 and the secondary third reduction shaft second bearing 29, and the secondary third reduction shaft 28 is connected to the secondary third reduction shaft through the secondary third reduction shaft second bearing 29. The second-stage fourth reduction shaft output gear 30 is connected; the second-stage fourth reduction assembly includes a second-stage fourth reduction face gear 32, a second-stage fourth reduction shaft first bearing 33, a second-stage fourth reduction shaft 34, a second-stage fourth reduction shaft second bearing 35 and a second-stage fourth reduction shaft output gear 36, wherein one end of the second-stage fourth reduction face gear 32 is meshed and connected with the other side of the first-stage first reduction shaft output gear 8, one end and the other end of the second-stage fourth reduction shaft 34 are connected with the second-stage fourth reduction shaft first bearing 33 and the second-stage fourth reduction shaft second bearing 35, and the other end of the second-stage fourth reduction shaft 34 is connected to the second-stage fourth reduction shaft output gear 36 through the second-stage fourth reduction shaft second bearing 35.The secondary first reduction face gear 14 is meshed with the secondary second reduction face gear 20 and the primary second reduction shaft output gear 13 at the same time, transmitting power to the secondary first reduction shaft 16 and the secondary second reduction shaft 22, realizing coaxial reversal; the secondary first reduction shaft 16 is supported by the secondary first reduction shaft first bearing 15 and the secondary first reduction shaft second bearing 17, and the secondary second reduction shaft 22 is supported by the secondary second reduction shaft first bearing 21 and the secondary second reduction shaft second bearing 23, and the power is output by the secondary first reduction shaft output gear 18 and the secondary second reduction shaft output gear 24 respectively.

[0036] Furthermore, if Figure 2 As shown, the rotor mechanism includes a first rotor shaft face gear 19, a first rotor shaft 38, a first rotor 39, a second rotor shaft face gear 25, a second rotor shaft 40, a second rotor 41, a third rotor shaft face gear 31, a third rotor shaft 42, a third rotor 43, a fourth rotor shaft face gear 37, a fourth rotor shaft 44 and a fourth rotor 45; wherein one end of the first rotor shaft face gear 19 is connected to the secondary first reduction shaft output gear 18, and the other end is connected to the first rotor shaft 38 through the first rotor shaft 38. 39; one end of the second rotor shaft face gear 25 is connected to the second-stage second reduction shaft output gear 24, and the other end is connected to the second rotor 41 through the second rotor shaft 40; one end of the third rotor shaft face gear 31 is connected to the second-stage third reduction shaft output gear 30, and the other end is connected to the third rotor 43 through the third rotor shaft 42; one end of the fourth rotor shaft face gear 37 is connected to the second-stage fourth reduction shaft output gear 36, and the other end is connected to the fourth rotor 45 through the fourth rotor shaft 44. The power is transmitted from the second-stage first reduction shaft output gear 18 to the first rotor shaft face gear 19, which in turn drives the first rotor shaft 38 to rotate, and finally realizes the rotation of the first rotor 39; similarly, the second-stage second reduction output gear 24 drives the second rotor shaft face gear 25 to rotate, and then drives the second rotor shaft 40 to rotate, and finally realizes the rotation of the second rotor 41. It should be noted that the secondary first reduction shaft output gear 18 and the secondary second reduction output gear 24 rotate in opposite directions, thereby achieving the first rotor shaft 38 and the second rotor shaft 40 rotating in the same direction.

[0037] When the main reducer is used, the carrier is a drone, and the input mechanism is connected to the motor of the drone. The drone is driven by the motor to fly in the air. During the flight, the cooperation of the primary reduction mechanism and the secondary reduction mechanism improves the flight efficiency of the drone. Secondly, the coordination of the primary reduction mechanism and the secondary reduction mechanism reduces the unbalanced loss in the power transmission process and improves the transmission efficiency of the drone.

[0038] In a second aspect, an embodiment of the present invention provides an aircraft, including an aircraft body, on which is mounted the above-mentioned single-engine four-rotor UAV main reducer based on face gears.

[0039] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit its protection scope. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that after reading the present invention, those skilled in the art can still make various changes, modifications or equivalent substitutions to the specific implementation methods of the invention, but these changes, modifications or equivalent substitutions are all within the protection scope of the pending claims of the invention.

Claims

1. A main reducer for a single-engine quad-rotor UAV based on face gears, characterized in that: include: An input mechanism, one end of which is connected to an external power output device, and the other end is connected to a first-stage reduction mechanism; The two-stage reduction mechanism comprises two sets of two-stage reduction devices, wherein the two sets of two-stage reduction devices are arranged at one end and the other end of the one-stage reduction mechanism and are perpendicular to the axial direction of the one-stage reduction mechanism; There are two secondary reduction devices in each group, and both secondary reduction devices are provided with a rotor mechanism.

2. The main reducer of the single-engine quad-rotor UAV based on face gear according to claim 1 is characterized in that: The first-stage reduction mechanism comprises a first-stage reduction device and a second-stage reduction device, wherein the first-stage reduction device and the second-stage reduction device are arranged on two opposite sides of the other end of the input mechanism and are transmission-connected with the other end of the input mechanism; One set of the secondary reduction devices is arranged at the end of the first stage first reduction device, and the other set of the secondary reduction devices is arranged at the end of the first stage second reduction device, and the two sets of the secondary reduction devices are separated from each other.

3. The main reducer of the single-engine quad-rotor UAV based on face gear according to claim 2 is characterized in that: The first stage first reduction gear device and the second stage second reduction gear device overlap axially.

4. The main reducer of the single-engine quad-rotor UAV based on face gear according to claim 2 is characterized in that: The two sets of secondary reduction devices are axially parallel.

5. The main reducer of the single-engine quad-rotor UAV based on face gear according to claim 2, characterized in that: The first stage reduction device and the second stage reduction device have the same structure.

6. The main reducer of the single-engine quad-rotor UAV based on face gear according to claim 2, characterized in that: The two sets of two-stage reduction devices have the same structure.

7. The main reducer of a single-engine quad-rotor UAV based on face gears according to claim 1, characterized in that: Two secondary reduction devices are symmetrically arranged at the ends of the primary reduction mechanism.

8. The main reducer of the single-engine quad-rotor UAV based on face gear according to claim 7, characterized in that: The two secondary reduction devices rotate in opposite directions so that the two rotor mechanisms rotate in the same direction.

9. The main reducer of a single-engine quad-rotor UAV based on face gears according to claim 1, characterized in that: The power output device is a motor or an engine.

10. An aircraft, comprising an aircraft body, characterized in that: The aircraft body is equipped with a single-engine quad-rotor UAV main reducer based on face gears as described in any one of claims 1 to 9.

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