A circuitous transmission and same speed system for a small coaxial twin-rotor UAV

Abstract

The present invention discloses a circuitous transmission and same-speed system for a small coaxial twin-rotor UAV, comprising two sets of longitudinally mounted secondary belt reduction systems and a same-speed system; the upper reduction mechanism comprises a transmission gear set, a motor, a coaxial shaft, a rotor outer shaft, and a belt, which can realize the control of the rotation speed of the lower rotor outer shaft. The lower reduction mechanism comprises a transmission gear set, a motor, a coaxial shaft, a rotor inner shaft, and a belt, which can realize the control of the rotation speed of the upper rotor inner shaft. The same-speed system comprises two nylon gears of the same outer dimensions, which mesh with each other to realize the adjustment and control of the same rotation speed of the upper and lower rotors. The present invention adopts a circuitous secondary transmission structure and a same-speed meshing mechanism, which realizes the lightness, compactness, and reliability of the transmission system while meeting a high transmission ratio, and realizes the same-speed control of the upper and lower rotors, greatly reducing the collision risk of the upper and lower blades, thereby improving the safety of the coaxial twin-rotor UAV.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft design, and more particularly to a circuitous transmission and iso-rotation speed system of a small coaxial twin-rotor unmanned aerial vehicle. Background Art

[0002] Coaxial helicopters use coaxial reverse-rotating upper and lower rotors to provide lift, and achieve heading control by changing the counter-torque of the upper and lower rotors to balance them. No tail rotor is required, and they have the advantages of small size, compact structure, and high hovering efficiency. Coaxial twin-rotor helicopters have upper and lower rotors that rotate one positively and one negatively around the same theoretical axis. Due to the opposite rotation, the torques generated by the two rotors balance each other in the flight state with unchanged heading. Since there is no tail rotor, the fuselage of the coaxial helicopter is generally within the area of ​​the propeller disc, and the total longitudinal dimension of the body is the propeller disc diameter. In this way, under the same propeller disc load, engine, and total weight, the overall longitudinal dimension of the coaxial twin-rotor helicopter is only about 60% of that of a single-rotor helicopter.

[0003] The Russian Kamov Design Bureau has developed and produced a series of manned coaxial helicopters, which are widely used in the national economy and military fields. In China, Beihang University independently developed a coaxial unmanned helicopter in the 1980s, successfully achieved autonomous navigation flight, and began to apply it in different fields. As the energy power of unmanned aerial vehicles has been widely driven by lithium battery motors, the Beihang University Helicopter Research Institute has also successfully developed a 50 kg electric coaxial unmanned helicopter.

[0004] In the prior art, the conventional equal speed scheme refers to the upper and lower rotors being reversed through gears and maintaining the same reduction ratio through gears. Generally speaking, the upper rotor shaft and the lower rotor shaft of a coaxial helicopter are both reversed through inner and outer shafts. The inner and outer shafts of the upper and lower rotors are reversed through the bevel gears in the main reducer. Therefore, the main reducer is both a power transmission reduction device and a reversing device for the upper and lower rotors. The reversing and same speed devices used in this scheme are realized through bevel gears, which are heavy and are not conducive to the lightweight design of small coaxial twin-rotor drones.

[0005] Therefore, how to provide a small coaxial twin-rotor UAV circuitous transmission and same speed system is a problem that technicians in this field need to solve urgently. Summary of the invention

[0006] In view of this, the present invention provides a circuitous transmission and same speed system for a small coaxial twin-rotor UAV, which can solve at least one of the above-mentioned technical problems.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A small coaxial twin-rotor UAV circuitous transmission and same speed system, including an upper reduction mechanism and a lower reduction mechanism; the upper reduction mechanism includes: a longitudinal inverted motor, an upper coaxial shaft, a rotor outer shaft, an upper gear, an upper first-stage reduction transmission system and an upper second-stage reduction transmission system; the upper first-stage reduction transmission system and the upper second-stage reduction transmission system are arranged in a longitudinally partially overlapping manner; the upper first-stage reduction transmission system includes: an upper first-stage reduction output pulley, an upper first-stage reduction belt, and an upper first-stage reduction driven pulley; the upper second-stage reduction transmission system includes: an upper second-stage reduction driving wheel, an upper second-stage reduction The upper gear is fixedly mounted on the upper concentric shaft; the ... The lower reduction mechanism comprises: a longitudinally positive motor, a lower concentric shaft, a rotor inner shaft, a lower gear, a lower first-stage reduction transmission system and a lower second-stage reduction transmission system; the lower first-stage reduction transmission system and the lower second-stage reduction transmission system are arranged in a longitudinally partially overlapping manner; the lower first-stage reduction transmission system comprises: a lower first-stage reduction output pulley, a lower first-stage reduction belt, and a lower first-stage reduction driven pulley; the lower second-stage reduction transmission system comprises: a lower second-stage reduction driving wheel, a lower second-stage reduction belt and a lower second-stage reduction driven wheel; the output shaft of the longitudinally positive motor and The next-stage reduction output pulley is concentrically fixedly connected; the next-stage reduction belt is simultaneously meshed with the next-stage reduction output pulley and the next-stage reduction driven pulley, and is tightened; the lower concentric shaft is rotatably installed on the fuselage, and the next-stage reduction driven pulley, the next-stage secondary reduction driving wheel and the lower gear are all fixed on the lower concentric shaft; the upper gear is meshed with the lower gear; the next-stage secondary reduction belt is simultaneously meshed with the next-stage secondary reduction driving wheel and the next-stage secondary reduction driven wheel, and is tightened; the next-stage secondary reduction driven wheel is fixedly connected to the rotor inner shaft.

[0009] The small coaxial twin-rotor UAV circuitous transmission and same speed system provided by the present invention has the advantages of smooth transmission, buffering and shock absorption, simple structure, easy use and maintenance, and good flexibility and elasticity. While meeting the high transmission ratio, the transmission system can be fixed, light, compact and reliable.

[0010] Preferably, the upper gear and the lower gear are both nylon gears and have the same size.

[0011] The beneficial effects of adopting the above technical solution are that the nylon gear is light in weight, fatigue-resistant, shock-absorbing and has good self-lubricating properties.

[0012] Preferably, the upper gear and the lower gear are fixedly connected to the upper coaxial shaft and the lower coaxial shaft respectively by screws.

[0013] The beneficial effects of adopting the above technical solution are that the connection is fixed by screws, the structure is stable, and the process is simple.

[0014] Preferably, the upper rotor is fixedly connected to the rotor inner shaft, and the lower rotor is fixedly connected to the rotor outer shaft.

[0015] The beneficial effect of adopting the above technical solution is that the rotor speed can be controlled by controlling the rotation speed of the rotor outer shaft and the rotor inner shaft.

[0016] Preferably, the rotor inner shaft and the rotor outer shaft are concentrically assembled via inner shaft bearings.

[0017] The beneficial effect of adopting the above technical solution is that it can ensure that the inner rotor shaft and the outer rotor shaft are concentric.

[0018] Preferably, the contour centers of the lower secondary reduction driven wheel and the upper secondary reduction driven wheel coincide with each other in the longitudinal direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0020] Figure 1 The accompanying drawing is a schematic diagram of the structure of the present invention;

[0021] Figure 2 for Figure 1 A partial enlarged view of

[0022] Figure 3 It is a structural schematic diagram of the upper speed reduction mechanism in the present invention;

[0023] Figure 4 It is a structural schematic diagram of the lower speed reduction mechanism in the present invention.

[0024] Wherein, each figure is marked as:

[0025] 1-next-stage reduction belt, 2-next-stage reduction output pulley, 3-longitudinal upright motor, 4-lower secondary reduction driven pulley, 5-rotor inner shaft, 6-lower secondary reduction belt, 7-lower concentric shaft, 8-lower secondary reduction driving wheel, 9-next-stage reduction driven pulley, 10-lower gear, 11-upper gear, 12-previous-stage reduction driven pulley, 13-upper secondary reduction driving wheel, 14-upper concentric shaft, 15-upper secondary reduction belt, 16-upper secondary reduction driven wheel, 17-rotor outer shaft, 18-longitudinal inverted motor, 19-previous-stage reduction output pulley, 20-previous-stage reduction belt, 21-upper rotor, 22-lower rotor. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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] The embodiment of the present invention discloses a circuitous transmission and same speed system of a small coaxial twin-rotor UAV, including an upper reduction mechanism and a lower reduction mechanism; the upper reduction mechanism includes: a longitudinal inverted motor 18, an upper coaxial shaft 14, a rotor outer shaft 17, an upper gear 11, an upper first-stage reduction transmission system and an upper second-stage reduction transmission system; the upper first-stage reduction transmission system and the upper second-stage reduction transmission system are arranged in a longitudinally partially overlapping manner; the upper first-stage reduction transmission system includes: an upper first-stage reduction output pulley 19, an upper first-stage reduction belt 20, and an upper first-stage reduction driven pulley 16; the upper second-stage reduction transmission system includes: an upper second ... The upper concentric shaft 14 is rotatably mounted on the machine body, and the upper concentric shaft 14 is fixedly mounted on the upper concentric shaft 14; the ... The upper secondary reduction driven wheel 16 is fixedly connected to the rotor outer shaft 17; the lower reduction mechanism includes: a longitudinal positive motor 3, a lower concentric shaft 7, a rotor inner shaft 5, a lower gear 10, a lower reduction transmission system and a lower secondary reduction transmission system; the lower reduction transmission system and the lower secondary reduction transmission system are arranged in a longitudinally partially overlapping manner; the lower reduction transmission system includes: a lower reduction output pulley 2, a lower reduction belt 1, and a lower reduction driven pulley 9; the lower secondary reduction transmission system includes: a lower secondary reduction driving wheel 8, a lower secondary reduction belt 6 and a lower secondary reduction driven pulley Wheel 9; the output shaft of the longitudinally upright motor 3 is concentrically fixedly connected with the next-stage reduction output pulley 2; the next-stage reduction belt 1 is meshed with the next-stage reduction output pulley 2 and the next-stage reduction driven pulley 9 at the same time, and is tightened; the lower concentric shaft 7 is rotatably installed on the fuselage, and the next-stage reduction driven pulley 9, the next-stage reduction driving wheel 8 and the lower gear 10 are all fixed on the lower concentric shaft; the upper gear 11 and the lower gear 10 are meshed; the next-stage reduction belt 6 is meshed with the next-stage reduction driving wheel 8 and the next-stage reduction driven wheel 4 at the same time, and is tightened; the lower-stage reduction driven wheel 4 is fixedly connected to the rotor inner shaft 5.

[0028] The upper gear 11 and the lower gear 10 are both nylon gears and have the same size.

[0029] The upper gear 11 and the lower gear 10 are fixedly connected to the upper coaxial shaft 14 and the lower coaxial shaft 7 respectively by screws.

[0030] The upper rotor 21 is fixedly connected to the rotor inner shaft 5, and the lower rotor 22 is fixedly connected to the rotor outer shaft 17. The rotor inner shaft 5 and the rotor outer shaft 17 are concentrically assembled through the inner shaft bearing.

[0031] The contour centers of the lower secondary reduction driven wheel 4 and the upper secondary reduction driven wheel 16 coincide with each other in the longitudinal direction.

[0032] The working process of a roundabout transmission and same-speed system of a small coaxial twin-rotor UAV disclosed by the present invention is as follows: the control system controls the longitudinal inverted motor 18 to work, driving the upper-stage reduction output pulley 19 to rotate. Since the upper-stage reduction belt 20 is meshed with the upper-stage reduction output pulley 19 and the upper-stage reduction driven pulley 12 at the same time, the upper-stage reduction driven pulley 12 is driven to rotate, thereby driving the upper-stage second-stage reduction driving wheel 13 and the upper gear 11 to rotate; the upper-stage second-stage reduction driven wheel 16 rotates; the rotor outer shaft 17 rotates, and the lower rotor 22 rotates; similarly, the longitudinal positive motor 3 drives the upper rotor 21 to rotate. Since the upper gear 11 is meshed with the lower gear 10, the same speed control of the upper and lower rotors of the small coaxial twin-rotor UAV can be achieved.

[0033] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0034] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A small coaxial twin-rotor UAV circuitous transmission and same speed system, characterized in that: It includes an upper speed reduction mechanism and a lower speed reduction mechanism; The upper reduction mechanism comprises: a longitudinal inverted motor (18), an upper coaxial shaft (14), a rotor outer shaft (17), an upper gear (11), an upper first-stage reduction transmission system and an upper second-stage reduction transmission system; the upper first-stage reduction transmission system and the upper second-stage reduction transmission system are arranged to overlap each other in the longitudinal direction; the upper first-stage reduction transmission system comprises: an upper first-stage reduction output pulley (19), an upper first-stage reduction belt (20), and an upper first-stage reduction driven pulley (16); the upper second-stage reduction transmission system comprises: an upper second-stage reduction driving pulley (13), an upper second-stage reduction belt (15), and an upper second-stage reduction driven pulley (16); The output shaft of the longitudinal inverted motor (18) is coaxially fixedly connected to the upper-stage reduction output pulley (19), and the upper-stage reduction belt (20) is simultaneously meshed with the upper-stage reduction output pulley (19) and the upper-stage reduction driven pulley (12), and is tightened; the upper coaxial shaft (14) is rotatably mounted on the machine body, and the upper-stage reduction driven pulley (12), the upper-stage reduction driving pulley (13) and the upper gear (11) are fixedly mounted on the upper coaxial shaft (14); The upper secondary speed reduction belt (15) is meshed with the upper secondary speed reduction driving wheel (13) and the upper secondary speed reduction driven wheel (16) at the same time, and is tightened; the upper secondary speed reduction driven wheel (16) is fixedly connected to the rotor outer shaft (17); The lower reduction mechanism comprises: a longitudinally upright motor (3), a lower concentric shaft (7), a rotor inner shaft (5), a lower gear (10), a lower first-stage reduction transmission system and a lower second-stage reduction transmission system; the lower first-stage reduction transmission system and the lower second-stage reduction transmission system are arranged to overlap each other in the longitudinal direction; the lower first-stage reduction transmission system comprises: a lower first-stage reduction output pulley (2), a lower first-stage reduction belt (1), and a lower first-stage reduction driven pulley (9); the lower second-stage reduction transmission system comprises: a lower second-stage reduction driving pulley (8), a lower second-stage reduction belt (6), and a lower second-stage reduction driven pulley (9); The output shaft of the longitudinally upright motor (3) is coaxially fixedly connected with the next-stage reduction output pulley (2); the next-stage reduction belt (1) is simultaneously meshed with the next-stage reduction output pulley (2) and the next-stage reduction driven pulley (9), and is tightened; the lower concentric shaft (7) is rotatably mounted on the machine body, and the next-stage reduction driven pulley (9), the next-stage reduction driving pulley (8) and the lower gear (10) are all fixed on the lower concentric shaft; the upper gear (11) is meshed with the lower gear (10); The lower secondary reduction belt (6) is simultaneously meshed with the lower secondary reduction driving wheel (8) and the lower secondary reduction driven wheel (4), and is tightened; the lower secondary reduction driven wheel (4) is fixedly connected to the rotor inner shaft (5).

2. A small coaxial twin-rotor UAV circuitous transmission and same speed system according to claim 1, characterized in that: The upper gear (11) and the lower gear (10) are both nylon gears and have the same size.

3. A small coaxial twin-rotor UAV circuitous transmission and same speed system according to claim 1, characterized in that: The upper gear (11) and the lower gear (10) are fixedly connected to the upper coaxial shaft (14) and the lower coaxial shaft (7) respectively by means of screws.

4. A small coaxial twin-rotor UAV circuitous transmission and same speed system according to claim 1, characterized in that: The upper rotor (21) is fixedly connected to the rotor inner shaft (5), and the lower rotor (22) is fixedly connected to the rotor outer shaft (17).

5. A small coaxial twin-rotor UAV circuitous transmission and same speed system according to claim 4, characterized in that: The rotor inner shaft (5) and the rotor outer shaft (17) are concentrically assembled via inner shaft bearings.

6. A small coaxial twin-rotor UAV circuitous transmission and same speed system according to claim 4, characterized in that: The contour centers of the lower secondary reduction driven wheel (4) and the upper secondary reduction driven wheel (16) coincide with each other in the longitudinal direction.

Images