Face gear transmission-based coaxial reversal dual-rotor structure and aircraft

Abstract

The invention discloses a coaxial reversal dual-rotor structure based on face gear transmission and an aircraft, the dual-rotor structure comprises an outer rotor shaft, and an inner rotor shaft is rotatably connected in the outer rotor shaft; the first propeller is arranged at the top of the inner rotor shaft; the second propeller is arranged at the top of the outer rotor shaft, and the first propeller is located above the second propeller; the first face gear pair is connected with the bottom of the outer rotor shaft through a first bolt group; the second face gear pair is connected with the bottom of the inner rotor shaft through a second bolt group; one end of the input shaft is connected with the first face gear pair, the other end of the input shaft is connected with the second face gear pair, and the input shaft is used for connecting external driving equipment. Two groups of face gears are adopted for transmission, so that coaxial reverse rotation of the double rotor wings is realized; meanwhile, through first-stage face gear transmission, the reduction ratio of multi-stage bevel gear-planetary gear transmission can be achieved; moreover, the overall structure is compact, the transmission ratio is large, transmission stages can be reduced, and the transmission system weight is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft, and in particular relates to a coaxial counter-rotating double-rotor structure based on face gear transmission and an aircraft. Background Art

[0002] As the country has included the low-altitude economy in the category of strategic emerging industries, rotorcraft, as a key carrier of the low-altitude economy, has become the focus of research for many aviation companies. Low-altitude rotorcraft require simple structure, high power density, high reliability, and vertical take-off and landing and air hovering functions. At present, although rotorcraft has made some progress in vertical take-off and landing, energy efficiency and speed optimization, it still faces problems such as complex transmission system, limited load capacity and insufficient endurance time.

[0003] There are mainly single-rotor aircraft, coaxial twin-rotor aircraft and multi-rotor aircraft. Among them, the coaxial twin-rotor aircraft adopts two coaxial counter-rotating rotors arranged in an upper and lower manner. Its aerodynamic force is symmetrically distributed, and the reverse torque cancels each other out. Compared with the single-rotor aircraft, there is no need for a vertical tail rotor to balance the reverse torque generated by the rotation of the rotor. Therefore, all the power can be used to drive the rotor, and the vertical take-off and landing and hovering efficiency are higher. It can effectively shorten the fuselage length, reduce the weight and power consumption of the whole machine, and have good maneuverability. Compared with multi-rotors such as quad-rotors, hexa-rotors, and octo-rotors, the coaxial twin-rotor aircraft has a simple structure, a smaller machine size, a longer endurance time, a stronger load capacity, and a faster flight speed. However, the existing coaxial twin-rotor aircraft transmission system is mostly used in heavy-load military helicopters. It has a complex structure and high noise. It usually requires a multi-stage gear transmission with bevel gear reversing and planetary gear output to ensure that the two rotors can accurately rotate in the opposite direction and operate in coordination. However, due to the low power-to-weight ratio and low transmission efficiency of multi-stage transmission, high requirements for structural stiffness and strength, especially the manufacturing and installation precision errors of bevel gear pairs, will cause eccentric loads and affect flight reliability. At the same time, the maintenance cost of bevel gear pairs is high, which is difficult to meet the use requirements of low-altitude aircraft. Under the premise of meeting the high power-to-weight ratio, high transmission efficiency and high reliability requirements of low-altitude aircraft, and ensuring a large output torque, the weight and volume of the transmission system of low-altitude flying rotorcraft should be reduced as much as possible.

[0004] In the prior art, the invention patent discloses a coaxial counter-rotating twin-rotor reduction transmission configuration (CN111483590 A), which adopts two face gears of the same size arranged in reverse up and down, and a cylindrical gear is placed between the two face gears. The cylindrical gear rotates in a certain direction, which can realize the same-speed reversal of the upper and lower gears, thereby realizing the coaxial reversal of the hollow outer rotor shaft and the inner rotor shaft. However, the pinion teeth of the transmission structure are subject to the bidirectional cyclic load of the upper and lower gears, and are prone to fatigue damage. At the same time, due to the influence of assembly errors and system stiffness, there are differences in the transmission of the pinion and the upper and lower gears, resulting in uneven power distribution of the upper and lower gears, that is, the output power of the upper and lower gears is different, the aerodynamic force is not completely symmetrically distributed, and the reversal torque cannot offset each other, affecting the performance of the coaxial counter-rotating twin-rotor system. Summary of the invention

[0005] The object of the present invention is to provide a coaxial counter-rotating twin-rotor structure and aircraft based on face gear transmission. On the first hand, it is used to solve the technical defects in the prior art of low power-to-weight ratio, low transmission efficiency, high requirements for structural stiffness and strength, especially the manufacturing and installation precision errors of bevel gear pairs, which will cause unbalanced loads and affect the reliability of flight; on the second hand, it is used to solve the problem that the pinion teeth are easily fatigued due to the bidirectional cyclic load of the upper and lower gears. At the same time, due to the influence of assembly errors and system stiffness, there are differences in the transmission of the pinion and the upper and lower gears, resulting in uneven power distribution of the upper and lower gears, that is, the output power of the upper and lower gears is different, the aerodynamic force is not completely symmetrically distributed, the reverse torque cannot offset each other, and the technical defects of affecting the performance of the coaxial counter-rotating twin-rotor system.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, a coaxial counter-rotating twin-rotor structure based on face gear transmission is provided, comprising: an outer rotor shaft, in which the inner rotor shaft is rotatably connected; A first propeller and a second propeller, wherein the first propeller is disposed on the top of the inner rotor shaft; the second propeller is disposed on the top of the outer rotor shaft, and the first propeller is located above the second propeller; The first face gear pair is connected to the bottom of the outer rotor shaft through a first bolt group; The second face gear pair is connected to the bottom of the inner rotor shaft through a second bolt group; An input shaft, one end of which is connected to the first face gear pair, and the other end of which is connected to the second face gear pair, wherein the input shaft is used to connect to an external driving device.

[0007] Further, the first face gear pair includes a first cylindrical gear and a first face gear, and the second face gear pair includes a second cylindrical gear and a second face gear; The first cylindrical gear is arranged at one end of the input shaft, and the second cylindrical gear is arranged at the other end of the input shaft; The first face gear and the second face gear are coaxially arranged, the first cylindrical gear cooperates with the first face gear, and the second cylindrical gear cooperates with the second face gear; The first face gear is connected to the bottom of the outer rotor shaft through the first bolt group; The second face gear is connected to the bottom of the inner rotor shaft through the second bolt group; Wherein, under the drive of the external driving device, the first face gear drives the outer rotor shaft to rotate, and the second face gear drives the inner rotor shaft to rotate, and the inner rotor shaft rotates in opposite directions to the outer rotor shaft.

[0008] Furthermore, the inner rotor shaft is provided with a first bearing and a second bearing, and the first bearing is located below the second bearing; The inner ring of the first bearing matches the outer diameter of the inner rotor shaft, and the outer ring of the first bearing matches the inner hole of the outer rotor shaft.

[0009] Furthermore, the first bearing is a spherical roller bearing.

[0010] Furthermore, the second bearing is a cylindrical roller bearing.

[0011] Furthermore, the inner rotor shaft is located outside the inner part of the outer rotor shaft and is provided with a bearing end cover, a shaft sleeve and a third round nut; The bearing end cover is located below the first bearing, the shaft sleeve is located above the first bearing, and the third round nut is located above the second bearing.

[0012] Furthermore, it also includes: The sliding bearing is arranged on the top of the first propeller, the outer diameter of the sliding bearing matches with the inner hole of the outer rotor shaft, and the inner hole of the sliding bearing matches with the outer diameter of the inner rotor shaft.

[0013] Further, the first cylindrical gear and the second cylindrical gear have the same number of teeth; The first face gear and the second face gear also have the same number of teeth.

[0014] Further, the first cylindrical gear and the second cylindrical gear are both circumferentially positioned by splines; Furthermore, the first cylindrical gear is fixed to the input shaft via a first cylindrical nut; and the second cylindrical gear is fixed to the input shaft via a second cylindrical nut.

[0015] In a second aspect, an aircraft is provided, including a light-loaded single-engine low-altitude rotorcraft and an electric vertical take-off and landing aircraft, wherein the light-loaded single-engine low-altitude rotorcraft and the electric vertical take-off and landing aircraft are equipped with the coaxial counter-rotating double-rotor structure based on face gear transmission as described above.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. By adopting two sets of face gear transmission, the coaxial reversal of the twin rotors is realized; at the same time, through the first-stage face gear transmission, the reduction ratio of the multi-stage bevel gear-planetary gear transmission can be achieved; and the overall structure is compact and the transmission ratio is large, which can reduce the number of transmission stages, reduce the weight of the transmission system, improve the transmission efficiency and power-to-weight ratio, the face gear overlap is higher, the load-bearing capacity is good, the transmission is stable, and the noise of the effective coaxial reversal transmission can be reduced.

[0017] 2. The precise matching of the first cylindrical gear and the first face gear, and the second cylindrical gear and the second face gear ensures the efficient and smooth transmission of power from the input shaft to the inner and outer rotor shafts, and realizes the reversal of the inner and outer rotor shafts under coaxial conditions, which is crucial to improving the stability and controllability of the aircraft.

[0018] 3. The first bearing is the key supporting component between the inner rotor shaft and the outer rotor shaft. Its inner ring is tightly matched with the inner rotor shaft, and its outer ring is also tightly matched with the inner hole of the outer rotor shaft, ensuring the stability and accuracy of the inner rotor shaft during rotation. The addition of the second bearing further enhances this stability. Through the joint action of the two bearings, the inner rotor shaft can rotate more smoothly, reducing the performance degradation caused by vibration and deviation.

[0019] 4. The first bearing is a spherical roller bearing, which can bear the axial load of the inner rotor shaft and ensure the stable operation of the rotor system.

[0020] 5. The second bearing is a cylindrical roller bearing, which can bear the radial load of the inner rotor shaft.

[0021] 6. The bearing cover and the sleeve together provide double protection for the first bearing, preventing interference and damage from the external environment, thereby extending the service life of the bearing. At the same time, the sleeve reduces the direct contact between the inner rotor shaft and the outer rotor shaft, reduces the wear caused by friction, and further improves the durability of the bearing and the entire rotor system.

[0022] 7. The sliding bearing cooperates with the first bearing and the second bearing to achieve three-point support, improve the support stiffness of the inner rotor shaft, and effectively improve the stability and reliability of the rotor system.

[0023] 8. Since the first cylindrical gear and the second cylindrical gear have the same number of teeth, the transmission ratio between them is one to one, which ensures the accuracy and stability of the transmission. Similarly, the first face gear and the second face gear have the same number of teeth, which also ensures the accuracy of the transmission between them. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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.

[0025] Figure 1 A three-dimensional schematic diagram of a coaxial counter-rotating twin-rotor structure based on face gear transmission provided by the present invention; Figure 2 A cross-sectional view of the coaxial counter-rotating twin-rotor structure based on face gear transmission provided by the present invention; Figure 3 A front view of a coaxial counter-rotating twin-rotor structure based on face gear transmission provided by the present invention; Among them: 1. first propeller; 2. second propeller; 3. inner rotor shaft; 4. outer rotor shaft; 5. input shaft; 6. first face gear pair; 61. first cylindrical gear; 62. first face gear; 7. second face gear pair; 71. second cylindrical gear; 72. second face gear; 8. axis; 9. first round nut; 10. second round nut; 11. first bolt group; 12. second bolt group; 13. bearing end cover; 14. first bearing; 15. bushing; 16. second bearing; 17. third round nut; 18. sliding bearing. DETAILED DESCRIPTION

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] As the country has included the low-altitude economy in the category of strategic emerging industries, rotorcraft, as a key carrier of the low-altitude economy, has become the focus of research for many aviation companies. Low-altitude rotorcraft require simple structure, high power density, high reliability, and vertical take-off and landing and air hovering functions. At present, although rotorcraft has made some progress in vertical take-off and landing, energy efficiency and speed optimization, it still faces problems such as complex transmission system, limited load capacity and insufficient endurance time.

[0032] There are mainly single-rotor aircraft, coaxial twin-rotor aircraft and multi-rotor aircraft. Among them, the coaxial twin-rotor aircraft adopts two coaxial counter-rotating rotors arranged in an upper and lower manner. Its aerodynamic force is symmetrically distributed, and the reverse torque cancels each other out. Compared with the single-rotor aircraft, there is no need for a vertical tail rotor to balance the reverse torque generated by the rotation of the rotor. Therefore, all the power can be used to drive the rotor, and the vertical take-off and landing and hovering efficiency are higher. It can effectively shorten the fuselage length, reduce the weight and power consumption of the whole machine, and have good maneuverability. Compared with multi-rotors such as quad-rotors, hexa-rotors, and octo-rotors, the coaxial twin-rotor aircraft has a simple structure, a smaller machine size, a longer endurance time, a stronger load capacity, and a faster flight speed. However, the existing coaxial twin-rotor aircraft transmission system is mostly used in heavy-load military helicopters. It has a complex structure and high noise. It usually requires a multi-stage gear transmission with bevel gear reversing and planetary gear output to ensure that the two rotors can accurately rotate in the opposite direction and operate in coordination. However, due to the low power-to-weight ratio and low transmission efficiency of multi-stage transmission, high requirements for structural stiffness and strength, especially the manufacturing and installation precision errors of bevel gear pairs, will cause eccentric loads and affect flight reliability. At the same time, the maintenance cost of bevel gear pairs is high, which is difficult to meet the use requirements of low-altitude aircraft. Under the premise of meeting the high power-to-weight ratio, high transmission efficiency and high reliability requirements of low-altitude aircraft, and ensuring a large output torque, the weight and volume of the transmission system of low-altitude flying rotorcraft should be reduced as much as possible.

[0033] In the prior art, the invention patent discloses a coaxial counter-rotating twin-rotor reduction transmission configuration (CN111483590 A), which adopts two face gears of the same size arranged in reverse up and down, and a cylindrical gear is placed between the two face gears. The cylindrical gear rotates in a certain direction, which can realize the same-speed reversal of the upper and lower gears, thereby realizing the coaxial reversal of the hollow outer rotor shaft and the inner rotor shaft. However, the pinion teeth of the transmission structure are subject to the bidirectional cyclic load of the upper and lower gears, and are prone to fatigue damage. At the same time, due to the influence of assembly errors and system stiffness, there are differences in the transmission of the pinion and the upper and lower gears, resulting in uneven power distribution of the upper and lower gears, that is, the output power of the upper and lower gears is different, the aerodynamic force is not completely symmetrically distributed, and the reversal torque cannot offset each other, affecting the performance of the coaxial counter-rotating twin-rotor system.

[0034] In order to solve the above technical defects, the inventor provides a coaxial counter-rotating twin-rotor structure and an aircraft based on face gear transmission.

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings: like Figure 1-Figure 3As shown, in an embodiment of the present invention, a first aspect provides a coaxial counter-rotating twin-rotor structure based on face gear transmission, comprising an outer rotor shaft 4, in which an inner rotor shaft 3 is rotatably connected, and both the inner rotor shaft 3 and the outer rotor shaft 4 are hollow stepped shafts; a first propeller 1 and a second propeller 2, the first propeller 1 being arranged at the top of the inner rotor shaft 3; the second propeller 2 being arranged at the top of the outer rotor shaft 4, and the first propeller 1 being located above the second propeller 2; a first face gear pair 6 being connected to the bottom of the outer rotor shaft 4 through a first bolt group 11; a second face gear pair 7 being connected to the bottom of the inner rotor shaft 3 through a second bolt group 12; an input shaft 5, one end of which is connected to the first face gear pair 6, and the other end of which is connected to the second face gear pair 7, and the input shaft 5 is used to connect an external drive device. By adopting two sets of face gear transmission, the coaxial reversal of the twin rotors is realized; at the same time, through the first-stage face gear transmission, the reduction ratio of the multi-stage bevel-planetary gear transmission can be achieved; and the overall structure is compact and the transmission ratio is large, which can reduce the number of transmission stages, reduce the weight of the transmission system, and improve the transmission efficiency and power-to-weight ratio. The face gears have a higher overlap, good load-bearing capacity, and smooth transmission, which can reduce the noise of the effective coaxial reversal transmission. The first face gear pair 6 includes a first cylindrical gear 61 and a first face gear 62, and the second face gear pair 7 includes a second cylindrical gear 71 and a second face gear 72; the first cylindrical gear 61 is arranged at one end of the input shaft 5, and the second cylindrical gear 71 is arranged at the other end of the input shaft 5; the first face gear 62 and the second face gear 72 are coaxially arranged, the first cylindrical gear 61 cooperates with the first face gear 62, and the second cylindrical gear 71 cooperates with the second face gear 72; the first face gear 62 is connected to the bottom of the outer rotor shaft 4 through the first bolt group 11; the second face gear 72 is connected to the bottom of the inner rotor shaft 3 through the second bolt group 12; wherein, driven by the external driving device, the first face gear 62 drives the outer rotor shaft 4 to rotate, and the second face gear 72 drives the inner rotor shaft 3 to rotate, and the inner rotor shaft 3 rotates in opposite directions to the outer rotor shaft 4. The precise matching of the first cylindrical gear 61 and the first face gear 62, and the second cylindrical gear 71 and the second face gear 72, ensures the efficient and smooth transmission of power from the input shaft 5 to the inner and outer rotor shafts. Secondly, by using two sets of face gear pairs, the reversal of the inner and outer rotor shafts under the coaxial condition is realized, which improves the stability and controllability of the aircraft; and, due to the coaxial setting of the first face gear pair 6 and the second face gear pair 7, the entire structure is highly compact, reducing unnecessary space occupation and weight burden, and improving the flight efficiency and endurance of the aircraft.

[0036] like Figure 3As shown, the inner rotor shaft 3 is provided with a first bearing 14 and a second bearing 16, and the first bearing 14 is located below the second bearing 16; the inner ring of the first bearing 14 matches the outer diameter of the inner rotor shaft 3, and the outer ring of the first bearing 14 matches the inner hole of the outer rotor shaft 4. Specifically, the first bearing 14 is a self-aligning roller bearing, and the second bearing 16 is a cylindrical roller bearing. The first bearing 14 is a key supporting component between the inner rotor shaft 3 and the outer rotor shaft 4, and its inner ring is tightly matched with the inner rotor shaft 3, and the outer ring is also tightly matched with the inner hole of the outer rotor shaft 4, ensuring the stability and precision of the inner rotor shaft 3 during the rotation process. Secondly, the addition of the second bearing 16 further enhances this stability. Through the joint action of the two bearings, the inner rotor shaft 3 can rotate more smoothly, reducing the performance degradation caused by vibration and deviation. Furthermore, the first bearing 14 and the second bearing 16 jointly bear the radial and axial loads generated by the inner rotor shaft 3 during the rotation process, enhancing the bearing capacity of the entire rotor system.

[0037] like Figure 3 As shown, the inner rotor shaft 3 is located outside the inner part of the outer rotor shaft 4, and is provided with a bearing end cover 13, a sleeve 15 and a third round nut 17; the bearing end cover 13 is located below the first bearing 14, the sleeve 15 is located above the first bearing 14, and the third round nut 17 is located above the second bearing 16. The bearing end cover 13 is located below the first bearing 14, effectively sealing the bottom of the first bearing 14, preventing the entry of impurities and dust, and providing additional support to enhance the stability of the first bearing 14. The sleeve 15 is located above the first bearing 14. As a transition component between the inner rotor shaft 3 and the outer rotor shaft 4, it not only plays a positioning role, but also reduces the direct contact between the two, reducing wear and friction. The existence of the sleeve 15 also enables the inner rotor shaft 3 to rotate more smoothly. During use, the bearing end cover 13 and the sleeve 15 together provide double protection for the first bearing 14, preventing interference and damage from the external environment, thereby extending the service life of the bearing; the sleeve 15 reduces the direct contact between the inner rotor shaft 3 and the outer rotor shaft 4, reduces the wear caused by friction, and further improves the durability of the bearing and the entire rotor system.

[0038] Finally, the precise matching of the bearing end cover 13, the shaft sleeve 15 and the third round nut 17 reduces the vibration and noise of the rotor structure during rotation, thereby improving the comfort and concealment of the aircraft.

[0039] like Figure 1As shown, the structure further includes a sliding bearing 18, which is arranged on the top of the first propeller 1. The outer diameter of the sliding bearing 18 matches the inner hole of the outer rotor shaft 4, and the inner hole of the sliding bearing 18 matches the outer diameter of the inner rotor shaft 3. The sliding bearing 18 cooperates with the first bearing 14 and the second bearing 16 to achieve three-point support, improve the support stiffness of the inner rotor shaft, and effectively improve the stability and reliability of the rotor system.

[0040] like Figure 2 As shown, the first cylindrical gear 61 and the second cylindrical gear 71 have the same number of teeth; the first face gear 62 and the second face gear 72 also have the same number of teeth. The first cylindrical gear 61 and the first face gear 62 both have a module of m1; the second cylindrical gear 71 and the second face gear 72 both have a module of m2; and m1>m2. The first cylindrical gear 61 and the second cylindrical gear 71 have the same number of teeth Z1; the first face gear 62 and the second face gear 72 have the same number of teeth Z2, and Z2>Z1. Therefore, the first face gear pair 6 and the second face gear pair 7 have the same reduction ratio. The inner rotor shaft 3, the outer rotor shaft 4, the first face gear 62 and the second face gear 72 have the same axis 8. When the input shaft 5 rotates counterclockwise, the first face gear 62 and the outer rotor shaft 4 rotate counterclockwise, and the second face gear 72 and the inner rotor shaft 3 rotate clockwise. The two have the same speed and opposite rotation directions, thereby realizing the coaxial reverse rotation of the first propeller 1 and the second propeller 2 at the same speed. Furthermore, the first cylindrical gear 61 and the second cylindrical gear 71 are both circumferentially positioned by splines; and the first cylindrical gear 61 is fixed to the input shaft 5 by a first round nut 9 ; the second cylindrical gear 71 is fixed to the input shaft 5 by a second round nut 10 .

[0041] In a second aspect, an aircraft is provided, including a light-loaded single-engine low-altitude rotorcraft and an electric vertical take-off and landing aircraft, wherein the light-loaded single-engine low-altitude rotorcraft and the electric vertical take-off and landing aircraft are equipped with the coaxial counter-rotating double-rotor structure based on face gear transmission as described above.

[0042] 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 coaxial counter-rotating twin-rotor structure based on face gear transmission, characterized in that: include: An outer rotor shaft (4) rotatably connected to the inner rotor shaft (3); A first propeller (1) and a second propeller (2), wherein the first propeller (1) is arranged on the top of the inner rotor shaft (3); the second propeller (2) is arranged on the top of the outer rotor shaft (4), and the first propeller (1) is located above the second propeller (2); The first face gear pair (6) is connected to the bottom of the outer rotor shaft (4) through a first bolt group (11); The second face gear pair (7) is connected to the bottom of the inner rotor shaft (3) via a second bolt group (12); An input shaft (5) has one end connected to the first face gear pair (6) and the other end connected to the second face gear pair (7), and the input shaft (5) is used to connect to an external drive device.

2. The coaxial counter-rotating twin-rotor structure based on face gear transmission according to claim 1 is characterized in that: The first face gear pair (6) comprises a first cylindrical gear (61) and a first face gear (62), and the second face gear pair (7) comprises a second cylindrical gear (71) and a second face gear (72); The first cylindrical gear (61) is arranged at one end of the input shaft (5), and the second cylindrical gear (71) is arranged at the other end of the input shaft (5); The first face gear (62) and the second face gear (72) are coaxially arranged, the first cylindrical gear (61) cooperates with the first face gear (62), and the second cylindrical gear (71) cooperates with the second face gear (72); The first face gear (62) is connected to the bottom of the outer rotor shaft (4) via the first bolt group (11); The second face gear (72) is connected to the bottom of the inner rotor shaft (3) via the second bolt group (12); Wherein, under the drive of the external driving device, the first face gear (62) drives the outer rotor shaft (4) to rotate, and the second face gear (72) drives the inner rotor shaft (3) to rotate, and the inner rotor shaft (3) and the outer rotor shaft (4) rotate in opposite directions.

3. The coaxial counter-rotating twin-rotor structure based on face gear transmission according to claim 2 is characterized in that: A first bearing (14) and a second bearing (16) are provided on the inner rotor shaft (3), wherein the first bearing (14) is located below the second bearing (16); The inner ring of the first bearing (14) cooperates with the outer diameter of the inner rotor shaft (3), and the outer ring of the first bearing (14) cooperates with the inner hole of the outer rotor shaft (4).

4. The coaxial counter-rotating twin-rotor structure based on face gear transmission according to claim 3 is characterized in that: The first bearing (14) is a spherical roller bearing.

5. The coaxial counter-rotating twin-rotor structure based on face gear transmission according to claim 3 is characterized in that: The second bearing (16) is a cylindrical roller bearing.

6. The coaxial counter-rotating twin-rotor structure based on face gear transmission according to claim 1, characterized in that: The inner rotor shaft (3) is located outside the inner part of the outer rotor shaft (4) and is provided with a bearing end cover (13), a shaft sleeve (15) and a third round nut (17); The bearing end cover (13) is located below the first bearing (14), the shaft sleeve (15) is located above the first bearing (14), and the third round nut (17) is located above the second bearing (16).

7. The coaxial counter-rotating twin-rotor structure based on face gear transmission according to claim 1, characterized in that: Also includes: A sliding bearing (18) is arranged on the top of the first propeller (1), the outer diameter of the sliding bearing (18) being matched with the inner hole of the outer rotor shaft (4), and the inner hole of the sliding bearing (18) being matched with the outer diameter of the inner rotor shaft (3).

8. The coaxial counter-rotating twin-rotor structure based on face gear transmission according to claim 2, characterized in that: The first cylindrical gear (61) and the second cylindrical gear (71) have the same number of teeth; The first face gear (62) and the second face gear (72) also have the same number of teeth.

9. The coaxial counter-rotating twin-rotor structure based on face gear transmission according to claim 2, characterized in that: The first cylindrical gear (61) and the second cylindrical gear (71) are both positioned circumferentially by splines; Furthermore, the first cylindrical gear (61) is fixed to the input shaft (5) via a first cylindrical nut (9); and the second cylindrical gear (71) is fixed to the input shaft (5) via a second cylindrical nut (10).

10. An aircraft, including a light-loaded single-engine low-altitude rotorcraft and an electric vertical take-off and landing aircraft, characterized in that: The light-loaded single-engine low-altitude rotorcraft and the electric vertical take-off and landing aircraft are installed with a coaxial counter-rotating twin-rotor structure based on face gear transmission as described in any one of claims 1 to 9.

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