A flapping-wing aircraft capable of flapping-wing flapping-torsion co-frequency motion

Abstract

The application discloses a flapping-wing aircraft capable of making flapping wings flap-torsion same-frequency motion, and belongs to the technical field of flapping-wing aircrafts. The flapping-wing aircraft comprises a frame, a flight control system, a pair of flapping wings and a flapping-wing driving device. The flapping-wing driving device comprises a flapping-wing driving mechanism and a flapping-wing flap-torsion driving device. The flapping-wing flap-torsion driving device comprises a double-crank same-frequency different-phase driving mechanism arranged on the frame and a flap-torsion mechanism. The flap-torsion mechanism comprises a flap-torsion mechanism driving base and a pair of flapping-wing driving mechanisms with the same structure. The flap-torsion mechanism driving base is in longitudinal vertical face floating connection with the frame. The flapping-wing driving mechanism comprises a flapping-wing control arm and a pair of flapping-wing driving rocker arms with the same structure. The flapping arm and the torsion arm are connected together through a torsion connecting structure. The pair of flapping-wing driving mechanisms with the same structure are symmetrically arranged. The flapping-wing aircraft has the characteristics of simple structure, high mechanical efficiency and strong amplitude driving capacity.

Description

Technical Field

[0001] This invention relates to the field of flapping-wing aircraft technology. Background Technology

[0002] Bionic flapping-wing aircraft are a type of miniature aircraft that draws inspiration from the flight patterns and principles of birds, bats, insects, and other organisms. Their aim is to improve the flight performance of miniature aircraft by utilizing the efficient flight mechanisms of living organisms. Due to their light weight, small size, portability, low operating costs, and biomimetic and stealth characteristics, bionic flapping-wing aircraft can be used in military fields such as mountain reconnaissance, target surveillance, covert patrols, and counter-terrorism early warning. They can also be used in civilian fields such as scientific research, agricultural and forestry protection, aerial surveying, and environmental monitoring.

[0003] Currently, many countries around the world have invested significant human and material resources in the research of bird-inspired flapping-wing aircraft, and have successfully developed several models. Representative examples include: Festo's "Smartbird" from Germany, RoboRaven from the University of Maryland, Phoenix from MIT, and in China, the "Little Falcon" and "Carrier Pigeon" from Northwestern Polytechnical University, the "HIT-Phoenix" from Harbin Institute of Technology, and the "Golden Eagle" from Nanjing University of Aeronautics and Astronautics.

[0004] Although micro flapping-wing aircraft possess numerous advantages and promising applications in certain fields, most existing flapping-wing aircraft employ a single-degree-of-freedom flapping coupled with passive torsion motion. While the wing surface undergoes some passive flexible deformation during flapping to ensure a certain amount of thrust, it is difficult to improve wing loading and aerodynamic efficiency, resulting in flight performance far inferior to that of naturally flying organisms. Existing publicly available literature and video data show that bird wings possess considerable deformability. In addition to passive deformations such as chordal torsion and spanwise bending induced by aerodynamic and inertial forces, bird wings exhibit complex active deformations during flapping, including distinct three-stage extension, sweeping, and folding. These active deformations are particularly pronounced in large and medium-sized birds (such as geese, falcons, eagles, and hawks). The morphological and kinematic parameters of bird wings are the result of natural selection and evolution; the synergistic effect of these parameters enables birds to achieve excellent aerodynamic performance. Therefore, studying and learning from bird flight patterns is of great significance for improving the flight performance of bird-inspired flapping-wing aircraft.

[0005] Most existing flapping-wing aircraft employ single-degree-of-freedom flapping-wing mechanisms, relying on the passive, flexible deformation of the wing to improve flight efficiency. This propulsion method not only has low biomimicry but also suffers from aerodynamic efficiency significantly lower than that of birds. To further improve the aerodynamic performance of flapping-wing aircraft, some aircraft have implemented bird-like flapping motion principles through multi-degree-of-freedom flapping-wing drive mechanisms. While these mechanisms mimic most of the motions, they result in overly complex mechanisms, high weight, and low reliability.

[0006] Chinese invention patent "A flapping wing device for realizing flapping and active twisting of the wing surface" (authorization announcement number CN103241379B, authorization date September 9, 2015) discloses a flapping wing device for realizing flapping and active twisting of the wing surface. This device uses a set of bevel gears to transmit power to the rear end of the wing, realizing two degrees of freedom of flapping and twisting motion of the wing surface. Its shortcomings are that an additional set of gears is used for power transmission, and two sets of crank-rocker arms are required to drive the front and rear wing spars respectively. On the other hand, since the front and rear spars have different flapping phases, the flapping process will cause deformation of the wing surface, which will seriously affect the aerodynamic performance of the wing. Chinese invention patent "A biomimetic flapping wing drive mechanism and driving method for active twisting and folding" (authorization announcement number CN110466757A, authorization date October 9, 2020) discloses a flapping device with three degrees of freedom that simulates the flight of a bird. This device uses two sets of gears to drive the left and right wings respectively, generating wing twisting and folding by individually driving the front and rear wing spars. Its drawbacks are that the entire mechanism is driven by two sets of gears, which increases the weight, and the twisting and folding requires increasing the structural complexity of the wings, making it difficult to achieve lightweighting and miniaturization, thus limiting its application in flapping-wing aircraft.

[0007] It is evident that the shortcomings of existing flapping wing drive mechanisms mainly lie in their complex structure, low mechanical efficiency, and poor amplitude-changing drive capability. Therefore, it is of great significance to provide a novel flapping wing drive mechanism to solve the relevant problems of existing flapping wing drive mechanisms. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a flapping-wing aircraft that can make flapping and twisting movements at the same frequency, which has the characteristics of simple structure, high mechanical efficiency and strong amplitude driving capability.

[0009] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0010] A flapping-wing aircraft capable of flapping and twisting motions at the same frequency includes a frame, a flight control system, a pair of flapping wings and a flapping-wing drive device;

[0011] The flapping wing drive system includes a flapping wing drive mechanism and a flapping wing flapping-torsion drive system;

[0012] The flapping wing drive mechanism includes a drive motor and a reduction gear set mounted on the frame. The drive motor is connected to the power input end of the reduction gear set, and the power output end of the reduction gear set drives the flapping wing flapping-torsion drive device to work.

[0013] The flapping-torsion drive device for the flapping wing includes a double-crank, co-frequency, out-of-phase drive mechanism and a flapping-torsion mechanism mounted on the frame;

[0014] The double-crank synchronous out-of-phase drive mechanism includes a crank-connecting rod mechanism drive shaft mounted on the frame and a front crank-connecting rod mechanism and a rear crank-connecting rod mechanism mounted on the crank-connecting rod mechanism drive shaft. The connecting rod in the front crank-connecting rod mechanism is the front drive connecting rod, and the connecting rod in the rear crank-connecting rod mechanism is the rear drive connecting rod. When the crank-connecting rod mechanism drive shaft drives the front crank-connecting rod mechanism and the rear crank-connecting rod mechanism to rotate, the crank connecting ends of the front drive connecting rod and the rear drive connecting rod mechanism rotate around the crank-connecting rod mechanism drive shaft. The positions of the crank connecting ends of the front drive connecting rod and the rear drive connecting rod mechanism in their respective cranks ensure that when they rotate, the phase of the crank connecting end of the front drive connecting rod is greater than 0° to 64° over the crank connecting ends of the front and rear drive connecting rod mechanisms, thereby forming a torsional motion amplitude control angle. The drive motor is connected to the crank-connecting rod mechanism drive shaft through a reduction gear set to drive the front crank-connecting rod mechanism and the rear crank-connecting rod mechanism to rotate.

[0015] The flapping-torsion mechanism includes a flapping-torsion mechanism drive base and a pair of flapping wing drive mechanisms with identical structures;

[0016] The front end of the flapping-torsion mechanism drive base is hinged to the front drive link of the double-crank same-frequency out-of-phase drive mechanism; the rear end of the flapping-torsion mechanism drive base is hinged to the rear drive link of the double-crank same-frequency out-of-phase drive mechanism. The flapping-torsion mechanism drive base is connected to the frame in a longitudinal vertical floating connection so that the flapping-torsion mechanism drive base moves along the longitudinal vertical plane of the flapping-wing aircraft fuselage under the drive of the front drive link and the rear drive link.

[0017] The flapping wing drive mechanism includes a flapping wing control arm and a pair of flapping wing drive rockers with identical structures;

[0018] The flapping wing control arm includes a rocker arm support, a flapping arm, a torsion arm, and a torsion connection structure;

[0019] The rocker arm support is fixedly connected to the frame, and the inner end of the flapping arm is hinged to the rocker arm support so that the flapping arm can flap up and down relative to the frame. The torsion arm is provided with a flapping wing connection structure for connecting with the flapping wing.

[0020] The torsion connection structure includes a flange shaft, an inner flange stepped bearing, an outer flange stepped bearing, a torsion arm fixed flange, and a secondary flange. The torsion arm fixed flange is fixed at the inner end of the torsion arm, and a torsion arm flange shaft connection hole is provided at the inner end of the torsion arm along its axial direction. A flapping arm flange shaft connection hole is provided at the outer end of the flapping arm along its axial direction. The flange shaft includes a bearing stop, an inner connecting shaft located inside the bearing stop, and an outer connecting shaft located outside the bearing stop. The inner connecting shaft and the outer connecting shaft are coaxially arranged.

[0021] The flapping arm and the torsion arm are connected together by a torsion connection structure: the inner connecting shaft of the stop is inserted into the flange shaft connection hole of the flapping arm and fixed together with the flapping arm; the outer connecting shaft of the stop is inserted into the flange shaft connection hole of the torsion arm; an outer flange stepped bearing is set adjacent to the outer side of the bearing stop; an inner flange stepped bearing is set adjacent to the inner side of the bearing stop; a secondary flange is set inside the inner flange stepped bearing; the torsion arm fixing flange and the secondary flange are fixed together with bolts, so that the inner ring of the inner flange stepped bearing and the inner ring of the outer flange stepped bearing are respectively fixed to the bearing stop; the outer ring of the inner flange stepped bearing is fixed to the secondary flange; and the outer ring of the outer flange stepped bearing is fixed to the torsion arm fixing flange, thereby fixing the flapping arm and the torsion arm together axially along the same axis, forming the axis of the flapping wing control arm; and the torsion arm can rotate around the axis of the flapping wing control arm.

[0022] A pair of identical flapping wing drive rockers include a front flapping wing drive rocker and a rear flapping wing drive rocker, each comprising a ball joint connecting rod and a drive arm connected together by a ball joint; and the front flapping wing drive rocker and the rear flapping wing drive rocker are symmetrically arranged with respect to the torsion arm: the lower end of the ball joint connecting rod of the front flapping wing drive rocker is connected to the front ball joint of the flapping-torsion mechanism drive base, the rear end of the drive arm of the front flapping wing drive rocker is fixedly connected to the torsion arm, the lower end of the ball joint connecting rod of the rear flapping wing drive rocker is connected to the rear ball joint of the flapping-torsion mechanism drive base, and the front end of the drive arm of the rear flapping wing drive rocker is fixedly connected to the torsion arm;

[0023] The flapping wing is fixed to the torsion arm via a flapping wing connecting structure;

[0024] A pair of identical flapping wing drive mechanisms are symmetrically arranged on the left and right; the flapping wing drive mechanism on the left is the left flapping wing drive mechanism, and the flapping wing drive mechanism on the right is the right flapping wing drive mechanism.

[0025] The invention is further improved in that:

[0026] The connection structure of the flapping-torsion mechanism drive base and the frame in a longitudinal vertical floating connection is as follows: a base slider is provided at the front end of the flapping-torsion mechanism drive base, and a vertical slide groove adapted to the base slider is provided on the frame to form a sliding pair, so that the flapping-torsion mechanism drive base slides up and down along the slide groove; the rear end of the flapping-torsion mechanism drive base is hinged to the front end of the rocker arm, and the rear end of the rocker arm is hinged to the rear end of the frame, so that the flapping-torsion mechanism drive base can perform pitching motion; thereby making the flapping-torsion mechanism drive base swing along the longitudinal vertical plane of the flapping-wing aircraft fuselage.

[0027] The torsional motion amplitude control angle has an angle adjustment structure to adjust the torsional motion amplitude of the flapping wing 2: the crank of the front crank-connecting rod mechanism and / or the rear crank-connecting rod mechanism is provided with two or more connecting rod connecting holes to change the position of the front drive connecting rod crank connecting end and / or the rear drive connecting rod crank connecting end in their respective cranks, thereby adjusting the angle of the torsional motion amplitude control angle.

[0028] The flapping wing drive mechanism includes a reduction gear set comprising a front-stage gear set and a rear-stage transmission gear set. The front-stage gear set includes a small-diameter transmission gear and a large-diameter transmission gear set coaxially. The large-diameter transmission gear 28 of the front-stage gear set serves as the power input end of the reduction gear set, while the rear-stage transmission gear shaft serves as the power output end of the reduction gear set. The drive motor shaft in the flapping wing drive mechanism is equipped with a shaft gear, which meshes with the large-diameter transmission gear of the front-stage gear set. The small-diameter transmission gear of the front-stage gear set meshes with the rear-stage transmission gear set, and the rear-stage transmission gear shaft drives the crank-connecting rod mechanism transmission shaft to rotate.

[0029] The torsion arm is provided with a connection structure for connecting with the flapping wing: the outer end of the torsion arm is provided with a wing root insertion hole along its axial direction, the wing root of the flapping wing is inserted into the wing root insertion hole and fixedly connected to the torsion arm through the wing root fixing pin.

[0030] The beneficial effects of adopting the above technical solution are as follows:

[0031] This invention employs a flapping-torsion drive device to achieve active torsional flapping motion of the flapping wing during flight. Compared with the prior art, it has the following advantages: (1) The flapping mechanism and the torsion mechanism are coupled, and the rotational motion of the front crank-connecting rod mechanism and the rear crank-connecting rod mechanism is transformed into a flapping-torsion mechanism driving the base to swing along the longitudinal vertical plane of the flapping wing aircraft fuselage. The connection structure of the longitudinal vertical plane floating connection ensures the lateral stiffness of the mechanism and reduces the complexity of the mechanism and the wing structure. (2) The flapping process and the torsion process share the same motor drive, which simplifies the system complexity. In addition, with this structural design, the flapping motion and the torsion motion can have the same period and can achieve a phase difference of 90°, thereby further achieving the following effects: the torsion angle of the flapping wing is 0° at the apex of the downward flapping and the apex of the upward flapping, and the torsion angle is the largest at the middle of the upward flapping and the middle of the downward flapping. This motion is closer to the movement of birds and has the advantages of high biomimicry, high aerodynamic efficiency and large effective load. (3) The torsional motion amplitude control angle has an angle adjustment structure to change the position of the front drive connecting rod crank connection end and / or the rear drive connecting rod crank connection end in their respective cranks, so as to achieve the purpose of adjusting the front and rear crank radii and the front and rear crank phase difference, thereby changing the torsional amplitude without changing the flapping amplitude.

[0032] Therefore, the present invention has the characteristics of simple structure, high mechanical efficiency, and strong variable amplitude driving capability. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of an ornithopter;

[0034] Figure 2 yes Figure 1 Axonometric view of the flapping wing drive mechanism;

[0035] Figure 3 yes Figure 2 The left view;

[0036] Figure 4 yes Figure 2 The main view;

[0037] Figure 5 yes Figure 2 Axonometric view of the flapping-torsion drive mechanism of the flapping wing;

[0038] Figure 6 yes Figure 5 Axonometric drawing of a double-crank, same-frequency, out-of-phase drive mechanism;

[0039] Figure 7 yes Figure 5 Axonometric drawing of the flapping-torsion mechanism;

[0040] Figure 8 yes Figure 5 Axonometric drawing of the flapping-torsion mechanism;

[0041] Figure 9 yes Figure 7 A schematic diagram of the torsion connection structure;

[0042] Figure 10 yes Figure 2 A schematic diagram of the structure of a medium reduction gear set.

[0043] In the attached diagram: 1. Frame; 2. Flapping wing; 3. Drive motor; 4. Crank-connecting rod mechanism drive shaft; 5. Front drive connecting rod; 6. Rear drive connecting rod; 7. Flap-torsion mechanism drive base; 8. Rocker arm support; 9. Flapping arm; 10. Torsion arm; 11. Torsion arm fixing flange; 12. Sub-flange; 13. Bearing stop; 14. Inner connecting shaft of the stop; 15. Outer connecting shaft of the stop; 16. Inner ring of the bearing on the inner flange of the stop; 17. Stepped shaft on the outer flange of the stop. 18. Inner ring of the bearing; 19. Outer ring of the stepped bearing on the inner flange of the stop; 20. Outer ring of the stepped bearing on the outer flange of the stop; 21. Ball joint connecting rod; 22. Drive arm; 23. Base slider; 24. Vertical slide groove; 25. Rocker arm; 26. Connecting rod connecting hole; 27. Rear drive gear; 28. Small diameter drive gear; 29. ​​Large diameter drive gear; 30. Rear drive gear shaft; 31. Rotary shaft gear; 32. Flange shaft fixing pin; 33. Flange root insertion hole; 34. Flange root fixing pin hole.

[0044] The orientation descriptions in this application refer to the orientation of the flapping-wing aircraft. "Front" refers to the direction closer to the nose of the flapping-wing aircraft; "inner end" refers to the end closer to the longitudinal centerline of the flapping-wing aircraft fuselage; and "outer end" refers to the end farther from the longitudinal centerline of the flapping-wing aircraft fuselage. Detailed Implementation

[0045] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0046] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, welding, and bonding that are mature in the prior art, and will not be described in detail here.

[0047] Depend on Figures 1-10 As shown in the embodiment, this embodiment includes a frame 1, a flight control system [Pixracer Mini flight control system], a pair of flapping wings 2 and a flapping wing drive device;

[0048] The flapping wing drive system includes a flapping wing drive mechanism and a flapping wing flapping-torsion drive system;

[0049] The flapping wing drive mechanism includes a drive motor 3 and a reduction gear set mounted on the frame 1. The drive motor 3 is connected to the power input end of the reduction gear set, and the power output end of the reduction gear set drives the flapping wing flapping-torsion drive device to work.

[0050] The flapping-torsion drive device for the flapping wing includes a double-crank co-frequency out-of-phase drive mechanism and a flapping-torsion mechanism mounted on the frame 1;

[0051] The double-crank synchronous out-of-phase drive mechanism includes a crank-connecting rod mechanism transmission shaft 4 mounted on the frame 1 and a front crank-connecting rod mechanism and a rear crank-connecting rod mechanism mounted on the crank-connecting rod mechanism transmission shaft 4. The connecting rod in the front crank-connecting rod mechanism is the front drive connecting rod 5, and the connecting rod in the rear crank-connecting rod mechanism is the rear drive connecting rod 6. When the crank-connecting rod mechanism transmission shaft 4 drives the front crank-connecting rod mechanism and the rear crank-connecting rod mechanism to rotate, the crank connecting ends of the front drive connecting rod and the rear drive connecting rod rotate around the crank-connecting rod mechanism transmission shaft 4. The crank connecting ends of the front drive connecting rod and the rear drive connecting rod are located in their respective cranks so that when they rotate, the phase of the front drive connecting rod crank connecting end is greater than 0° to 64° over the front and rear drive connecting rod crank connecting ends, thereby forming a torsional motion amplitude control angle. The drive motor 3 is connected to the crank-connecting rod mechanism transmission shaft 4 through a reduction gear set to drive the front crank-connecting rod mechanism and the rear crank-connecting rod mechanism to rotate.

[0052] The flapping-torsion mechanism includes a flapping-torsion mechanism drive base 7 and a pair of flapping wing drive mechanisms with identical structures;

[0053] The front end of the flapping-torsion mechanism drive base 7 is hinged to the front drive link 5 of the double-crank synchronous and out-of-phase drive mechanism; the rear end of the flapping-torsion mechanism drive base 7 is hinged to the rear drive link 6 of the double-crank synchronous and out-of-phase drive mechanism. The flapping-torsion mechanism drive base 7 is longitudinally and vertically floatingly connected to the frame 1, so that under the drive of the front drive link 5 and the rear drive link 6, the flapping-torsion mechanism drive base 7 moves along the longitudinal vertical plane of the flapping-wing aircraft fuselage; when the crank-connecting rod mechanism transmission shaft 4 drives the front crank-connecting rod mechanism and the rear crank-connecting rod mechanism... When the handle linkage mechanism rotates, the front drive linkage 5 and the rear drive linkage 6 cause the flapping-torsion mechanism drive base 7 to swing up and down. The control angle of the torsional motion amplitude formed by the crank connection end of the front drive linkage and the crank connection end of the rear drive linkage during rotation causes the flapping-torsion mechanism drive base 7 to swing up and down while the angle with the horizontal plane is constantly changing, thus producing a torsional effect to make a back-and-forth torsional motion, thereby causing the flapping-torsion mechanism drive base 7 to swing along the longitudinal vertical plane of the flapping-wing aircraft fuselage.

[0054] The flapping wing drive mechanism includes a flapping wing control arm and a pair of flapping wing drive rockers with identical structures;

[0055] The flapping wing control arm includes a rocker arm support 8, a flapping arm 9, a torsion arm 10, and a torsion connection structure;

[0056] The rocker arm support 8 is fixedly connected to the frame 1, and the inner end of the flapping arm 9 is hinged to the rocker arm support 8 so that the flapping arm 9 can flap up and down relative to the frame 1. The torsion arm 10 is provided with a flapping wing connection structure for connecting with the flapping wing 2.

[0057] The torsion connection structure includes a flange shaft, an inner flange stepped bearing, an outer flange stepped bearing, a torsion arm fixing flange 11, and a secondary flange 12. The torsion arm fixing flange 11 is fixed at the inner end of the torsion arm 10, and a torsion arm flange shaft connection hole is provided at the inner end of the torsion arm 10 along its axial direction. A flapping arm flange shaft connection hole is provided at the outer end of the flapping arm 9 along its axial direction. The flange shaft includes a bearing stop 13, an inner connecting shaft 14 located inside the bearing stop 13, and an outer connecting shaft 15 located outside the bearing stop 13. The inner connecting shaft 14 and the outer connecting shaft 15 are coaxially arranged.

[0058] The flapping arm 9 and the torsion arm 10 are connected together by a torsion connection structure: the inner connecting shaft 14 of the stop is inserted into the flange shaft connection hole of the flapping arm and fixed to the flapping arm 9 by the flange shaft fixing pin 31; the outer connecting shaft 15 of the stop is inserted into the flange shaft connection hole of the torsion arm; an outer flange stepped bearing is set adjacent to the outer side of the bearing stop 13; an inner flange stepped bearing is set adjacent to the inner side of the bearing stop 13; the auxiliary flange 12 is set inside the inner flange stepped bearing; the torsion arm fixing flange 11 and the auxiliary flange 12 are connected by bolts. The bearings are fixed together with bolts so that the inner ring 16 of the inner flange stepped bearing and the inner ring 17 of the outer flange stepped bearing are fixed to the bearing stop 13 respectively, the outer ring 18 of the inner flange stepped bearing is fixed to the auxiliary flange 12, and the outer ring 19 of the outer flange stepped bearing is fixed to the torsion arm fixing flange 11. This makes the flapping arm 9 and the torsion arm 10 axially fixed together along the same axis, forming the flapping wing control arm axis; and the torsion arm 10 can rotate around the flapping wing control arm axis.

[0059] A pair of identical flapping wing drive rockers include a front flapping wing drive rocker and a rear flapping wing drive rocker, each including a ball joint connecting rod 20 and a drive arm 21 connected together by a ball joint; and the front flapping wing drive rocker and the rear flapping wing drive rocker are symmetrically arranged with respect to the torsion arm 10: the lower end of the ball joint connecting rod 20 of the front flapping wing drive rocker is connected to the front ball joint of the flapping-torsion mechanism drive base 7, the rear end of the drive arm 21 of the front flapping wing drive rocker is fixedly connected to the torsion arm 10, the lower end of the ball joint connecting rod 20 of the rear flapping wing drive rocker is connected to the rear ball joint of the flapping-torsion mechanism drive base 7, and the front end of the drive arm 21 of the rear flapping wing drive rocker is fixedly connected to the torsion arm 10;

[0060] The flapping wing 2 is fixed to the torsion arm 10 via the flapping wing connecting structure;

[0061] A pair of identical flapping wing drive mechanisms are symmetrically arranged on the left and right; the flapping wing drive mechanism on the left is the left flapping wing drive mechanism, and the flapping wing drive mechanism on the right is the right flapping wing drive mechanism.

[0062] The flapping-torsion mechanism drives the base 7 to swing up and down, so that the front flapping wing drive rocker and the rear flapping wing drive rocker of the left flapping wing drive mechanism and the right flapping wing drive mechanism drive their respective flapping arms 9 to flap. At the same time, the flapping-torsion mechanism drives the base 7 to twist back and forth, so that the front flapping wing drive rocker and the rear flapping wing drive rocker of the left flapping wing drive mechanism and the right flapping wing drive mechanism drive their respective torsion arms 10 to twist around the axis of the flapping wing control arm, thereby driving a pair of flapping wings 2 to flap and torsion in the same frequency.

[0063] The connection structure of the flapping-torsion mechanism drive base 7 and the frame 1 in a longitudinal vertical floating connection is as follows: a base slider 22 is provided at the front end of the flapping-torsion mechanism drive base 7, and a vertical slide groove 23 adapted to the base slider 22 is provided on the frame 1 to form a sliding pair, so that the flapping-torsion mechanism drive base 7 slides up and down along the slide groove 23; the rear end of the flapping-torsion mechanism drive base 7 is hinged to the front end of the rocker arm 24, and the rear end of the rocker arm 24 is hinged to the rear end of the frame 1, so that the flapping-torsion mechanism drive base 7 can perform pitching motion; thereby making the flapping-torsion mechanism drive base 7 swing along the longitudinal vertical plane of the flapping-wing aircraft fuselage.

[0064] The torsional motion amplitude control angle has an angle adjustment structure to adjust the torsional motion amplitude of the flapping wing 2: the crank of the front crank-connecting rod mechanism and / or the rear crank-connecting rod mechanism is provided with two or more connecting rod connecting holes 25 to change the position of the front drive connecting rod crank connecting end and / or the rear drive connecting rod crank connecting end in their respective cranks, thereby adjusting the angle of the torsional motion amplitude control angle, so as to adjust the torsional motion amplitude of the flapping wing 2 without changing the flapping amplitude of the flapping wing 2.

[0065] The flapping wing drive mechanism includes a reduction gear set comprising a front gear set and a rear transmission gear 26. The front gear set includes a small-diameter transmission gear 27 and a large-diameter transmission gear 28 arranged coaxially. The large-diameter transmission gear 28 of the front gear set is the power input end of the reduction gear set, and the rear transmission gear shaft 29 is the power output end of the reduction gear set. The drive motor shaft in the flapping wing drive mechanism is equipped with a shaft gear 30, which meshes with the large-diameter transmission gear 28 of the front gear set. The small-diameter transmission gear 27 of the front gear set meshes with the rear transmission gear 26. The rear transmission gear shaft 29 drives the crank-connecting rod mechanism transmission shaft 4 to rotate.

[0066] The torsion arm 10 is provided with a connection structure for connecting with the flapping wing 2: the outer end of the torsion arm 10 is provided with a wing root insertion hole 32 along its axial direction, the wing root of the flapping wing 2 is inserted into the wing root insertion hole 32 and fixedly connected to the torsion arm 10 through the wing root fixing pin.

Claims

1. A flapping-wing aircraft capable of flapping and twisting motions at the same frequency, characterized in that: It includes a frame (1), a flight control system, a pair of flapping wings (2) and a flapping wing drive device; The flapping wing drive device includes a flapping wing drive mechanism and a flapping wing flapping-torsion drive device; The flapping wing drive mechanism includes a drive motor (3) and a reduction gear set mounted on the frame (1). The drive motor (3) is connected to the power input end of the reduction gear set, and the power output end of the reduction gear set drives the flapping wing flapping-torsion drive device to work. The flapping wing flapping-torsion drive device includes a double-crank in-frequency out-of-phase drive mechanism and a flapping-torsion mechanism mounted on the frame (1); The double-crank synchronous and out-of-phase drive mechanism includes a crank-connecting rod mechanism transmission shaft (4) mounted on the frame (1) and a front crank-connecting rod mechanism and a rear crank-connecting rod mechanism mounted on the crank-connecting rod mechanism transmission shaft (4); the connecting rod in the front crank-connecting rod mechanism is a front drive connecting rod (5), and the connecting rod in the rear crank-connecting rod mechanism is a rear drive connecting rod (6); when the crank-connecting rod mechanism transmission shaft (4) drives the front crank-connecting rod mechanism and the rear crank-connecting rod mechanism to rotate, the crank connecting end of the front drive connecting rod is connected to the crank connecting end of the rear drive connecting rod. The end rotates around the transmission shaft (4) of the crank-connecting rod mechanism, and the front drive connecting rod crank connection end and the rear drive connecting rod crank connection end are located in their respective cranks so that when they rotate, the front drive connecting rod crank connection end is ahead of the rear drive connecting rod crank connection end by a phase > 0° to 64°, thereby forming a torsional motion amplitude control angle. The drive motor (3) is connected to the transmission shaft (4) of the crank-connecting rod mechanism through the reduction gear set to drive the front crank-connecting rod mechanism and the rear crank-connecting rod mechanism to rotate. The flapping-torsion mechanism includes a flapping-torsion mechanism drive base (7) and a pair of flapping wing drive mechanisms with identical structures; The front end of the flapping-torsion mechanism drive base (7) is hinged to the front drive link (5) of the double crank synchronous phase drive mechanism; the rear end of the flapping-torsion mechanism drive base (7) is hinged to the rear drive link (6) of the double crank synchronous phase drive mechanism; the flapping-torsion mechanism drive base (7) is connected to the frame (1) in a longitudinal vertical floating connection, so that under the drive of the front drive link (5) and the rear drive link (6), the flapping-torsion mechanism drive base (7) moves along the longitudinal vertical plane of the flapping wing aircraft fuselage; The flapping wing drive mechanism includes a flapping wing control arm and a pair of flapping wing drive rockers with the same structure; The flapping wing control arm includes a rocker arm support (8), a flapping arm (9), a torsion arm (10), and a torsion connection structure; The rocker arm support (8) is fixedly connected to the frame (1), and the inner end of the flapping arm (9) is hinged to the rocker arm support (8) so that the flapping arm (9) can flap up and down relative to the frame (1). The torsion arm (10) is provided with a flapping wing connection structure for connecting with the flapping wing (2). The torsion connection structure includes a flange shaft, an inner flange stepped bearing, an outer flange stepped bearing, a torsion arm fixing flange (11), and a secondary flange (12). The torsion arm fixing flange (11) is fixed at the inner end of the torsion arm (10), and a torsion arm flange shaft connection hole is provided at the inner end of the torsion arm (10) along its axial direction. A flapping arm flange shaft connection hole is provided at the outer end of the flapping arm (9) along its axial direction. The flange shaft includes a bearing stop (13), an inner connecting shaft (14) located inside the bearing stop (13), and an outer connecting shaft (15) located outside the bearing stop (13). The inner connecting shaft (14) and the outer connecting shaft (15) are coaxially arranged. The flapping arm (9) and the torsion arm (10) are connected together by a torsion connection structure: the inner connecting shaft (14) of the stop is inserted into the flange shaft connecting hole of the flapping arm and fixed together with the flapping arm (9); the outer connecting shaft (15) of the stop is inserted into the flange shaft connecting hole of the torsion arm; an outer flange stepped bearing is provided adjacent to the outer side of the bearing stop (13); an inner flange stepped bearing is provided adjacent to the inner side of the bearing stop (13); the auxiliary flange (12) is provided inside the inner flange stepped bearing; the torsion arm fixing flange (11) and the auxiliary flange (12) are connected by bolts. The bearings are fixedly connected together so that the inner ring (16) of the inner flange step bearing and the inner ring (17) of the outer flange step bearing are fixed to the bearing stop (13) respectively, the outer ring (18) of the inner flange step bearing is fixed to the auxiliary flange (12), and the outer ring (19) of the outer flange step bearing is fixed to the torsion arm fixing flange (11), so that the flapping arm (9) and the torsion arm (10) are axially fixed together along the same axis, and the same axis forms the flapping wing control arm axis; and the torsion arm (10) can rotate about the flapping wing control arm axis. A pair of identical flapping wing drive rockers include a front flapping wing drive rocker and a rear flapping wing drive rocker, each including a ball joint connecting rod (20) and a drive arm (21) connected together by a ball joint; and the front flapping wing drive rocker and the rear flapping wing drive rocker are symmetrically arranged relative to the torsion arm (10): the lower end of the ball joint connecting rod (20) of the front flapping wing drive rocker is connected to the front ball joint of the flapping-torsion mechanism drive base (7), the rear end of the drive arm (21) of the front flapping wing drive rocker is fixedly connected to the torsion arm (10), the lower end of the ball joint connecting rod (20) of the rear flapping wing drive rocker is connected to the rear ball joint of the flapping-torsion mechanism drive base (7), and the front end of the drive arm (21) of the rear flapping wing drive rocker is fixedly connected to the torsion arm (10); The flapping wing (2) is fixed to the torsion arm (10) through the flapping wing connecting structure; A pair of identical flapping wing drive mechanisms are symmetrically arranged on the left and right sides; the flapping wing drive mechanism located on the left side is the left flapping wing drive mechanism, and the flapping wing drive mechanism located on the right side is the right flapping wing drive mechanism.

2. A flapping-wing aircraft according to claim 1, characterized in that: The connection structure of the flapping-torsion mechanism drive base (7) and the frame (1) in a longitudinal vertical floating connection is as follows: a base slider (22) is provided at the front end of the flapping-torsion mechanism drive base (7), and a vertical slide groove (23) adapted to the base slider (22) is provided on the frame (1) to form a sliding pair, so that the flapping-torsion mechanism drive base (7) slides up and down along the slide groove (23); the rear end of the flapping-torsion mechanism drive base (7) is hinged to the front end of the rocker arm (24), and the rear end of the rocker arm (24) is hinged to the rear end of the frame (1), so that the flapping-torsion mechanism drive base (7) can perform pitching motion; thereby making the flapping-torsion mechanism drive base (7) swing along the longitudinal vertical plane of the flapping-wing aircraft fuselage.

3. A flapping-wing aircraft according to claim 1, characterized in that: The torsional motion amplitude control angle has an angle adjustment structure to adjust the torsional motion amplitude of the flapping wing (2): the crank of the front crank connecting rod mechanism and / or the rear crank connecting rod mechanism is provided with two or more connecting rod connecting holes (25) to change the position of the front drive connecting rod crank connecting end and / or the rear drive connecting rod crank connecting end in their respective cranks, thereby adjusting the angle of the torsional motion amplitude control angle.

4. A flapping-wing aircraft according to claim 1, characterized in that: The flapping wing drive mechanism includes a reduction gear set comprising a front gear set and a rear transmission gear (26). The front gear set comprises a small-diameter transmission gear (27) and a large-diameter transmission gear (28) arranged coaxially. The large-diameter transmission gear (28) of the front gear set is the power input end of the reduction gear set, and the rear transmission gear shaft (29) is the power output end of the reduction gear set. The drive motor shaft in the flapping wing drive mechanism is provided with a shaft gear (30). The shaft gear (30) meshes with the large-diameter transmission gear (28) of the front gear set, and the small-diameter transmission gear (27) of the front gear set meshes with the rear transmission gear (26). The rear transmission gear shaft (29) drives the crank-connecting rod mechanism transmission shaft (4) to rotate.

5. A flapping-torsion drive device for a flapping wing aircraft according to any one of claims 1 to 4, characterized in that: The torsion arm (10) is provided with a connection structure for connecting with the flapping wing (2): the outer end of the torsion arm (10) is provided with a wing root insertion hole (32) along its axial direction, the wing root of the flapping wing (2) is inserted into the wing root insertion hole (32) and fixedly connected to the torsion arm (10) through the wing root fixing pin.

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