Flapping-wing mechanism based on incomplete gear transmission

Abstract

The present invention provides a flapping-wing mechanism based on incomplete gear transmission, including a skeleton support structure, a reduction gear structure, a flapping-wing rod structure, a transmission gear structure, a transmission main shaft structure and a motor structure; the motor structure, the reduction gear structure, the transmission main shaft structure, the transmission gear structure and the flapping-wing rod structure are sequentially connected in transmission. A motor output shaft gear is arranged on the output shaft of the motor. The reduction gear structure includes a first reduction gear and a double-layer gear; the transmission gear structure includes a first incomplete gear, a second incomplete gear and a third incomplete gear; in the present invention, the transmission gear structure is used to cooperate with the flapping-wing rod structure to convert the rotational motion of the main shaft structure driven by the motor into the flapping motion of the flapping-wing rod structure through a plurality of incomplete gears, without a quick return characteristic and with uniform speed changes. And through the mutual meshing between the gears, the technical effects of high flapping synchronization and stable and consistent transmission ratio can be achieved.

Description

Technical Field

[0001] The present invention relates to the field of bionic aircraft, and in particular to a flapping-wing driving mechanism driven by an incomplete gear and capable of achieving large-angle flapping, in particular, a flapping-wing mechanism based on an incomplete gear transmission. Background Art

[0002] Flapping-wing aircraft imitate birds or insects, relying on flapping mechanisms to drive wings to flap back and forth to generate lift to overcome gravity. Compared with fixed-wing and rotary-wing aircraft, flapping-wing aircraft have a high degree of bionics, small size, high concealment, and flexible mobility. They have broad application prospects in the civil and military fields and have received widespread attention at home and abroad.

[0003] The flapping mechanism is the core component of the flapping-wing aircraft. The transmission mechanism is used to convert the continuous rotational motion of the motor into the reciprocating motion of the wings. The flapping mechanism is used to amplify the output torque of the motor and reduce the speed to adapt to the optimal flapping frequency. The design of the transmission mechanism needs to achieve the largest possible flapping amplitude to provide a greater average lift, ensure the transmission ratio, and reduce the instability of the high-speed flapping process. The structural skeleton needs to overcome the periodic vibration caused by the flapping process and ensure the strength of the rotating mechanism. The current flapping-wing drive mechanisms are mainly the following:

[0004] The Chinese patent authorization announcement number is CN109795685A, and the name is a gear rack pair flapping wing drive mechanism based on an external meshing planetary gear reducer. A flapping wing transmission mechanism using an external meshing planetary gear reducer and a gear rack pair connecting rod as a rocker arm is disclosed. The mechanism uses an external meshing planetary gear reducer to achieve a compact structure and a large reduction ratio, and has high transmission efficiency and is relatively stable. However, the flapping angle of the mechanism is small, and a high-frequency large-angle output cannot be achieved.

[0005] The Chinese patent application publication number is CN113911342A, and its name is a bionic flapping wing micro-aircraft with controllable flapping amplitude based on wing root elastic energy storage. A flapping wing mechanism with an elastic element added at the wing root is disclosed. The wing root elastic stop structure is introduced to store the inertial work of flapping wing flapping as elastic potential energy at the end and beginning of flapping, and release it at the initial stage of the next flapping of the wing, thereby improving the transmission efficiency. However, there is a collision during the contact process of the elastic energy storage element, which causes additional vibration to the high-frequency and large-angle flapping wing motion, affecting the flapping wing stability.

[0006] Patent document CN113665808A is titled A flapping mechanism for a micro flapping-wing aircraft based on a wire transmission mechanism. A flapping-wing mechanism that uses a wire transmission to drive a flapping-wing connecting rod to achieve reciprocating swing is disclosed. This solution can achieve a large swing angle, and the flapping-wing rods on both sides are in the same phase, which can effectively avoid the quick return characteristics of the traditional crank rocker and reduce the impact force on the mechanism during the transmission process. However, the wire transmission mechanism is subjected to a large force at the flapping amplitude, which will produce a certain elastic deformation, resulting in insufficient tension of the rope, unstable transmission ratio, and a swing angle that does not meet the expected design, while reducing the service life.

[0007] In summary, the existing flapping-wing transmission mechanism still cannot meet the requirements of large angle, high flapping-wing stability and stable transmission ratio at the same time. It is necessary to design a new flapping-wing drive mechanism.

[0008] Patent document CN113071666A discloses a micro flapping-wing aircraft with adjustable wing flapping angle, which belongs to the field of micro bionic aircraft, and includes a frame part, a transmission device, a flapping device and an adjustment device. The frame part includes a fuselage, a head, a tail wing and a counterweight balance block, and the head and the tail wing are fixedly connected to the fuselage; the transmission device includes a motor, a reduction gear set and a transmission gear, and the two large gears are meshed with each other to achieve synchronous and symmetrical movement of the wings on both sides; the flapping device includes a crank, a rack, and a wing, and one end of the crank is fixedly connected to the large gear, and together with the rack, it forms an eccentric crank rocker mechanism; the adjustment device includes a limit slider and a fan-shaped roller; by changing the radius of the fan-shaped roller or the position where it is connected to the support plate, the up and down flapping angle of the wing can be adjusted. However, the maximum flapping angle of this scheme is still relatively small. Summary of the invention

[0009] In view of the defects in the prior art, an object of the present invention is to provide a flapping-wing mechanism based on incomplete gear transmission.

[0010] A flapping-wing mechanism based on incomplete gear transmission provided by the present invention comprises a skeleton support structure, a reduction gear structure, a flapping-wing rod structure, a transmission gear structure, a transmission main shaft structure and a motor structure;

[0011] The transmission spindle structure and the motor structure are installed on the skeleton support structure;

[0012] The motor structure, the reduction gear structure, the transmission main shaft structure, the transmission gear structure and the flapping-wing lever structure are sequentially transmission-connected.

[0013] Preferably, the motor structure includes a motor and a motor fixing plate; the motor is mounted on the skeleton support structure through the motor fixing plate;

[0014] The output shaft of the motor is provided with a motor output shaft gear, and the motor output shaft gear is meshed with the reduction gear structure.

[0015] Preferably, the reduction gear structure includes a first reduction gear and a double-layer gear;

[0016] The double-layer gear comprises a first-layer gear and a second-layer gear; the first-layer gear and the second-layer gear are coaxially arranged, the motor output shaft gear is meshed with the first-layer gear, and the second-layer gear is meshed with the first reduction gear.

[0017] Preferably, the transmission main shaft structure includes a first transmission shaft, a first fixed bearing and a second fixed bearing. The first reduction gear is mounted on the first transmission shaft and can drive the first transmission shaft to rotate. The first transmission shaft is installed on the skeleton support structure through the first fixed bearing and the second fixed bearing.

[0018] Preferably, the transmission gear structure comprises a first incomplete gear, a second incomplete gear and a third incomplete gear;

[0019] The first incomplete gear includes a first tooth portion and a first arc portion, the second incomplete gear includes a second tooth portion and a second arc portion, and the third incomplete gear includes a third tooth portion and a third arc portion; the second incomplete gear and the third incomplete gear are both provided with a polygonal groove structure;

[0020] The first incomplete gear is mounted on the transmission main shaft structure and can rotate along with the rotation of the transmission main shaft structure;

[0021] When the first incomplete gear rotates, the first tooth portion can mesh with the second tooth portion and the third tooth portion in sequence to drive the second incomplete gear and the third incomplete gear to rotate in sequence.

[0022] Preferably, the flapping-wing rod structure comprises a first gear connecting assembly, a second gear connecting assembly, a first wing connecting rod, a second wing connecting rod, a first flapping-wing rod, a second flapping-wing rod, a first wing root connecting rod and a second wing root connecting rod;

[0023] The first gear connecting assembly and the second gear connecting assembly each include a gear portion and a connecting pin, wherein the connecting pin is arranged at the center of the gear portion and extends along the axial direction of the gear portion;

[0024] The connecting pin in the first gear connecting assembly matches the polygonal groove structure of the second incomplete gear; the connecting pin in the second gear connecting assembly matches the polygonal groove structure of the third incomplete gear; the gear portion in the first gear connecting assembly meshes with the gear portion in the second gear connecting assembly;

[0025] The first flapping-wing lever is connected to the gear portion of the first gear connecting assembly, and the second flapping-wing lever is connected to the gear portion of the second gear connecting assembly;

[0026] The first wing connecting rod and the second wing connecting rod are respectively mounted on the first flapping wing rod and the second flapping wing rod;

[0027] The first wing root connecting rod is used to coaxially connect the second incomplete gear with the first gear connecting assembly, and the second wing root connecting rod is used to coaxially connect the third incomplete gear with the second gear connecting assembly.

[0028] Preferably, the skeleton support structure comprises a first side support plate, a second side support plate, an upper plate, a middle plate, and a bottom plate;

[0029] The first side support plate and the second side support plate are each provided with a first notch, a second notch and a third notch;

[0030] The first notch matches with the convex groove of the upper plate, the second notch matches with the convex groove of the middle plate, and the third notch matches with the convex groove of the bottom plate;

[0031] The bottom plate is provided with a motor installation position for installing the motor structure;

[0032] The first fixed bearing is mounted on the middle plate, and the second fixed bearing is mounted on the bottom plate.

[0033] Preferably, the flapping-wing rod structure further comprises a first flapping-wing rod cover plate and a second flapping-wing rod cover plate;

[0034] The ends of the first flapping-wing rod and the second flapping-wing rod are both concave groove structures, and the two concave groove structures are respectively used to fix the first wing connecting rod and the second wing connecting rod; the first flapping-wing rod cover plate and the second flapping-wing rod cover plate serve as end covers, and are respectively connected to the top or bottom of the first flapping-wing rod and the second flapping-wing rod through pins.

[0035] Preferably, the motor is a coreless motor.

[0036] Preferably, an anti-slip structure is provided between the first transmission shaft and the first incomplete gear, and the anti-slip structure adopts any of the following methods:

[0037] The sides of the first transmission shaft and the first incomplete gear are both provided with holes, and the first transmission shaft and the first incomplete gear are tightly fitted by self-tapping bolts to ensure that there is no slipping during the transmission process;

[0038] The first transmission shaft and the first incomplete gear are ensured to be non-slip during the transmission process by means of a keyway structure.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] 1. The present invention utilizes a transmission gear structure to cooperate with a flapping-wing lever structure, and converts the rotational motion of the main shaft structure driven by the motor into the flapping motion of the flapping-wing lever structure through a plurality of incomplete gears, without a quick return characteristic, and with uniform speed changes. In addition, the first flapping-wing lever and the second flapping-wing lever are mutually transmitted by a gear meshing method, which can achieve a high flapping-wing synchronization and a stable and consistent transmission ratio.

[0041] 2. In the present invention, the first incomplete gear is provided with a first arc portion, which can ensure that the movement of the meshing gap area is controllable, and a large-angle flapping wing can be achieved by adjusting the number of teeth and the module of the first incomplete gear.

[0042] 3. The present invention can achieve a flapping angle of 180° through the design of gear parameters, thereby achieving large-angle flapping. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0044] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0045] Figure 2 It is a structural schematic diagram of the flapping-wing rod structure of the present invention;

[0046] Figure 3 It is a structural schematic diagram of the transmission gear structure of the present invention;

[0047] Figure 4 It is a structural schematic diagram of the reduction gear structure of the present invention;

[0048] Figure 5 It is a structural schematic diagram of the skeleton support structure of the present invention;

[0049] Figure 6 It is a structural schematic diagram of the transmission main shaft structure of the present invention;

[0050] Figure 7 It is a phase diagram of the present invention when flapping wing 0°;

[0051] Figure 8 It is a phase diagram of the present invention when flapping 180°;

[0052] Fig. 9 It is a schematic diagram of calculating the angle of the first arc portion of the first incomplete gear of the present invention.

[0053] The figure shows:

[0054]

[0055] DETAILED DESCRIPTION

[0056] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0057] The present invention provides a flapping wing mechanism based on incomplete gear transmission, such as Figure 1 As shown, it includes a skeleton support structure 1, a reduction gear structure 2, a flapping-wing rod structure 4, a transmission gear structure 5, a transmission main shaft structure 6 and a motor structure; the transmission main shaft structure and the motor structure are installed on the skeleton support structure 1; the motor structure, the reduction gear structure 2, the transmission main shaft structure 6, the transmission gear structure 5 and the flapping-wing rod structure 4 are sequentially connected in transmission.

[0058] The motor structure drives the reduction gear structure 2 to rotate the transmission main shaft structure 6. The transmission gear structure 5 is used to convert the rotational motion of the transmission main shaft structure into the periodic motion of the transmission gear structure 5. The flapping-wing rod structure 4 is used to convert the periodic motion of the transmission gear structure 5 into the flapping motion of the flapping-wing rod structure 4.

[0059] like Figure 1 and Figure 5 As shown, the motor structure includes a motor 7 and a motor fixing plate 3; the motor 7 is mounted on the skeleton support structure 1 through the motor fixing plate 3; the output shaft of the motor 7 is provided with a motor output shaft gear 19, and the motor output shaft gear is meshed with the reduction gear structure 2. Considering the power and output torque factors, the motor needs to output a larger power. At the same time, the size and weight factors of the motor should be limited. Preferably, the motor 7 is preferably a 8520 model hollow cup motor, which can provide sufficient power.

[0060] like Figure 4As shown, the reduction gear structure 2 is used to increase the output torque of the motor, reduce the output speed, and finally match the flapping frequency. The reduction gear structure 2 includes a first reduction gear 17 and a double-layer gear 18; the double-layer gear 18 includes a first layer gear and a second layer gear; the first layer gear and the second layer gear are coaxially arranged, the motor output shaft gear 19 is meshed with the first layer gear, and the second layer gear is meshed with the first reduction gear 17. The reduction gear structure 2 is used to increase the output torque of the motor 7, reduce the speed, match the wing rotational inertia, and achieve an appropriate flapping frequency. In a preferred example, the motor output shaft gear 19 and the first layer gear in the double-layer gear 18 are both 0.3 modulus, the motor output shaft gear 19 has 7 teeth, and the first layer gear has 42 teeth; the second layer gear in the double-layer gear 18 and the first reduction gear 17 are both 0.5 modulus, the second layer gear in the double-layer gear 18 has 8 teeth, and the first reduction gear 17 has 30 teeth, and the transmission ratio of the two is 22.5.

[0061] The transmission main shaft structure is the key component for transmitting torque and is the place where the present invention is subjected to the greatest force. Figure 6 As shown, the transmission main shaft structure includes a first transmission shaft 15, a first fixed bearing 241 and a second fixed bearing 242. The first reduction gear 17 is sleeved on the first transmission shaft 15 and can drive the first transmission shaft 15 to rotate. The first transmission shaft 15 is installed on the skeleton support structure 1 through the first fixed bearing 241 and the second fixed bearing 242. Preferably, the first transmission shaft 15 is a carbon fiber round rod with a diameter of 2 mm, and the first fixed bearing 241 and the second fixed bearing 242 are flange bearings with an inner diameter of 2 mm and an outer diameter of 5 mm.

[0062] like Figure 3 As shown, the transmission gear structure 5 includes a first incomplete gear 12, a second incomplete gear 141 and a third incomplete gear 142; the first transmission shaft 15 passes through the first incomplete gear 12, so that the first incomplete gear 12 obtains power.

[0063] The first incomplete gear 12 includes a first tooth portion and a first arc portion 16, the second incomplete gear 141 includes a second tooth portion and a second arc portion 131, and the third incomplete gear 142 includes a third tooth portion and a third arc portion 132. A polygonal groove structure 20 is provided on the second incomplete gear 141 and the third incomplete gear 142. In a preferred example, the polygon is a square. The groove structure 20 is located at the center of the third incomplete gear 142 and penetrates the third incomplete gear 142. In a preferred example, the first arc portion 16, the second arc portion 131, and the third arc portion 132 are all locking arcs. The first incomplete gear 12 is sleeved on the transmission main shaft structure and can rotate with the rotation of the transmission main shaft structure, that is, the first transmission shaft 15 passes through the first incomplete gear 12, so that the first incomplete gear 12 obtains power. When the first incomplete gear 12 rotates, the first tooth portion can mesh with the second tooth portion and the third tooth portion in sequence to drive the second incomplete gear 141 and the third incomplete gear 142 to rotate in sequence. Specifically, the first incomplete gear 12 meshes with the second incomplete gear 141 and the third incomplete gear 142 on both sides in turn during one rotation. It is worth noting that the first tooth and the last tooth top height coefficient of the first tooth portion of the first incomplete gear 12 are smaller than those of other teeth to prevent the teeth from getting stuck; in addition, in order to prevent the first incomplete gear 12 from getting stuck by contacting the second incomplete gear 141 and the third incomplete gear 142 respectively, a certain gap is left in each meshing stroke.

[0064] In a preferred example, the first arc portion 16 is a convex arc structure, the second arc portion 131 and the third arc portion 132 are concave arc structures, and a tooth groove phase difference needs to be left when assembling the second incomplete gear 141 and the third incomplete gear 142 to avoid transmission jamming; the radius, arc length and starting and ending points of the first arc portion 16 need to ensure that the first arc portion 16 fits with the second arc portion 131 and the third arc portion 132 at the gap during the meshing process. In another preferred example, the first arc portion 16 is a convex slide groove structure, the second arc portion 131 and the third arc portion 132 are concave slide groove structures, and the first arc portion 16 of the first incomplete gear 12 is respectively meshed with the concave slide groove structure of the second incomplete gear 141 and the concave slide groove structure of the third incomplete gear 142, to ensure the stability of the transmission ratio during the flapping process. During the meshing of the first arc portion 16 with the second arc portion 131 and the third arc portion 132 , it is necessary to reduce friction. Grease or ball friction may be used to reduce friction.

[0065] In a preferred example, the first incomplete gear 12 is a 0.5 module, a pitch circle diameter of 7mm, and is provided with 6 teeth. The second incomplete gear 141 and the third incomplete gear 142 are a 0.5 module, a pitch circle diameter of 6mm, and are provided with 6 teeth, and the center distance is 6.5mm. The convex arc radius of the first arc portion 16 is 3.03mm, and the concave arc radius of the second arc portion 131 and the third arc portion 132 is 3.47mm. The tooth top height coefficient of the last tooth of the first incomplete gear 12 is 0.517, the tooth top height coefficient of the first tooth is selected as 0.45, the tooth top circle radius of the first tooth is 3.725mm, and the tooth top circle radius of the last tooth is 3.7585mm. In this embodiment, the angle between the starting point of the locking arc of the driving wheel and the center line of the last tooth is 25.14°, and the arc length is selected as 15°. The angle between the starting point of the first arc portion 16 and the center line of the last tooth of the first tooth portion is 27.16°, and the arc length is selected as 15°.

[0066] like Figure 1 and Figure 2 As shown, the flapping wing rod structure 4 includes a first gear connecting assembly 61, a second gear connecting assembly 62, a first wing connecting rod 81, a second wing connecting rod 82, a first flapping wing rod 91, a second flapping wing rod 92, a first wing root connecting rod 111 and a second wing root connecting rod 112; the first gear connecting assembly 61 and the second gear connecting assembly 62 both include a gear portion 8 and a connecting pin, the connecting pin is arranged at the center of the circle of the gear portion 8 and extends along the axial direction of the gear portion 8; in a preferred example, the gear portion 8 is an incomplete gear structure. The connecting pin in the first gear connecting assembly 61 matches the polygonal groove structure 20 of the second incomplete gear 141; the connecting pin in the second gear connecting assembly 62 matches the polygonal groove structure 20 of the third incomplete gear 142; by using the close fit between the connecting pin and the groove, it can be achieved that the first gear connecting assembly 61 and the second incomplete gear 141 do not move relative to each other, and the second gear connecting assembly 62 and the third incomplete gear 142 do not move relative to each other, so as to achieve a good connection. The gear part 8 in the first gear connecting assembly 61 and the gear part 8 in the second gear connecting assembly 62 mesh with each other to keep the wings in a symmetrical position. Specifically, during the transmission process, the gear part 8 in the first gear connecting assembly 61 and the gear part 8 in the second gear connecting assembly 62 mesh with each other and always mesh with each other. In a preferred example, the gear part 8 in the first gear connecting assembly 61 and the gear part 8 in the second gear connecting assembly 62 are both 0.5 modulus, with a pitch circle diameter of 12 mm and a number of teeth of 6.

[0067] like Figure 1 and Figure 2As shown, the first flapping-wing rod 91 is connected to the gear portion 8 of the first gear connecting component 61, and the second flapping-wing rod 92 is connected to the gear portion 8 of the second gear connecting component 62; in a preferred example, the first flapping-wing rod 91 is integrally connected to the gear portion 8 of the first gear connecting component 61.

[0068] The first wing connecting rod 81 and the second wing connecting rod 82 are respectively mounted on the first flapping wing rod 91 and the second flapping wing rod 92; the first wing root connecting rod 111 is used to coaxially connect the second incomplete gear 141 with the first gear connecting assembly 61, and the second wing root connecting rod 112 is used to coaxially connect the third incomplete gear 142 with the second gear connecting assembly 62. Specifically, the second incomplete gear 141, the first gear connecting assembly 61, the third incomplete gear 142 and the second gear connecting assembly 62 are all provided with circular through holes, and the wing root connecting rods are used as pins to fix them on the skeleton support structure 1.

[0069] The skeleton support structure 1 is a plate structure and is provided with weight-reducing holes. The skeleton support structure 1 is a key component for supporting the strength of the flapping wing mechanism. Figure 5 As shown, the skeleton support structure 1 includes a first side support plate 201, a second side support plate 202, an upper plate 21, an intermediate plate 22, and a bottom plate 23; the first side support plate 201 and the second side support plate 202 are both provided with a first notch 2011, a second notch 2012, and a third notch 2013; the first notch 2011 cooperates with the convex groove of the upper plate 21, the second notch 2012 cooperates with the convex groove of the intermediate plate 22, and the third notch 2013 cooperates with the convex groove of the bottom plate 23; the bottom plate 23 is provided with a motor mounting position for mounting the motor structure; the first fixed bearing 241 is mounted on the intermediate plate 22, and the second fixed bearing 242 is mounted on the bottom plate 23. The motor generally refers to a hollow cup motor, and the motor fixing plate 3 and the bottom plate 23 play a role in supporting the motor together.

[0070] Specifically, the bottom plate 23 is provided with a motor positioning through hole, a gear positioning through hole and a motor fixing plate mounting through hole. The four motor fixing plate mounting through holes are matched and aligned with the mounting holes 301 on the motor fixing plate 3 and connected by rivets; preferably, the motor fixing plate 3 has a total of 4 pieces, the first two pieces have 6mm motor mounting circular holes for fitting the motor end faces, and the back two pieces have 8.5mm motor mounting circular holes for fixing the motor position. The double-layer gear 18 is connected to the middle plate 22 and the bottom plate 23 respectively by pins to determine the position. Figure 6As shown, the first reduction gear 17 is connected to the middle plate 22 and the bottom plate 23 through bearings to determine the position. The lower surface of the flange ring of the second fixed bearing 242 is in close contact with the upper surface of the bottom plate 23, and the upper surface of the second fixed bearing 242 is in close contact with the lower surface of the secondary reduction gear. The lower surface of the flange ring of the first fixed bearing 241 is in close contact with the upper surface of the first reduction gear 17, and the upper surface of the flange ring of the first fixed bearing 241 is in close contact with the lower surface of the middle plate 22. The upper surface of the first fixed bearing 241 is in close contact with the bottom surface of the first incomplete gear 12. In a preferred example, holes are opened on the side surfaces of the first transmission shaft 15 and the first incomplete gear 12, and the first transmission shaft 15 and the first incomplete gear 12 are tightly fitted by self-tapping bolts to ensure that there is no slipping during the transmission process. In another preferred example, the first transmission shaft 15 and the first incomplete gear 12 are ensured to be non-slipping during the transmission process through a keyway structure.

[0071] like Figure 1 , Figure 2 As shown, in a preferred example, the flapping-wing rod structure 4 also includes a first flapping-wing gear washer 101, a second flapping-wing gear washer 102, a first flapping-wing rod cover plate 71 and a second flapping-wing rod cover plate 72; the first flapping-wing gear washer 101 and the second flapping-wing gear washer 102 are respectively installed above the first gear connecting component 61 and the second gear connecting component 62; the ends of the first flapping-wing rod 91 and the second flapping-wing rod 92 are both concave groove structures, and the two concave groove structures are respectively used to fix the first wing connecting rod 81 and the second wing connecting rod 82; the first flapping-wing rod cover plate 71 and the second flapping-wing rod cover plate 72 serve as end covers, and are respectively connected to the top or bottom of the first flapping-wing rod 91 and the second flapping-wing rod 92 by pins. In a preferred example, as Figure 2 As shown, the transmission gear structure 5 further includes a first gear washer 51 and a second gear washer 52, and the first gear washer 51 and the second gear washer 52 are respectively installed under the second incomplete gear 141 and the third incomplete gear 142. Preferably, the first flapping wing gear washer 101, the second flapping wing gear washer 102, the first gear washer 51, and the second gear washer 52 are all 0.5 mm thick graphite washers to increase the axial preload.

[0072] The working principle of the present invention is as follows:

[0073] like Figure 1 , Figure 3 , Figure 7 , Figure 8As shown, the motor 7 drives the first transmission shaft 15 through the reduction gear structure 2 so that the first tooth portion of the first incomplete gear 12 first meshes with the second tooth portion of the second incomplete gear 141, driving the second incomplete gear 141 to move, and the second incomplete gear 141, the first gear connecting assembly 61, the first wing connecting rod 81 and the first flapping wing rod 91 are sequentially driven, thereby driving the first flapping wing rod 91 to move; at the same time, because the gear portion 8 in the first gear connecting assembly 61 and the gear portion 8 in the second gear connecting assembly 62 are meshed with each other; therefore, the second flapping wing rod 92 will also move with the movement of the second gear connecting assembly 62, and at this time, the first flapping wing rod 91 and the second flapping wing rod 92 simultaneously flap up. Subsequently, the first tooth portion of the first incomplete gear 12 leaves the meshing area of ​​the second tooth portion of the second incomplete gear 141, and the first arc portion 16 of the first incomplete gear 12 cooperates with the second arc portion 131 of the second incomplete gear 141, so that the flapping wing rod remains stationary. Then, the first tooth portion of the first incomplete gear 12 meshes with the third tooth portion of the third incomplete gear 142, causing the two flapping-wing rods to flap down at the same time. Then, the first tooth portion of the first incomplete gear 12 leaves the meshing area of ​​the third tooth portion of the third incomplete gear 142, and the first arc portion 16 of the first incomplete gear 12 cooperates with the third arc portion 132 of the third incomplete gear 142, causing the flapping-wing rod to remain stationary again, completing a flapping process.

[0074] The first incomplete gear 12 in the middle is alternately meshed with the second incomplete gear 141 and the third incomplete gear 142 on both sides, and the second incomplete gear 141 and the third incomplete gear 142 on both sides are respectively connected to the first gear connecting assembly 61 and the second gear connecting assembly 62 to achieve synchronous movement. The flapping wing rod is connected to the gear connecting assembly and moves synchronously with the gear connecting assembly.

[0075] Since the first tooth portion of the first incomplete gear 12 cannot mesh with the second tooth portion of the second incomplete gear 141 and the third tooth portion of the third incomplete gear 142 at the same time, in order to prevent jamming, a transmission gap of a certain angle needs to be reserved. In order to ensure the controllability of the flapping motion of the transmission gap, arc portions are provided on the first incomplete gear 12, the second incomplete gear 141 and the third incomplete gear 142. The sum of the curvature radii of the first arc portion 16 and the second arc portion 131 is equal to the center distance, and the sum of the curvature radii of the first arc portion 16 and the third arc portion 132 is equal to the center distance to stabilize the transmission ratio of the transmission gap. A large angle can be obtained by adjusting the number of meshing teeth of the first incomplete gear 12. The gear transmission can achieve stable transmission torque, there is no quick return characteristic, and the flapping stability is high. Adding a locking arc in the transmission gap can ensure a stable transmission ratio at any point in the transmission process.

[0076] The working conditions of this embodiment are described by taking one flapping cycle as an example. Figure 7 In the embodiment, the flapping angles of the first flapping wing rod 91 and the second flapping wing rod 92 are 0°. The clockwise rotation of the second flapping wing rod 92 is positive, and the counterclockwise rotation of the first flapping wing rod 91 is positive. In the initial state of the cycle, the first flapping wing rod 91 and the second flapping wing rod 92 are both at 0°. Driven by the motor and driven by the reduction gear structure 2 and the transmission main shaft structure 6, the first incomplete gear 12 rotates clockwise and enters the meshing area of ​​the second incomplete gear 141, driving the second incomplete gear 141 to move counterclockwise. The second incomplete gear 141 drives the right flapping wing rod, i.e., the first flapping wing rod 91, to rotate counterclockwise through the square slot, and the right flapping wing rod, i.e., the first flapping wing rod 91 drives the left second flapping wing rod 92 to rotate clockwise through gear meshing. When all the tooth profiles of the first incomplete gear 12 are fully engaged with the driven incomplete second incomplete gear 141, they enter the meshing gap. The first arc portion 16 contacts the second arc portion 131. At this time, the incomplete gears and the flapping wing rods on both sides are locked, and the flapping angle of the flapping wing rods on both sides is 180°. Figure 8 As shown. The motor continues to rotate, driving the first incomplete gear 12 to enter the tooth meshing area of ​​the third incomplete gear 142, driving the third incomplete gear 142 to rotate counterclockwise. The third incomplete gear 142 drives the second flapping wing rod 92 on the left to rotate counterclockwise through the square slot, and the second flapping wing rod 92 on the left drives the first flapping wing rod 91 on the right to rotate clockwise through gear meshing. When all the tooth profiles of the first incomplete gear 12 are meshed with the third incomplete gear 142 on the left, they enter the meshing gap, and the first arc portion 16 contacts the second arc portion 131. At this time, the flapping wing rods of the incomplete gears on both sides are locked again, and the flapping angles of the flapping wing rods on both sides return to 0°.

[0077] The following describes the process of calculating the relevant parameters. In this embodiment, the flapping angle is 180°. Fig. 9 shown.

[0078] (1) Determine the module, number of teeth, and center distance

[0079] According to the size and processing conditions of the flapping mechanism, a 0.5 module gear is selected. The first incomplete gear 12 has a full tooth z1 of 14 teeth, and the second incomplete gear 141 and the third incomplete gear 142 have a full tooth z2 of 12 teeth. The center distance is calculated by formula 1) to be 6.5 mm

[0080]

[0081] In this embodiment, the number of teeth z1' of the first incomplete gear 12 is 6, and the number of teeth z2' of the second incomplete gear 141 and the third incomplete gear 142 are both 6.

[0082] (2) Calculation of pressure angle

[0083] Set the gear pressure angle α to 20° and the tooth top height coefficient =1, and the tooth top pressure angle is calculated using formula 2). The top pressure angle of the first incomplete gear 12 is 34.69°, and the top pressure angles of the second incomplete gear 141 and the third incomplete gear 142 are 36.34°.

[0084]

[0085] (3) Calculate the tooth top height coefficient of the last tooth of the first incomplete gear 12, and select the tooth top height coefficient of the first tooth of the first incomplete gear 12

[0086] The tooth top height coefficient of the last tooth of the first incomplete gear 12 can be calculated by formula 3)

[0087]

[0088] Where L can be calculated by formula 4)

[0089]

[0090] Where δ2 can be calculated by formula 5)

[0091]

[0092] Where γ can be calculated by formula 6)

[0093]

[0094] Through formula 3) to formula 6), we can get the calculation results of γ=12.45°, δ2=27.46°, L=7.5mm, Taking into account that the first tooth top height coefficient is slightly lower than the last tooth top height coefficient, the first tooth top height coefficient is taken as 0.45.

[0095] (4) Calculate the tooth top pressure angle of the first and last teeth of the first incomplete gear 12

[0096] The formula for calculating the tooth top pressure angle can be calculated by formula 7). After calculation, the tooth top pressure angle of the last tooth is α as =28°, the pressure angle of the first tooth top is α am =28.94°

[0097]

[0098] (5) Calculate the radius of the first arc 16

[0099] The radius of the first arc portion 16 can be calculated by formula 8)

[0100]

[0101] Where Δθ can be calculated by formula 9)

[0102]

[0103] Where θ can be calculated by formula 10)

[0104] θ=δ-2γ 10)

[0105] Where δ can be calculated by formula 11)

[0106]

[0107] By calculating through formula 8)-12), we can get the result of δ=30°, θ=5.08°, Δθ=8.18°, R=3.03mm

[0108] (6) The angle Qs between the radial direction passing through the starting point of the first arc portion 16 and the center line of the last tooth of the first tooth portion can be calculated by formula 12)

[0109] Q s =β2-λ2 12)

[0110] Where λ2 can be calculated by formula 13) and β2 can be calculated by formula 14

[0111]

[0112]

[0113] After calculation, it is 4.54°, β2 is 29.69°, and Qs=25.14°

[0114] (7) Calculate the angle Qe between the radial direction passing through the starting point of the second arc portion 131 and the middle line of the last tooth of the second tooth portion, which can be calculated by formula 15)

[0115]

[0116] The calculated results are γ=12.45°, Qe=27.46°. The angle marking diagram is shown in the attached figure. Fig. 9 shown.

[0117] (8) Calculate the third arc portion 132. The calculation process of the third arc portion is the same as that of the second arc portion 131. Refer to step (7).

[0118] In the present invention, a transmission gear structure is used in conjunction with a flapping-wing rod structure to convert the rotational motion of a main shaft structure driven by a motor into a flapping motion of a flapping-wing rod structure through a plurality of incomplete gears. There is no quick return characteristic and the speed changes evenly. The symmetrical flapping strength achieved by the gear meshing method is high and the transmission ratio is stable and consistent. The first incomplete gear 12 is provided with a first arc portion 16 to ensure that the motion in the meshing gap area is controllable. Large-angle flapping can be achieved by adjusting the number of gears and the module.

[0119] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0120] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A flapping wing mechanism based on incomplete gear transmission, characterized in that: It comprises a skeleton support structure (1), a reduction gear structure (2), a flapping-wing rod structure (4), a transmission gear structure (5), a transmission main shaft structure (6) and a motor structure; The transmission main shaft structure and the motor structure are mounted on the skeleton support structure (1); The motor structure, the reduction gear structure (2), the transmission main shaft structure (6), the transmission gear structure (5) and the flapping-wing lever structure (4) are sequentially connected in transmission; The transmission gear structure (5) comprises a first incomplete gear (12), a second incomplete gear (141) and a third incomplete gear (142); The first incomplete gear (12) comprises a first tooth portion and a first arc portion (16), the second incomplete gear (141) comprises a second tooth portion and a second arc portion (131), and the third incomplete gear (142) comprises a third tooth portion and a third arc portion (132); the second incomplete gear (141) and the third incomplete gear (142) are both provided with a polygonal groove structure (20); The first incomplete gear (12) is sleeved on the transmission main shaft structure and can rotate along with the rotation of the transmission main shaft structure; When the first incomplete gear (12) rotates, the first tooth portion can mesh with the second tooth portion and the third tooth portion in sequence, so as to drive the second incomplete gear (141) and the third incomplete gear (142) to rotate in sequence.

2. The flapping-wing mechanism based on incomplete gear transmission according to claim 1, characterized in that: The motor structure comprises a motor (7) and a motor fixing plate (3); the motor (7) is mounted on the skeleton support structure (1) via the motor fixing plate (3); The output shaft of the motor (7) is provided with a motor output shaft gear (19), and the motor output shaft gear is meshed with the reduction gear structure (2).

3. The flapping-wing mechanism based on incomplete gear transmission according to claim 2, characterized in that: The reduction gear structure (2) comprises a first reduction gear (17) and a double-layer gear (18); The double-layer gear (18) comprises a first-layer gear and a second-layer gear; the first-layer gear and the second-layer gear are coaxially arranged, the motor output shaft gear (19) is meshed with the first-layer gear, and the second-layer gear is meshed with the first reduction gear (17).

4. The flapping-wing mechanism based on incomplete gear transmission according to claim 3, characterized in that: The transmission main shaft structure comprises a first transmission shaft (15), a first fixed bearing (241) and a second fixed bearing (242); the first reduction gear (17) is mounted on the first transmission shaft (15) and can drive the first transmission shaft (15) to rotate; the first transmission shaft (15) is mounted on the skeleton support structure (1) via the first fixed bearing (241) and the second fixed bearing (242).

5. The flapping-wing mechanism based on incomplete gear transmission according to claim 1, characterized in that: The flapping-wing lever structure (4) comprises a first gear connecting assembly (61), a second gear connecting assembly (62), a first wing connecting rod (81), a second wing connecting rod (82), a first flapping-wing lever (91), a second flapping-wing lever (92), a first wing root connecting rod (111) and a second wing root connecting rod (112); The first gear connecting assembly (61) and the second gear connecting assembly (62) both comprise a gear portion (8) and a connecting pin, wherein the connecting pin is arranged at the center of the gear portion (8) and extends along the axial direction of the gear portion (8); The connecting pin in the first gear connecting assembly (61) matches the polygonal groove structure (20) of the second incomplete gear (141); the connecting pin in the second gear connecting assembly (62) matches the polygonal groove structure (20) of the third incomplete gear (142); the gear portion (8) in the first gear connecting assembly (61) meshes with the gear portion (8) in the second gear connecting assembly (62); The first flapping wing lever (91) is connected to the gear portion (8) of the first gear connecting assembly (61), and the second flapping wing lever (92) is connected to the gear portion (8) of the second gear connecting assembly (62); The first wing connecting rod (81) and the second wing connecting rod (82) are respectively mounted on the first flapping wing rod (91) and the second flapping wing rod (92); The first wing root connecting rod (111) is used to coaxially connect the second incomplete gear (141) with the first gear connecting assembly (61), and the second wing root connecting rod (112) is used to coaxially connect the third incomplete gear (142) with the second gear connecting assembly (62).

6. The flapping-wing mechanism based on incomplete gear transmission according to claim 4, characterized in that: The skeleton support structure (1) comprises a first side support plate (201), a second side support plate (202), an upper plate (21), a middle plate (22), and a bottom plate (23); The first side support plate (201) and the second side support plate (202) are both provided with a first notch (2011), a second notch (2012) and a third notch (2013); The first notch (2011) cooperates with the convex groove of the upper plate (21), the second notch (2012) cooperates with the convex groove of the middle plate (22), and the third notch (2013) cooperates with the convex groove of the bottom plate (23); The bottom plate (23) is provided with a motor installation position for installing the motor structure; The first fixed bearing (241) is mounted on the middle plate (22), and the second fixed bearing (242) is mounted on the bottom plate (23).

7. The flapping-wing mechanism based on incomplete gear transmission according to claim 1, characterized in that: The flapping-wing rod structure (4) further comprises a first flapping-wing rod cover plate (71) and a second flapping-wing rod cover plate (72); The ends of the first flapping wing rod (91) and the second flapping wing rod (92) are both concave groove structures, and the two concave groove structures are respectively used to fix the first wing connecting rod (81) and the second wing connecting rod (82); the first flapping wing rod cover plate (71) and the second flapping wing rod cover plate (72) serve as end covers, and are respectively connected to the top end or the bottom end of the first flapping wing rod (91) and the second flapping wing rod (92) through pins.

8. The flapping-wing mechanism based on incomplete gear transmission according to claim 2, characterized in that: The motor (7) is a coreless motor.

9. The flapping-wing mechanism based on incomplete gear transmission according to claim 1, characterized in that: An anti-slip structure is provided between the first transmission shaft (15) and the first incomplete gear (12), wherein the anti-slip structure adopts any of the following methods: The first transmission shaft (15) and the first incomplete gear (12) are both provided with holes on their sides, and the first transmission shaft (15) and the first incomplete gear (12) are tightly fitted together by self-tapping bolts to ensure that there is no slipping during the transmission process; The first transmission shaft (15) and the first incomplete gear (12) are connected by a keyway structure to ensure that there is no slipping during the transmission process.

Images