Damping device and fixed-wing UAV recovery system using the same

Abstract

The present invention provides a damping device and a fixed-wing unmanned aerial vehicle recovery system using the same. The damping device includes a bracket, a support shaft, a rope storage member, a brake disc, and an elastic member. The support shaft extends through the brake disc, a friction member is provided between the rope storage member and the brake disc, the support shaft includes a lead screw segment that engages with the rope storage member in a helical transmission, and a smooth rod segment for the elastic member to be sleeved. The brake disc includes a columnar portion and a disc-shaped portion. The bracket includes an intermediate sidewall through which the columnar portion passes. Corresponding through-holes in the columnar portion and the intermediate sidewall, as well as an axial hole in the brake disc and the support shaft, respectively form inner and outer sliding pairs with axial freedom. At least one of the two sliding pairs is an axially movable pair that also includes a rotation-stopping structure. The present invention utilizes the support shaft to achieve installation of the elastic member, and the rotation-stopping structure in the sliding pair to guide the brake disc, thereby reducing the number of components, simplifying the structure, facilitating manufacturing and assembly, and reducing bending deformation of the support shaft.

Description

Technical Field

[0001] The invention relates to a damping device and a fixed-wing unmanned aerial vehicle recovery system using the damping device. Background Art

[0002] In the field of fixed-wing UAV recovery, whether using traditional net recovery or hook-and-rope recovery methods like SkyHook and SideArm, damping devices are required to dissipate the target's kinetic energy. Because the recovery process requires a long buffer stroke, to maintain a compact recovery device, a common damping device solution is used: the recovery rope is pre-wound on a drum. During recovery, the rope is pulled out, and a rotary damper applies damping to the drum, preventing its rotation. This damping force is then transmitted through the rope to the target, braking and decelerating the target. The rotary dampers used in these solutions often utilize established products, such as block brakes, shoe brakes, disc brakes, and electromagnetic brakes. These brakes are generally friction brakes, featuring a brake wheel, drum, or disc fixed to the drum. Spring force or hydraulic (or gas) pressure drives the brake pads, shoes, calipers, or friction plates to apply force, providing the required frictional resistance torque.

[0003] For fixed-wing UAV recovery systems, to ensure the safety of the recovery target, improve recovery efficiency, and achieve a compact and simplified system structure, it is generally desirable to maximize the recovery overload without exceeding the UAV's tolerance threshold, thereby compressing the buffer stroke. However, the friction torque of existing damping devices is typically maintained at a constant value within a certain range. Furthermore, due to the elasticity of the recovery system, the braking force applied to the UAV fluctuates, with its peak value often decreasing as the buffer stroke increases, thus failing to effectively shorten the buffer stroke.

[0004] In this regard, a Chinese invention patent application with application publication number CN112340045A discloses a small aircraft net-collision recovery device, comprising a recovery net energy absorption device (i.e., a damping device), a recovery net, a bracket, a traction rope, and a pulley. One end of the traction rope is fixedly connected to the periphery of the recovery net after passing through the pulley, and the other end is wound around the damping device. The damping device includes a support frame, a screw rod, a support plate, a guide shaft, an elastic member, a fixed plate, a brake pad, a brake disc, and a rotating disc. The screw rod and the guide shaft both pass through the fixed disc and the support plate, and both ends are fixedly connected to the support frame. The fixed disc is fixedly connected to the guide shaft. A spring is clamped between the fixed disc and the support plate. A guide rod extending to the left and passing through the fixed disc is fixed on the support plate, and the spring is sleeved on the outside of the guide rod. A brake pad is installed on the side of the support plate near the rotating disc, and a brake disc is installed on the side of the rotating disc near the support plate. The rotating disc is fixedly connected to the ball nut and mounted on the screw rod, and the traction rope is wound around the rotating disc.

[0005] During use, the aircraft impacts the recovery net, driving it forward. The net stretches the traction rope, which in turn drives the rotating disc to rotate about its axis. During this rotation, the disc translates leftward along the lead screw, forcing the brake disc and brake pads to press against each other, generating a frictional resistance torque that decelerates the disc's rotation. This hinders the extension of the traction rope, slowing the recovery net and the aircraft, absorbing their kinetic energy until the aircraft's kinetic energy is reduced to zero. The initial recovery overload during this process is very small, but as the spring is gradually compressed, the elastic force increases, the positive pressure between the brake disc and brake pads increases, and the frictional resistance torque also increases, significantly reducing the time and distance required for the aircraft to reach zero kinetic energy after impact with the net.

[0006] However, the structure of the above-mentioned damping device is relatively complicated. In addition to using a screw (i.e., a support shaft) and a rotating disk to form a spiral transmission pair, a guide shaft is also provided to guide the movement of the support disk (i.e., a brake disk). At the same time, a guide rod is also provided, which is dedicated to the installation of the spring and guides the compression of the spring. There are multiple guide shafts, guide rods and springs evenly distributed along the circumference, resulting in a large number of parts in the entire damping device, which is more troublesome to manufacture and assemble, and the size is relatively large, occupying more installation and layout space.

[0007] At the same time, since the support plate and the fixed plate are both hollowly mounted on the screw rod, the screw rod cannot obtain auxiliary support from the support plate, the fixed plate and the guide rod, and can only be supported at both ends of the support frame with a larger span. During operation, the screw rod is easily bent and deformed under the tension of the traction rope.

[0008] Furthermore, simulations and tests have shown that the rotational inertia of the damping device's rotating portion significantly impacts recovery overload during the initial recovery phase. The brake disc in the damping device, fixed to the drum and rotating synchronously with it, is typically made of steel or cast iron. This results in a relatively large moment of inertia in the rotating portion, making it difficult to suppress the initial recovery impact overload. Furthermore, due to the fixed connection between the fixed disc and the guide shaft, the pre-compression of the spring cannot be adjusted. Consequently, it cannot output different resistance torque characteristics according to actual needs, and thus cannot meet the overload control requirements under different recovery conditions. Summary of the Invention

[0009] The purpose of the present invention is to provide a damping device to solve the problems of the existing damping device having a large number of parts, complex structure, and relatively troublesome manufacturing and assembly, as well as the easy bending and deformation of the lead screw; the purpose of the present invention is also to provide a fixed-wing UAV recovery system to solve the problems of the existing recovery system having a large number of parts, complex structure, and relatively troublesome manufacturing and assembly, as well as the easy bending and deformation of the lead screw.

[0010] To achieve the above objectives, the damping device in the present invention adopts the following technical solutions:

[0011] The cam is secured to the brake disc and has a locking mechanism which allows the cam to move relative to the brake disc and to engage with the brake disc when the cam is engaged.

[0012] The beneficial effects of the above technical solution are: the support shaft includes a screw section and a smooth rod section, the screw section is spirally transmitted with the rope storage member, and the elastic member is sleeved on the smooth rod section, which fully utilizes the length of the support shaft itself. There is no need to set up a guide rod for the elastic member, which reduces the number of components such as elastic members and guide rods, simplifies the structure, and facilitates manufacturing and assembly.

[0013] The brake disc includes a columnar part and a disc-shaped part, and the bracket includes an intermediate side wall for the columnar part to pass through. The columnar part and the corresponding through holes on the intermediate side wall, as well as the axial hole of the brake disc and the support shaft respectively form inner and outer sliding pairs with axial freedom. Among the two sliding pairs with axial freedom, at least one is an axial moving pair that also contains a rotation-stop structure. This not only facilitates guiding the brake disc and reduces the number of guiding components, but also ensures that the brake disc does not rotate when the rope storage part rotates. At the same time, the support shaft can be supported on the intermediate side wall by the brake disc, providing the rope storage part with auxiliary support with a closer span, so as to reduce the bending deformation of the support shaft caused by the tension of the traction rope, and the resulting jamming of the spiral pair and poor contact of the friction pair.

[0014] Furthermore, the columnar part is cylindrical, and the through hole on the middle side wall for the columnar part to pass through is a cylindrical hole. The two form an axial moving pair including the anti-rotation structure, and the anti-rotation structure includes a guide key installed on the outer surface of the columnar part and a guide groove arranged on the wall of the through hole and cooperating with the guide key.

[0015] The beneficial effect of the above technical solution is that the reason why a anti-rotation structure is not set on the inner sliding pair but on the outer sliding pair is to directly transmit the braking torque applied to the brake disc to the middle side wall of the bracket, rather than indirectly transmitting it to the right end side wall of the bracket through the support shaft via a longer path, so as to make the braking more reliable. At the same time, it avoids torsional deformation and stress superposition of the support shaft under the action of the brake disc torque, so that the support shaft is more reasonably stressed, the service life is longer, and the working reliability of the entire device is higher.

[0016] Furthermore, the bracket also includes a left end side wall and a right end side wall, and both ends of the support shaft are respectively installed on the left and right end side walls. An adjustment mechanism that can adjust the pre-compression amount of the elastic member is provided between the right end side wall and the elastic member. The adjustment mechanism includes a positioning ring with an adjustable distance to the right end side wall, and the right end of the elastic member is pressed on the positioning ring. The support shaft also includes an installation section for installing the positioning ring, and the position of the positioning ring relative to the installation section is adjustable.

[0017] The beneficial effects of the above technical solution are: the adjustment mechanism can adjust the pre-compression amount of the elastic part, so as to facilitate the output of resistance torque with different characteristics according to actual needs, and meet the overload control requirements under different recovery conditions; the adjustment mechanism includes a positioning ring, which is convenient for the top pressure of the right end of the elastic part, and the support shaft includes an installation section, which is convenient for the installation and position adjustment of the positioning ring.

[0018] Furthermore, the mounting section is part of the light bar section, the positioning ring is sleeved on the outside of the light bar section and can slide axially along the light bar section, a threaded hole is provided on the side wall of the right end portion, and the adjustment mechanism also includes a locking screw, which passes through the threaded hole through threaded engagement and presses against the right end face of the positioning ring.

[0019] The beneficial effect of the above technical solution is that the limit distance from the positioning ring to the side wall of the right end is adjusted by the set screw, thereby adjusting the pre-compression amount and pre-tightening force of the elastic member, which is simple, easy and reliable.

[0020] Furthermore, the elastic part includes an external compression spring and an internal compression spring arranged inside the external compression spring. The left end face of the positioning ring includes an outer ring surface for the right end of the external compression spring to press against and an inner ring surface for the right end of the internal compression spring to press against and protruding from the outer ring surface. The left end of the internal compression spring presses against the right end face of the brake disc, and the right end of the brake disc is provided with a step structure, and the left end of the external compression spring presses against the step structure.

[0021] The beneficial effects of the above technical solution are: the inner compression spring and the outer compression spring are combined to form an elastic part, which can easily obtain the required output characteristics; the left end face of the positioning ring includes an outer ring surface for the right end of the outer compression spring to press and an inner ring surface for the right end of the inner compression spring to press and protruding from the outer ring surface; at the same time, the right end portion of the brake disc is provided with a step structure, the left end of the outer compression spring presses on the step structure, and the left end of the inner compression spring directly presses on the end face of the brake disc, which facilitates the deformation of the inner compression spring and the outer compression spring.

[0022] Furthermore, the bracket includes a first bracket and a second bracket fixedly connected together, the first bracket includes two parallel left and right side walls arranged left and right, and a seat plate connecting the bottoms of the two, the second bracket includes two parallel front and rear side walls arranged front and back, and a connecting wall connected to the right ends of the two, the left ends of the front and rear side walls are fixed on the right side wall, the left side wall constitutes the left end side wall, the right side wall constitutes the middle side wall, and the connecting wall constitutes the right end side wall.

[0023] The beneficial effects of the above technical solution are: the bracket structure is simple, easy to manufacture and assemble, and convenient to form the left end side wall, the right end side wall and the middle side wall.

[0024] Furthermore, the left end of the support shaft is provided with a left support section passing through the left end side wall, and the right end of the support shaft is provided with a right support section passing through the right end side wall. Grooves are provided on the end faces of the left support section and the right support section. The damping device also includes strip baffles respectively embedded in the grooves and fixedly connected to the left end side wall and the right end side wall.

[0025] The beneficial effect of the above technical solution is that the anti-rotation installation of the support shaft is achieved by providing the groove and installing the strip-shaped baffle, the structure is simple, and processing, manufacturing and assembly are convenient.

[0026] Furthermore, a countersunk hole with a diameter larger than the brake disc shaft hole is provided on the left end face of the disc-shaped part, and a cylindrical socket for inserting into the countersunk hole is provided on the right end face of the rope storage part, and a chip storage ring groove is provided at the root of the outer cylindrical surface of the cylindrical socket.

[0027] The beneficial effect of the above technical solution is that the cylindrical sleeve and the annular groove structure can accommodate friction debris and particulate matter, preventing them from falling into the thread groove of the support shaft screw section and affecting the normal operation of the screw pair.

[0028] Furthermore, a brake pad is arranged between the rope storage member and the brake disc as a friction member. The brake pad is fixed on the end face of the rope storage member opposite to the brake disc and forms a friction pair with the left end face of the brake disc. The brake pad includes a plurality of discrete friction plates, and the gap between adjacent friction plates extends radially along the rope storage member.

[0029] The beneficial effects of this technical solution are as follows: Brake pads typically utilize composite materials based on non-metallic organic materials, resulting in low density and light weight. This reduces the moment of inertia of the rope storage element, thereby minimizing the impact overload experienced by the drone during the initial recovery phase. Furthermore, the gaps between adjacent friction pads allow debris or particulate matter within the chip storage groove to be discharged by gravity, or by centrifugal force during the high-speed rotation of the rope storage element.

[0030] To achieve the above objectives, the fixed-wing UAV recovery system of the present invention adopts the following technical solutions:

[0031] A fixed-wing unmanned aerial vehicle recovery system includes a traction rope and a damping device. The damping device includes a bracket, a support shaft fixed to the bracket, a rope storage member assembled on the support shaft via a helical transmission pair, and a brake disc arranged on one axial side of the rope storage member. The support shaft passes through the brake disc. The rope storage member is used to wind the traction rope. The opposite ends of the rope storage member and the brake disc are used to form a friction pair, or a friction member is additionally provided between the rope storage member and the brake disc. The damping device also includes an elastic member arranged on the side of the brake disc away from the rope storage member. The support shaft includes a screw segment that cooperates with the helical transmission of the rope storage member and a smooth rod segment for the elastic member to be sleeved. The brake disc includes a columnar portion and a disc-shaped portion for use with the rope storage member or the friction member. The bracket includes an intermediate sidewall for the columnar portion to pass through. The columnar portion and the intermediate sidewall have corresponding through-holes, and the axial hole of the brake disc and the support shaft respectively form inner and outer sliding pairs with axial freedom. At least one of the two sliding pairs with axial freedom is an axial moving pair that also includes a rotation-stop structure.

[0032] The beneficial effects of the above technical solution are: the support shaft includes a screw section and a smooth rod section, the screw section is spirally transmitted with the rope storage member, and the elastic member is sleeved on the smooth rod section, which fully utilizes the length of the support shaft itself. There is no need to set up a guide rod for the elastic member, which reduces the number of components such as elastic members and guide rods, simplifies the structure, and facilitates manufacturing and assembly.

[0033] The brake disc includes a columnar part and a disc-shaped part, and the bracket includes an intermediate side wall for the columnar part to pass through. The columnar part and the corresponding through holes on the intermediate side wall, as well as the axial hole of the brake disc and the support shaft respectively form inner and outer sliding pairs with axial freedom. Among the two sliding pairs with axial freedom, at least one is an axial moving pair that also contains a rotation-stop structure. This not only facilitates guiding the brake disc and reduces the number of guiding components, but also ensures that the brake disc does not rotate when the rope storage part rotates. At the same time, the support shaft can be supported on the intermediate side wall by the brake disc, providing the rope storage part with auxiliary support with a closer span, so as to reduce the bending deformation of the support shaft caused by the tension of the traction rope, and the resulting jamming of the spiral pair and poor contact of the friction pair.

[0034] Furthermore, the columnar part is cylindrical, and the through hole on the middle side wall for the columnar part to pass through is a cylindrical hole. The two form an axial moving pair including the anti-rotation structure, and the anti-rotation structure includes a guide key installed on the outer surface of the columnar part and a guide groove arranged on the wall of the through hole and cooperating with the guide key.

[0035] The beneficial effect of the above technical solution is that the reason why a anti-rotation structure is not set on the inner sliding pair but on the outer sliding pair is to directly transmit the braking torque applied to the brake disc to the middle side wall of the bracket, rather than indirectly transmitting it to the right end side wall of the bracket through the support shaft via a longer path, so as to make the braking more reliable. At the same time, it avoids torsional deformation and stress superposition of the support shaft under the action of the brake disc torque, so that the support shaft is more reasonably stressed, the service life is longer, and the working reliability of the entire device is higher.

[0036] Furthermore, the bracket also includes a left end side wall and a right end side wall, and both ends of the support shaft are respectively installed on the left and right end side walls. An adjustment mechanism that can adjust the pre-compression amount of the elastic member is provided between the right end side wall and the elastic member. The adjustment mechanism includes a positioning ring with an adjustable distance to the right end side wall, and the right end of the elastic member is pressed on the positioning ring. The support shaft also includes an installation section for installing the positioning ring, and the position of the positioning ring relative to the installation section is adjustable.

[0037] The beneficial effects of the above technical solution are: the adjustment mechanism can adjust the pre-compression amount of the elastic part, so as to facilitate the output of resistance torque with different characteristics according to actual needs, and meet the overload control requirements under different recovery conditions; the adjustment mechanism includes a positioning ring, which is convenient for the top pressure of the right end of the elastic part, and the support shaft includes an installation section, which is convenient for the installation and position adjustment of the positioning ring.

[0038] Furthermore, the mounting section is part of the light bar section, the positioning ring is sleeved on the outside of the light bar section and can slide axially along the light bar section, a threaded hole is provided on the side wall of the right end portion, and the adjustment mechanism also includes a locking screw, which passes through the threaded hole through threaded engagement and presses against the right end face of the positioning ring.

[0039] The beneficial effect of the above technical solution is that the limit distance from the positioning ring to the side wall of the right end is adjusted by the set screw, thereby adjusting the pre-compression amount and pre-tightening force of the elastic member, which is simple, easy and reliable.

[0040] Furthermore, the elastic part includes an external compression spring and an internal compression spring arranged inside the external compression spring. The left end face of the positioning ring includes an outer ring surface for the right end of the external compression spring to press against and an inner ring surface for the right end of the internal compression spring to press against and protruding from the outer ring surface. The left end of the internal compression spring presses against the right end face of the brake disc, and the right end of the brake disc is provided with a step structure, and the left end of the external compression spring presses against the step structure.

[0041] The beneficial effects of the above technical solution are: the inner compression spring and the outer compression spring are combined to form an elastic part, which can easily obtain the required output characteristics; the left end face of the positioning ring includes an outer ring surface for the right end of the outer compression spring to press and an inner ring surface for the right end of the inner compression spring to press and protruding from the outer ring surface; at the same time, the right end portion of the brake disc is provided with a step structure, the left end of the outer compression spring presses on the step structure, and the left end of the inner compression spring directly presses on the end face of the brake disc, which facilitates the deformation of the inner compression spring and the outer compression spring.

[0042] Furthermore, the bracket includes a first bracket and a second bracket fixedly connected together, the first bracket includes two parallel left and right side walls arranged left and right, and a seat plate connecting the bottoms of the two, the second bracket includes two parallel front and rear side walls arranged front and back, and a connecting wall connected to the right ends of the two, the left ends of the front and rear side walls are fixed on the right side wall, the left side wall constitutes the left end side wall, the right side wall constitutes the middle side wall, and the connecting wall constitutes the right end side wall.

[0043] The beneficial effects of the above technical solution are: the bracket structure is simple, easy to manufacture and assemble, and convenient to form the left end side wall, the right end side wall and the middle side wall.

[0044] Furthermore, the left end of the support shaft is provided with a left support section passing through the left end side wall, and the right end of the support shaft is provided with a right support section passing through the right end side wall. Grooves are provided on the end faces of the left support section and the right support section. The damping device also includes strip baffles respectively embedded in the grooves and fixedly connected to the left end side wall and the right end side wall.

[0045] The beneficial effect of the above technical solution is that the anti-rotation installation of the support shaft is achieved by providing the groove and installing the strip-shaped baffle, the structure is simple, and processing, manufacturing and assembly are convenient.

[0046] Furthermore, a countersunk hole with a diameter larger than the brake disc shaft hole is provided on the left end face of the disc-shaped part, and a cylindrical socket for inserting into the countersunk hole is provided on the right end face of the rope storage part, and a chip storage ring groove is provided at the root of the outer cylindrical surface of the cylindrical socket.

[0047] The beneficial effect of the above technical solution is that the cylindrical sleeve and the annular groove structure can accommodate friction debris and particulate matter, preventing them from falling into the thread groove of the support shaft screw section and affecting the normal operation of the screw pair.

[0048] Furthermore, a brake pad is arranged between the rope storage member and the brake disc as a friction member. The brake pad is fixed on the end face of the rope storage member opposite to the brake disc and forms a friction pair with the left end face of the brake disc. The brake pad includes a plurality of discrete friction plates, and the gap between adjacent friction plates extends radially along the rope storage member.

[0049] The beneficial effects of this technical solution are as follows: Brake pads typically utilize composite materials based on non-metallic organic materials, resulting in low density and light weight. This reduces the moment of inertia of the rope storage element, thereby minimizing the impact overload experienced by the drone during the initial recovery phase. Furthermore, the gaps between adjacent friction pads allow debris or particulate matter within the chip storage groove to be discharged by gravity, or by centrifugal force during the high-speed rotation of the rope storage element. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 is a perspective view of Example 1 of the damping device of the present invention;

[0051] Figure 2 is a cross-sectional view of Example 1 of the damping device of the present invention;

[0052] Figure 3 is a perspective view of Example 2 of the damping device of the present invention;

[0053] Figure 4 is a cross-sectional view of Example 2 of the damping device of the present invention;

[0054] Figure 5 The “output resistance torque-speed” characteristic curve of the elastic member of the damping device in the present invention (first configuration: Example 1, initial zero preload contact of the friction pair);

[0055] Figure 6 The “output resistance torque-speed” characteristic curve of the elastic member of the damping device in the present invention (second configuration: Example 1, the friction pair is initially non-contact);

[0056] Figure 7 This is a characteristic curve diagram of the “output resistance torque-rotation number” of the elastic member of the damping device in the present invention (third configuration: Example 2, the friction pair is initially not in contact).

[0057] In the figure: 1, drum; 11, drum edge rib; 12, cylindrical sleeve; 13, chip storage ring groove; 2, support shaft; 21. Screw section; 22. Screw section; 23. Left support section; 24. Right support section; 25. Strip baffle; 3. First bracket; 31. Left side wall; 32. Right side wall; 33. Seat plate; 34. First support hole; 4. Second bracket; 41. Front side wall; 42. Rear side wall; 43. Connecting wall; 44. Second support hole; 5. Brake disc; 51. Columnar portion; 511. First outer peripheral surface; 512. Second outer peripheral surface; 513. Third outer peripheral surface; 52. Disc-shaped portion; 53. Guide key; 54. Rib plate; 6. Brake pad; 7. Elastic member; 71. External compression spring; 72. Internal compression spring; 73. Disc spring; 8. Pad; 9. Adjustment mechanism; 91. Positioning ring; 911. Inner annular surface; 912. Outer annular surface; 92. Set screw; 93. Lock nut; 94. Positioning plate; 10. Traction rope. DETAILED DESCRIPTION

[0058] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention and are not intended to limit the present invention. That is, the embodiments described herein are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and illustrated in the drawings herein may be arranged and designed in various different configurations.

[0059] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely intended to represent selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0060] It should be noted that relational terms such as "first" and "second" that may appear are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, terms such as "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article or device. In the absence of further limitations, an element defined by a sentence such as "including a..." does not exclude the presence of other identical elements in the process, method, article or device that includes the element.

[0061] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0062] Example 1 of the damping device of the present invention is as follows Figure 1 and Figure 2 As shown, it includes a bracket, a support shaft 2 fixed to the bracket, a rope storage member assembled on the support shaft 2 through a spiral transmission pair, and a brake disc 5 arranged on one axial side of the rope storage member. The rope storage member in this embodiment is cylindrical and is called a reel 1. The reel 1 is made of a lightweight aluminum-plastic composite material. The center hole is provided with a trapezoidal internal thread. The rope storage ring groove formed by the outer cylindrical surface of the reel 1 and the drum edge rib 11 is used to wind and store the traction rope 10.

[0063] The bracket comprises a first bracket 3 and a second bracket 4, which are fixedly connected together. The first bracket 3 comprises two parallel, left and right side walls 31 and 32, and a base plate 33 connected at their bottoms. The second bracket 4 comprises two parallel, front and rear side walls 41 and 42, which are arranged in a front-to-rear manner, and a connecting wall 43 connecting their right ends. The left ends of the front and rear side walls 41 and 42 are fixed to the right side wall 32. The left side wall 31 forms the left end side wall of the bracket, the right side wall 32 forms the middle side wall of the bracket, and the connecting wall 43 forms the right end side wall of the bracket.

[0064] A first support hole 34 is provided in the left end sidewall. The left end of the support shaft 2 is provided with a left support segment 23 that passes through the first support hole 34. A second support hole 44 is provided in the right end sidewall. The right end of the support shaft 2 is provided with a right support segment 24 that passes through the second support hole 44. The middle portion of the support shaft 2 is a working section, the diameter of which is larger than that of the end support segments. Therefore, shaft shoulders are formed at each end support segment. The left support segment 23 forms a hole-shaft fit with the first support hole 34 and is axially positioned with the left end sidewall via the shaft shoulder. The right support segment 24 forms a hole-shaft fit with the second support hole 44 and is axially positioned with the right end sidewall via the shaft shoulder. Grooves are provided on the end faces of both the left and right support segments 23 and 24. The damping device also includes strip-shaped baffles 25, respectively embedded in the grooves and fixedly connected to the left and right end sidewalls via screws. These strip-shaped baffles 25 provide circumferential positioning of the support shaft 2, preventing rotation.

[0065] The working sections of support shaft 2, from left to right, consist of a lead screw section 21 and a smooth rod section 22. Lead screw section 21 engages with drum 1 in a helical transmission. The threads of lead screw section 21 are trapezoidal external threads that match the internal threads in the center hole of drum 1. Thus, lead screw section 21 and the center hole of drum 1 form a sliding helical transmission pair. As drum 1 rotates, it simultaneously moves axially. The pitch of lead screw section 21 matches the diameter of the traction rope 10, enabling automatic rope arrangement as the drum reels in.

[0066] like Figure 1 and Figure 2 As shown, the brake disc 5 is installed adjacent to the right side of the drum 1 and is fitted onto the support shaft 2 through a hole-shaft clearance fit, meaning that the support shaft 2 extends through the brake disc 5. A friction member is also provided between the drum 1 and the brake disc 5. The brake disc 5 is made of steel and comprises a columnar portion 51 and a disc-shaped portion 52 for use with the friction member. A countersunk hole having a diameter greater than the axial hole of the brake disc 5 is provided on the left end face of the disc-shaped portion 52. A cylindrical sleeve 12 for insertion into the countersunk hole is provided on the right end face of the drum 1. A chip storage annular groove 13 is provided at the root of the outer cylindrical surface of the cylindrical sleeve 12. The cylindrical sleeve 12 and the annular groove structure can accommodate friction debris and particulate matter, preventing them from falling into the thread groove of the support shaft lead screw segment and affecting the normal operation of the screw pair.

[0067] Furthermore, the friction member comprises a brake pad 6, which is fixed to the end face of the drum 1 opposite the brake disc 5 and forms a friction pair with the left end face of the brake disc 5. The brake pad 6 comprises multiple discrete friction plates, with the gaps between adjacent friction plates extending radially along the drum 1. Brake pads in the industry typically utilize composite materials based on non-metallic organic materials. These materials have low density and are lightweight, resulting in a smaller moment of inertia for the drum 1 and helping to reduce the impact overload experienced by the drone during the initial recovery phase. Furthermore, the gaps between adjacent friction plates allow debris or particulate matter within the chip storage groove 13 to be discharged by gravity, or by centrifugal force when the drum 1 rotates at high speed.

[0068] The columnar portion 51 passes through the middle sidewall. The columnar portion 51, the corresponding through-hole in the middle sidewall, and the axial hole of the brake disc 5 and the support shaft 2 respectively form inner and outer sliding pairs with axial freedom. Furthermore, the sliding pair formed by the columnar portion 51 and the middle sidewall is an axially movable pair that also includes a rotation-stopping structure. This not only facilitates guiding the brake disc 5 and reduces the number of guide components, but also ensures that the brake disc 5 does not rotate when the reel 1 rotates. At the same time, the support shaft 2 can be supported on the middle sidewall by the brake disc 5, providing auxiliary support for the reel 1 with a closer span, thereby reducing bending deformation of the support shaft 2 caused by the tension of the traction rope, and the resulting stuck motion of the spiral pair and poor contact of the friction pair.

[0069] Specifically, the columnar portion 51 is cylindrical, and the through hole on the middle side wall through which the columnar portion 51 passes is a cylindrical hole. The aforementioned anti-rotation structure includes a guide key 53 mounted on the outer surface of the columnar portion 51 and a guide groove provided on the wall of the through hole and cooperating with the guide key 53. The reason why the anti-rotation structure is provided on the outer sliding pair instead of the inner sliding pair is to transmit the braking torque applied to the brake disc 5 directly to the middle side wall of the bracket, rather than indirectly transmitting it to the side wall of the right end of the bracket via the support shaft 2 over a longer path, so as to make the braking more reliable and avoid torsional deformation and stress superposition of the support shaft 2 under the torque of the brake disc 5, so that the force applied to the support shaft 2 is more reasonable, the service life is longer, and the working reliability of the entire device is higher.

[0070] Combine Figure 1 and Figure 2 As shown, the outer circumference of the columnar part 51 is a stepped cylindrical shape, and the outer circumference of the columnar part 51 includes a first outer circumference 511, a second outer circumference 512 and a third outer circumference 513 whose diameters decrease successively from left to right. A plurality of ribs 54 are welded and fixed between the first outer circumference 511 and the right end face of the disc-shaped part 52. The above-mentioned guide key 53 is installed on the second outer circumference 512, and the above-mentioned guide groove is a through groove that passes through the left and right. The guide key 53 and the guide groove form a sliding key match, so that the columnar part 51 of the brake disc and the middle side wall form an axial moving pair connection.

[0071] The damping device further comprises an elastic member 7 arranged on the right side of the brake disc 5 (ie, away from the side of the reel 1), and the elastic member 7 is sleeved on the outside of the light bar section 22, as shown in FIG. Figure 2 As shown, the elastic member 7 is a combination of two cylindrical helical compression springs of different specifications, namely an outer compression spring 71 with a larger middle diameter and wire diameter and an inner compression spring 72 with a smaller middle diameter and wire diameter. The inner compression spring 72 is sleeved on the light bar section 22, and the outer compression spring 71 is nested outside the inner compression spring 72.

[0072] An adjustment mechanism for adjusting the pre-compression amount of the elastic member 7 is provided between the right end side wall and the elastic member 7. The adjustment mechanism includes a positioning ring 91 whose distance from the right end side wall is adjustable. The right end of the elastic member 7 presses against the positioning ring 91. The support shaft 2 also includes a mounting section for mounting the positioning ring 91. The position of the positioning ring 91 relative to the mounting section is adjustable. In this embodiment, the mounting section is part of the light bar section 22. The positioning ring 91 is sleeved on the outside of the light bar section 22 and can slide axially along the light bar section 22. A threaded hole is provided on the right end side wall. The above-mentioned adjustment mechanism also includes a set screw 92. The set screw 92 passes through the threaded hole through a threaded fit and presses against the right end face of the positioning ring 91. The limit distance between the positioning ring 91 and the right end side wall is adjusted by the set screw 92, thereby adjusting the pre-compression amount and pre-tightening force of the elastic member 7. This is simple, easy and reliable. The adjustment mechanism also includes a lock nut 93 connected to the set screw 92. The lock nut 93 locks the set screw 92 on the right side of the right end side wall to prevent the set screw 92 from loosening relative to the right end side wall and then withdrawing to the right.

[0073] like Figure 2 As shown, the left end surface of the positioning ring 91 includes an outer annular surface 912 and an inner annular surface 911 protruding from the outer annular surface 912. The right end of the external compression spring 71 presses against the outer annular surface 912, the right end of the internal compression spring 72 presses against the inner annular surface 911, and the left end of the internal compression spring 72 presses against the right end surface of the brake disc 5. A shoulder is formed between the second outer circumferential surface 512 and the third outer circumferential surface 513 of the columnar portion 51. The damping device further includes a backing plate 8 that is sleeved on the third outer circumferential surface 513 and presses against the shoulder. The left end of the external compression spring 71 presses against the right end surface of the backing plate 8. The thickness of the backing plate 8 is less than the length of the third outer circumferential surface 513, thus forming a step structure on the right end surface of the backing plate 8. The left end of the external compression spring 71 is equivalent to pressing against the step structure, thereby facilitating deformation.

[0074] The working principle of the damping device in the fixed-wing UAV recovery system of the present invention is:

[0075] When the traction rope 10 wound on the drum 1 is pulled out from the right end of the drum 1, the drum 1 is driven to rotate and move right, and the brake pad 6 contacts the left end surface of the brake disc 5 to form a friction pair. As the drum 1 moves right and pushes the brake disc 5 to move right, the outer compression spring 71 and the inner compression spring 72 are continuously compressed, and the pressure between the two surfaces of the friction pair continues to increase. The resistance torque provided by the friction pair continues to increase, thereby continuously increasing the tension on the pulled traction rope 10. When the present invention is applied to a fixed-wing UAV recovery system, the increasing resistance torque output characteristic (such as Figure 5 The braking force of the recovery rope can be compensated for the decreasing trend of the braking force due to the increase of the buffer stroke, thereby compressing the buffer stroke and buffer time by keeping the braking overload stable during the entire buffering process, thereby making the recovery system compact while shortening the recovery time and improving the recovery efficiency.

[0076] The present invention does not limit the initial axial position of the drum 1 on the support shaft 2. In actual use, before the drum 1 releases the traction rope 10, the drum 1 and the brake disc 5 can be in contact or even pressed by the brake pad 6, or they can be in a separated state. By adjusting the initial axial position of the drum 1 on the support shaft 2 and the axial position of the positioning ring 91, the torque-rotation (or angle) characteristic curve of the output resistance torque of the present invention can be adjusted to achieve a translation of the characteristic curve along the horizontal axis (such as Figure 6 ), thereby adapting to the overload control requirements of the fixed-wing UAV recovery system of the present invention under different recovery conditions. By replacing, increasing, decreasing, changing specifications, and altering the combination, the output characteristics of the compression springs, either as a single unit or as a combination, can be modified to achieve different output resistance torque-rotation (or rotation angle) characteristic curves to meet the various overload control requirements of the fixed-wing UAV recovery system of the present invention under different recovery conditions.

[0077] Example 2 of the damping device of the present invention is as follows Figure 3 and Figure 4 As shown, the difference from embodiment 1 is that the elastic member in this embodiment is a disc spring 73, and a plurality of disc springs 73 are combined to obtain an output resistance torque-rotation number (or rotation angle) characteristic curve as shown in FIG. Figure 7 As shown, the left end of the disc spring assembly is supported on the right end face of the brake disc 5, and the right end is supported on the left end face of the positioning plate 94 (another form of positioning ring, whose left end face is a plane). In this embodiment, the pad 8 in Example 1 is eliminated.

[0078] In other embodiments of the damping device: the disc spring combination can be changed from a simple "opposing" combination to a "opposing-overlapping" composite combination, and the number of overlapping assemblies can be set as needed, or disc springs of different thicknesses can be used for combination.

[0079] In other embodiments of the damping device: the application field of the damping device is not limited to the fixed-wing UAV recovery system, and can be widely used in various other working situations that require resistance to release the traction rope.

[0080] In other embodiments of the damping device, the rope storage member is not a drum, but is composed of two side discs and a plurality of fixed rods as in patent document CN112340045A, and the traction rope is wound around the outside of the fixed rods.

[0081] In other embodiments of the damping device: the cylindrical sleeve is not provided on the right end surface of the reel, and the countersunk hole is not provided on the left end surface of the disc-shaped portion.

[0082] In other embodiments of the damping device, the brake pad can be fixed to the left end surface of the brake disc to form a friction pair with the right end surface of the rope storage member; or the manufacturing material of one of the rope storage member and the brake disc is sufficient to directly form a friction pair with the opposite ends of the rope storage member and the brake disc.

[0083] In other embodiments of the damping device, the columnar portion may not be cylindrical, but may be hexagonal or square. In this case, the columnar portion can be directly guided by machining a hexagonal hole or a square hole on the middle side wall.

[0084] In other embodiments of the damping device: when the elastic member includes an inner compression spring and an outer compression spring, the right end of the brake disc may not be provided with a pad, but a step structure may be directly machined on the brake disc itself for the end of the outer compression spring to press against.

[0085] In other embodiments of the damping device: the elastic member may also be an elastic rubber sleeve.

[0086] In other embodiments of the damping device: the mounting section is not part of the light bar section, but a threaded section. In this case, the positioning ring is directly threadedly connected to the mounting section, and the position of the positioning ring relative to the mounting section can be directly changed by rotating the positioning ring.

[0087] In other embodiments of the damping device: the left support section and the right support section of the support shaft can be processed into a square column shape, and the support holes are also square holes, so that the left support section and the right support section can directly stop rotation after passing through the left side wall and the connecting wall respectively.

[0088] In other embodiments of the damping device: the structure of the bracket can be designed and processed as needed, and can be integrated or split.

[0089] In other embodiments of the damping device, the adjustment mechanism may not be provided, and the pre-compression amount of the elastic member is not adjustable.

[0090] In other embodiments of the damping device: the screw transmission pair between the rope storage member and the support shaft is a rolling screw transmission pair, such as a ball screw pair.

[0091] In other embodiments of the damping device: the sliding pair formed between the axial hole of the brake disc and the support shaft is an axial moving pair that also contains a rotation-stopping structure; or, the sliding pair formed by the columnar part and the corresponding through hole on the middle side wall, and the sliding pair formed between the axial hole of the brake disc and the support shaft both contain a rotation-stopping structure.

[0092] An embodiment of the fixed-wing UAV recovery system of the present invention is as follows: the fixed-wing UAV recovery system includes a traction rope and a damping device. The specific structure of the damping device is the same as the damping device in the above embodiment and will not be repeated here.

[0093] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The scope of patent protection of the present invention shall be based on the claims. Any equivalent structural changes made using the description and drawings of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A damping device comprising a bracket, a support shaft (2) fixed to the bracket, a rope storage member assembled on the support shaft (2) via a spiral transmission pair, and a brake disc (5) arranged on one axial side of the rope storage member, the support shaft (2) passing through the brake disc (5), the rope storage member being used to wind a traction rope (10), the opposite ends of the rope storage member and the brake disc (5) being used to form a friction pair, or a friction member being additionally arranged between the rope storage member and the brake disc (5), the damping device further comprising an elastic member (7) arranged on a side of the brake disc (5) away from the rope storage member, characterized in that: The support shaft (2) includes a screw segment (21) that is spirally driven with the rope storage member and a smooth rod segment (22) for the elastic member (7) to be sleeved. The brake disc (5) includes a columnar portion (51) and a disc-shaped portion (52) for use with the rope storage member or the friction member. The bracket includes an intermediate side wall for the columnar portion (51) to pass through. The columnar portion (51) and the corresponding through holes on the intermediate side wall, as well as the axial hole of the brake disc (5) and the support shaft (2) respectively form inner and outer sliding pairs with axial freedom. At least one of the two sliding pairs with axial freedom is an axial moving pair that also has a rotation-stopping structure.

2. The damping device according to claim 1, characterized in that: The columnar portion (51) is cylindrical, and the through hole on the middle side wall for the columnar portion (51) to pass through is a cylindrical hole. The two form an axial moving pair including the anti-rotation structure. The anti-rotation structure includes a guide key (53) installed on the outer surface of the columnar portion (51) and a guide groove arranged on the wall of the through hole and cooperating with the guide key (53).

3. The damping device according to claim 1 or 2, characterized in that: The bracket further comprises a left end side wall and a right end side wall, and both ends of the support shaft (2) are respectively mounted on the left and right end side walls. An adjusting mechanism for adjusting the pre-compression amount of the elastic member (7) is provided between the right end side wall and the elastic member (7), and the adjusting mechanism comprises a positioning ring (91) whose distance to the right end side wall is adjustable. The right end of the elastic member (7) presses against the positioning ring (91). The support shaft (2) further comprises a mounting section for mounting the positioning ring (91), and the position of the positioning ring (91) relative to the mounting section is adjustable.

4. The damping device according to claim 3, characterized in that: The mounting section is a part of the light bar section (22); the positioning ring (91) is sleeved on the outside of the light bar section (22) and can slide axially along the light bar section (22); a threaded hole is provided on the side wall of the right end portion; the adjustment mechanism further comprises a set screw (92); the set screw (92) passes through the threaded hole through thread engagement and then presses against the right end surface of the positioning ring (91).

5. The damping device according to claim 3, characterized in that: The elastic member (7) includes an outer compression spring (71) and an inner compression spring (72) arranged inside the outer compression spring (71); the left end surface of the positioning ring (91) includes an outer ring surface (912) for the right end of the outer compression spring (71) to press against, and an inner ring surface (911) for the right end of the inner compression spring (72) to press against and protruding from the outer ring surface (912); the left end of the inner compression spring (72) presses against the right end surface of the brake disc (5); the right end of the brake disc (5) is provided with a step structure, and the left end of the outer compression spring (71) presses against the step structure.

6. The damping device according to claim 3, characterized in that: The bracket comprises a first bracket (3) and a second bracket (4) fixedly connected together, wherein the first bracket (3) comprises two parallel left side walls (31) and right side walls (32) arranged left and right, and a seat plate (33) connecting the bottoms of the two brackets, and the second bracket (4) comprises two parallel front side walls (41) and rear side walls (42) arranged front and back, and a connecting wall (43) connected at the right ends of the two brackets, wherein the left ends of the front side walls (41) and the rear side walls (42) are fixed on the right side wall (32), the left side wall (31) constitutes the left end side wall, the right side wall (32) constitutes the middle side wall, and the connecting wall (43) constitutes the right end side wall.

7. The damping device according to claim 3, characterized in that: The left end of the support shaft (2) is provided with a left support section (23) passing through the left end side wall, and the right end of the support shaft (2) is provided with a right support section (24) passing through the right end side wall. The end surfaces of the left support section (23) and the right support section (24) are both provided with grooves. The damping device also includes strip-shaped baffles (25) respectively embedded in the grooves and fixedly connected to the left end side wall and the right end side wall.

8. The damping device according to claim 1 or 2, characterized in that: A countersunk hole with a diameter larger than the axial hole of the brake disc (5) is provided on the left end surface of the disc-shaped part (52), and a cylindrical insert (12) for inserting into the countersunk hole is provided on the right end surface of the rope storage member. A chip storage ring groove (13) is provided at the root of the outer cylindrical surface of the cylindrical insert (12).

9. The damping device according to claim 1 or 2, characterized in that: A brake pad (6) is provided between the rope storage member and the brake disc (5) as a friction member. The brake pad (6) is fixed on the end surface of the rope storage member opposite to the brake disc (5) and forms a friction pair with the left end surface of the brake disc (5). The brake pad (6) includes a plurality of separate friction plates, and the gaps between adjacent friction plates extend radially along the rope storage member.

10. A fixed-wing UAV recovery system, comprising a towing rope, characterized in that: It also includes a damping device as claimed in any one of claims 1 to 9.

Images