Rotor unmanned aerial vehicle propeller fixing device and unmanned aerial vehicle

Abstract

The invention relates to a rotor unmanned aerial vehicle propeller fixing device and an unmanned aerial vehicle. The fixing device comprises a stop rod, a worm, a turbine, a first driving unit and a motor. One end of the stop rod is in transmission connection with the first driving unit, the other end of the stop rod is provided with a stop part, the stop rod has a first state and a second state under the driving of the first driving unit, and in the first state, the stop part interferes with propeller blades; the worm is in transmission connection with the motor and the turbine, the worm and the turbine are rotatably arranged on the unmanned aerial vehicle, the worm is meshed with the turbine, a fixing part is arranged on the turbine, the turbine has a third state and a fourth state under the driving of the motor, and in the third state, the fixing part rotates to abut against the propeller blades. The clamping component is matched with the stop component to position and fix the propeller of the multi-rotor unmanned aerial vehicle, automatic fixing of the propeller can be achieved, and the problem that at present, fixing of the propeller can only be completed manually and cannot be completed automatically is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of fixed-propeller multi-rotor unmanned aerial vehicles, and specifically to a propeller fixing device for a rotor unmanned aerial vehicle and an unmanned aerial vehicle. Background Art

[0002] With the development of the low-altitude economy, the application scenarios of multi-rotor unmanned aerial vehicles are becoming more and more extensive. When a multi-rotor unmanned aerial vehicle is in a storage state, in order to prevent the propellers from rotating randomly during transportation and causing damage to the propellers, it is usually necessary to fix the propellers. The existing methods for fixing propellers include: using a propeller blade protector to fix the propellers, disassembling the propellers and storing them separately, and using a tie strap or the like to tie the propellers.

[0003] The above-mentioned methods for fixing propellers all need to be manually operated by staff. However, in fully automated unmanned application scenarios that require a high degree of automation, the propellers of multi-rotor unmanned aerial vehicles need to be automatically fixed to achieve automatic storage, and the above-mentioned manual methods are no longer applicable. Summary of the Invention

[0004] In order to solve the above deficiencies in the prior art, the present invention provides a propeller fixing device for a rotor unmanned aerial vehicle, including a stop rod, a worm, a turbine, a first driving unit, and a motor.

[0005] One end of the stop rod is drivingly connected to the first driving unit, and the other end is provided with a stop portion. Under the drive of the first driving unit, the stop rod includes a first state and a second state. In the first state, the stop portion interferes with the propeller blade, and in the second state, the stop portion does not interfere with the propeller blade. The first state is used to interfere with the propeller blade to prevent the rotation of the propeller blade, and the second state is used for the normal rotation of the propeller blade.

[0006] The worm is drivingly connected to the motor and the turbine. The worm and the turbine are rotatably arranged on the unmanned aerial vehicle. The worm and the turbine are meshed. A fixing portion is provided on the turbine. Under the drive of the motor, the turbine includes a third state and a fourth state. In the third state, the fixing portion rotates to abut against the propeller blade, and in the fourth state, the fixing portion rotates to not interfere with the propeller blade. The third state is used to abut against the propeller blade to limit the rotation of the blade, so that the blade is not easily damaged during transportation, and the fourth state is used for the normal rotation of the propeller blade.

[0007] In use, a weak current is input to the propeller motor in the drone to make the propeller rotate at a low speed. Then, through the first driving unit, the stop rod is moved to the first state where it interferes with the movement of the propeller blade. When the propeller rotating at a low speed touches the stop portion on the stop rod, the propeller is stopped. Then, the motor is controlled to drive the worm to rotate, thereby driving the engaged turbine to rotate, so that the fixing portion on it rotates to the third state where it abuts against the propeller blade, realizing the automatic fixing of the propeller. Of course, the specific position setting of the turbine needs to be designed in combination with the preset position of the stop rod for stopping the propeller blade. It can be the blade stopped by abutting against the stop rod, or other blades. After the blade is fixed, the stop rod can be moved to the second state, or the stop rod can be kept in the first state. When automatically releasing the propeller, controlling the stop rod to be in the second state and the turbine to be in the fourth state can realize the automatic release of the propeller.

[0008] Further, there are two turbines, which are arranged on opposite sides of the worm. The fixing portions on the two turbines respectively abut against the upper surface and the lower surface of the propeller blade in the third state, abutting against the blade from both sides of the blade, making the fixing of the blade more stable.

[0009] Further, the fixing portion includes a collet ejector pin and a compression spring. The fixing portion is provided with an open sliding groove, the compression spring is arranged at the bottom of the sliding groove, one end of the collet ejector pin is arranged outside the opening, and the other end abuts against the compression spring. In the third state, the collet ejector pin abuts against the propeller blade, making the effect of the fixing portion abutting against the blade better.

[0010] Further, the fixing portion includes a clamping rod and a collet. The collet includes a collet sleeve, a collet end cover, a collet ejector pin and a compression spring. One end of the collet sleeve is open, and the collet end cover is provided with a through hole. The collet end cover is arranged on the collet sleeve to form an open sliding groove. The collet ejector pin includes a sliding portion and a ejector pin portion. The sliding portion abuts against the compression spring and is slidably arranged in the open sliding groove. The ejector pin portion is slidably arranged in the through hole on the collet sleeve. In the third state, the ejector pin portion abuts against the propeller blade. The clamping rod is provided with a first mounting hole, and the collet sleeve is arranged in the first mounting hole.

[0011] Further, a central through hole along the length direction of the worm is provided in the middle of the worm, and the stop rod is slidably arranged in the central through hole. On the one hand, the central through hole of the worm can be used as the sliding groove of the stop rod, reducing the use of materials and the total weight of the drone. On the other hand, the volume of the drone can be reduced.

[0012] Further, the stop rod is made of a slender material, such as steel wire. The stop portion includes a blocking portion formed by bending the slender material. The blocking portion deviates from the axis direction of the stop rod, so that when the propeller blade stops in the first state, the blade and the stop rod are aligned, making the process of fixing the blade more stable.

[0013] Further, the first driving unit includes a rotary driving member, a connecting member, a connecting rod and a slider. The rotary driving member is a motor or a rocker-driven electromagnet. The connecting member is drivingly connected to the output end of the rotary driving member. The slider is used to connect the stop rod. The connecting rod is hinged to the connecting member and the slider, converting the rotary motion of the rotary driving member into a linear displacement motion.

[0014] The present invention also provides an unmanned aerial vehicle, including a plurality of the above-mentioned rotor unmanned aerial vehicle propeller fixing devices. The first driving units in each fixing device share the rotary driving member and the connecting member. The connecting member connects each connecting rod, and the linear motion of the stop rods in different directions can be realized by using one rotary driving member. The worm gears in each fixing device share a motor. A first bevel gear is provided at the output end of the motor, and a second bevel gear is provided on each worm gear. The first bevel gear meshes with each second bevel gear.

[0015] Further, it also includes a plurality of trough-shaped machine arms, including a trough bottom plate and two trough side plates. The distal end of the trough-shaped machine arm is connected to the propeller. A worm and gear mounting seat is provided on the trough-shaped machine arm, including a connecting plate and two mounting plates. The mounting plates are respectively connected to one trough side plate, the connecting plate connects the two mounting plates, the worm is rotatably connected to the mounting plate, and the gear is rotatably connected to the connecting plate, which can reduce the total weight of the unmanned aerial vehicle while having sufficient strength.

[0016] Further, it also includes a plurality of bevel gear mounting seats. A plurality of second mounting holes are provided on the frame, and the bevel gear mounting seats are mounted in the second mounting holes. A connecting column is provided on the second bevel gear, and the connecting columns on each second bevel gear are rotatably connected to the corresponding bevel gear mounting seats.

[0017] The present invention positions and fixes the propellers of the multi-rotor unmanned aerial vehicle through the clamping component and the stop component, realizes the automatic fixing of the propellers, solves the problem that the current propeller fixing can only be manually completed and cannot be automatically completed, can be applied to the application scenarios of the whole process automation and unmanned operation of the multi-rotor unmanned aerial vehicle during storage, and prevents the propellers from rotating randomly during transportation, thereby causing damage to the propellers. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 is the overall schematic diagram of the unmanned aerial vehicle of the present invention; Figure 2 is the exploded schematic diagram of the unmanned aerial vehicle of the present invention; Figure 3 It is a cross-sectional view of the third state of the present invention; Figure 4 It is a partially enlarged view of the cross-sectional view of the third state of the present invention; Figure 5 It is a cross-sectional view of the fourth state of the present invention; Figure 6 It is a partially enlarged view of the cross-sectional view of the fourth state of the present invention; Figure 7 It is a control timing diagram when automatically fixing the propeller in the present invention; Figure 8 It is a top view of the UAV structure in the third state of the present invention; Figure 9 It is a control timing diagram when automatically releasing the propeller in the present invention; Figure 10 It is a top view of the UAV structure in the fourth state of the present invention; In the figure: 1, stop rod; 2, worm; 3, turbine; 4, first drive unit; 5, motor; 6, stop portion; 7, propeller; 8, rotation drive member; 9, connecting member; 10, connecting rod; 11, slider; 12, fixing portion; 13, collet ejector pin; 14, compression spring; 15, open chute; 16, clamping rod; 17, collet; 18, collet sleeve; 19, collet end cap; 20, sliding portion; 21, ejector pin portion; 22, first mounting hole; 23, central through hole; 24, first bevel gear; 25, second bevel gear; 26, grooved arm; 27, groove bottom plate; 28, groove side plate; 29, worm and turbine mounting seat; 30, connecting plate; 31, mounting plate; 32, bevel gear mounting seat; 33, second mounting hole; 34, connecting column; 35, transmission system support frame; 36, support frame cover plate; 37, propeller motor. Detailed implementation manners

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Embodiment 1:

[0022] Refer to Figure 1 , Figure 2 In this embodiment, it is a propeller fixing device for a rotary-wing UAV, including a stop rod 1, a worm 2, a turbine 3, a first drive unit 4 and a motor 5.

[0023] One end of the stop lever 1 is drivingly connected to the first driving unit 4, and the other end is provided with a stop portion 6. Driven by the first driving unit 4, the stop lever 1 includes a first state and a second state. In the first state, the stop portion 6 interferes with the blades of the propeller 7. In the second state, the stop portion 6 does not interfere with the blades of the propeller 7. The first state is used to interfere with the blades of the propeller 7 to prevent the rotation of the blades of the propeller 7, and the second state is used for the normal rotation of the blades of the propeller 7.

[0024] Preferably, the first driving unit 4 includes a rotary driving member 8, a connecting member 9, a connecting rod 10 and a slider 11. The rotary driving member 8 is a motor or a rocker-driven electromagnet. In this embodiment, a rocker-driven electromagnet is adopted. The connecting member 9 is drivingly connected to the output end of the rotary driving member 8. The slider 11 is used to connect the stop lever 1. The connecting rod 10 is hinged to the connecting member 9 and the slider 11 to convert the rotary motion of the rotary driving member 8 into a linear displacement motion.

[0025] The worm is drivingly connected to the motor 5 and the turbine 3. The worm 2 and the turbine 3 are rotatably arranged on the UAV. The worm 2 and the turbine 3 are engaged. A fixing portion 12 is provided on the turbine 3. Driven by the motor 5, the turbine 3 includes a third state and a fourth state. In the third state, the fixing portion 12 rotates to abut against the blades of the propeller 7. In the fourth state, the fixing portion 12 rotates to not interfere with the blades of the propeller 7. The third state is used to abut against the blades of the propeller 7 to limit the rotation of the blades, so that the blades are not easily damaged during transportation. The fourth state is used for the normal rotation of the blades of the propeller 7.

[0026] Preferably, in this embodiment, there are two turbines 3, which are arranged on opposite sides of the worm 2. The fixing parts 12 on the two turbines 3 respectively abut against the upper surface and the lower surface of the blade of the propeller 7 in the third state, abutting against the blade from both sides of the blade, and the fixing of the blade is more stable. Further preferably, the fixing part 12 includes a chuck thimble 13 and a compression spring 14. The fixing part 12 is provided with an open chute 15. The compression spring 14 is arranged at the bottom of the chute. One end of the chuck thimble 13 is arranged outside the opening, and the other end abuts against the compression spring 14. In the third state, the chuck thimble 13 abuts against the blade of the propeller 7, making the effect of the fixing part 12 abutting against the blade better. The fixing part 12 includes a clamping rod 16 and a chuck 17. The chuck 17 includes a chuck sleeve 18, a chuck end cover 19, a chuck thimble 13 and a compression spring 14. One end of the chuck sleeve 18 is open, and the chuck end cover 19 is provided with a through hole. The chuck end cover 19 is arranged on the chuck sleeve 18 to form an open chute 15. The chuck thimble 13 includes a sliding part 20 and a thimble part 21. The sliding part 20 abuts against the compression spring 14 and is slidably arranged in the open chute 15. The thimble part 21 is slidably arranged in the through hole on the chuck sleeve 18. In the third state, the thimble part 21 abuts against the blade of the propeller 7. The clamping rod 16 is provided with a first mounting hole 22, and the chuck sleeve 18 is arranged in the first mounting hole 22. The sliding part 20 is provided with a through hole. When the chuck thimble 13 moves axially, the gas on both sides of the sliding part 20 can flow, preventing the formation of a sealed space on both sides of the sliding part 20 and hindering the movement of the chuck thimble 13.

[0027] Preferably, a central through hole 23 along the length direction of the worm 2 is provided in the middle of the worm 2. The stop rod 1 is slidably arranged in the central through hole 23. On the one hand, the central through hole 23 of the worm 2 can be used as the sliding groove of the stop rod 1, reducing the use of materials and the total weight of the drone. On the other hand, the volume of the drone can be reduced. Further preferably, the stop rod 1 is made of a slender material, such as steel wire. The stop part 6 includes a blocking part formed by bending the slender material. The blocking part deviates from the axis direction of the stop rod 1, so that when the blade of the propeller 7 stops in the first state, the blade and the stop rod 1 are aligned, making the process of fixing the blade more stable.

[0028] See Figures 3 - 10, during use, a weak current is input to the propeller motor 37 in the drone to make the propeller 7 rotate at a low speed. Then, through the first driving unit 4, the stop lever 1 is moved to the first state where it interferes with the movement of the propeller 7 blades. When the propeller 7 rotating at a low speed touches the stop portion 6 on the stop lever 1, the propeller 7 is stopped. Then, the motor 5 is controlled to drive the worm 2 to rotate, thereby driving the engaged turbine 3 to rotate, so that the fixing portion 12 thereon rotates to the third state where it abuts against the propeller 7 blades, realizing the automatic fixing of the propeller 7. Of course, the specific position setting of the turbine 3 needs to be designed in combination with the preset position of the stop lever 1 for stopping the propeller 7 blades. It can be the blade that abuts against the stop of the stop lever 1, or other blades. After the blade is fixed, the stop lever 1 can be moved to the second state, or the stop lever 1 can be kept in the first state. When automatically releasing the propeller 7, controlling the stop lever 1 to be in the second state and the turbine 3 to be in the fourth state can realize the automatic release of the propeller 7.

[0029] Embodiment 2:

[0030] See Figure 1 、 Figure 2 , this embodiment is a drone, including several propeller fixing devices for the rotor drone in Embodiment 1. This embodiment takes four fixing devices as an example for illustration. The first driving units 4 in each fixing device share a rotary driving member 8 and a connecting member 9. The connecting member 9 connects each connecting rod 10. Using one rotary driving member 8 can realize the linear movement of the stop lever 1 in different directions. In this embodiment, the connecting member 9 is set as circular, which can connect each connecting rod better. The worms 2 in each fixing device share a motor 5. A first bevel gear 24 is provided at the output end of the motor 5, and a second bevel gear 25 is provided on each worm 2. The first bevel gear 24 meshes with each second bevel gear 25. The use of power output components can be reduced, and the total weight of the drone can be reduced. Of course, for the solution where the stop lever 1 is arranged in the central through hole 23 of the worm 2, a through hole for the stop lever 1 to slide is provided on the corresponding second bevel gear 25.

[0031] Preferably, it further includes several trough-shaped machine arms 26, including a trough bottom plate 27 and two trough side plates 28. The distal end of the trough-shaped machine arm 26 is connected to the propeller 7. A turbine and worm mounting seat 29 is provided on the trough-shaped machine arm 26, including a connecting plate 30 and two mounting plates 31. The mounting plates 31 are respectively connected to one trough side plate 28, and the connecting plate 30 connects the two mounting plates 31. The turbine 3 is rotatably connected to the mounting plate 31, and the worm 2 is rotatably connected to the connecting plate 30, which can reduce the total weight of the drone while having sufficient strength. Preferably, it further includes several bevel gear mounting seats 32. Several second mounting holes 33 are provided on the frame, and the bevel gear mounting seats 32 are mounted in the second mounting holes 33. A connecting column 34 is provided on the second bevel gear 25, and the connecting columns 34 on each second bevel gear 25 are rotatably connected to the corresponding bevel gear mounting seats 32.

[0032] The drone further includes a frame component, which includes a transmission system support frame 35, a support frame cover plate 36, and grooved arms. There are four grooved arms in total, and the shape and size of each grooved arm are exactly the same. The transmission system support frame 35 is a hollow cuboid structure, and mounting holes are provided at its bottom for sleeving and fixedly connecting with the outer shell of the motor. Second mounting holes 33 are provided on its four peripheral side surfaces for sleeving and fixedly connecting with the bevel gear mounting seat 32, ensuring that the axes of the four second bevel gears 25 are all in the same plane perpendicular to the axis of the first bevel gear 24. The support frame cover plate 36 is fixedly connected directly above the transmission system support frame 35. The support frame cover plate 36 is fixedly connected with the outer shell of the rocker driving electromagnet, and makes the rocker driving electromagnet coaxial with the axis of the motor 5, so as to ensure that the movements of the respective stop rods 1 along their respective axes are synchronous and the displacements are consistent. The four grooved arms are radially fixedly connected to the bottom surface of the transmission system support frame 35, and their outer sides are fixedly connected with the outer shell of the propeller motor 37, and in the middle thereof, they are fixedly connected with the worm and gear mounting seat 29. The grooves provided along the axial direction of the grooved arms can also give the fixing part 12 on the lower side turbine 3 a rotation space, making the overall drone more compact. The propeller plane of the propeller 7 coincides with the axis of the worm 2, which can ensure that the fixing part 12 generates the same clamping force on both sides of the propeller 7, making the fixing more stable.

[0033] See Figures 3 - 10 , in use, a weak current is input to the propeller motor 37 in the drone to make the propeller 7 rotate at a low speed, and then the first driving unit 4 is driven. The rocker driving electromagnet rotates a certain angle under the action of an applied voltage, so that each stop rod 1 moves to the first state where it interferes with the movement of the propeller blade of the propeller 7. When the propeller 7 rotating at a low speed touches the stop part 6 on the stop rod 1, the propeller 7 is stopped. According to the number of propeller blades, a certain power-on time is set. After all the propellers 7 are stopped, then the motor 5 is controlled to drive each worm 2 to rotate, thereby driving the engaged turbine 3 to rotate, so that the fixing part 12 thereon rotates to the third state where it abuts against the propeller blade of the propeller 7, realizing the automatic fixing of the propeller 7. Of course, the specific position setting of the turbine 3 needs to be designed in combination with the preset position of the stop rod 1 for stopping the propeller blade of the propeller 7. It can be the propeller blade that abuts against the stop rod 1 to stop, or other propeller blades. After the propeller blade is fixed, the stop rod 1 can be moved to the second state, or the stop rod 1 can be kept in the first state. Stopping the voltage of the rocker driving electromagnet can make the stop rod 1 move to the second state. When automatically releasing the propeller 7, controlling each stop rod to be in the second state and each turbine 3 to be in the fourth state can realize the automatic release of each propeller 7.

[0034] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these changes and modifications.

Claims

1. A propeller fixing device for a rotary-wing unmanned aerial vehicle, characterized in that, It includes a stop rod, a worm, a turbine, a first driving unit and a motor; one end of the stop rod is drivingly connected to the first driving unit, and the other end is provided with a stop portion. Under the drive of the first driving unit, the stop rod includes a first state and a second state. In the first state, the stop portion interferes with the propeller blade, and in the second state, the stop portion does not interfere with the propeller blade; the worm is drivingly connected to the motor and the turbine. The worm and the turbine are rotatably arranged on the unmanned aerial vehicle, and the worm and the turbine are engaged. The turbine is provided with a fixing portion. Under the drive of the motor, the turbine includes a third state and a fourth state. In the third state, the fixing portion rotates to abut against the propeller blade, and in the fourth state, the fixing portion rotates to not interfere with the propeller blade.

2. The propeller fixing device of the rotary-wing unmanned aerial vehicle according to claim 1, characterized in that There are two turbines, which are arranged on opposite sides of the worm. The fixing portions on the two turbines respectively abut against the upper surface and the lower surface of the propeller blade in the third state.

3. The propeller fixing device of the rotary-wing unmanned aerial vehicle according to claim 2, characterized in that, The fixing portion includes a collet chuck and a compression spring. The fixing portion is provided with an open sliding groove. The compression spring is arranged at the bottom of the sliding groove. One end of the collet chuck is arranged outside the opening, and the other end abuts against the compression spring. In the third state, the collet chuck abuts against the propeller blade.

4. The propeller fixing device of the rotary-wing unmanned aerial vehicle according to claim 3, characterized in that, The fixing portion includes a clamping rod and a chuck. The chuck includes a chuck sleeve, a chuck end cover, a collet chuck and a compression spring. One end of the chuck sleeve is open. The chuck end cover is provided with a through hole. The chuck end cover is arranged on the chuck sleeve to form an open sliding groove; the collet chuck includes a sliding portion and a thimble portion. The sliding portion abuts against the compression spring and is slidably arranged in the open sliding groove. The thimble portion is slidably arranged in the through hole on the chuck sleeve. In the third state, the thimble portion abuts against the propeller blade; the clamping rod is provided with a first mounting hole, and the chuck sleeve is arranged in the first mounting hole.

5. The propeller fixing device of the rotary-wing unmanned aerial vehicle according to claim 1, characterized in that, A central through hole along the length direction of the worm is provided in the middle of the worm, and the stop rod is slidably arranged in the central through hole.

6. The propeller fixing device for a rotor UAV according to claim 5, characterized in that, The stop rod is made of an elongated material. The stop portion includes a blocking portion formed by bending the elongated material. The blocking portion deviates from the axis direction of the stop rod, so that when the propeller blade stops in the first state, the blade and the stop rod are aligned.

7. The propeller fixing device of the rotor unmanned aerial vehicle according to claim 1, characterized in that, The first driving unit includes a rotary driving member, a connecting member, a connecting rod and a slider. The rotary driving member is a motor or a rocker driving electromagnet; the connecting member is drivingly connected to the output end of the rotary driving member. The slider is used to connect the stop rod, and the connecting rod is hinged to the connecting member and the slider.

8. A drone, characterized in that, It includes a plurality of propeller fixing devices for a rotary-wing unmanned aerial vehicle as described in claim 7. The first driving units in each fixing device share the rotary driving member and the connecting member; the worms in each fixing device share the motor. A first bevel gear is provided at the output end of the motor, and a second bevel gear is provided on each worm. The first bevel gear meshes with each second bevel gear.

9. The drone according to claim 8, characterized in that, It further includes a plurality of grooved machine arms, which include a grooved bottom plate and two grooved side plates. The distal end of the grooved machine arm is connected to the propeller; a turbine and worm mounting seat is provided on the grooved machine arm, which includes a connecting plate and two mounting plates. The mounting plates are respectively connected to one grooved side plate, the connecting plate connects the two mounting plates, the turbine is rotatably connected to the mounting plate, and the worm is rotatably connected to the connecting plate.

10. The drone according to claim 8, characterized in that, It further includes a plurality of bevel gear mounting seats, and a plurality of second mounting holes are provided on the frame, and the bevel gear mounting seats are mounted in the second mounting holes; a connecting column is provided on the second bevel gear, and the connecting columns on each second bevel gear are rotatably connected to the corresponding bevel gear mounting seats.

Images