An opening and closing propeller mechanism for vertical take-off and landing aircraft

Abstract

The present invention relates to the field of aircraft, and in particular to an opening and closing propeller mechanism for vertical take-off and landing aircraft, comprising a base, an upper propeller hub and a lower propeller hub being provided at the upper end of the base, propeller blades being fixedly connected at both ends of the upper propeller hub and the lower propeller hub, a turntable being fixedly connected at the bottom end of the lower propeller hub, the turntable being rotatably matched with the base, a driving motor being fixedly provided at the bottom end of the base, a switching assembly being provided inside the upper propeller hub and the lower propeller hub, the switching assembly comprising a rotating sleeve, the top end of the rotating sleeve being fixedly connected to the inner wall of the upper propeller hub, the bottom end of the rotating sleeve being rotatably matched with the inner wall of the lower propeller hub, a cylindrical cam being coaxially provided inside the rotating sleeve, the top end of the cylindrical cam being fixedly connected to the rotating sleeve via a fixed gasket. The propeller blades in the present invention can be switched between an overlapping parallel state and a crossed vertical state, which can greatly reduce the air resistance of the aircraft during level flight on the runway, and at the same time improve the lift effect and balance stability of the aircraft during vertical take-off.

Description

Technical Field

[0001] The present invention relates to the technical field of aircraft, and in particular to an opening and closing propeller mechanism for a vertical take-off and landing aircraft. Background Art

[0002] A vertical take-off and landing (VTOL) aircraft is an aircraft that can take off and land vertically and hover like a helicopter, while also flying horizontally like a fixed-wing aircraft. These aircraft combine the advantages of both helicopters and fixed-wing aircraft, possessing the capabilities of vertical take-off and landing, hovering, and horizontal flight. Their diverse technological principles hold enormous potential for application.

[0003] Chinese patent publication number CN221294109U discloses a vertical take-off and landing (VTOL) aircraft comprising a fuselage and 2N tilt-rotors, with wings positioned on either side of the fuselage and a tail at the rear. The 2N tilt-rotors are symmetrically mounted on either side of the fuselage, with a portion of the 2N tilt-rotors located on the tail. N is a natural number greater than or equal to 2, and at least the tilt-rotors located on the tail are fully tilt-rotors. This VTOL aircraft can address the significant airflow interference between the tilt-rotors on the tail and the tail, making pitch control difficult in existing VTOL aircraft. However, this aircraft utilizes rotors with multiple blades fixed at equal intervals to a hub. When the aircraft is in level flight on a runway, the airflow acting on the blades significantly increases air resistance. Furthermore, the torque exerted on the blades is detrimental to the blade lifespan. Summary of the Invention

[0004] The purpose of the present invention is to provide an opening and closing propeller mechanism for a vertical take-off and landing aircraft, aiming to solve the above-mentioned technical problems.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A propeller opening and closing mechanism for a vertical take-off and landing aircraft comprises a base, an upper propeller hub and a lower propeller hub are provided at the upper end of the base, propeller blades are fixedly connected to both ends of the upper propeller hub and the lower propeller hub, a turntable is fixedly connected to the bottom end of the lower propeller hub, the turntable rotates with the base, a drive motor is fixedly provided at the bottom of the base, a switching assembly is provided inside the upper propeller hub and the lower propeller hub, the switching assembly comprises a rotating sleeve, the top end of the rotating sleeve is fixedly connected to the inner wall of the upper propeller hub, the bottom end of the rotating sleeve rotates with the inner wall of the lower propeller hub, a cylindrical cam is coaxially provided inside the rotating sleeve, and the top end of the cylindrical cam is fixedly connected to the rotating sleeve via a fixed gasket.

[0007] A lifting assembly is provided in the cylindrical cam, and the lifting assembly includes a lower limit plate, a push rod and an upper limit plate. The push rod slides coaxially through the top of the cylindrical cam, and the upper and lower ends of the push rod are fixedly connected to the lower limit plate and the upper limit plate respectively. Lower limit posts are fixedly provided on the top of both ends of the lower limit plate, and upper limit posts are fixedly provided on the bottom of both ends of the upper limit plate. An upper limit hole corresponding to the upper limit post is provided through the bottom of the upper hub, and a lower limit hole corresponding to the lower limit post is provided through the bottom of the lower hub.

[0008] A cam groove is set through the outer wall of the cylindrical cam, and the cam groove includes a lower limit straight groove, an inclined slide groove and an upper limit straight groove. The two ends of the inclined slide groove are smoothly connected to the lower limit straight groove and the upper limit straight groove respectively. A cam pin is fixedly connected to the outer wall of the push rod, and the cam pin is adapted to be slidably installed in the cam groove.

[0009] A linear servo is provided below the lower limit plate and is fixedly mounted on a servo seat. An output end of the linear servo is fixedly connected to the lower limit plate, and an output end of the drive motor is fixedly connected to the servo seat.

[0010] As a further solution of the present invention: the upper limit plate is arranged in the upper hub, a locking bolt is fixedly provided at the center of the upper end of the upper limit plate, the locking bolt is connected to the top of the push rod, and a stop hole facing the locking bolt is provided at the top of the upper hub.

[0011] As a further solution of the present invention: a hole edge is provided on the edge of the upper end of the upper limit hole extending upward.

[0012] As a further solution of the present invention: a positioning hole is provided through the top of the lower hub, and the positioning hole is provided in a one-to-one correspondence with the upper limit positioning hole.

[0013] As a further solution of the present invention: the cam pin slides out from the lower limit straight groove and slides into the upper limit straight groove through the inclined groove, which will drive the cylindrical cam to rotate 90° synchronously.

[0014] As a further solution of the present invention: the vertical displacement distance of the cam pin sliding from the lower limit straight groove to the upper limit straight groove is less than the sum of the hole depths of the upper limit hole and the positioning hole.

[0015] As a further solution of the present invention: the vertical displacement distance of the cam pin sliding from the lower limit straight groove to the upper limit straight groove is greater than the spacing distance between the top end of the lower limit column and the lower limit hole.

[0016] As a further solution of the present invention, the bottom of the upper hub and the top of the lower hub are rotationally engaged via a thrust bearing.

[0017] As a further solution of the present invention: the outer wall of the rotating sleeve is rotatably installed in the lower hub through a deep groove ball bearing, and a round nut is provided on the bottom of the outer side of the rotating sleeve.

[0018] The beneficial effects of the present invention are as follows: by arranging a cylindrical cam and a lifting assembly, in the initial state, the two groups of blades on the upper hub and the lower hub are parallel and overlapped with each other. At this time, the upper limit column is passed through the upper limit hole of the upper hub and the positioning hole of the lower hub. The upper hub and the lower hub are relatively constrained and fixed, so that the two groups of blades can always maintain a parallel and overlapping state without circumferential rotation and displacement. When the aircraft is in level flight, the blades follow the direction of level flight, which can greatly reduce the air resistance of the aircraft during level flight on the runway. When the linear servo pushes the lower limit plate upward, the push rod will drive the cam pin to move linearly. Utilizing the sliding cooperation between the cam pin and the cam groove, the cam pin will drive the cylindrical cam and the upper propeller hub to rotate when moving, until it rotates 90° so that the two sets of blades cross and are vertical. At this time, the upper limit post is out of the positioning hole but is still inserted into the upper limit hole. At the same time, the lower limit post is inserted into the lower limit hole. The upper propeller hub and the lower propeller hub remain relatively stable, so that the two sets of blades can always maintain a cross-vertical state, thereby improving the lift effect and balance stability of the aircraft during vertical takeoff. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 It is a schematic diagram of the internal structure of the present invention.

[0022] Figure 3 It is a cross-sectional schematic diagram of the upper hub and the lower hub in the present invention.

[0023] Figure 4 It is a schematic diagram of the internal structure of the upper hub and the lower hub in the present invention.

[0024] Figure 5 It is a structural diagram of the switching component in the present invention.

[0025] Figure 6 It is a structural schematic diagram of the lifting assembly in the present invention.

[0026] Figure 7 It is a structural schematic diagram of the cylindrical cam in the overlapping state of the present invention.

[0027] Figure 8 It is a structural schematic diagram of the cylindrical cam in the open and closed states of the present invention.

[0028] Figure 9 It is a structural schematic diagram of the blades in the present invention when they are in an open and closed state.

[0029] In the figure: 1. Base; 2. Drive motor; 3. Upper propeller hub; 301. Upper limit hole; 302. Stop hole; 303. Thrust bearing; 4. Lower propeller hub; 401. Positioning hole; 402. Lower limit hole; 403. Deep groove ball bearing; 404. Round nut; 5. Blade; 6. Turntable; 7. Switching assembly; 710. Rotating sleeve; 720. Cylindrical cam; 721. Lower limit straight groove; 722. Inclined slide groove; 723. Upper limit straight groove; 730. Fixing gasket; 8. Lifting assembly; 810. Lower limit plate; 811. Lower limit column; 812. Mounting sleeve; 820. Push rod; 821. Cam pin; 830. Upper limit plate; 831. Upper limit column; 832. Locking bolt; 9. Linear servo; 901. Servo seat. DETAILED DESCRIPTION

[0030] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] See also Figure 1 、 Figure 2 、 Figure 3 and Figure 5 As shown, the present invention is an opening and closing propeller mechanism for a vertical take-off and landing aircraft, comprising a base 1, an upper propeller hub 3 and a lower propeller hub 4 are provided at the upper end of the base 1, both ends of the upper propeller hub 3 and the lower propeller hub 4 are fixedly connected with propeller blades 5, the bottom end of the lower propeller hub 4 is fixedly connected with a turntable 6, the turntable 6 rotates with the base 1, a driving motor 2 is fixedly provided at the bottom of the base 1, a switching assembly 7 is provided inside the upper propeller hub 3 and the lower propeller hub 4, the switching assembly 7 includes a rotating sleeve 710, the top end of the rotating sleeve 710 is fixedly connected to the inner wall of the upper propeller hub 3, the bottom end of the rotating sleeve 710 rotates with the inner wall of the lower propeller hub 4, a cylindrical cam 720 is coaxially provided inside the rotating sleeve 710, and the top end of the cylindrical cam 720 is fixedly connected to the rotating sleeve 710 through a fixing gasket 730.

[0032] Specifically, since the rotating sleeve 710 is fixedly connected to the upper hub 3 and rotates with the lower hub 4, when the cylindrical cam 720 rotates, it will drive the rotating sleeve 710 to rotate synchronously, thereby causing the upper hub 3 to rotate relative to the lower hub 4, and thus being able to adjust the angle between the two groups of blades 5.

[0033] like Figure 3-Figure 6As shown, a lifting assembly 8 is provided in the cylindrical cam 720, and the lifting assembly 8 includes a lower limit plate 810, a push rod 820 and an upper limit plate 830. The push rod 820 slides coaxially through the top of the cylindrical cam 720, and the upper and lower ends of the push rod 820 are fixedly connected to the lower limit plate 810 and the upper limit plate 830 respectively. Lower limit columns 811 are fixedly provided on the top of both ends of the lower limit plate 810, and upper limit columns 831 are fixedly provided on the bottom of both ends of the upper limit plate 830. An upper limit hole 301 corresponding to the upper limit column 831 is provided through the bottom of the upper hub 3, and a lower limit hole 402 corresponding to the lower limit column 811 is provided through the bottom of the lower hub 4.

[0034] like Figure 2-Figure 7 As shown, a cam groove is set through the outer wall of the cylindrical cam 720, and the cam groove includes a lower limit straight groove 721, an inclined slide groove 722 and an upper limit straight groove 723. The two ends of the inclined slide groove 722 are smoothly connected to the lower limit straight groove 721 and the upper limit straight groove 723 respectively. A cam pin shaft 821 is fixedly connected to the outer wall of the push rod 820, and the cam pin shaft 821 is adapted to be slidably installed in the cam groove.

[0035] Among them, a linear servo 9 is provided below the lower limit plate 810 , and the linear servo 9 is fixedly mounted on the servo seat 901 . The output end of the linear servo 9 is fixedly connected to the lower limit plate 810 , and the output end of the drive motor 2 is fixedly connected to the servo seat 901 .

[0036] Specifically, by setting the cylindrical cam 720 and the lifting assembly 8, in the initial state, the two groups of blades 5 of the upper hub 3 and the lower hub 4 are parallel and overlapped with each other. At this time, the upper limit column 831 is passed through the upper limit hole 301 of the upper hub 3 and the positioning hole 401 of the lower hub 4. The upper hub 3 and the lower hub 4 are relatively constrained and fixed, so that the two groups of blades 5 can always maintain a parallel and overlapping state without circumferential rotation and displacement. When the aircraft is in level flight, the blades 5 are directed in the direction of level flight, which can greatly reduce the air resistance of the aircraft during level flight on the runway. When the linear servo 9 pushes the lower limit plate 810 upward, the push rod 820 will drive the cam pin 821 to move linearly. By utilizing the sliding cooperation between the cam pin 821 and the cam groove, the cam pin 821 will drive the cylindrical cam 720 and the upper hub 3 to rotate when moving, until it rotates 90° so that the two groups of blades 5 cross and are vertical. At this time, the upper limit column 831 is out of the positioning hole 401 but is still inserted into the upper limit hole 301. At the same time, the lower limit column 811 is inserted into the lower limit hole 402. The upper hub 3 and the lower hub 4 remain relatively stable, so that the two groups of blades 5 can always maintain a cross-vertical state, thereby improving the lift effect and balance stability of the aircraft during vertical takeoff.

[0037] It should be noted that the opening and closing propeller structure in the present invention can be applied to aircraft in other fields, and is not limited to vertical take-off and landing aircraft.

[0038] like Figure 4-Figure 6 As shown, the upper limit plate 830 is arranged in the upper hub 3, and a locking bolt 832 is fixedly provided at the center of the upper end of the upper limit plate 830. The locking bolt 832 is connected to the top of the top rod 820, and a stop hole 302 facing the locking bolt 832 is provided at the top of the upper hub 3.

[0039] Specifically, when the linear servo 9 pushes the lower limit plate 810 to lift upward, the upper limit plate 830 will also move synchronously until the locking bolt 832 abuts against and enters the stop hole 302. At this time, the cam pin 821 will also move into the upper limit straight groove 723 at the top, thereby being able to stop and limit the lifting process of the upper limit plate 830 and the lower limit plate 810 to avoid lifting too high.

[0040] like Figure 4 and Figure 6 As shown, the edge of the upper end of the upper limit hole 301 extends upward to form a hole edge.

[0041] Specifically, the hole edge can effectively increase the depth of the upper limit hole 301 to prevent the upper limit post 831 from falling out of the upper limit hole 301 .

[0042] like Figure 4 and Figure 6 As shown, a positioning hole 401 is provided through the top of the lower hub 4 , and the positioning hole 401 is provided in a one-to-one correspondence with the upper limit hole 301 .

[0043] Specifically, the positioning hole 401 not only corresponds to the position of the upper limit hole 301, but also has a diameter consistent with the upper limit hole 301, so that the upper limit column 831 can penetrate the upper limit hole 301 and extend downward into the positioning hole 401 in the initial state.

[0044] like Figure 2-Figure 9 As shown, the cam pin 821 slides out from the lower limit straight groove 721 and slides into the upper limit straight groove 723 through the inclined groove 722, which will drive the cylindrical cam 720 to rotate 90 degrees synchronously.

[0045] Furthermore, the vertical displacement distance of the cam pin 821 sliding from the lower limit straight groove 721 to the upper limit straight groove 723 is less than the sum of the hole depths of the upper limit hole 301 and the positioning hole 401 .

[0046] Furthermore, the vertical displacement distance of the cam pin 821 sliding from the lower limit straight groove 721 to the upper limit straight groove 723 is greater than the spacing distance between the top end of the lower limit column 811 and the lower limit hole 402 .

[0047] Specifically, in the initial state, the two groups of blades 5 remain parallel and overlapped. At this time, the upper limit post 831 is simultaneously inserted into the upper limit hole 301 and the positioning hole 401, so that the upper hub 3 and the lower hub 4 remain relatively fixed. At the same time, the cam pin 821 is located in the lower limit straight groove 721. When the cam pin 821 slides upward from the lower limit straight groove 721, the upper limit post 831 will be disengaged from the positioning hole 401. When the cam pin 821 continues to move upward and slides along the inclined groove 722, it will drive the cylinder The cam 720 starts to rotate until the cam pin 821 is lifted to the upper limit straight groove 723. At this time, the cylindrical cam 720 rotates 90°. At the same time, the upper limit column 831 is still inserted into the upper limit hole 301, and the lower limit column 811 will be inserted into the lower limit hole 402 as the lifting process progresses. The restraining and limiting effect of the upper limit column 831 and the lower limit column 811 is utilized to keep the upper hub 3 and the lower hub 4 relatively fixed without rotational displacement, thereby allowing the two groups of blades 5 to maintain a cross-vertical state.

[0048] like Figure 2 and Figure 4 As shown, the bottom of the upper hub 3 and the top of the lower hub 4 are rotatably engaged via a thrust bearing 303 .

[0049] Specifically, the upper hub 3 and the lower hub 4 can rotate relative to each other via the thrust bearing 303 , which is beneficial to the smooth progress of the angle rotation adjustment process of the blade 5 .

[0050] like Figure 4 As shown, the outer wall of the rotating sleeve 710 is rotatably mounted in the lower hub 4 through a deep groove ball bearing 403 , and a round nut 404 is provided at the outer bottom of the rotating sleeve 710 .

[0051] Specifically, the deep groove ball bearing 403 effectively ensures the stability of the rotating sleeve 710 when rotating relative to the lower hub 4 , and the round nut 404 is used to axially fix the deep groove ball bearing 403 .

[0052] The working principle of the present invention is as follows: Figures 1-9As shown, in the initial state, the two groups of blades 5 of the upper hub 3 and the lower hub 4 are parallel and overlapped with each other. At this time, the upper limit column 831 is inserted into the upper limit hole 301 of the upper hub 3 and the positioning hole 401 of the lower hub 4. At the same time, the cam pin 821 is located in the lower limit straight groove 721. The upper hub 3 and the lower hub 4 are relatively constrained and fixed, so that the two groups of blades 5 can always maintain a parallel and overlapping state. The blades 5 generate torque when subjected to airflow without circumferential rotation displacement, thereby reducing the air resistance of the aircraft in level flight. When the linear servo 9 pushes the lower limit plate 810 upward, the push rod 820 will drive the cam pin 821 to move linearly. When the cam pin 821 slides upward from the lower limit straight groove 721, the upper limit column 831 will be released upward from the positioning hole 401. When the cam pin 821 continues to move upward and slides along the inclined groove 722, it will drive the cylindrical cam 720 to start rotating until the cam pin 821 is lifted into the upper limit straight groove 723. At this time, the cylindrical cam 7 20 rotates 90°, and at the same time, the upper limit post 831 is still inserted into the upper limit hole 301, and the lower limit post 811 will be inserted into the lower limit hole 402 during the lifting process. By utilizing the restraining and limiting effects of the upper limit post 831 and the lower limit post 811, the upper hub 3 and the lower hub 4 remain relatively fixed without rotational displacement, and the two groups of blades 5 can always maintain a cross-vertical state, thereby improving the lift effect and balance stability of the aircraft during vertical takeoff.

[0053] The above is a detailed description of an embodiment of the present invention. However, the content described is only a preferred embodiment of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A propeller opening and closing mechanism for a vertical take-off and landing aircraft, comprising a base (1), an upper propeller hub (3) and a lower propeller hub (4) being provided at the upper end of the base (1), and propeller blades (5) being fixedly connected to both ends of the upper propeller hub (3) and the lower propeller hub (4), characterized in that: A switching assembly (7) is provided inside the upper propeller hub (3) and the lower propeller hub (4), and the switching assembly (7) includes a rotating sleeve (710), the top end of the rotating sleeve (710) is fixedly connected to the inner wall of the upper propeller hub (3), and the bottom end of the rotating sleeve (710) is rotationally engaged with the inner wall of the lower propeller hub (4), and a cylindrical cam (720) is coaxially provided inside the rotating sleeve (710), and the top end of the cylindrical cam (720) is fixedly connected to the rotating sleeve (710) via a fixing gasket (730); A lifting assembly (8) is provided in the cylindrical cam (720), and the lifting assembly (8) includes a lower limit plate (810), a push rod (820) and an upper limit plate (830). The push rod (820) coaxially slides through the top of the cylindrical cam (720), and the upper and lower ends of the push rod (820) are fixedly connected to the lower limit plate (810) and the upper limit plate (830) respectively. The top of both ends of the lower limit plate (810) is fixedly provided with a lower limit column (811), and the bottom of both ends of the upper limit plate (830) is fixedly provided with an upper limit column (831). The bottom of the upper propeller hub (3) is penetrated by an upper limit hole (301) corresponding to the upper limit column (831), and the bottom of the lower propeller hub (4) is penetrated by a lower limit hole (402) corresponding to the lower limit column (811). The upper limit plate (830) is arranged in the upper hub (3), and a locking bolt (832) is fixedly provided at the center of the upper end of the upper limit plate (830), and the locking bolt (832) is connected to the top of the top rod (820), and a stop hole (302) facing the locking bolt (832) is provided at the top of the upper hub (3); The edge of the upper end of the upper positioning hole (301) is extended upward to form a hole edge, and the top of the lower hub (4) is penetrated by a positioning hole (401), and the positioning hole (401) is provided in a one-to-one correspondence with the upper positioning hole (301).

2. The propeller opening and closing mechanism for a vertical take-off and landing aircraft according to claim 1, characterized in that: The bottom end of the lower hub (4) is fixedly connected to a turntable (6), the turntable (6) is rotatably matched with the base (1), a driving motor (2) is fixedly provided at the bottom of the base (1), a linear servo (9) is provided below the lower limit plate (810), the linear servo (9) is fixedly mounted on the servo seat (901), an output end of the linear servo (9) is fixedly connected to the lower limit plate (810), and an output end of the driving motor (2) is fixedly connected to the servo seat (901).

3. The opening and closing propeller mechanism for a vertical take-off and landing aircraft according to claim 1, characterized in that: A cam groove is provided on the outer wall of the cylindrical cam (720), and the cam groove includes a lower limit straight groove (721), an inclined slide groove (722), and an upper limit straight groove (723). The two ends of the inclined slide groove (722) are smoothly connected to the lower limit straight groove (721) and the upper limit straight groove (723). A cam pin shaft (821) is fixedly connected to the outer wall of the push rod (820), and the cam pin shaft (821) is adapted to be slidably installed in the cam groove.

4. The opening and closing propeller mechanism for a vertical take-off and landing aircraft according to claim 3, characterized in that: The cam pin (821) slides out of the lower limit straight groove (721) and slides into the upper limit straight groove (723) via the inclined groove (722), thereby driving the cylindrical cam (720) to rotate synchronously by 90°.

5. The opening and closing propeller mechanism for a vertical take-off and landing aircraft according to claim 4, characterized in that: The vertical displacement distance of the cam pin (821) when sliding from the lower limit straight groove (721) to the upper limit straight groove (723) is less than the sum of the hole depths of the upper limit hole (301) and the positioning hole (401).

6. The opening and closing propeller mechanism for a vertical take-off and landing aircraft according to claim 5, characterized in that: The vertical displacement distance of the cam pin (821) sliding from the lower limit straight groove (721) to the upper limit straight groove (723) is greater than the spacing distance between the top end of the lower limit column (811) and the lower limit hole (402).

7. The opening and closing propeller mechanism for a vertical take-off and landing aircraft according to claim 1, characterized in that: The bottom of the upper propeller hub (3) and the top of the lower propeller hub (4) are rotationally engaged via a thrust bearing (303).

8. The opening and closing propeller mechanism for a vertical take-off and landing aircraft according to claim 1, characterized in that: The outer wall of the rotating sleeve (710) is rotatably mounted in the lower hub (4) via a deep groove ball bearing (403), and a round nut (404) is provided at the outer bottom of the rotating sleeve (710).

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