Opening and closing paddle for vertical take-off and landing aircraft

Abstract

The utility model discloses an opening and closing propeller for a vertical take-off and landing aircraft, which relates to the technical field of aircraft propelling devices and comprises a four-blade rotor wing, a main driving device, a central transmission shaft and an adjusting disc. The main driving device is mounted in the aircraft stay bar, the central transmission shaft is mounted above the main driving device, and the four-blade rotor is mounted at the top of the central transmission shaft; the four-blade rotor wing is divided into a fixed paddle and a movable paddle, the fixed paddle is arranged above the movable paddle, the fixed paddle is fixedly connected with the main driving device through a central transmission shaft, and the movable paddle is in sliding connection with the central transmission shaft; an adjusting disc is installed between the lower end of the movable paddle and the main driving device, a crossed roller bearing is installed on the adjusting disc, the upper portion of an inner ring of the crossed roller bearing is connected with the lower portion of the movable paddle, and a pair of matched conical positioning rings are arranged on the lower portion of the inner ring and the upper portion of the aircraft supporting rod; a linear steering engine is installed on an aircraft supporting rod and connected with an adjusting disc through a steering engine push rod to drive the adjusting disc to move up and down. The aircraft can achieve the effects of reducing flight resistance and improving the flight performance of the aircraft.

Description

Technical Field

[0001] The utility model relates to the technical field of aircraft propulsion devices, in particular to an opening and closing propeller for vertical take-off and landing aircraft. Background Art

[0002] A vertical take-off and landing aircraft is able to take off and land vertically, and uses propellers to provide power and lift. For a vertical take-off and landing aircraft with a composite configuration, it includes a lift propeller and a thrust propeller, wherein the lift propeller provides vertical upward lift and the thrust propeller provides propulsion in the direction of flight. In the cruising state, the wings of the aircraft are sufficient to provide lift to meet flight requirements, and the lift propellers do not need to work. However, the lift propellers need to remain consistent with the direction of the struts, otherwise the lift propellers will increase the windward area of ​​the aircraft and increase flight resistance. In order to reduce the windward area of ​​the rotor, the traditional lift rotor is designed as a two-blade rotor, which can enable it to reach a feathered state, consistent with the direction of the struts.

[0003] However, the pulling force provided by the rotor is related to the number of rotor blades. A two-blade propeller has only two blades and provides limited lift. In order to provide sufficient lift for the aircraft to take off, multiple lift rotors are required to provide sufficient lift. The increase in the number of lift rotors leads to an increase in the number of supporting motors, wiring harnesses and related structures, which will increase the weight of the aircraft and reduce flight performance. Based on this, the utility model proposes an opening and closing propeller for a vertical take-off and landing aircraft. Utility Model Content

[0004] The main purpose of the utility model is to provide an opening and closing propeller for a vertical take-off and landing aircraft, which can effectively solve the problems in the background technology.

[0005] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0006] A retractable propeller for a vertical take-off and landing aircraft, comprising: a four-blade rotor (11), a main drive device (12), a central transmission shaft (13) and an adjustment plate (14); the main drive device (12) is installed inside an aircraft strut (1), the central transmission shaft (13) is installed above the main drive device (12), and the four-blade rotor (11) is installed on the top of the central transmission shaft (13);

[0007] The four-blade rotor (11) is divided into two groups, each group is a separate two-blade rotor, and is divided into a fixed propeller (111) and a moving propeller (112) according to the connection method with the main drive device (12), the fixed propeller (111) is above the moving propeller (112), the fixed propeller (111) and the main drive device (12) are fixedly connected via a central transmission shaft (13), and the moving propeller (112) and the central transmission shaft (13) are slidably connected;

[0008] An adjustment plate (14) is installed between the lower end of the moving propeller (112) and the main drive device (12), the adjustment plate (14) comprising a cross roller bearing (142), the upper portion of the inner ring of the cross roller bearing (142) being connected to the lower portion of the propeller hub of the moving propeller (112), and a pair of matching conical positioning rings being arranged at the lower portion of the inner ring of the cross roller bearing (142) and the upper portion of the aircraft strut (1);

[0009] A linear servo (15) is installed on the aircraft strut, and the linear servo (15) is connected to the adjustment plate (14) via a servo push rod (151) to drive the adjustment plate (14) to move up and down.

[0010] The above-mentioned opening and closing propeller for a vertical take-off and landing aircraft, wherein a linear bearing (131) is arranged on the outer surface of a central transmission shaft (13), and the central transmission shaft (13) is connected to a moving propeller (112) via the linear bearing (131), so that the moving propeller (112) can move up and down relative to the central transmission shaft (13), and the main driving device (12) rotates to drive the central transmission shaft (13) to rotate, thereby driving the rotor of the moving propeller (112) to rotate.

[0011] A retractable propeller for a vertical take-off and landing aircraft as described above, wherein the fixed propeller (111) comprises a two-blade fixed propeller rotor (1111) and a fixed propeller hub (1112), the fixed propeller hub (1112) having a closed upper end and a fixed lower end connected to a linear bearing (131) of a central transmission shaft (13) below via a flange at the bottom.

[0012] A retractable propeller for a vertical take-off and landing aircraft as described above, wherein the moving propeller (112) comprises a two-blade moving propeller rotor (1121) and a moving propeller hub (1122), the moving propeller hub (1122) being a hollow structure, and the central transmission shaft (13) passing through the hollow structure of the moving propeller hub (1122), thereby achieving a rotatable sleeve connection between the moving propeller (112) and the central transmission shaft (13).

[0013] In the above-mentioned opening and closing propeller for a vertical take-off and landing aircraft, a spiral slide groove (1123) is provided on the inner ring surface of the moving propeller hub (1122) and cooperates with the slide shaft of the central transmission shaft (13) so that the slide shaft can rotate along the spiral slide groove (1123).

[0014] In the above-mentioned opening and closing propeller for a vertical take-off and landing aircraft, vertical slide grooves (1124) are respectively arranged at the upper and lower ends of the spiral slide groove (1123) for the slide shaft to be embedded therein, so that when the fixed propeller (111) rotates, the central transmission shaft (12) can drive the moving propeller (112) to rotate.

[0015] In the above-mentioned opening and closing propeller for a vertical take-off and landing aircraft, the vertical slide groove length at the upper end of the spiral slide groove (1123) is greater than the vertical slide groove length at the lower end.

[0016] The above-mentioned opening and closing propeller for a vertical take-off and landing aircraft, wherein an adjustment plate (14) is connected to the lower end of a moving propeller hub (1122), the adjustment plate (14) comprising a mounting plate (141), a cross roller bearing (142) and a conical positioning ring (143), the inner part of the outer ring of the mounting plate (141) is connected to the outer ring of the cross roller bearing (142), and the outer part is connected to the end of a steering gear push rod (151), and the linear steering gear (15) adjusts the height of the mounting plate (141) by adjusting the length of the steering gear push rod (151).

[0017] In the above-mentioned opening and closing propeller for a vertical take-off and landing aircraft, the upper part of the inner ring of the cross roller bearing (142) is connected to the lower end of the moving propeller hub (1122), and the up and down movement of the adjustment plate (14) can drive the moving propeller hub (1122) to move up and down.

[0018] A foldable propeller for a vertical take-off and landing aircraft as described above, wherein the lower portion of the inner ring of the cross roller bearing (142) is connected to the conical positioning ring 1 (143), a conical positioning ring 2 (144) matching the conical positioning ring 1 (143) is arranged on the conical surface of the upper portion of the aircraft strut (1), and a roller (145) is arranged on the top of the conical positioning ring 2 (144) on the strut for auxiliary positioning.

[0019] Compared with the prior art, the utility model has the following beneficial effects: the utility model designs an opening and closing propeller for vertical take-off and landing aircraft, thereby realizing the use of a four-blade rotor to provide lift in a hovering state, reducing the number of rotor components, and in a horizontal cruising state, adjusting the four-blade lift rotor to a feathering state to minimize its frontal area, thereby reducing flight resistance and improving the flight performance of the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is the state diagram of the four-blade rotor opening for hovering flight;

[0021] Figure 2 This is the four-blade rotor feathering lock state diagram for horizontal cruise;

[0022] Figure 3 This is a diagram of the rotor and strut feathering state;

[0023] Figure 4 It is a schematic diagram of the relative positions of the fixed propeller, the central transmission shaft and the motor;

[0024] Figure 5 This is a schematic diagram of the positions of the fixed propeller, the moving propeller, the central transmission shaft and the adjustment plate;

[0025] Figure 6 It is a cross-sectional view of the interior of the chute;

[0026] Figure 7It is a partial schematic diagram of the adjustment disk;

[0027] Figure 8 It is a partial schematic diagram of the conical positioning ring of the adjusting disk and the conical positioning ring of the support rod;

[0028] Fig. 9 It is a partial schematic diagram of the support rod cone positioning ring with rollers;

[0029] Fig.10 It is a schematic diagram of the rotor rotation state;

[0030] Fig.11 It is a cross-sectional view of the rotating state;

[0031] Fig.12 It is a partial view of the conical positioning surface in the rotating state;

[0032] Fig.13 It is a schematic diagram of the intermediate process state of feathering;

[0033] Fig.14 It is a top view of the feathering state;

[0034] Fig.15 It is a side view of the feathering state;

[0035] Fig.16 This is the front view of the feathering state;

[0036] Fig.17 This is an internal cross-sectional view of the feathering state;

[0037] Fig.18 It is a partial view of the conical positioning surface in the feathering state;

[0038] Fig.19 This is a schematic diagram of the process status of the propeller ending.

[0039] In the figure: 1. strut; 2. left and right wings; 3. horizontal tail wing;

[0040] 11. Four-blade rotor; 12. Main drive device; 13. Central transmission shaft; 14. Adjustment plate; 15. Linear servo;

[0041] 111, fixed propeller; 1111, two-blade fixed propeller rotor; 1112, fixed propeller hub; 112, moving propeller; 1121, two-blade moving propeller rotor; 1122, moving propeller hub; 1123, spiral chute; 1124, vertical chute;

[0042] 131. Linear bearings;

[0043] 141. mounting plate; 142. cross roller bearing; 143. conical positioning ring 1; 144 conical positioning ring 2; 145 roller;

[0044] 151.Servo push rod. DETAILED DESCRIPTION

[0045] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further described below in conjunction with specific implementation methods.

[0046] Figure 1 This is a diagram of the rotor opening state of a vertical take-off and landing aircraft hovering. Figure 2 This is a diagram of the locked state of the four-blade rotor 11 of the vertical take-off and landing aircraft in horizontal cruising. As shown in the figure, the left and right struts 1 are integrated at the front end of the wing box section of the aircraft, the middle part is connected to the left and right wings 2 through a tilt axis, and the tail is connected to the horizontal tail wing 3 through a tilt axis. The left and right wings 2 and the horizontal tail wing 3 use fixed-angle five-blade rotors, which rotate through the tilt axis to achieve the hovering or cruising of the aircraft; the rotors on the left and right struts 1 are four-blade rotors with opening and closing propellers. Figure 1 As shown, in the hovering condition, the four-blade rotor of the aircraft is adjusted to the open state, and the aircraft is provided with lift through rotation. In the hovering takeoff state, the four-blade propeller is used to increase the lift of a single rotor component, thereby reducing the total number of lift rotors and the total weight of the rotor system, thus improving the flight performance of the aircraft. Figure 2 As shown, under the cruising condition, the four-blade propeller of the aircraft is adjusted to a feathered closed state. In the cruising state, the four-blade rotor is feathered and locked to reduce the frontal area in the cruising state and reduce the flight resistance.

[0047] The utility model designs the opening and closing oars on the left and right support rods. Figure 3 As shown, a retractable propeller for a vertical take-off and landing aircraft comprises a four-blade rotor 11, a main drive device 12, a central transmission shaft 13 and an adjustment plate 14; the main drive device 12 is installed inside the aircraft strut 1, the central transmission shaft 13 is installed above the main drive device 12, and the four-blade rotor 11 is installed on the top of the central transmission shaft 13; the four-blade rotor 11 is divided into two groups, each group is a separate two-blade rotor, and is divided into a fixed propeller 111 and a moving propeller 112 according to the connection method with the main drive device 12, the fixed propeller 111 is above the moving propeller 112, and the fixed propeller 111 and the main drive device 12 are fixedly connected through the central transmission shaft 13; the moving propeller 112 is located between the fixed propeller 111 and the main drive device 12, and the moving propeller 112 is slidably connected to the central transmission shaft 13; an adjusting disk 14 is installed between the lower part of the hub of the moving propeller 112 and the main drive device 12, and the adjusting disk 14 includes a cross roller bearing 142, and the upper part of the inner ring of the cross roller bearing 142 is connected to the lower part of the hub of the moving propeller 112, and can withstand the force along the axial direction; a pair of matching conical positioning rings are provided on the lower part of the inner ring of the cross roller bearing 142 and the upper part of the aircraft strut 1; a linear servo 15 is installed on the aircraft strut, which is connected to the outer ring of the bearing through a servo push rod 151, and drives the adjusting disk 14 to move up and down.

[0048] like Figure 4 As shown, the main drive device 12 can be a main drive motor or other power drive source, such as an engine, etc., to provide power for the rotation of the entire rotor. The main drive device 12 is located inside the strut 1 of the vertical take-off and landing aircraft. The output shaft of the main drive device 12 is connected to the central transmission shaft 13 upward. The central transmission shaft 13 extends to the outside of the strut 1. The outer surface of the central transmission shaft 13 is provided with a linear bearing 131. The central transmission shaft 13 is connected to the moving propeller 112 through the linear bearing 131, so that the moving propeller 112 can move up and down relative to the central transmission shaft 13. The rotation of the main drive device 12 drives the central transmission shaft 13 to rotate, thereby driving the moving propeller 112 rotor to rotate.

[0049] Alternatively, the linear bearing may be replaced by a sleeve, and the central transmission shaft is connected to the moving propeller via the sleeve. The linear bearing or the sleeve may be installed on the central transmission shaft or on the moving propeller.

[0050] Specifically, the fixed propeller 111 includes a two-blade fixed propeller rotor 1111 and a fixed propeller hub 1112. The fixed propeller hub 1112 is closed at the upper end, and the lower end is fixedly connected to the linear bearing 131 of the central transmission shaft 13 below through a flange at the bottom.

[0051] like Figure 5 As shown, a moving propeller 112 is installed between the fixed propeller 111 and the adjustment disk 14. The moving propeller 112 includes a two-blade moving propeller rotor 1121 and a moving propeller hub 1122. The moving propeller hub 1122 is a hollow structure, and the central transmission shaft 13 passes through the hollow structure of the moving propeller hub 1122 to achieve a rotatable socket connection between the moving propeller 112 and the central transmission shaft 13.

[0052] like Figure 6 As shown, the inner ring surface of the moving propeller hub 1122 is provided with a spiral groove 1123, which cooperates with the sliding shaft of the central transmission shaft 13 so that the sliding shaft can rotate along the groove. Preferably, the spiral groove 1123 is in a spiral form, 90° along the axial direction, so that the moving propeller 112 can rotate 90° relative to the central transmission shaft 13 when rotating. Vertical grooves 1124 are provided at the upper and lower ends of the spiral groove 1123 for embedding the sliding shaft therein, so that the central transmission shaft 13 can drive the moving propeller 112 to rotate when the fixed propeller 111 rotates.

[0053] Specifically, when the moving paddle 112 is driven to move up and down relative to the central transmission shaft 13 along the linear bearing 131, due to the limitation of the spiral slide 1123, the moving paddle 112 can only move along the spiral slide 1123, and the middle of the spiral slide 1123 is a spiral shape, so that when the moving paddle 112 moves to the middle spiral slide 1123, it can only move along the spiral track, realizing the up and down movement while rotating, so as to adjust the angle with the fixed paddle 111. When the moving paddle 112 rises to the highest point, the upper part of the moving paddle hub 1122 will support the central transmission shaft 13, so that the lift generated by the rotation of the moving paddle 112 is transmitted to the central transmission shaft 13, and at the end of the spiral slide 1123, the sliding shaft will enter the vertical slide 1124.

[0054] Preferably, because the moving paddle will continue to move downward when it reaches the paddle-following state, the vertical chute length at the upper end of the spiral chute is set to be longer than the vertical chute length at the lower end, so that the moving paddle has sufficient distance to rotate along the conical surface when moving downward.

[0055] like Figure 7 As shown, the lower end of the propeller hub 1122 is connected to the adjustment plate 14, and the adjustment plate 14 includes a mounting plate 141, a cross roller bearing 142 and a conical positioning ring 143. The inner part of the outer ring of the mounting plate 141 is connected to the outer ring of the cross roller bearing 142, and the outer part is connected to the end of the servo push rod of the linear servo 15. The linear servo 15 adjusts the height of the mounting plate 141 by adjusting the length of the servo push rod. The upper part of the inner ring of the cross roller bearing 142 is connected to the lower end of the propeller hub 1122. The up and down movement of the adjustment plate 14 can drive the propeller hub 1122 to move up and down. Figure 8 , 9 As shown, the lower part of the inner ring of the cross roller bearing 142 is connected to the conical positioning ring 143, and a conical positioning ring 144 matching the conical positioning ring 143 on the conical surface of the adjustment plate 14 is arranged on the conical surface of the upper part of the aircraft strut 1, and a roller 145 is arranged on the top of the conical positioning ring 144 on the strut for auxiliary positioning.

[0056] The utility model realizes the 90° state of the moving blade 112 and the fixed blade 111 and the principle of the rotor and the strut as follows:

[0057] The first process: In the ground state before the aircraft takes off, the four-blade rotor 11 is in the propeller-following state. At this time, the fixed blade 111, the moving blade 112 and the prop are kept in the same straight line direction, and the conical surface of the lower part of the adjustment plate 14 and the conical surface of the upper end of the prop are matched. When the aircraft is ready to rise, the linear servo 15 on the prop raises the adjustment plate 14, so that the conical surface of the adjustment plate 14 is separated from the conical surface on the prop. The linear servo 15 further raises the adjustment plate 14, and due to the effect of the spiral chute, the moving blade 112 rotates relative to the fixed blade 111 and reaches the end of the chute. The angle between the moving blade 112 and the fixed blade 111 is 90°, and the upper end of the moving blade hub 1122 supports the lower end of the fixed blade hub 1112. The main drive device 12 rotates, driving the fixed blade 111 to rotate, and the fixed blade 111 drives the moving blade 112 to rotate through the sliding shaft and the guide groove. The four-blade rotor 11 generates lift, so that the aircraft takes off.

[0058] Second process: After the aircraft takes off, it is ready to enter the cruise state, the main motor stops, and the four-blade rotor 11 stops. The linear servo 15 lowers the height of the adjustment disk 14. Due to the effect of the spiral chute 1123, the moving propeller 112 rotates in the opposite direction relative to the fixed propeller 111. The moving propeller 112 and the fixed propeller 111 are adjusted to the same angle. The linear servo 15 further lowers the height of the adjustment disk 14. The conical surface on the adjustment disk 14 begins to contact the conical surface on the strut 1. Due to the effect of the conical surface, the inner ring of the bearing of the adjustment disk 14 begins to rotate, thereby driving the moving propeller 112 to rotate. Due to the restrictions of the chute and the sliding shaft, the moving propeller 112 drives the fixed propeller 111 to rotate. When the conical surface is fully matched, the moving propeller 112 and the fixed propeller 111 reach a position consistent with the strut direction, realizing the feathering state, and the projection area in the flight direction is the smallest.

[0059] After the aircraft cruise state ends, the first process is repeated, the four-blade rotor 11 rotates, and the aircraft lands. After the aircraft lands, the second process is repeated, and the aircraft re-enters the feathering state.

[0060] like Figure 10-12 As shown, when the moving propeller 112 and the fixed propeller 111 are at 90 degrees, the moving propeller hub 1122 is at the highest position, the linear servo 15 servo push rod has the longest stroke, and the upper end of the moving propeller hub 1122 contacts the lower end of the fixed propeller 111 to transmit lift. The sliding shaft of the central transmission shaft 13 is located at the lower end of the sliding groove of the moving propeller 112. When the motor rotates, the fixed propeller 111 is driven to rotate through the mounting flange of the central transmission shaft 13, and the moving propeller 112 is driven to rotate through the sliding shaft and the sliding groove.

[0061] like Fig.13As shown, when it is necessary to adjust the moving propeller 112 to a state where the angle is consistent with the fixed propeller 111, the linear servo 15 shortens the servo push rod stroke, drives the adjustment plate 14 and the moving propeller hub 1122 to move downward, and due to the action of the linear bearing 131, the spiral slide groove 1123 and the slide shaft, the moving propeller 112 rotates during the downward movement, and at the end of the spiral part of the slide groove, the angles of the moving propeller 112 and the fixed propeller 111 are consistent.

[0062] like Figure 14-19 As shown, the linear servo 15 continues to shorten the stroke of the servo push rod 151, driving the adjustment disk 14 and the propeller hub 1122 to move downward. The sliding shaft enters the vertical slide groove 1124. At this time, the propeller 112 and the central transmission shaft 13 cannot rotate relative to each other, and the propeller 112 can only move up and down relative to the central transmission shaft 13. During the downward movement of the propeller hub 1122, the conical positioning ring 143 on the inner side of the adjustment disk 14 contacts the conical positioning ring 143 on the strut 1. Due to the downward force, the conical positioning ring 143 on the adjustment disk 14 begins to rotate relative to the conical positioning ring 143 of the strut until the two conical positioning rings 143 fit together. During the rotation process, the rotation of the conical positioning ring 143 drives the inner ring of the cross roller bearing 142 to rotate, and at the same time drives the propeller hub 1122 to rotate. However, the moving paddle 112 and the central transmission shaft 13 cannot rotate relative to each other due to the sliding groove, so the moving paddle 112 also drives the central transmission shaft 13 to rotate, so that the up and down movement and rotation of the conical positioning ring 143 on the adjustment plate 14 drive the position adjustment of the moving paddle 112, the fixed paddle 111 and the central transmission shaft 13. When the conical positioning ring 143 cooperates, the moving paddle 112 and the fixed paddle 111 reach the position of being aligned with the strut 1. At this time, as long as the linear servo 15 maintains the current position and the height of the adjustment plate 14 does not rise, the moving paddle 112 and the fixed paddle 111 can maintain the state of being aligned with the strut 1.

[0063] When it is necessary to adjust the moving blade 112 to a 90° state with the fixed blade 111 again, the linear servo 15 extends the stroke of the servo push rod 151, drives the adjustment plate 14 and the moving blade hub 1122 to make the sliding shaft disengage from the vertical slide groove 1124 and enter the spiral slide groove 1123, and the moving blade hub 1122 moves along the spiral slide groove 1123 toward the fixed blade 111 until it enters the upper vertical slide groove 1124. Due to the action of the linear bearing 131, the spiral slide groove 1123 and the sliding shaft, the moving blade 112 rotates during the upward movement, and after reaching the top of the spiral part of the slide groove, the slide groove enters the upper vertical slide groove, at which time the angle between the moving blade 112 and the fixed blade 111 is 90°, and the moving blade hub 1122 is at the highest position.

[0064] The above shows and describes the basic principle and main features of the utility model and the advantages of the utility model. Those skilled in the art should understand that the utility model is not limited by the above embodiments. The above embodiments and descriptions are only for explaining the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model may have various changes and improvements, which fall within the scope of the utility model to be protected. The scope of protection claimed by the utility model is defined by the attached claims and their equivalents.

Claims

1. A retractable propeller for a vertical take-off and landing aircraft, characterized in that: include: A four-blade rotor (11), a main drive device (12), a central transmission shaft (13) and an adjustment plate (14); the main drive device (12) is installed inside the aircraft strut (1), the central transmission shaft (13) is installed above the main drive device (12), and the four-blade rotor (11) is installed on the top of the central transmission shaft (13); The four-blade rotor (11) is divided into two groups, each group is a separate two-blade rotor, and is divided into a fixed propeller (111) and a moving propeller (112) according to the connection method with the main drive device (12), the fixed propeller (111) is above the moving propeller (112), the fixed propeller (111) and the main drive device (12) are fixedly connected via a central transmission shaft (13), and the moving propeller (112) and the central transmission shaft (13) are slidably connected; An adjustment plate (14) is installed between the lower end of the moving propeller (112) and the main drive device (12), the adjustment plate (14) comprising a cross roller bearing (142), the upper portion of the inner ring of the cross roller bearing (142) being connected to the lower portion of the moving propeller (112), and a pair of matching conical positioning rings being arranged at the lower portion of the inner ring of the cross roller bearing (142) and the upper portion of the aircraft strut (1); A linear servo (15) is installed on the aircraft strut, and the linear servo (15) is connected to the adjustment plate (14) via a servo push rod (151) to drive the adjustment plate (14) to move up and down.

2. The retractable propeller for a vertical take-off and landing aircraft according to claim 1, characterized in that: A linear bearing (131) is disposed on the outer surface of the central transmission shaft (13), and the central transmission shaft (13) is connected to the moving propeller (112) via the linear bearing (131), so that the moving propeller (112) can move up and down relative to the central transmission shaft (13), and the main driving device (12) rotates to drive the central transmission shaft (13) to rotate, thereby driving the rotor of the fixed propeller (111) to rotate.

3. The retractable propeller for a vertical take-off and landing aircraft according to claim 2, characterized in that: The fixed-propeller (111) comprises a two-blade fixed-propeller rotor (1111) and a fixed-propeller hub (1112); the fixed-propeller hub (1112) has a closed upper end and a fixed lower end connected to a linear bearing (131) of a central transmission shaft (13) below via a flange at the bottom.

4. The retractable propeller for a vertical take-off and landing aircraft according to claim 1, characterized in that: The propeller (112) comprises a two-blade propeller rotor (1121) and a propeller hub (1122); the propeller hub (1122) is a hollow structure, and the central transmission shaft (13) passes through the hollow structure of the propeller hub (1122), thereby achieving a rotatable sleeve connection between the propeller (112) and the central transmission shaft (13).

5. The retractable propeller for a vertical take-off and landing aircraft according to claim 4, characterized in that: The inner ring surface of the moving propeller hub (1122) is provided with a spiral slide groove (1123) which cooperates with the slide shaft of the central transmission shaft (13) so that the slide shaft can rotate along the spiral slide groove (1123).

6. The retractable propeller for a vertical take-off and landing aircraft according to claim 5, characterized in that: The upper and lower ends of the spiral slide groove (1123) are respectively provided with vertical slide grooves (1124) for allowing the slide shaft to be embedded therein, so that when the fixed propeller (111) rotates, the central transmission shaft (13) can drive the movable propeller (112) to rotate.

7. The retractable propeller for a vertical take-off and landing aircraft according to claim 6, characterized in that: The vertical chute length at the upper end of the spiral chute (1123) is set to be greater than the vertical chute length at the lower end.

8. The retractable propeller for a vertical take-off and landing aircraft according to claim 4, characterized in that: An adjustment plate (14) is connected to the lower end of the propeller hub (1122). The adjustment plate (14) comprises a mounting plate (141), a cross roller bearing (142) and a conical positioning ring (143). The inner part of the outer ring of the mounting plate (141) is connected to the outer ring of the cross roller bearing (142), and the outer part is connected to the end of a steering gear push rod (151). The linear steering gear (15) adjusts the height of the mounting plate (141) by adjusting the length of the steering gear push rod (151).

9. The retractable propeller for a vertical take-off and landing aircraft according to claim 8, characterized in that: The upper part of the inner ring of the cross roller bearing (142) is connected to the lower end of the propeller hub (1122), and the upward and downward movement of the adjustment plate (14) can drive the propeller hub (1122) to move upward and downward.

10. The retractable propeller for a vertical take-off and landing aircraft according to claim 9, characterized in that: The lower portion of the inner ring of the cross roller bearing (142) is connected to the first conical positioning ring (143), and a second conical positioning ring (144) matching the first conical positioning ring (143) is arranged on the conical surface of the upper portion of the aircraft strut (1), and a roller (145) is arranged on the top of the second conical positioning ring (144) on the strut for auxiliary positioning.

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