KR20220134832A - Aircraft with hollow type coaxial rotor structure - Google Patents

Abstract

The present invention provides a flying vehicle having a hollow coaxial inverted structure which has a simple structure, and also, has a clearance on which various devices and units can be mounted. The flying vehicle having the hollow coaxial inverted structure can facilitate a design change according to a purpose and satisfy excellent flight performance. To achieve the purpose of the present invention, the flying vehicle having the hollow coaxial inverted structure includes: a body unit; a main shaft having a hollow structure and forming a vertical axis by being connected to the body unit; a first rotor unit connected to the main shaft, and having a first rotor driving unit and a first rotor; a second rotor unit connected to the main shaft, and having a second rotor driving unit and a second rotor; and a gap control unit for controlling a gap between the first rotor unit and the second rotor unit on the vertical axis. The first rotor driving unit generates torque in a first direction around the vertical axis. The first rotor rotates in the first direction by the torque generated in the first rotor driving unit. The second rotor driving unit generates the torque in a second direction opposite to the first direction around the vertical axis. The second rotor rotates in the second direction by the torque generated in the second rotor driving unit.

Description

Aircraft with hollow coaxial inversion structure {AIRCRAFT WITH HOLLOW TYPE COAXIAL ROTOR STRUCTURE}

The present invention relates to an air vehicle having a coaxial reversal structure, and in detail, it can have excellent flight performance while simplifying the structure, is free to design changes according to the purpose of use, and has a hollow coaxial reversal structure with excellent compatibility. will be.

An aircraft having a coaxial inversion structure is an aircraft having two rotors inverted on one main axis, and in an aircraft having a coaxial inversion structure, the forward force (reaction force due to rotation) generated by one rotor is the other rotor. Since it disappears while rotating in the opposite direction, even if there is no tail rotor, there is an advantage of preventing the fluidity of the aircraft and changing the posture of the aircraft quickly and easily. It can be raised, so it has the advantage of improving the loading capacity and maneuverability. In addition, the aircraft of the coaxial reversal structure does not require a tail rotor, so the aircraft can be miniaturized, and has the advantage of large lift compared to the power used and excellent maneuverability and safety.

However, the coaxial reversal structure has a disadvantage in that the structure is complicated because two rotors rotating in opposite directions on one main axis must be provided, compared to a single rotor vehicle, and thus it is difficult to secure a free space.

In particular, since the aircraft of the coaxial reversal structure must be provided with not only two rotors on one main axis, but also two driving units that generate the rotational force required for each rotor, space utilization for installing various units in the area around the main axis is difficult. Very limited.

In addition, the rotor of the rotorcraft basically requires a pitch adjustment unit including a swash plate for adjusting the pitch of the blades and a link assembly for changing the inclination of the swash plate, such a pitch adjustment unit is also relatively small. There was a lot of difficulty in maintenance as there was not enough space for installation to be applied to an aircraft of that size, so design changes were not free, and even when maintenance was required during use, effective maintenance was difficult.

Therefore, there is a need for a new coaxial inversion structure that can have a simple structure while having a free space in which various devices and units can be mounted, and can easily change the design according to the purpose of use and satisfy excellent flight performance.

Republic of Korea Patent Publication No. 0675345 (2007.01.30.Announcement)

An object of the present invention for solving the above problems is a hollow coaxial inversion that can provide a mounting space for various devices and units while having a simple structure, and can easily change the design according to the purpose of use and satisfy excellent flight performance It is to provide a rescue vehicle.

An aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention for solving the above-described problems, the body portion; a main shaft having a hollow structure and coupled to the body to form a vertical axis; It is coupled to the main shaft and has a first rotor driving part for generating a rotational force in a first direction about the vertical axis, and a first rotor rotating in the first direction by the rotational force generated from the first rotor driving part. a first rotor unit; a second rotor driving part coupled to the main shaft and generating a rotational force in a second direction opposite to the first direction about the vertical axis; and a rotational force generated in the second rotor driving part in the second direction a second rotor unit having a second rotating rotor; And it characterized in that it comprises a gap adjusting unit for adjusting the distance between the first rotor unit and the second rotor unit with respect to the vertical axis.

In the vehicle having a hollow coaxial inversion structure according to an embodiment of the present invention, at least one of the first rotor unit and the second rotor unit may be movably coupled to the main shaft in the vertical axis direction, In this case, the spacing adjusting unit includes a first frame coupled to the first rotor unit, a second frame coupled to the second rotor unit and disposed to face the first frame, the first frame and the second frame Connecting the two frames, the first frame and the second frame may include a spacing adjusting member to close or spaced apart.

In the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention, the spacing adjusting member is formed to extend from the first frame to the second frame, and a first rack gear is formed on one side of the first frame. A rack member, a second rack member extending from the second frame in the direction of the first frame and having a second rack gear formed on one side thereof, and the second rack member to connect the first rack member and the second rack member A pinion gear geared simultaneously with the first rack gear and the second rack gear is formed, and may include a rotating member that is rotated by a driving force transmitted from the outside.

In the vehicle having a hollow coaxial inversion structure according to an embodiment of the present invention, the first rotor is rotatably coupled to the main shaft, and a first hub directly connected to the first rotor driving unit, and the first A first grip portion coupled to one side of the outer circumferential surface of the hub and rotatably coupled with respect to a first pitch axis crossing the vertical axis, a first blade coupled to the first grip portion, and the other side of the outer circumferential surface of the first hub However, it may include a second grip portion rotatably coupled with respect to a second pitch axis crossing the vertical axis, and a second blade coupled to the second grip portion.

In the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention, the first grip portion and the second grip portion are respectively connected to the first grip portion and rotate the first grip portion from the first hub about the first pitch axis. or by rotating the second grip part from the first hub about the second pitch axis to adjust the pitch of the first blade and the second blade may further include a pitch adjusting part.

In the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention, the pitch adjusting unit is rotatably coupled to the main shaft about the vertical axis, and the height is adjusted while moving in the vertical axis direction, or the A swash plate whose inclination angle is adjusted while being tilted about a vertical axis, a first link part connecting one side of the rotating part of the swash plate and the first grip part, the other side of the rotating part of the swash plate and the second grip part a second link unit connecting It may include a link assembly.

In the air vehicle having a hollow coaxial inversion structure according to an embodiment of the present invention, the link assembly includes a first link assembly, a second link assembly and a third link assembly that are spaced apart along the circumferential direction of the swash plate. may be included, and in this case, the interval between the first link assembly, the second link assembly and the third link assembly may be adjusted.

In the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention, the non-rotating portion of the swash plate may be provided with a plurality of fastening holes disposed at preset intervals along the circumferential direction, in this case, the The link assembly includes a first connection link having one end hinged to the pitch control driving unit, one end being hinged to the first connection link, and the other end being hinged to one fastening hole selected from among the plurality of fastening holes. 2 may include a connection link.

In the vehicle having a hollow coaxial inversion structure according to an embodiment of the present invention, the body portion includes a lower frame for rotatably supporting a lower end of the main shaft, and an upper frame for rotatably supporting an upper end of the main shaft. And, it may include a module unit mount detachably coupled to the lower frame or the upper frame.

In the vehicle having a hollow coaxial inversion structure according to an embodiment of the present invention, cables for power, communication and control may be wired inside the hollow of the main shaft, in which case the main shaft passes through the cable It may have one or more wiring holes for the purpose.

In the vehicle having a hollow coaxial inversion structure according to an embodiment of the present invention, the second rotor is disposed through the main shaft, and includes an extension shaft that is rotated by the rotational force generated by the second rotor driving unit You may.

In the vehicle having a hollow coaxial inversion structure according to an embodiment of the present invention, the second rotor is coupled to an end of the extension shaft passing through the main shaft, and a second hub that rotates in conjunction with the extension shaft and a third grip part coupled to one side of the outer circumferential surface of the second hub and rotatably coupled with respect to a third pitch axis intersecting the vertical axis, a third blade coupled to the third grip part, and the second hub It may further include a fourth grip portion coupled to the other side of the outer circumferential surface of the second grip portion rotatably coupled to a fourth pitch axis intersecting the vertical axis, and a fourth blade coupled to the fourth grip portion.

In the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention, the third grip part and the fourth grip part are respectively connected to the third grip part, and the third grip part rotates from the second hub about the third pitch axis. or by rotating the fourth grip part from the second hub about the fourth pitch axis to adjust the pitch of the third blade and the fourth blade may further include a pitch adjusting part.

According to the present invention, while the structure can be simplified through the hollow main shaft, it is possible to secure a free space in which various devices and units can be mounted through the gap adjusting unit.

According to the present invention, excellent flight performance can be ensured while designing is easy to change according to the purpose of use of the aircraft through the interval adjusting unit and the pitch adjusting unit.

1 is a side view of an aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention.
Figure 2 is a partial enlarged view of Figure 1 for explaining the rotor unit of the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention.
FIG. 3 is a view showing the interval adjusting unit of FIG. 2 .
Figure 4 is a partial enlarged view of Figure 1 for explaining the pitch control unit of the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention.
5 is a plan view of the swash plate of FIG. 4 .
6 is an exemplary view for explaining the collective pitch operation by the pitch adjusting unit of the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention.
7 is an exemplary view for explaining the cyclic pitch operation by the pitch adjusting unit of the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention.
8 is a side view of an aircraft having a hollow coaxial inversion structure according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention in which the above-described problems to be solved can be specifically realized will be described with reference to the accompanying drawings. In describing the present embodiments, the same names and reference numerals may be used for the same components, and an additional description thereof may be omitted.

1 is a side view of an aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention, and FIG. 2 is a rotor unit of an aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention. It is a partial enlarged view of FIG. 1 for

1 and 2, an aircraft having a hollow coaxial inversion structure according to the present invention includes a body portion 100, a main shaft 200, a first rotor unit 300 and a second rotor unit 400. may include

The body portion 100 may form the outer shape of the vehicle, and a series of devices and units for driving and controlling the vehicle may be installed and supported.

The body portion 100 may be provided in a cylindrical shape, of course, may be provided in a polygonal shape.

The body part 100 may include a lower frame 110 and an upper frame 120 .

The lower frame 110 may rotatably support the lower end of the main shaft 200 .

The upper frame 120 may rotatably support the upper end of the main shaft 200 .

In addition, the body 100 may further include module unit mounts 131 and 132 .

The module unit mounts 131 and 132 may be detachably coupled to the lower frame 110 , or may be detachably coupled to the upper frame 120 .

Various module units such as a battery, a camera, a sensor unit, a communication unit, and a control unit may be coupled to the module unit mounts 131 and 132 .

Basically, the aircraft may be provided with various module units according to the purpose of use, and each module unit is pre-coupled to the module unit mounts 131 and 132 and according to the purpose of use, the lower frame 110 or the upper frame 120. can be selectively coupled to. For example, the lower module unit mount 131 on which the battery B is mounted may be coupled to the lower frame 110 , and the upper module unit mount 132 equipped with the GPS and communication unit may be coupled to the upper frame 120 . have.

In addition, the body portion 100 may further include a cover frame.

The cover frame can protect a series of devices and units installed inside while forming the outer shape of the aircraft.

The cover frame may include a first cover frame 140 and a second cover frame 150 .

The first cover frame 140 may be coupled to the upper edge of the lower frame 110 , and may protect a series of devices and units disposed between the lower frame 110 and the first rotor 320 .

The second cover frame 150 may be disposed between the first rotor 320 and the second rotor 420 , and may be provided to connect the first rotor driving unit 310 and the second rotor driving unit 410 . .

At this time, in consideration of the case where the interval D between the first rotor driving unit 310 and the second rotor driving unit 410 is changed by the interval adjusting unit 500 to be described later, the second cover frame according to the present embodiment 150 can be changed in height.

For example, the second cover frame 150 may include a second lower cover frame and a second upper cover frame, wherein the second lower cover frame is coupled to the upper portion of the first rotor driving unit 310, and the second The upper cover frame is coupled to the lower portion of the second rotor driving unit 410, and the second lower cover frame and the second upper cover frame may have a structure slidable in the vertical direction. As another example, the second cover frame may be provided with a stretchable member such as a bellows.

The main shaft 200 may have a hollow structure, and may be coupled to the body portion 100 to form a vertical axis (C).

The main shaft 200 may be fixedly supported on the body portion 100 , the lower end may be supported on the lower frame 110 , and the upper end may be supported on the upper frame 120 .

Cables for power, communication, and control of units constituting the aircraft may be routed inside the hollow of the main shaft 200 .

In this case, the main shaft 200 may have one or more wiring holes for communicating the cables wired therein to the outside.

On such a main shaft 200, a first rotor driving unit 310, a first rotor 320, a second rotor driving unit 410, a second rotor 420, a spacing adjusting unit 500 and a pitch adjusting unit (to be described later) ( 600) may be installed.

The aircraft of the coaxial reversal structure according to this embodiment has a plurality of rotor units, that is, a first rotor 320 and a second rotor 420 in a state having a first rotor 320 and a second rotor 420 to each other. The default is to rotate in the opposite direction. That is, since the first rotor 320 and the second rotor 420 rotate in opposite directions to each other, the fluidity of the body part 100 can be stabilized without a tail rotor, and lift and thrust can be further increased.

The first rotor unit 300 may include a first rotor driving unit 310 and a first rotor 320 .

The first rotor driving unit 310 may be coupled to the main shaft 200 and may generate a rotational force in the first direction about the vertical axis C.

A brushless DC motor having a hollow shaft may be used as the first rotor driving unit 310 , and in this case, the main shaft 200 may pass through the hollow shaft of the brushless motor. Accordingly, the first rotor driving unit 310 may be moved in the vertical axis (C) direction on the main shaft 200, and the first rotor driving unit 310 may be moved in the vertical axis (C) direction as necessary and the height is to be adjusted. can

In addition, the first hub 321 of the first rotor 320 to be described later by the first rotor driving unit 310 may be directly connected to the first rotor driving unit 310 . As such, when the first rotor 320 is rotated by receiving the rotational force directly from the first rotor driving unit 310, friction is reduced compared to the case in which the first rotor receives the rotational force through a power transmission unit such as a gear, thereby reducing efficiency and operating performance. This can be improved. In addition, it is possible not only to reduce the manufacturing cost, but also to reduce noise and thrust loss, and to reduce the overall volume of the vehicle.

1, 2 and 4 , the first rotor 320 may be rotatably coupled to the main shaft 200 , and in the first direction by the rotational force generated by the first rotor driving unit 310 . can rotate

The first rotor 320 may be disposed under the first rotor driving unit 310 .

The first rotor 320 may include a first hub 321 , a first grip portion 322 , a first blade 323 , a second grip portion 324 , and a second blade 325 .

The first hub 321 may be rotatably coupled to the main shaft 200 , and may be directly connected to the first rotor driving unit 310 .

The first hub 321 directly connected to the first rotor driving unit 310 may be moved along the main shaft 200 in the vertical axis C direction together with the first rotor driving unit 310 .

The first grip part 322 is for coupling the first blade 323 to the first hub 321 , and one end may be coupled to one side of the outer circumferential surface of the first hub 321 . The first grip part 322 may be coupled to the first hub 321 to be rotatable about the first pitch axis PC1 crossing the vertical axis C.

The first grip portion 322 may have a first pin 322a. The first pin 322a may be disposed on one side eccentric from the first pitch axis PC1 . The first pin 322a may be coupled to a first link part 620 of a pitch adjusting part 600 to be described later.

The first blade 323 may be coupled to the first grip portion 322 , and the first blade 323 rotates about the vertical axis C in conjunction with the first hub 321 and the first grip portion 322 . can do.

The first pitch axis PC1 is an axis extending along the longitudinal direction of the first blade 323 , and the pitch of the first blade 323 may be adjusted while rotating about the first pitch axis PC1 .

The second grip part 324 is for coupling the second blade 325 to the first hub 321 , and one end may be coupled to the other side of the outer peripheral surface of the first hub 321 . The second grip part 324 may be coupled to the first hub 321 to be rotatable about the second pitch axis PC2 crossing the vertical axis C.

The second grip portion 324 may have a second pin 324a. The second pin 324a may be disposed on one side eccentric from the second pitch axis PC2 . The second pin 324a may be coupled to a second link part 630 of a pitch adjusting part 600 to be described later.

The second blade 325 may be coupled to the second grip portion 324 , and the second blade 325 rotates about the vertical axis C in conjunction with the first hub 321 and the second grip portion 324 . can do.

The second pitch axis PC2 is an axis extending along the longitudinal direction of the second blade 325 , and the pitch of the second blade 325 may be adjusted while rotating about the second pitch axis PC2 .

Although the embodiment describes the first rotor 320 having a pair of blades, of course, the first rotor 320 may have a plurality of blades such as four.

The second rotor unit 400 may include a second rotor driving unit 410 and a second rotor 420 .

The second rotor driving unit 410 may be coupled to the main shaft 200 and may generate a rotational force in the first direction about the vertical axis C.

The second rotor driving unit 410 may be disposed to be spaced apart from the first rotor driving unit 310 upward by a preset interval D on the main shaft 200 .

A brushless DC motor having a hollow shaft may be used as the second rotor driving unit 410 , and in this case, the main shaft 200 may pass through the hollow shaft of the brushless motor. Accordingly, the second rotor driving unit 410 may be moved in the vertical axis (C) direction on the main shaft 200, and the second rotor driving unit 410 may be moved in the vertical axis (C) direction as necessary, and the height may be adjusted. can

The second rotor 420 may be rotatably coupled to the main shaft 200 or the body portion 100 , and may rotate in the second direction by the rotational force generated by the second rotor driving unit 410 .

The second direction may be opposite to the first direction. That is, when the first direction is a clockwise direction, the second direction may be a counterclockwise direction.

1 and 2 , the second rotor 420 may be disposed above the second rotor driving unit 410 .

The second rotor 420 may include a second hub 421 , a third grip portion 422 , a third blade 423 , a fourth grip portion 424 , and a fourth blade 425 .

The second hub 421 may be rotatably coupled to the main shaft 200 or the body 100 , and may be directly connected to the second rotor driving unit 410 .

The second hub 421 directly connected to the second rotor driving unit 410 may be moved along the main shaft 200 in the vertical axis C direction together with the second rotor driving unit 410 .

The third grip part 422 is for coupling the third blade 423 to the second hub 421 , and one end may be coupled to one side of the outer circumferential surface of the second hub 421 . The third grip part 422 may be coupled to the second hub 421 to be rotatable about the third pitch axis PC3 crossing the vertical axis C.

The third blade 423 may be coupled to the third grip portion 422 , and the third blade 423 rotates about the vertical axis C in conjunction with the second hub 421 and the third grip portion 422 . can do.

The third pitch axis PC3 is an axis extending along the longitudinal direction of the third blade 423 , and the pitch of the third blade 423 may be adjusted while rotating about the third pitch axis PC3 .

The fourth grip part 424 is for coupling the fourth blade 425 to the second hub 421 , and one end may be coupled to the other side of the outer peripheral surface of the second hub 421 . The fourth grip part 424 may be coupled to the second hub 421 to be rotatable about the fourth pitch axis PC4 crossing the vertical axis C.

The fourth blade 425 may be coupled to the fourth grip portion 424 , and the fourth blade 425 rotates about the vertical axis C in conjunction with the second hub 421 and the fourth grip portion 424 . can do.

The fourth pitch axis PC4 is an axis extending along the longitudinal direction of the fourth blade 425 , and the pitch of the fourth blade 425 may be adjusted while rotating about the fourth pitch axis PC4 .

Although the embodiment describes the second rotor 420 having a pair of blades, of course, the second rotor 420 may have a plurality of blades such as four.

On the other hand, the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention may further include a spacing adjusting unit (500).

The interval adjusting unit 500 may adjust the interval D between the first rotor 320 and the second rotor 420 with respect to the vertical axis C. That is, the gap between the first blade 323 and the second blade 325 of the first rotor 320 and the third blade 423 and the fourth blade 425 of the second rotor 420 (D) can be adjusted.

FIG. 3 is a view showing the interval adjusting unit of FIG. 2 .

Referring to FIG. 3 , the spacing adjusting unit 500 according to the present embodiment may include a first frame 210 , a second frame 220 , and a spacing adjusting member 230 .

The first frame 210 may be coupled to the upper portion of the first rotor driving unit 310 .

The second frame 220 may be coupled to a lower portion of the second rotor driving unit 410 .

Accordingly, the first frame 210 and the second frame 220 may be disposed to face each other while being spaced apart in the vertical direction.

The spacing adjusting member 230 may connect the first frame 210 and the second frame 220 , and may make the first frame 210 and the second frame 220 close or spaced apart.

The spacing adjusting member 230 according to the embodiment may include a first rack member 231 , a second rack member 232 , and a rotation member 233 .

The first rack member 231 may be coupled to the first frame 210 and formed to extend in the direction of the second frame 220 , and the first rack gear 231a may be formed on one side in the vertical direction in the longitudinal direction. have.

The second rack member 232 may be coupled to the second frame 220 to extend in the direction of the first frame 210 , and may have a second rack gear 232a on one side facing the first rack gear 231a. may be formed in the vertical direction, which is the longitudinal direction.

The rotating member 233 is a gear member connecting the first rack member 231 and the second rack member 232 , and is simultaneously gear-coupled to the first rack gear 231a and the second rack gear 232a on the outer surface. A pinion gear 233a may be formed.

On the other hand, the gap adjusting member 230 may further include a guide member 234 for guiding the position and movement of the first rack member 231, the second rack member 232, and the rotating member 233.

The operation of the spacing adjusting unit 500 will be described as follows.

When the rotating member 233 is rotated counterclockwise by a driving force transmitted from the outside, the first rack member 231 is moved in the lower direction, and the second rack member 232 is moved in the upper direction, so that the first The frame 210 and the second frame 220 may be spaced apart from each other. Due to this, as the first rotor driving unit 310 coupled to the first frame 210 and the second rotor driving unit 410 coupled to the second frame 220 are spaced apart from each other, the first rotor 320 and the second The distance D between the rotors 420 may be increased.

And, when the rotating member 233 is rotated clockwise by the driving force transmitted from the outside, the first rack member 231 is moved in the upper direction, and the second rack member 232 is moved in the lower direction, The first frame 210 and the second frame 220 may be close to each other. Due to this, as the first rotor driving unit 310 coupled to the first frame 210 and the second rotor driving unit 410 coupled to the second frame 220 come closer to each other, the first rotor 320 and the second The distance D between the rotors 420 may be reduced.

Basically, as the distance D between the first rotor 320 and the second rotor 420 increases, the thrust of the first rotor 320 located at the lower side decreases, while the second rotor located at the upper side ( 420) can be increased.

In this way, the interval D between the first rotor 320 and the second rotor 420 may be set to various intervals according to the specifications and types of the aircraft used. As a result, since the interval D between the first rotor 320 and the second rotor 420 can be freely adjusted and set through the interval adjusting unit 500, various flight performance can be implemented according to the purpose of use of the vehicle. have.

In addition, in the space provided between the first rotor unit 300 and the second rotor unit 400 through the spacing adjusting unit 500, devices and units required for the aircraft may be additionally mounted.

Figure 4 is a partial enlarged view of Figure 1 for explaining the pitch control unit of the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention, Figure 5 is a plan view of the swash plate of Figure 4 .

4 and 5, further referring to, the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention may further include a pitch adjusting unit (600).

The pitch adjustment unit 600 is to adjust the pitch of the blade in order to change the lift and thrust for flight control of the aircraft.

Pitch refers to the angle of twist with respect to the rotation path plane of the blade.

According to the present embodiment, the pitch of the first rotor 320 may be changed, and the pitch of the second rotor 420 may not be changed. That is, the pitches of the first blade 323 and the second blade 325 may be adjusted, and the pitches of the third blade 423 and the fourth blade 425 may not be adjusted.

Specifically, the pitch adjusting unit 600 according to the present embodiment may be respectively connected to the first grip portion 322 and the second grip portion 324, and the first hub 321 about the first pitch axis PC1. The first grip part 322 may be rotated from the , or the second grip part 324 may be rotated from the first hub 321 about the second pitch axis PC2 . Accordingly, the pitch of the first blade 323 and the second blade 325 may be adjusted.

The pitch adjusting unit 600 according to this embodiment may be disposed under the first rotor 320 , the swash plate 610 , the first link unit 620 , the second link unit 630 , It may include a pitch control driver 630 and a link assembly 640 .

The swash plate 610 may be rotatably coupled to the main shaft 200 about the vertical axis C, and the height is adjusted while moving in the vertical axis C direction, or tilted around the vertical axis C. The inclination angle α can be adjusted.

The swash plate 610 may include a rotating part 611 and a non-rotating part 615 .

The rotating part 611 is a part rotating from the main shaft 200 about the vertical axis C, and may include a spherical joint 612 and a rotating plate 613 .

The spherical joint 612 may have a hollow shaft on the inside, and the main shaft 200 may pass through the hollow shaft. Accordingly, the spherical joint 612 may be moved in the vertical axis C direction on the main shaft 200 . In addition, the spherical joint 612 may be provided with a first spherical coupling portion on the outer peripheral surface.

The rotating plate 613 may be coupled to the spherical joint 612 , and a second spherical coupling part which is coupled in close contact with the first spherical coupling part may be provided inside. Accordingly, the rotation plate 613 is inclined with respect to the spherical joint 612 and the inclination angle α with respect to the vertical axis C can be adjusted.

The non-rotating part 615 may be coupled to the rotating plate 613 , and may be moved in association with the rotating plate 613 . The non-rotating part 615 may be provided in a ring shape surrounding the rotating plate 613 , and the ring-shaped non-rotating part 615 may be connected to the rotating plate 613 via a connecting rod 616 .

The non-rotating part 615 may be provided with a plurality of fastening holes 615a arranged at preset intervals along the circumferential direction. A second connection link 642 of a link assembly 640 to be described later may be coupled to the fastening hole 615a.

The first link unit 620 may connect one side of the rotating unit 611 and the first grip unit 322 , and the first link unit 620 includes an outer peripheral side of the rotating unit 611 and the first grip unit 322 . 1 pin 322a may be connected. Accordingly, the rotating part 611 of the swash plate 610 connected to the first grip part 322 through the first link part 620 may be rotated about the vertical axis C in conjunction with the first grip part 322 . .

The second link unit 630 may connect the other side of the rotating unit 611 and the second grip unit 324 , and the second link unit 630 includes the second side of the outer peripheral surface of the rotating unit 611 and the second grip unit 324 . 2 pins 324a may be connected. Therefore, the rotating part 611 of the swash plate 610 connected to the second grip part 324 through the second link part 630 may be rotated about the vertical axis C in conjunction with the second grip part 324. .

The pitch adjustment driving unit 630 may generate a driving force for adjusting the height or inclination angle of the swash plate 610 with respect to the vertical axis (C).

A plurality of pitch adjustment driving units 630 may be provided, and may be provided in a quantity corresponding to the quantity of the link assembly 640 to be described later. That is, each pitch adjustment driving unit 630 may independently operate the plurality of link assemblies 640 .

A servo motor may be used as the pitch adjustment driving unit 630 .

A plurality of link assemblies 640 may be provided, and each link assembly 640 may independently connect the pitch control driving unit 630 and the non-rotating unit 615 .

The link assembly 640 according to this embodiment may include a first link assembly, a second link assembly, and a third link assembly.

The first link assembly may include a first connection link 641 and a second connection link 642 .

One end of the first connection link 641 may be hinge-coupled to the pitch control driving unit 630 , and the other end may be hinge-coupled to the second connection link 642 .

The second connection link 642 may be formed to extend in the vertical direction, one end may be hinged to the first connection link 641 , and the other end may be connected to the non-rotating part 615 of the swash plate 610 . can be hinged. In this case, the second connection link 642 may be selectively hinged to one of the plurality of fastening holes 615a formed in the non-rotating part 615 .

The first link assembly 640A may be rotated at the other end around one end of the first connecting link 641 according to the operation of the pitch adjusting driving unit 630, and thus the second connecting link 642 is a vertical axis. It can be moved up and down in parallel with (C). As a result, the swash plate 610 coupled to the second connection link 642 is inclined about the vertical axis C as one side of the outer circumferential surface moves in the vertical direction so that the inclination angle α can be adjusted.

The second link assembly and the third link assembly may be configured in the same manner as the above-described first link assembly, and a redundant description thereof will be omitted.

However, referring to Figure 5 (a), the first link assembly (640A), the second link assembly (640B) and the third link assembly (640C) according to the present invention in advance along the circumferential direction of the swash plate (610) It may be arranged to have a set separation distance, in which case the separation distance may be adjusted.

That is, the first link assembly 640A, the second link assembly 640B, and the third link assembly 640C are selectively provided in the plurality of fastening holes 615a formed in the non-rotating part 615 of the swash plate 610. By being coupled, it is possible to adjust and set the separation distance of the first link assembly (640A), the second link assembly (640B) and the third link assembly (640C).

In this way, according to the separation distance of the first link assembly 640A, the second link assembly 640B and the third link assembly 640C disposed along the circumferential direction of the swash plate 610, the flight performance sensitivity of the vehicle can be adjusted

For example, as shown in FIG. 5 , the second link assembly 640B and the third link assembly 640C from the first link assembly 640A may be spaced apart from each other at intervals of 90 degrees, and in this case, the second link The assembly 640B and the second link assembly 640C may be spaced apart at intervals of 180 degrees.

That is, when the separation distance between the first link assembly 640A and the second link assembly 640B and the third link assembly 640C is relatively narrow, the first link assembly 640A and the second link assembly Even a relatively small operation of the 640B and the third link assembly 640C can form a large inclination angle α of the swash plate 610, thus increasing the flight performance sensitivity of the vehicle.

Here, the vertical axis C, which is the central axis of the swash plate 610, and the straight line connecting the connection part of the swash plate 610 and the first link assembly 640A may coincide with the front and rear flight direction of the aircraft, In this case, it is possible to increase the sensitivity of the forward and backward flight performance of the vehicle.

Although not shown, as another example, the first link assembly 640A, the second link assembly 640B and the third link assembly 640C may be equally spaced apart at intervals of 120 degrees, respectively, and as another example, the first The second link assembly 640B and the third link assembly 640C from the link assembly 640A may be disposed spaced apart from each other at intervals of 145 degrees.

In this case, since the separation distance between the first link assembly 640A, the second link assembly 640B, and the third link assembly 640C is relatively long compared to the above-described embodiment, the swash plate 610 is In order to form the same inclination angle α, relatively large operations of the first link assembly 640A, the second link assembly 640B, and the third link assembly 640C may be required. Accordingly, the sensitivity of the flight performance of the vehicle may be lowered as compared with the above-described embodiment. However, due to the first link assembly 640A, the second link assembly 640B, and the third link assembly 640C maintaining a relatively wide interval, the swash plate 610 with the adjusted inclination angle α is relatively stable. There are advantages to being supported.

Hereinafter, the operation of the pitch adjusting unit 600 according to the present invention will be described.

6 is an exemplary view for explaining the collective pitch operation by the pitch adjusting unit of the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention.

For convenience of explanation in the process of explaining the action of the pitch adjusting unit 600, the link assembly 640 is made of a first link assembly 640A and a second link assembly 640B arranged at intervals of 180 degrees, and this Correspondingly, a case in which the pitch adjustment driving unit 630 includes the first pitch adjustment driving unit 630A and the second pitch adjusting driving unit 630B will be described as an example.

First, basically, lift, weight, thrust, and drag act on an aircraft. Lift supports the weight, and if the thrust overwhelms the drag, the aircraft can fly in the required direction. have.

If, in a windless condition, when a stationary flight of the vehicle is required, the rotation path plane of the blade may be in a state parallel to the horizontal plane. In this stationary flight, lift and thrust, drag and weight act in the same direction, and the sum of lift and thrust is equal to the sum of weight and drag.

In such a stationary flight, if the sum of lift and thrust is greater than the sum of drag and weight by increasing thrust, the aircraft can achieve ascending flight. The vehicle can implement descending flight.

Referring to FIG. 6, when the ascending flight of the aircraft is required, the first link assembly 640A and the second link assembly 640B by the first pitch adjustment driving unit 630A and the second pitch adjustment driving unit 630B are It can be raised to the same height. Then, the swash plate 610 may be raised while maintaining a horizontal state, and together with this, the first link unit 620 and the second link unit 630 may be raised to the same height.

Then, the first grip portion 322 coupled to the first link portion 620 with the first pin 322a is rotated about the first pitch axis PC1 to change the pitch angle of the first blade 323 . thrust can be increased. And the second grip portion 324 coupled to the second link portion 630 with the second pin 324a rotates about the second pitch axis PC2 to change the pitch angle of the second blade 325 to generate thrust. can increase In this case, the first blade 323 and the second blade 325 may have the same pitch angle. (See Fig. 4)

In this way, when the thrust is increased by changing the pitch angles of the first blade 323 and the second blade 325, the flying vehicle can be implemented to ascend.

Conversely, when the descending flight of the aircraft is required, the first link assembly 640A and the second link assembly 640B are descended to the same height by the first pitch adjustment driving unit 630A and the second pitch adjustment driving unit 630B. can be Then, the swash plate 610 may be lowered while maintaining a horizontal state, and together with this, the first link unit 620 and the second link unit 630 may be lowered to the same height.

Then, the first grip portion 322 coupled to the first link portion 620 by the first pin 322a is rotated counterclockwise about the first pitch axis PC1 to change the pitch angle of the first blade 323 . This can reduce thrust. And the second grip portion 324 coupled to the second link portion 630 with the second pin 324a is rotated counterclockwise about the second pitch axis PC2 to change the pitch angle of the second blade 325 . thrust can be reduced. In this case, the first blade 323 and the second blade 325 may have the same pitch angle. (See Fig. 4)

In this way, when the thrust is reduced by changing the pitch angles of the first blade 323 and the second blade 325, descending flight of the aircraft can be implemented.

Of course, the aircraft according to the present embodiment may implement ascending flight by increasing the rotational speed of the first rotor 320 or the second rotor 420 to increase thrust, and the first rotor 320 or the second rotor 420 ) to reduce the thrust by lowering the rotational speed to realize descending flight.

On the other hand, if the pitch angle of the first blade 323 and the second blade 325 is changed in the stationary flight state, ascending or descending flight of the vehicle can be implemented as described above. In this case, the aircraft of the coaxial inversion structure Since there is no tail rotor, when only one thrust of the first rotor 320 and the second rotor 420 is changed, due to the torque difference acting on the first rotor 320 and the second rotor 420, The vehicle may be rotated about the vertical axis (C). That is, the yaw flight of the vehicle may be implemented.

7 is an exemplary view for explaining the cyclic pitch operation by the pitch adjusting unit of the aircraft having a hollow coaxial inversion structure according to an embodiment of the present invention.

Referring to FIG. 7 , when horizontal flight of the vehicle is required, the first link assembly 640A may be descended by the first pitch adjustment driving unit 630A, and the second by the second pitch adjustment driving unit 630B. The link assembly 640B may be raised. Then, the swash plate 610 may be inclined to form an inclination angle (α: see FIG. 5), and with this, the first link unit 620 may be lowered and the second link unit 630 may be raised. .

Then, as the first grip portion 322 coupled to the first link portion 620 with the first pin 322a is rotated about the first pitch axis PC1, the pitch angle of the first blade 323 is changed. The pitch angle of the second blade 325 is changed as the second grip part 324 coupled to the second link part 630 by the second pin 324a is rotated about the second pitch axis PC2. can be In this case, the first blade 323 and the second blade 325 may have different pitch angles. (See Fig. 4)

That is, when the swash plate 610 maintains the inclination angle α, the pitch angle of the first blade 323 and the second blade 325 is continuously changed every time it rotates once about the vertical axis C. can be

As a result, as shown in (b) of FIG. 7 , when the first blade 323 or the second blade 325 passes through the left region in the drawing, a relatively small thrust may be generated. In addition, when the first blade 323 or the second blade 325 passes through the right region in the drawing, a relatively large thrust may be generated. Ultimately, the vehicle can implement horizontal flight in the direction of the arrow.

Of course, during horizontal flight of the vehicle, a dissymmetry of lift may occur. Lift imbalance is a phenomenon in which the lift generated on the rotation path plane of the blade is not uniform and unbalanced.

Supplementally, when the forward flight of the aircraft is required in the stationary flight state in which the blade rotates at a constant rotational speed, the swash plate 610 is tilted in the forward direction through the cyclic pitch adjustment as shown in FIG. can be implemented. At this time, assuming that the aircraft is flying forward at a speed of 100 km/h, the relative speed of 100 km/h increases in the area of the blade moving forward with respect to the relative wind, and the relative speed of 100 km/h decreases in the area of the blade that retreats to the relative wind. . As a result, the forward-flying vehicle may have lift imbalance in the left and right areas of the rotation path plane of the blade, which may cause a tilting phenomenon without being able to accurately fly forward in the direction required by the vehicle.

As a result, the inclination direction of the swash plate 610 during horizontal flight of the vehicle should be more precisely controlled in consideration of the lift imbalance, but in this embodiment, the understanding of the operation according to the cyclic pitch adjustment of the pitch adjustment unit 600 is provided. For this reason, it was explained without considering the lift imbalance.

Hereinafter, an aircraft having a hollow coaxial inversion structure according to another embodiment of the present invention will be described.

8 is a side view of an aircraft having a hollow coaxial inversion structure according to another embodiment of the present invention.

Referring to FIG. 8 , an aircraft having a hollow coaxial inversion structure according to another embodiment of the present invention also includes a body portion 100 , a main shaft 200 , a first rotor unit 300 , and a second rotor unit 400 . ) is included.

The aircraft according to the present embodiment may be configured in the same manner as the aircraft shown in FIG. 1 and most of the components. However, the vehicle according to this embodiment has a difference in the arrangement structure of components constituting the vehicle compared to the vehicle shown in FIG. 1 . The vehicle according to the present embodiment will be mainly described with respect to the differences from the above-described embodiment.

First, in the aircraft shown in FIG. 1 , the first rotor unit 300 is disposed on the lower side, the second rotor unit 400 is disposed on the upper side, and the first rotor unit 300 is based on the interval adjusting unit 500 . ) and the second rotor unit 400 face each other to form a symmetrical structure. However, in the aircraft shown in FIG. 8 , with the first rotor unit 300 interposed therebetween, the second rotor driving unit 410 is disposed on the lower side of the first rotor unit 300 , and the upper side of the first rotor unit 300 . There is a difference in that the second rotor 420 is disposed.

To this end, the second rotor 420 according to the present embodiment may further include an extension shaft 427 .

The extension shaft 427 may be disposed through the main shaft 200 . The extension shaft 427 may be rotated with respect to the main shaft 200 about the vertical axis C, and may be moved in the vertical axis C direction with respect to the main shaft 200 .

The extension shaft 427 may have a hollow structure, and may have a hollow structure like the main shaft 200 .

The second rotor driving unit 410 may be directly connected to the lower end of the extension shaft 427 passing through the main shaft 200 .

The second hub 421 of the second rotor 420 may be coupled to the upper end of the extension shaft 427 passing through the main shaft 200 .

Accordingly, the extension shaft 427 may be rotated by the rotational force generated by the second rotor driving unit 410 , and this rotational force may be transmitted to the second hub 421 of the second rotor 420 .

In addition, the aircraft according to this embodiment may also include a spacing adjusting unit 500 for adjusting the distance D between the first rotor unit 300 and the second rotor unit 400 with respect to the vertical axis C, and , The spacing adjusting unit 500 according to the present embodiment may be disposed between the first rotor driving unit 310 and the second rotor driving unit 410 .

By using the spacing adjusting unit 500 , the first rotor unit 300 is moved up and down on the main shaft 200 , or the second rotor unit 400 is moved up and down on the main shaft 200 . While doing so, the distance D between the first rotor unit 300 and the second rotor unit 400 may be adjusted and set.

In addition, in the vehicle shown in FIG. 1 , the pitch adjusting unit 600 is provided in the first rotor 320 , but in the aircraft shown in FIG. 8 , the pitch adjusting unit 600 is provided in the second rotor 420 . There is also a difference in point.

To this end, the second rotor 420 according to the present embodiment may be rotatably coupled to the body portion 100, the second hub 421, the third grip portion 422, the third blade 423, A fourth grip portion 424 and a fourth blade 425 may be further included.

The second hub 421 may be coupled to an end of the extension shaft 427 passing through the main shaft 200 and rotate in conjunction with the extension shaft 427 .

The third grip part 422 is for coupling the third blade 423 to the second hub 421 , and one end may be coupled to one side of the outer circumferential surface of the second hub 421 . The third grip part 422 may be coupled to the second hub 421 to be rotatable about the third pitch axis PC3 crossing the vertical axis C.

The third grip part 422 may have a third pin. The third pin may be disposed on one side eccentric from the third pitch axis PC3 . The third pin may be coupled to the first link unit 620 of the pitch adjusting unit 600 .

The third blade 423 may be coupled to the third grip portion 422 , and the third blade 423 rotates about the vertical axis C in conjunction with the second hub 421 and the third grip portion 422 . can do.

The fourth grip part 424 is for coupling the fourth blade 425 to the second hub 421 , and one end may be coupled to the other side of the outer peripheral surface of the second hub 421 . The fourth grip part 424 may be coupled to the second hub 421 to be rotatable about the fourth pitch axis PC4 crossing the vertical axis C.

The fourth grip portion 424 may have a fourth pin. The fourth pin may be disposed on one side eccentric from the fourth pitch axis PC4. The fourth pin may be coupled to the second link unit 630 of the pitch adjusting unit 600 .

The fourth blade 425 may be coupled to the fourth grip portion 424 , and the fourth blade 425 rotates about the vertical axis C in conjunction with the second hub 421 and the fourth grip portion 424 . can do.

In addition, in the pitch adjusting unit 600 according to the present embodiment, the pitch of the first rotor 320 does not change, and the pitch of the second rotor 420 may be changed, unlike the above-described embodiment. That is, the pitches of the first blade 323 and the second blade 325 may not be adjusted, and the pitches of the third blade 423 and the fourth blade 425 may be adjusted.

That is, the pitch adjusting unit 600 according to the present embodiment may be respectively connected to the third grip portion 422 and the fourth grip portion 424, and the third grip portion ( 422 may be rotated or the fourth grip portion 424 may be rotated from the second hub 421 about the fourth pitch axis PC4. Accordingly, the pitch of the third blade 423 and the fourth blade 425 may be adjusted.

The detailed configuration and operation of the pitch adjusting unit 600 according to the present embodiment will be omitted for the same reason as the pitch adjusting unit according to the above-described embodiment, and repeated descriptions will be omitted.

In addition, it has been described that the pitch adjusting unit 600 according to the above-described embodiment is provided in the first rotor 320 , and the pitch adjusting unit 600 according to another embodiment is provided in the second rotor 420 . Although described as that, of course, the pitch adjusting unit 600 may be provided together in the first rotor 320 and the second rotor 420 .

Although the preferred embodiment of the present invention has been described with reference to the drawings as described above, those skilled in the art may vary the present invention in various ways without departing from the spirit and scope of the present invention as set forth in the following claims. may be modified or changed.

100: body 200: main shaft
300: first rotor unit 310: first rotor driving unit
320: first rotor 400: second rotor unit
410: second rotor driving unit 420; 2nd rotor
500: interval control unit 600: pitch control unit

Claims (13)

body part;
a main shaft having a hollow structure and coupled to the body to form a vertical axis;
It is coupled to the main shaft and has a first rotor driving part for generating a rotational force in a first direction about the vertical axis, and a first rotor rotating in the first direction by the rotational force generated from the first rotor driving part. a first rotor unit;
a second rotor driving part coupled to the main shaft and generating a rotational force in a second direction opposite to the first direction about the vertical axis; and a rotational force generated in the second rotor driving part in the second direction a second rotor unit having a second rotating rotor; and
Aircraft having a hollow coaxial inversion structure, characterized in that it comprises a space adjusting unit for adjusting the distance between the first rotor unit and the second rotor unit with respect to the vertical axis. According to claim 1,
At least one of the first rotor unit and the second rotor unit is movably coupled in the vertical axis direction on the main shaft,
The interval adjusting unit,
a first frame coupled to the first rotor unit;
a second frame coupled to the second rotor unit and disposed to face the first frame;
Connecting the first frame and the second frame, the vehicle having a hollow coaxial inversion structure, characterized in that it comprises a space adjusting member for making the first frame and the second frame close or spaced apart. 3. The method of claim 2,
The spacing adjusting member,
a first rack member extending from the first frame in a direction of the second frame and having a first rack gear formed on one side thereof;
a second rack member extending from the second frame in a direction of the first frame and having a second rack gear formed on one side thereof;
A pinion gear geared simultaneously with the first rack gear and the second rack gear is formed to connect the first rack member and the second rack member, and a rotating member rotated by an external driving force. Aircraft having a hollow coaxial inversion structure, characterized in that. According to claim 1,
The first rotor is
a first hub rotatably coupled to the main shaft and directly connected to the first rotor driving unit;
a first grip portion coupled to one side of the outer circumferential surface of the first hub and rotatably coupled with respect to a first pitch axis crossing the vertical axis;
a first blade coupled to the first grip portion;
a second grip portion coupled to the other side of the outer circumferential surface of the first hub and rotatably coupled with respect to a second pitch axis crossing the vertical axis;
An aircraft having a hollow coaxial inversion structure, characterized in that it includes a second blade coupled to the second grip portion. 5. The method of claim 4,
The first grip portion and the second grip portion are respectively connected to the first grip portion and rotate the first grip portion from the first hub about the first pitch axis, or the second grip portion from the first hub about the second pitch axis By rotating the grip portion, the aircraft having a hollow coaxial inversion structure, characterized in that it further comprises a pitch adjusting portion for adjusting the pitch of the first blade and the second blade. 6. The method of claim 5,
The pitch adjustment unit,
a swash plate rotatably coupled to the main shaft about the vertical axis, the height of which is adjusted while moving in the vertical axis direction, or the inclination angle of which is adjusted while tilting about the vertical axis;
a first link part connecting one side of the rotating part of the swash plate and the first grip part;
a second link part connecting the other side of the rotating part of the swash plate to the second grip part;
a plurality of pitch control driving units for generating a driving force for adjusting the height or inclination angle of the swash plate;
Aircraft having a hollow coaxial inversion structure, characterized in that it comprises a plurality of link assemblies connecting each of the pitch control driving part and the non-rotating part of the swash plate. 7. The method of claim 6,
The link assembly includes a first link assembly, a second link assembly, and a third link assembly disposed to be spaced apart along the circumferential direction of the swash plate,
An air vehicle having a hollow coaxial inversion structure, characterized in that the interval between the first link assembly, the second link assembly and the third link assembly is adjustable. 7. The method of claim 6,
The non-rotating portion of the swash plate is provided with a plurality of fastening holes arranged at preset intervals along the circumferential direction,
The link assembly is
A first connection link having one end hinge-coupled to the pitch control driving unit;
An aircraft having a hollow coaxial inversion structure, characterized in that one end portion is hinged to the first connecting link and the other end includes a second connecting link hinged to one of the plurality of fastening holes. According to claim 1,
The body part,
a lower frame for rotatably supporting the lower end of the main shaft;
an upper frame for rotatably supporting the upper end of the main shaft;
Aircraft having a hollow coaxial inversion structure, characterized in that it comprises a module unit mount detachably coupled to the lower frame or the upper frame. According to claim 1,
Cables for power, communication and control are wired inside the hollow of the main shaft,
The main shaft is an aircraft having a hollow coaxial inversion structure, characterized in that it has one or more wiring holes for passing the cable through. According to claim 1,
The second rotor,
An aircraft having a hollow coaxial inversion structure, which is disposed through the main shaft and includes an extended shaft that is rotated by the rotational force generated by the second rotor driving unit. 12. The method of claim 11,
The second rotor,
a second hub coupled to an end of the extension shaft passing through the main shaft and rotating in conjunction with the extension shaft;
a third grip portion coupled to one side of the outer circumferential surface of the second hub and rotatably coupled to a third pitch axis crossing the vertical axis;
a third blade coupled to the third grip portion;
a fourth grip portion coupled to the other side of the outer peripheral surface of the second hub and rotatably coupled with respect to a fourth pitch axis crossing the vertical axis;
Aircraft having a hollow coaxial inversion structure, characterized in that it further comprises a fourth blade coupled to the fourth grip portion. 13. The method of claim 12,
Each of the third grip part and the fourth grip part is connected to the third grip part and rotates the third grip part from the second hub about the third pitch axis, or the fourth grip part rotates the third grip part from the second hub about the fourth pitch axis. By rotating the grip portion, the air vehicle having a hollow coaxial inversion structure, characterized in that it further comprises a pitch adjusting unit for adjusting the pitch of the third blade and the fourth blade.

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