Variable diameter rotor, method of varying rotor diameter, and tiltrotor aircraft

Abstract

This invention discloses a variable-diameter rotor, a method for variable-diameter rotor, and a tiltrotor aircraft, relating to the field of aircraft technology. The variable-diameter rotor includes a rotor root, rotor tip, spar, skin, and support components. The spar connects the rotor root and rotor tip at both ends. The skin includes three sections: section one, section two, and section three. The support components include support component one and support component two. Support component one is fixedly connected to the spar and section one, and is located on the side of section one near the rotor root, giving section one a cavity near the rotor tip. Support component two connects the spar and section two. Section two includes multiple blocks along its circumference. Support component two includes multiple struts, which connect the blocks and the spar. The struts and spar are telescopic. This invention significantly improves the aerodynamic efficiency of the fixed-wing aircraft during cruise by adjusting the rotor's working diameter and rotor disk area, enhancing the overall flight performance and achieving optimized aerodynamic performance in both flight modes.

Description

Technical Field

[0001] This invention relates to the field of aircraft technology, and in particular to a variable diameter rotor, a rotor diameter variation method, and a tiltrotor aircraft. Background Technology

[0002] A tiltrotor aircraft is a hybrid aircraft that combines the vertical takeoff and landing capabilities of a helicopter with the high-speed cruise capabilities of a fixed-wing aircraft. A typical example is the American V-22 Osprey. This type of aircraft tilts its rotor / propulsion system as a whole. During vertical takeoff and landing, it operates in helicopter mode, providing lift; during cruise, it tilts to a horizontal position, acting as a propulsion propeller, and relies on its wings to generate lift, thus achieving efficient forward flight.

[0003] However, existing tiltrotor aircraft generally employ fixed-geometry rotor systems, whose rotor disk areas must meet the high lift requirements during vertical takeoff and landing, and are typically designed to be quite large. This rotor configuration, "optimized for hovering," introduces significant aerodynamic disadvantages when transitioning to fixed-wing cruise mode: on the one hand, the excessively large rotor disk area leads to a sharp increase in drag during forward flight; on the other hand, large-diameter rotors are prone to tip velocities approaching or exceeding the speed of sound at high speeds, causing shock wave drag, vibration, and noise, limiting flight speed and reducing propulsion efficiency. Furthermore, large-disk rotors are difficult to match with the small-diameter, high-speed characteristics of efficient propellers in cruise mode, resulting in overall cruise performance far lower than that of comparable fixed-wing aircraft.

[0004] To address these issues, existing technologies have attempted to compensate through methods such as variable rotation speed, variable pitch, or tilt angle optimization. However, none of these methods can fundamentally resolve the inherent contradiction that "large rotor disks are better for hovering, while small rotor disks are better for cruising." In recent years, although research has proposed the concept of retractable or foldable rotors, these often suffer from problems such as complex structures, heavy weight, low reliability, or insufficient storage space, making them difficult to apply effectively in engineering practice. In particular, there is a lack of a practical solution that can ensure both structural strength and flight safety while achieving smooth, reliable, and compact folding during mode transitions.

[0005] Therefore, there is an urgent need for a new type of rotor structure that can dynamically adjust the effective rotor disk area under different flight modes, so as to significantly improve the aerodynamic efficiency and flight economy of fixed-wing aircraft during the cruise phase while ensuring vertical take-off and landing performance, thereby breaking through the performance bottleneck of existing tiltrotor aircraft. Summary of the Invention

[0006] The purpose of this invention is to provide a variable diameter rotor, a rotor diameter variation method, and a tiltrotor aircraft to solve the problems existing in the above-mentioned related technologies, realize the adjustment of the rotor working diameter and rotor disk area, significantly improve the aerodynamic efficiency during the cruise phase of the fixed wing, enhance the overall flight performance of the aircraft, and achieve a balance between optimized aerodynamic performance in two flight modes.

[0007] To achieve the above objectives, the present invention provides the following solution: This invention discloses a variable diameter rotor, comprising: paddle root; paddle tip; The wing spars are connected at both ends to the rotor root and the rotor tip, respectively. The skin includes three unconnected segments arranged sequentially along the spars; segment three surrounds the propeller tip. The support assembly includes support assembly one and support assembly two; support assembly one is fixedly connected to the spar and the first section respectively, and is located on the side of the first section near the rotor root, so that the side of the first section near the rotor tip has a receiving cavity; support assembly two is connected to the spar and the second section respectively. The second section includes multiple blocks along its circumference; the second support assembly includes multiple support rods, which are respectively connected to the blocks and the wing spars; the support rods and the wing spars are telescopic, so that the variable diameter rotor has an deployed state and a folded state; In the unfolded state, segment one, segment two, and segment three abut against each other in sequence; in the folded state, segment two is housed in the accommodating cavity, and segment one abuts against segment three.

[0008] In some examples, the number of blocks is six, namely, upper surface skin, trailing edge upper surface skin, trailing edge lower surface skin, lower surface skin, leading edge lower surface skin, and leading edge upper surface skin; the upper surface skin is located on the upper side of the middle of the second segment, and the lower surface skin is located on the lower side of the middle of the second segment; the trailing edge upper surface skin is located on the upper side of the trailing edge of the second segment, and the trailing edge lower surface skin is located on the lower side of the trailing edge of the second segment; the leading edge upper surface skin is located on the upper side of the leading edge of the second segment, and the leading edge lower surface skin is located on the lower side of the leading edge of the second segment.

[0009] In some examples, there are three support rods, namely support rod one, support rod two, and support rod three; the middle of the support rod is fixedly connected to the wing beam; the two ends of support rod one are respectively connected to the upper surface skin and the lower surface skin; the two ends of support rod two are respectively connected to the leading edge upper surface skin and the trailing edge upper surface skin; the two ends of support rod three are respectively connected to the leading edge lower surface skin and the trailing edge lower surface skin.

[0010] In some examples, the two ends of the second support rod and the two ends of the third support rod are respectively hinged to the corresponding blocks; the ends of the second support rod and the ends of the third support rod are connected to the corresponding blocks through an angle adjustment assembly, so that the angle of the blocks is adjustable.

[0011] In some examples, the two ends of the first support rod are hinged to the corresponding blocks; the ends of the first support rod are connected to the corresponding blocks via an angle adjustment assembly, making the angle of the blocks adjustable.

[0012] In some examples, the length of the variable diameter rotor is R, the position of the rotor root ranges from 0 to 0.2R, the position of the first support assembly ranges from 0.2R to 0.6R, the position of the accommodating cavity ranges from 0.6R to 0.75R, the position of the second support assembly ranges from 0.75R to 0.9R, and the position of the rotor tip ranges from 0.9R to R.

[0013] This invention also discloses a method for variable diameter rotors, using the aforementioned variable diameter rotor, comprising the following steps: Shorten all the support rods to move all the blocks toward the wing spars; shorten the wing spars to move all the blocks toward the accommodating cavity until section one and section three abut against each other, thereby achieving the folding of the variable diameter rotor; Extend the spar to a preset length so that all the blocks are moved out of the receiving cavity; extend all the support rods so that all the blocks are moved away from the spar until the second section smoothly abuts against the first section and the third section respectively, thereby realizing the deployment of the variable diameter rotor.

[0014] In some examples, the tiltrotor ascends in vertical takeoff and landing mode before the variable diameter rotor is folded. After the variable diameter rotor is folded and before the variable diameter rotor is deployed, the tiltrotor is adjusted to fixed-wing cruise mode; After the variable-diameter rotor is deployed, the tiltrotor lands in vertical takeoff and landing mode.

[0015] In some examples, the tilt angle of a portion of the block is adjusted before the variable-diameter rotor is folded.

[0016] The present invention also discloses a tiltrotor aircraft, including the above-mentioned variable diameter rotor.

[0017] Compared with related technologies, the present invention achieves the following technical effects: When the variable-diameter rotor is in the deployed state, the spars extend to their maximum effective length. Support assembly one maintains the structural rigidity of section one and forms a stable accommodating cavity space. The struts of support assembly two simultaneously extend outward to predetermined positions, circumferentially expanding multiple blocks of section two to a standard airfoil profile. This ensures that sections one, two, and three are sequentially and tightly joined, forming a complete and continuous aerodynamic blade shape. At this point, the rotor has its maximum effective diameter and disk area, generating sufficient lift to meet the performance requirements for vertical takeoff and landing and hovering.

[0018] When switching to the folding state is required, the flight control system issues control commands. First, the struts of support assembly two retract inward, causing multiple blocks of section two to fold inward, reducing the overall cross-sectional dimensions of section two. Then, the wing spars retract axially towards the rotor root, completely housing the folded section two within the receiving cavity near the rotor tip of section one. At this point, the end of section one directly abuts against section three, significantly reducing the effective rotor diameter and rotor disk area, thereby greatly reducing forward drag, improving propulsion efficiency, and adapting to high-speed cruise conditions for fixed-wing aircraft.

[0019] In summary, this invention significantly improves the aerodynamic efficiency of the fixed-wing aircraft during the cruise phase by adjusting the rotor working diameter and the rotor disk area, thereby enhancing the overall flight performance of the aircraft and achieving a balance between optimized aerodynamic performance in both flight modes. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the variable diameter rotor deployment state in some examples of the present invention; Figure 2 for Figure 1 A sectional view of the section where the second part of the middle section is located; Figure 3 For some examples of the present invention Figure 2 A schematic diagram of step one in the folding process of the structure shown; Figure 4 For some examples of the present invention Figure 2 A schematic diagram of step two in the folding process of the structure shown; Figure 5 For some examples of the present invention Figure 2 The diagram shows step three of the folding process of the structure shown. Figure 6 For some examples of the present invention Figure 2The diagram shows step four of the folding process of the structure shown. Figure 7 for Figure 5 A schematic diagram of the corresponding variable diameter rotor; Figure 8 This is a comparison diagram of the positions before and after the second fold of section two.

[0022] In the diagram: 100 - Variable diameter rotor; 1 - Rotor root; 2 - Rotor tip; 3 - Spall; 4 - Skin; 5 - Support assembly; 41 - Section 1; 42 - Section 2; 43 - Section 3; 51 - Support assembly 2; 421 - Block; 422 - Upper surface skin; 423 - Trailing edge upper surface skin; 424 - Trailing edge lower surface skin; 425 - Lower surface skin; 426 - Leading edge lower surface skin; 427 - Leading edge upper surface skin; 511 - Support rod 1; 512 - Support rod 2; 513 - Support rod 3. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The purpose of this invention is to provide a variable diameter rotor, a rotor diameter variation method, and a tiltrotor aircraft to solve the problems existing in the above-mentioned related technologies, realize the adjustment of the rotor working diameter and rotor disk area, significantly improve the aerodynamic efficiency during the cruise phase of the fixed wing, enhance the overall flight performance of the aircraft, and achieve a balance between optimized aerodynamic performance in two flight modes.

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] Reference Figures 1-8 This embodiment provides a variable diameter rotor 100, including rotor root 1, rotor tip 2, spar 3, skin 4, and support assembly 5.

[0027] The spar 3 is connected to the rotor root 1 and rotor tip 2 at both ends. The skin 4 includes three sections 41, 42, and 43, which are arranged sequentially along the spar 3 and are not connected to each other (meaning they are not integrally connected). Section 43 surrounds the rotor tip 2. The support assembly 5 includes support assembly 1 and support assembly 2 51. Support assembly 1 is fixedly connected to the spar 3 and section 41, and is located on the side of section 41 closer to the rotor root 1, so that the side of section 41 closer to the rotor tip 2 has a cavity. Support assembly 2 51 is connected to the spar 3 and section 42.

[0028] Section 2 42 includes multiple blocks 421 along its circumference. Support assembly 2 51 includes multiple struts, which connect the blocks 421 and the wing spar 3 respectively. The struts and wing spar 3 are telescopic, allowing the variable diameter rotor 100 to have an deployed state and a folded state. In the deployed state, sections 1 41, 2 42, and 3 43 abut against each other in sequence. In the folded state, section 2 42 is housed within the receiving cavity, and sections 1 41 abut against section 3 43.

[0029] The working principle of the variable diameter rotor 100 in this embodiment is as follows: When the variable diameter rotor 100 is in the deployed state, refer to Figure 1 With spar 3 extended to its maximum effective length, support assembly one maintains the structural rigidity of section one 41 and forms a stable accommodating cavity space. Support assembly two 51's struts simultaneously extend outward to predetermined positions, circumferentially expanding multiple blocks 421 of section two 42 to a standard airfoil profile. This ensures that sections one 41, section two 42, and section three 43 are sequentially and tightly joined, forming a complete and continuous rotor aerodynamic shape. At this point, the rotor has its maximum effective diameter and disk area, generating sufficient lift to meet the performance requirements for vertical takeoff and landing and hovering.

[0030] When it is necessary to switch to the folded state, the flight control system issues a control command. (Refer to...) Figure 4 , Figure 5 First, the support rods of component 2 51 retract inward, causing multiple blocks 421 of section 2 42 to converge inward, thus reducing the overall cross-sectional dimensions of section 2 42. The structure after convergence can be referenced. Figure 7 Subsequently, the wing spars 3 retracts axially towards the rotor root 1, completely housing the folded section two 42 within the receiving cavity of section one 41 near the rotor tip 2. At this point, the end of section one 41 directly abuts against section three 43, significantly reducing the effective rotor diameter and rotor disk area, thereby greatly reducing forward drag and improving propulsion efficiency, making it suitable for high-speed cruise operations of fixed-wing aircraft. The folded structure can be referenced. Figure 6 .

[0031] When it is necessary to restore the deployed state, the spar 3 extends axially toward the rotor tip 2, completely pushing out section two 42 housed in the accommodating cavity. Subsequently, the struts of support assembly two 51 extend outward, driving multiple blocks 421 of section two 42 to circumferentially expand and reset to the standard airfoil profile, so that section one 41, section two 42, and section three 43 are once again tightly abutted in sequence, and the rotor returns to its maximum diameter state, regaining the lift performance required for vertical take-off and landing and hovering.

[0032] In some examples, refer to Figure 2There are six blocks 421: upper surface skin 422, trailing edge upper surface skin 423, trailing edge lower surface skin 424, lower surface skin 425, leading edge lower surface skin 426, and leading edge upper surface skin 427. Upper surface skin 422 is located on the upper side of the middle of block 42, and lower surface skin 425 is located on the lower side of the middle of block 42. Trailing edge upper surface skin 423 is located on the upper side of the trailing edge of block 42, and trailing edge lower surface skin 424 is located on the lower side of the trailing edge of block 42. Leading edge upper surface skin 427 is located on the upper side of the leading edge of block 42, and leading edge lower surface skin 426 is located on the lower side of the leading edge of block 42.

[0033] Six blocks 421 together constitute the complete airfoil aerodynamic profile of section two 42. In the deployed state, they work together to provide lift, and in the folded state, they reduce the cross-sectional dimensions by retracting. The upper surface skin 422 and the lower surface skin 425, as the main load-bearing and aerodynamic surfaces in the middle of the airfoil, bear most of the lift load of section two 42. During folding, they contract inward along the airfoil chord in the vertical direction, reducing the airfoil thickness. The trailing edge upper surface skin 423 and the trailing edge lower surface skin 424 together form the airfoil trailing edge profile, and the leading edge upper surface skin 427 and the leading edge lower surface skin 426 together form the smooth leading edge surface of the airfoil. Each block 421 moves under the drive of the corresponding strut of support assembly two 51, ensuring a smooth transition and accurate positioning of the airfoil profile during folding and deployment.

[0034] In some examples, refer to Figure 2 There are three support rods: support rod 1 (511), support rod 2 (512), and support rod 3 (513). The wing beam 3 is fixedly connected to the middle of each support rod. Support rod 1 (511) is connected to the upper surface skin 422 and the lower surface skin 425 at both ends, respectively. Support rod 2 (512) is connected to the upper surface skin 427 at the front edge and the upper surface skin 423 at the rear edge at both ends, respectively. Support rod 3 (513) is connected to the lower surface skin 426 at the front edge and the lower surface skin 424 at the rear edge at both ends. Support rod 1 (511) is perpendicular to both support rods 2 (512) and 3 (513).

[0035] Support rod 511 serves as the driving component in the thickness direction of the airfoil. Its middle section is fixed to the center of the spar 3, and its two ends are hinged to the upper surface skin 422 and the lower surface skin 425, respectively. (Refer to...) Figure 5 When the support rod 511 extends or retracts, it can simultaneously drive the upper surface skin 422 and the lower surface skin 425 to move in the same direction in opposite directions along the thickness of the airfoil, ensuring that the movement trajectories of the two always coincide on the same axis, making the forces on the upper and lower sides of the wing beam 3 more balanced, and reducing or eliminating the additional bending moment generated by unilateral drive.

[0036] Support rod 512 serves as the drive component in the width direction of the upper part of the airfoil. Its middle section is fixed to the upper part of the spar 3, and its two ends are connected to the leading edge upper surface skin 427 and the trailing edge upper surface skin 423, respectively. (Refer to...) Figure 4 When strut 2 512 extends or retracts along the width of the airfoil, it simultaneously drives the upper surface skin 427 on the leading edge and the upper surface skin 423 on the trailing edge to move in a collinear, opposite, synchronous manner. This ensures that the retraction and extension actions of the two are completely synchronized and their trajectories are collinear, avoiding airfoil profile deviations caused by inconsistent movements between the two. The function of strut 3 513 is the same as that of strut 2 512.

[0037] This solution uses only three drive components to achieve precise control of six blocks 421. Compared with the drive scheme where each support rod corresponds to a block 421, it reduces the number of support rods, lowers the structural weight and complexity, and ensures the motion synchronization and collinearity of the corresponding blocks 421. It eliminates the need for complex electronic control synchronization algorithms, significantly improving the reliability and consistency of the mechanism's actions.

[0038] In some examples, refer to Figure 2 Both ends of support rod 2 512 and support rod 3 513 are hinged to the corresponding blocks 421. The ends of support rod 2 512 and support rod 3 513 are connected to the corresponding blocks 421 through an angle adjustment assembly, making the angle of block 421 adjustable.

[0039] The hinge structure and the angle adjustment component together constitute the deflection drive and positioning mechanism of block 421, realizing precise angle control and reliable locking of the six blocks 421, ensuring sufficient folding and closing and accurate unfolding and resetting.

[0040] Reference Figure 3 The leading edge upper surface skin 427 and the trailing edge upper surface skin 423 deflect synchronously around the hinge point, and the leading edge lower surface skin 426 and the trailing edge lower surface skin 424 deflect synchronously around the hinge point. This deflection action reduces the angle between the leading edge upper surface skin 427 and the trailing edge upper surface skin 423, as well as the maximum vertical distance between the leading edge lower surface skin 426 and the trailing edge lower surface skin 424. This provides space to avoid the upper surface skin 422 and the lower surface skin 425, allowing the distance between the upper surface skin 422 and the lower surface skin 425 to be adjusted to a smaller value, ensuring that section two 42 can be completely stored in the accommodating cavity after folding.

[0041] In some examples, refer to Figure 2 Both ends of the support rod 511 are hinged to the corresponding blocks 421. The ends of the support rod 511 are connected to the corresponding blocks 421 through an angle adjustment assembly, making the angle of the blocks 421 adjustable.

[0042] The hinged connection between the support rod 511 and the upper surface skin 422 and the lower surface skin 425, along with the matching angle adjustment assembly, further increases the number of adjustable angle blocks 421, so as to avoid interference during folding by adjusting the angle.

[0043] In some examples, refer to Figure 1 The length of the variable diameter rotor 100 is R, the position range of the rotor root 1 is 0 to 0.2R, the position range of the first support assembly is 0.2R to 0.6R, the position range of the accommodating cavity is 0.6R to 0.75R, the position range of the second support assembly 51 is 0.75R to 0.9R, and the position range of the rotor tip 2 is 0.9R to R.

[0044] The 0 to 0.2R section, where the rotor root 1 is located, serves as the main load-bearing area connecting the rotor and the hub, bearing all the centrifugal loads and bending moments generated by rotor rotation. A fully rigid structure ensures connection reliability and structural safety. The 0.2R to 0.6R section, where support component one is located, is the main load-bearing section of the blade. Through rigid support, it forms a high-strength airfoil structure, bearing most of the rotor's lift load and providing a stable structural foundation for the subsequent housing cavity. The 0.6R to 0.75R section, where the housing cavity is located, is a dedicated storage space. Its axial length perfectly matches the length of the 0.75R to 0.9R foldable section, where support component two 51 is located, ensuring that the foldable section can be fully stored without any wasted space. The 0.75R to 0.9R section, where support component two 51 is located, is relatively far from the rotor root 1, and its load is relatively small, making it suitable for a foldable mechanism. The 0.9R to R section, where the rotor tip 2 is located, retains its complete aerodynamic shape. After folding, it directly abuts against the end of the housing cavity, ensuring the streamlined blade tip and avoiding additional aerodynamic drag. The above-mentioned segmentation ratio ensures the structural strength of the main load-bearing area of ​​the blade, achieves compactness when folded and stored, and enables the rotor to have optimal aerodynamic performance in both deployed and folded states.

[0045] This embodiment also provides a rotor diameter variation method, using the above-mentioned variable diameter rotor 100, including the following steps: Shorten all struts, causing all blocks 421 to move toward the wing spars 3. Shorten the wing spars 3, causing all blocks 421 to move toward the accommodating cavity until section one 41 and section three 43 abut against each other, thus achieving the folding of the variable diameter rotor 100.

[0046] Extend the spar 3 to a preset length, so that all blocks 421 are moved out of the receiving cavity. Extend all the support rods, so that all blocks 421 are moved away from the spar 3, until section two 42 smoothly abuts against section one 41 and section three 43 respectively, so as to realize the deployment of the variable diameter rotor 100.

[0047] The working principle of this rotor diameter variation method is as follows: Shortening all struts allows all sections 421 to move towards the wing sparb 3, creating the necessary space for subsequent axial retraction and fundamentally preventing the skin 4 from scraping, jamming, or interfering with the inner wall of the accommodating cavity during axial movement. Shortening the wing sparb 3 allows all sections 421 to move towards the accommodating cavity until section one 41 and section three 43 abut against each other, forming a continuous folded blade shape. This achieves an active reduction in the effective rotor diameter, enabling the rotor to adapt to the low-drag, high-efficiency aerodynamic requirements of high-speed cruise mode for fixed wings.

[0048] Extend the spar 3 to a preset length, moving all sections 421 out of the accommodating cavity, providing ample operating space for subsequent radial expansion operations, and ensuring that each section 421 is not constrained or restricted by the accommodating cavity structure during deployment. Extend all struts, moving all sections 421 away from the spar 3, until section two 42 smoothly abuts against section one 41 and section three 43 respectively, restoring the complete and continuous aerodynamic shape of the rotor blades, allowing the rotor to return to its maximum effective diameter, and meeting the high lift requirements of vertical takeoff and landing and hovering modes.

[0049] In some examples, the tiltrotor ascends in vertical takeoff and landing (VTOL) mode before the variable-diameter rotor 100 is folded. After the variable-diameter rotor 100 is folded, and before it is deployed, the tiltrotor adjusts to fixed-wing cruise mode. After the variable-diameter rotor 100 is deployed, the tiltrotor lands in VTOL mode.

[0050] Before the variable diameter rotor 100 is folded, the tiltrotor takes off in vertical takeoff and landing mode to ensure that the rotor always maintains the maximum disk area to provide sufficient lift and control margin in complex airflow environments at low altitudes, avoiding the risk of sudden lift changes and flight loss of control caused by low-altitude mechanism actions.

[0051] After the variable diameter rotor 100 is folded and before it is unfolded, the tiltrotor aircraft is adjusted to the fixed-wing cruise mode. At this time, the rotor diameter has been reduced, and the small rotor disk configuration is highly matched with the aerodynamic requirements of high-speed cruise conditions, which can significantly reduce forward drag and improve propulsion efficiency.

[0052] After the variable diameter rotor 100 is deployed, the tiltrotor aircraft lands in vertical takeoff and landing mode, ensuring that the rotor is fully deployed and recovers maximum lift capacity before entering the low-altitude landing phase, providing sufficient lift reserve and control response speed for vertical landing.

[0053] In some examples, the tilt angle of a portion of block 421 is adjusted before the variable diameter rotor 100 is folded.

[0054] Before the support rod retraction is initiated, the tilt angles of the upper front surface skin 427, lower front surface skin 426, upper rear surface skin 423, and lower rear surface skin 424 are individually adjusted using the angle adjustment component. This directly reduces the maximum vertical spacing between the upper front surface skin 427 and the upper rear surface skin 423, as well as the maximum vertical spacing between the lower front surface skin 426 and the lower rear surface skin 424. This provides space to avoid the upper surface skin 422 and the lower surface skin 425, allowing the spacing between the upper surface skin 422 and the lower surface skin 425 to be adjusted to a smaller value, ensuring that section two 42 can be completely stored in the accommodating cavity after folding.

[0055] This embodiment also provides a tiltrotor aircraft, including the aforementioned variable-diameter rotor 100. Since this tiltrotor aircraft includes an upward-moving variable-diameter rotor 100, it also possesses the corresponding advantages of a variable-diameter rotor 100, which will not be elaborated here.

[0056] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A variable diameter rotor (100), characterized in that, include: Paddle root(1); Paddle tip (2); The wing spars (3) are connected at both ends to the rotor root (1) and the rotor tip (2); The skin (4) includes three sections (41), (42), and (43) arranged sequentially along the spar (3) and not connected to each other; the third section (43) surrounds the blade tip (2). The support assembly (5) includes support assembly one and support assembly two (51); support assembly one is fixedly connected to the spar (3) and the section one (41) respectively, and is located on the side of the section one (41) near the rotor root (1), so that the side of the section one (41) near the rotor tip (2) has a receiving cavity; support assembly two (51) is connected to the spar (3) and the section two (42) respectively. The second section (42) includes multiple blocks (421) along its circumference; the second support component (51) includes multiple support rods, which are respectively connected to the blocks (421) and the wing beam (3); the support rods and the wing beam (3) are telescopic, so that the variable diameter rotor (100) has an unfolded state and a folded state; In the unfolded state, section one (41), section two (42), and section three (43) abut against each other in sequence; in the folded state, section two (42) is housed in the accommodating cavity, and section one (41) abuts against section three (43).

2. The variable diameter rotor (100) according to claim 1, characterized in that: The number of blocks (421) is six, namely, upper surface skin (422), trailing edge upper surface skin (423), trailing edge lower surface skin (424), lower surface skin (425), leading edge lower surface skin (426), and leading edge upper surface skin (427); the upper surface skin (422) is located on the upper side of the middle part of the second segment (42), and the lower surface skin (425) is located on the lower side of the middle part of the second segment (42); the trailing edge upper surface skin (423) is located on the upper side of the trailing edge of the second segment (42), and the trailing edge lower surface skin (424) is located on the lower side of the trailing edge of the second segment (42); the leading edge upper surface skin (427) is located on the upper side of the leading edge of the second segment (42), and the leading edge lower surface skin (426) is located on the lower side of the leading edge of the second segment (42).

3. The variable diameter rotor (100) according to claim 2, characterized in that: The number of support rods is three, namely support rod one (511), support rod two (512) and support rod three (513); the middle part of the support rod is fixedly connected to the wing beam (3); the two ends of support rod one (511) are respectively connected to the upper surface skin (422) and the lower surface skin (425); the two ends of support rod two (512) are respectively connected to the leading edge upper surface skin (427) and the trailing edge upper surface skin (423); the two ends of support rod three (513) are respectively connected to the leading edge lower surface skin (426) and the trailing edge lower surface skin (424).

4. The variable diameter rotor (100) according to claim 3, characterized in that: Both ends of the second support rod (512) and both ends of the third support rod (513) are respectively hinged to the corresponding blocks (421); the ends of the second support rod (512) and the third support rod (513) are connected to the corresponding blocks (421) through an angle adjustment component, so that the angle of the blocks (421) is adjustable.

5. The variable diameter rotor (100) according to claim 3, characterized in that: The two ends of the first support rod (511) are hinged to the corresponding block (421); the end of the first support rod (511) is connected to the corresponding block (421) through an angle adjustment component, so that the angle of the block (421) is adjustable.

6. The variable diameter rotor (100) according to claim 1, characterized in that: The length of the variable diameter rotor (100) is R, the position range of the rotor root (1) is 0 to 0.2R, the position range of the first support assembly is 0.2R to 0.6R, the position range of the accommodating cavity is 0.6R to 0.75R, the position range of the second support assembly (51) is 0.75R to 0.9R, and the position range of the rotor tip (2) is 0.9R to R.

7. A method for changing the diameter of a rotor, characterized in that, Using the variable diameter rotor (100) as described in any one of claims 1 to 6 includes the following steps: Shorten all the support rods so that all the blocks (421) move toward the spar (3); shorten the spar (3) so that all the blocks (421) move toward the accommodating cavity until the first section (41) abuts against the third section (43), thereby achieving the folding of the variable diameter rotor (100); Extend the wing spars (3) to a preset length so that all the blocks (421) are moved out of the accommodating cavity; extend all the support rods so that all the blocks (421) are moved away from the wing spars (3) until the second section (42) smoothly abuts against the first section (41) and the third section (43) respectively, thereby realizing the deployment of the variable diameter rotor (100).

8. The rotor diameter variation method according to claim 7, characterized in that: Before the variable diameter rotor (100) is folded, the tiltrotor ascends in vertical takeoff and landing mode; After the variable diameter rotor (100) is folded and before the variable diameter rotor (100) is unfolded, the tiltrotor is adjusted to fixed-wing cruise mode; After the variable diameter rotor (100) is deployed, the tiltrotor lands in vertical takeoff and landing mode.

9. The rotor diameter variation method according to claim 7, characterized in that: Before the variable diameter rotor (100) is folded, the operation of adjusting the tilt angle of a portion of the block (421) is also included.

10. A tiltrotor aircraft, characterized in that, Including the variable diameter rotor (100) as described in any one of claims 1 to 6.

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