A vertical takeoff and landing aircraft

Abstract

This application relates to the field of aircraft technology, providing a vertical takeoff and landing (VTOL) aircraft, comprising a main cabin and landing gear, a tilting frame, and at least two sets of propeller units mounted on the tilting frame. The tilting frame can tilt relative to the main cabin in the vertical plane by adjusting the propeller thrust, eliminating the need for an additional tilting power unit. The aircraft is also equipped with a pair of folding wings, whose opening and folding relative to the tilting frame enables a smooth transition from VTOL to level flight. Through an integrated tilting frame and differential thrust control, the structure is significantly simplified, and combined with the folding wings, it provides a novel low-altitude aircraft configuration different from pure multi-rotor configurations and tilting compound wing configurations. It provides aerodynamic lift through the folding wings, reducing energy consumption without relying on breakthroughs in high-energy-density battery technology; furthermore, it eliminates the need for an additional tilting power unit, reducing structural complexity and improving reliability; simultaneously, the folding wings reduce the required takeoff and landing space.

Description

Technical Field

[0001] This application relates to the field of aircraft technology, and more specifically, to vertical takeoff and landing aircraft. Background Technology

[0002] With the development of urban air mobility (UAM), electric vertical takeoff and landing (eVTOL) aircraft have become the development trend of vertical takeoff and landing aircraft due to their advantages such as not requiring a runway and being able to take off and land in confined spaces. Traditional eVTOL aircraft typically adopt a pure multi-rotor configuration or a fixed-wing + tiltrotor (or "tilt-rotor compound") configuration to achieve switching between vertical takeoff and landing and horizontal flight modes.

[0003] However, several technical bottlenecks remain in existing technologies. A pure multi-rotor configuration lacks aerodynamic lift during level flight, resulting in low aerodynamic efficiency, high energy consumption, and severely limited range. A fixed-wing + tiltrotor configuration with independent tiltrotor power units is structurally extremely complex, increasing system weight and reducing reliability. Furthermore, while existing folding wing structures effectively reduce takeoff and landing space, they rely heavily on independent and complex drive systems, which not only increases energy loss but also raises the risk of failure, making it difficult to meet market demands for miniaturization and high reliability.

[0004] The information disclosed in the background section is only intended to enhance the understanding of the background of this application, and therefore may contain information that is not part of the prior art known to those skilled in the art. Summary of the Invention

[0005] This application provides a vertical takeoff and landing (VTOL) aircraft to address the problems of existing aircraft having independently installed tilt propulsion units, complex structures, and low reliability.

[0006] To achieve the above objectives, this application provides the following technical solution: A vertical takeoff and landing aircraft, comprising: The main cabin and landing gear, wherein the landing gear is located at the bottom of the main cabin and is used to support the main cabin; The tilting frame is a closed frame structure, which includes two opposing longitudinal members. The two longitudinal members are symmetrically arranged on both sides of the main cabin, and the middle part of either longitudinal member is pivotally connected to the side of the main cabin via a rotating shaft, so that the tilting frame can tilt relative to the main cabin in the vertical plane. At least two propeller units are located on the tilting frame. The at least two propeller units are configured to adjust the angle of the tilting frame relative to the main cabin by adjusting their respective rotational speeds to generate differential thrust, thereby controlling the spatial attitude of the vertical take-off and landing aircraft for vertical take-off and landing, transition and level flight.

[0007] Optionally, it also includes: A pair of folding wings are symmetrically arranged on both sides of the main cabin. Each folding wing is pivotally connected to the outer end of the longitudinal strut on the corresponding side. The folding wings are unfolded or folded relative to the tiltable frame through a wing attitude adjustment system.

[0008] Optionally, the wing attitude adjustment system includes a drive motor; The folding wing is driven by the drive motor to unfold or fold the folding wing relative to the tilting frame.

[0009] Optionally, the wing attitude adjustment system includes a passive mechanical linkage mechanism; The folding wing is connected to the tiltable frame via the passive mechanical linkage mechanism, so that the folding wing can unfold or fold relative to the tiltable frame as the longitudinal rod tilts.

[0010] Optionally, the passive mechanical linkage mechanism includes: The first helical gear is fixed to the side of the main cabin, and its central axis is coaxial with the rotation axis of the tiltable frame; The second helical gear meshes with the first helical gear at one end, and is rotatably connected to the longitudinal rod via a bearing at the other end. The axis of rotation of the second helical gear is parallel to the longitudinal direction of the main cabin. The connector has one end fixed to the rotating shaft of the second helical gear and the other end provided with a sliding element; The lower surface of the folding wing is provided with an arc-shaped slide rail, and the sliding member slides in cooperation with the arc-shaped slide rail; The first helical gear is fixed to the main cabin and remains stationary. When the tiltable frame tilts relative to the main cabin, the tiltable frame rotates synchronously relative to the first helical gear, causing the second helical gear to mesh with the first helical gear and drive the second helical gear to rotate around its own rotation axis. Through the connecting member, the sliding member is driven to slide along the arc-shaped slide rail, so that the folding wing unfolds or folds relative to the tiltable frame.

[0011] Optionally, the propeller device is a fixed ducted propeller; The fixed ducted propeller includes a duct, a propeller, and a propeller drive assembly. Both the propeller drive assembly and the propeller are located inside the duct, and the propeller is connected to the duct via the propeller drive assembly. The duct and the corresponding tilting frame are integrally formed.

[0012] Optionally, the closed frame structure further includes two opposing transverse members, and the longitudinal member and the transverse member are connected end to end to form the closed frame structure; The propeller assembly consists of four sets, with one set of the propeller assembly located at each end of the length direction of each transverse member. The four sets of propeller assemblies are symmetrically arranged about the longitudinal center plane of the tilting frame.

[0013] Optionally, the main cabin includes a cabin body and a hatch, the hatch being located on top of the cabin body and hinged to the cabin body to enable opening and closing.

[0014] Optionally, the main cabin is equipped with at least one manned seat, which is fixed to the bottom of the cabin and located at the center of gravity of the vertical takeoff and landing aircraft; the center of gravity of the vertical takeoff and landing aircraft is located below the rotation center of the rotatable frame.

[0015] Optionally, the closed frame is a rectangular frame, and the tiltable frame is arranged around the outer contour of the main cabin.

[0016] The vertical takeoff and landing aircraft provided in this application embodiment has the following technical advantages compared to the prior art: First, this application features at least two propeller units mounted on a tilting frame. Multi-degree-of-freedom control can be achieved through individual motor speed adjustment of the propeller units, enabling the tilting frame to tilt vertically relative to the main cabin without the need for an additional tilting power unit. The propeller units, combined with the tilting frame, achieve a smooth transition between hovering and forward flight. It possesses both vertical takeoff and landing capabilities and forward flight performance, requiring no runway and adapting to complex takeoff and landing environments such as urban and mountainous areas. During forward flight, the tilting thrust direction is adjusted, reducing hovering energy consumption and increasing range and endurance. Secondly, this application provides a novel low-altitude aircraft configuration that differs from pure multi-rotor configurations and tilting compound wing configurations by combining a tilting frame and a folding wing. It provides aerodynamic lift through the folding wing, reducing energy consumption without relying on breakthroughs in high-energy-density battery technology; it also eliminates the need for an additional tilting power unit, reducing structural complexity and improving reliability; and the folding wing reduces the required takeoff and landing space. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments of this application and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the overall structure of the aircraft provided in the embodiments of this application; Figure 2 A schematic diagram of the flight status of a vertical takeoff and landing aircraft provided in the embodiments of this application; Figure 3 This is a schematic diagram of the aircraft occupant boarding status provided in an embodiment of this application; Figure 4 This is a schematic diagram of the occupant seating status of an aircraft provided in an embodiment of this application; Figure 5 This is a schematic diagram of the aircraft parking space provided in the embodiments of this application; Figure 6 This is a schematic diagram of the tilting frame provided in the embodiments of this application; Figure 7 This is a structural schematic diagram of the main cabin and landing gear provided in an embodiment of this application; Figure 8 Design schematic diagram of a vertical takeoff and landing aircraft provided for embodiments of this application; Figure 9 A schematic diagram of the main cabin layout provided for an embodiment of this application; Figure 10 This is a schematic diagram of the structure of the wing in a vertical position, provided in an embodiment of this application. Figure 11 This is a schematic diagram of the structure of an airfoil in its deployed state, provided in an embodiment of this application. Figure 12 This is a schematic diagram of the structure of an airfoil in a horizontal state, provided in an embodiment of this application. Figure 13 This is an assembly diagram of the first helical gear and the second helical gear provided in the embodiments of this application.

[0018] Figure label: Vertical takeoff and landing aircraft 100, tilting frame 200, main cabin 300, propeller assembly 400, landing gear 500, folding wings 600 Longitudinal member 210, transverse member 220, passive mechanical linkage mechanism 230; First helical gear 231, second helical gear 232, connector 233, arc-shaped slide 234; 301. Cabin hull 302. Battery module 303. Electronic control module 304. Detailed Implementation

[0019] This invention discloses a vertical takeoff and landing aircraft to solve the problems of existing aircraft having independently set tilt propulsion units, complex structures, and low reliability.

[0020] To make the technical solutions and advantages of the embodiments of this application clearer, the exemplary embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0021] Please see Figure 1-13 In one specific embodiment, the vertical takeoff and landing aircraft 100 provided in this application includes: The main cabin 300 and landing gear 500 are located at the bottom of the main cabin 300 and are used to support the main cabin 300. The tilting frame 200 is a closed frame structure, which includes two opposing longitudinal members 210 and two opposing transverse members 220. The longitudinal members 210 and transverse members 220 are connected end to end to form a closed frame. The two longitudinal members 210 are symmetrically arranged on the transverse sides of the main cabin 300, and the middle part of either longitudinal member 210 is pivotally connected to the side of the main cabin 300 through a rotating shaft, so that the tilting frame 200 can tilt relative to the main cabin 300 in the vertical plane. At least two sets of propeller units 400 are located on two transverse rods 220 respectively. The at least two sets of propeller units 400 are configured to generate differential thrust by adjusting their respective rotation speeds, thereby changing the angle and thrust direction of the tiltable frame 200 relative to the main cabin 300, thereby controlling the attitude of the vertical take-off and landing aircraft 100 and realizing the function of vertical take-off and landing and transitioning to level flight.

[0022] The main cabin 300, as the core structure of the aircraft, is used to accommodate occupants or cargo, as well as payloads, batteries, flight control systems, etc. The landing gear 500 is located at the bottom of the main cabin 300 and provides support and cushioning during ground parking, takeoff, and landing. As the basic platform of the aircraft, it ensures ground stability and internal functional integration. The tilting frame 200 consists of two longitudinal members 210 and two transverse members 220 connected end to end to form a closed frame, such as a rectangular or near-rectangular irregular frame structure. Here, longitudinal refers to the longitudinal direction of the aircraft, and transverse refers to the left and right direction of the aircraft. The tilting frame 200 is arranged around the outer contour of the main cabin 300. The two longitudinal members 210 are symmetrically arranged on the transverse sides of the main cabin 300. The middle part of each longitudinal member 210 is pivotally connected to the side of the main cabin 300 via a rotating shaft, such as the left and right side walls of the main cabin 300. The entire frame can tilt in the vertical plane around the rotating shaft, that is, swing from front to back or from back to front. The closed frame provides structural rigidity and facilitates propeller installation and load distribution; the central pivot of the tiltable frame 200 results in a small tilting moment and a compact structure; tilting in the vertical plane allows the aircraft to switch from vertical takeoff and landing (VTOL) mode to forward cruise mode. In VTOL mode, the frame is horizontally positioned with the propeller pointing vertically upwards; in forward cruise mode, the frame tilts forward, and the propeller thrusts forward. The tilt angle α of the tiltable frame 200 is 0° (vertical) - 85~90° (level flight).

[0023] Preferably, there are at least two sets of propeller units 400, and more preferably three sets; each set is mounted on the tilting frame 200, and differential thrust is generated by independently adjusting the speed of each propeller. During the vertical takeoff and landing phase: the tilting frame 200 is in a horizontal or near-horizontal state, the propeller thrust is vertically upward, and all propeller units 400 accelerate synchronously to provide total lift to overcome gravity and achieve vertical takeoff. When attitude control is performed, the left propeller accelerates and the right propeller decelerates, generating a rolling torque to finely adjust the roll / yaw attitude. During the transition flight phase: the differential speed of the front and rear propellers can cause the tilting frame 200 to tilt forward at a certain angle, and the propeller thrust generates a horizontal component to propel the aircraft forward until the level flight phase. During the landing phase, the frame returns to horizontal, the propellers decelerate, and the aircraft lands smoothly.

[0024] The aforementioned device requires no additional control surfaces or vectoring nozzles; multi-degree-of-freedom control can be achieved solely through motor speed regulation of the propeller assembly 400. The propeller assembly 400, combined with the tilting frame 200, enables a smooth transition between hovering and level flight. It possesses both vertical takeoff and landing capabilities and level flight performance, requiring no runway and adapting to complex takeoff and landing environments such as urban and mountainous areas. The closed frame surrounds the main cabin 300, resulting in symmetrical mass distribution. The rotation axis is located in the middle of the longitudinal link 210, resulting in a short lever arm during tilting, low drive power requirements, and minimal vibration. Multi-dimensional attitude control can be achieved simply by adjusting motor speed, simplifying the flight control system. The multi-propeller arrangement provides power redundancy, allowing for safe return even in the event of a single point of failure. The number of propeller groups can be adjusted according to payload requirements to adapt to different mission scenarios, such as logistics, manned transport, and inspection.

[0025] In one alternative embodiment, the vertical takeoff and landing aircraft 100 further includes: A pair of folding wings 600 are symmetrically arranged on both sides of the main cabin 300. Each folding wing 600 is pivotally connected to the outer end of the longitudinal rod 210 on the corresponding side, so that the folding wings 600 can rotate and unfold or fold relative to the tilting frame 200 as the tilting frame 200 tilts, such as automatically flipping between vertical and horizontal attitudes.

[0026] The folding wings 600 are symmetrically arranged longitudinally in the main cabin 300 to ensure aerodynamic balance and improve flight stability. Each wing is installed at the outer end of the longitudinal strut 210, that is, the end away from the main cabin 300. It adopts a pivot structure, which allows the wing to rotate around the axis. It uses the existing structure (longitudinal strut 210) as support, without the need for additional supports, thus reducing weight. The outer end installation can maximize the wingspan and improve cruise lift. The folding wing 600 is connected to the tilting frame 200 and can be unfolded or folded relative to the tilting frame 200, preferably flipping between vertical and horizontal attitudes. Specifically, this can be achieved through an independent drive unit or through a passive mechanical linkage mechanism 230. When parked or in vertical takeoff and landing (VTOL) attitude, the folding wing 600 is vertically retracted, parallel to or slightly outward of the side wall of the main cabin 300, which helps to reduce the frontal area during VTOL and avoids interfering with the downward airflow of the propeller. In level flight attitude, the propeller assembly 400 drives the tilting frame 200 to rotate, which in turn drives the folding wing 600 to unfold to the horizontal, generating aerodynamic lift as a fixed wing. The propeller thrust is forward, and the propeller does not need to provide more upward thrust, thereby reducing propulsion energy consumption.

[0027] Compared to similar wingless or fixed-wing aircraft, this invention offers the following technical advantages: improved cruise efficiency, extended range; during level flight, the wing provides aerodynamic lift, significantly reducing the thrust required by the propeller, thereby saving energy and increasing range. During takeoff and landing, the wing retracts, avoiding collisions with the ground and obstacles, reducing the need for takeoff and landing space; simultaneously, it reduces propeller wake interference from the wing, improving hovering stability. The structure is simple, lightweight, and highly reliable; the overall width is minimized when retracted, facilitating parking, transportation, or entry into confined spaces. Utilizing existing moving parts (longitudinal strut 210) as the wing carrier enables integrated functional design, demonstrating system-level innovation.

[0028] Specifically, during the vertical takeoff and landing (VTOL) phase, the tilting frame is horizontal relative to the main cabin (tilt angle α is 0°), and the propeller thrust is vertically upward. During forward flight, the frame tilts forward (α is 85~90°) to generate a horizontal thrust component. Furthermore, the aircraft is equipped with a pair of folding wings, which are opened and folded relative to the tilting frame via a wing attitude control unit. This wing attitude control unit can be implemented by an independent wing folding drive motor, or by a linkage mechanism between the wing and the tilting frame, with the wings opening and folding achieved by tilting the frame. This application significantly simplifies the structure through an integrated tilting frame and differential thrust control, achieving high reliability and low energy consumption (level flight power consumption reduced to 30% for multi-rotor configurations), without relying on breakthroughs in high-energy-density battery technology. Its compact design reduces the takeoff and landing space requirement (≤3.5m × 2.5m) to that of traditional compound-wing aircraft.

[0029] In one embodiment, the folding wing 600 is driven to flip by an independent wing folding drive motor, enabling the folding wing to unfold or fold relative to the tilting frame. It is built into the end of the longitudinal strut 210 or installed inside the pivot, and its torque can be increased through a reduction gear set. It can unfold or retract the wing as needed at any stage of flight; it also supports asymmetric operation, making attitude control more precise; and ensures the reliability of the aircraft's actions under low-speed, windless, or inverted flight conditions. The wing can be forcibly retracted before landing to avoid grounding damage; and in case of malfunction, the wing position can be locked to prevent flutter or loss of control.

[0030] like Figure 10-12As shown, in one specific embodiment, the folding wing 600 is connected to the tilting frame 200 via a passive mechanical linkage mechanism 230, and automatically flips as the longitudinal link 210 tilts. During vertical takeoff and landing, the tilting frame 200 is in a horizontal or near-horizontal state, and the folding wing 600 is in a vertically folded state due to the passive mechanical linkage mechanism 230 adhering to the longitudinal link 210; this prevents the wing from obstructing the propeller airflow and ensures stable takeoff and landing. During the transition to forward flight, the tilting frame 200 tilts forward; the longitudinal link 210 drives the folding wing 600 at its outer end to gradually open relative to the tilting frame 200; under the combined action of the differential thrust of the propeller assembly 400 and the aerodynamic lift of the folding wing 600, the folding wing 600 automatically flips around the pivot to a horizontally deployed state; at this time, the wing generates lift, shares part of the load, and improves cruise efficiency. During the return landing phase, the differential thrust of the propeller unit is adjusted to drive the tilting frame 200 back to upright, and the wings subsequently swing back to a vertical attitude, completing the automatic retraction. It has no independent drive mechanism, and only relies on the passive mechanical linkage mechanism 230 to achieve attitude switching; reducing failure points, it is suitable for manned or logistics scenarios with high reliability requirements.

[0031] Furthermore, the folding wing 600 is connected to the tilting frame 200 via a passive mechanical linkage mechanism 230, and automatically unfolds or folds as the longitudinal rod 210 tilts.

[0032] The passive mechanical linkage mechanism 230 can be configured as a linkage mechanism, a gear transmission pair, or a sliding guide pin mechanism. If a linkage mechanism is configured, one end is hinged to the main cabin 300, and the other end is hinged to a linkage on the inner side of the wing, converting the frame tilt angle into the wing opening and folding angle by a proportional 90-degree rotation. The passive mechanical linkage mechanism 230 is connected to both the folding wing 600 and the tilting frame 200, converting the motion of the tilting frame 200 into the unfolding and folding motion of the folding wing 600. It requires no additional motors, cables, or controllers, reducing potential points of failure and improving system reliability. It utilizes the mechanical energy of the frame tilt to complete the wing attitude switching with zero additional energy consumption.

[0033] In one specific embodiment, the passive mechanical linkage mechanism 230 includes: The first helical gear 231 is fixed at the outer end of the main cabin 300, and its central axis is coaxial with the rotation axis of the tiltable frame 200. The second helical gear 232 meshes with the first helical gear 231 at one end and is rotatably connected to the longitudinal rod 210 via a bearing at the other end. The axis of rotation of the second helical gear 232 is along the longitudinal direction of the main cabin 300. The connector 233 has one end fixed to the rotating shaft of the second helical gear 232, and the other end is provided with a sliding member; The lower surface of the folding wing 600 is provided with an arc-shaped slide rail 234, and the sliding component slides in conjunction with the arc-shaped slide rail 234; The first helical gear 231 is fixed to the main cabin 300 and remains stationary. When the tiltable frame 200 tilts relative to the main cabin 300, the tiltable frame 200 rotates synchronously relative to the first helical gear 231, causing the second helical gear 232 to mesh with the first helical gear 231 and drive the second helical gear 232 to rotate around its own rotation axis. Through the connector 233, the sliding member is driven to slide along the arc-shaped slide rail 234, so that the folding wing 600 unfolds or folds relative to the tiltable frame 200.

[0034] The first helical gear 231 is fixed to the main cabin 300 and remains stationary, without rotating relative to the main cabin 300. The central axis of the first helical gear 231 is the same as the rotation axis of the main cabin 300, which is the Y-axis. The second helical gear 232 is mounted on the longitudinal member 210. When the tiltable frame 200 rotates relative to the main cabin 300, it drives the second helical gear 232 to mesh with the first helical gear 231, thus driving the second helical gear 232 to rotate. The second helical gear 232 is located on the longitudinal member 210, and its rotation is parallel to the longitudinal direction of the main cabin 300, i.e., the X-axis. It is set along the front-rear direction of the aircraft and forms a spatial perpendicular mesh with the first helical gear 231 at an angle of 90°, thus achieving smooth transmission. The second helical gear 232 rotates around the X-axis, causing the connecting piece 233 fixed thereto to swing. The sliding piece moves with the connecting piece 233 and slides in the arc-shaped slide 234 on the lower surface of the folding wing 600. The curvature center of the arc-shaped slide 234 is close to the wing pivot, which converts the curved displacement of the sliding piece into the folding wing 600's rotation around the pivot.

[0035] The second helical gear 232 can be connected to the longitudinal rod 210 through a bearing and a bearing housing.

[0036] The specific workflow is as follows: Initial state (parking or vertical take-off and landing stage): the tilting frame 200 is horizontal (0° tilt angle); the folding wing 600 is in a vertically retracted posture; the sliding component is located at one end of the arc-shaped slide 234.

[0037] Forward tilt of the frame (transition from flight to level flight): The propeller assembly 400 drives the entire tiltable frame 200 to tilt forward around the Y-axis (e.g., to 60°); the first helical gear remains stationary; the tiltable frame 200 drives the second helical gear 232 to mesh with the first helical gear 231, and at the same time the second helical gear 232 is driven to rotate around the X-axis; the connecting piece 233 swings, pushing the sliding piece to move along the arc-shaped slide 234; the folding wing 600 is pushed until it reaches a horizontally unfolded attitude.

[0038] Cruise mode: The wings provide aerodynamic lift, reducing energy consumption; The return process is executed in reverse.

[0039] It utilizes the mechanical energy generated by the changes in the aircraft's configuration without requiring additional energy; all components are located at the junction of the wing and longitudinal struts 210, without increasing the overall aircraft envelope. The gear transmission ratio is constant, and the wing roll angle has a strict functional relationship with the frame tilt angle, which facilitates flight control modeling.

[0040] The propeller device 400 is a fixed ducted propeller; in other embodiments, it can also be an open propeller, which can be configured as needed. Specifically, the fixed ducted propeller includes a duct, a propeller, and a propeller drive assembly. Both the propeller drive assembly and the propeller are located inside the duct, and the propeller is connected to the duct via the propeller drive assembly; the duct and the corresponding transverse rod 220 are integrally formed.

[0041] The duct is an annular shell that surrounds the propeller, serving to rectify, pressurize, and protect it. The propeller provides thrust, and the propeller drives the components, including the motor, reducer, and mounting bracket, all of which are located inside the duct, forming a closed or semi-closed power unit. The propeller is fixed to the duct via the drive components. The duct and the transverse strut 220 are integrally designed and molded from carbon fiber, which strengthens the structural mechanics of the duct as a tilting frame and optimizes the aerodynamic shape, reducing interference resistance between the strut and the duct.

[0042] In another embodiment, the propeller assembly 400 is in three or four sets; when it is set to four sets, each transverse link 220 has a propeller assembly 400 at both ends along its length, and the four sets of propeller assemblies 400 are symmetrically arranged along the longitudinal center plane of the tilting frame 200. A propeller assembly 400 is installed at the left and right ends of each transverse link 220, and the four sets of propeller assemblies 400 are symmetrically arranged through the longitudinal center plane, which is a symmetrical plane passing through the centerline of the main cabin 300 in the fore-and-aft direction and perpendicular to the ground; this ensures that the line of action of the resultant thrust passes through the aircraft's center of gravity, avoiding yaw moment.

[0043] In another embodiment, when the propeller device 400 is set to three sets, two sets of propeller devices 400 are set on the transverse rod 220 at the top of the main cabin 300, and one set of propeller devices 400 is set on the transverse rod 220 at the bottom of the main cabin 300. The number of sets can be set as needed, and all are within the protection scope of this application.

[0044] In one optional embodiment, the main cabin 300 includes a cabin body 301 and a canopy 302. The canopy 302 is located on top of the cabin body 301 and is hinged to it. The cabin body 301 is used to accommodate occupants or payloads and to install landing gear 500, etc. The canopy 302 is an openable closed component. The canopy 302 is located above the main cabin 300 to avoid interference from the wings / propellers when the side doors open. The top opening facilitates vertical entry and exit, which is especially suitable for narrow take-off and landing platforms. It reduces aerodynamic drag during flight. The canopy 302 is opened and closed by hinges or pivots, avoiding the propeller downwash airflow area, making opening and closing safer. It is convenient for operation in confined spaces such as rooftops and ship decks. It provides a wide field of vision, which is beneficial for occupants to observe the environment above. Specifically, the canopy 302 rotates open from front to rear, and after opening, occupants can enter the interior of the occupant cabin from the front. By optimizing the layout of the passenger compartment, heavier components such as the power battery and electronic control system, as well as the weight of the occupants themselves, are placed below the center of rotation of the passenger compartment. Figure 8 , 9 As shown, the center of gravity of the crew cabin is roughly located below the center of rotation. L = 9 × A (projected area along the wind direction) × d (distance from aerodynamic force to the axis of rotation) / m (total mass of the aircraft). The gravitational torque autonomously cancels out the tilt disturbance, eliminating the need for an active stabilization system (such as a gyroscope / trimming motor).

[0045] Setting principle: Considering the aerodynamic loads (such as crosswinds and turbulence) experienced by the frame and wings during flight, which are related to the aerodynamic force (Fa) and the distance (d) from its point of application to the axis of rotation, i.e. According to the static stability design requirements for aircraft, the restoring moment is typically required to be ≥ 1.3 times the disturbance moment, that is: Based on the most demanding flight envelope conditions (such as encountering a crosswind while hovering), the aerodynamic disturbance force can be approximated as: Fa=1 / 2·ρ·v 2 ·Cd·A in: ρ: Air density (1.225 kg / m³ at sea level) v: Gust velocity (15 m / s according to EASA CS-23 standard) Cd: Aerodynamic drag coefficient (approximately 0.5) A: Windward area (projected area along the wind direction) Therefore: L≥1.3·0.5 ·ρ·v 2 ·Cd·A·d / (m·g)≈9·A·d / m.

[0046] Furthermore, the main cabin 300 is equipped with at least one passenger seat, which is fixed to the bottom of the cabin 301 and located near the aircraft's center of gravity to improve flight stability. Occupants can enter and exit vertically through the top, avoiding interference from the propeller or folding wings 600 when the side doors open. In emergencies, passengers can eject or evacuate quickly. The seat can be configured as a single or double seat and is equipped with safety devices. A control panel or foot pedal is located in front of the seat. A battery module 303, an electronic control module 304, or storage space are located under the passenger seat, enabling space reuse. This layout, based on gravity, ensures that regardless of the rotation of the tilting frame 200, the main cabin 300 maintains a vertical seating position throughout the entire flight (including vertical takeoff and landing, transitional flight, and level flight), without requiring electrical adjustments to the cabin's attitude.

[0047] The following explanation uses a four-propeller configuration 400 as an example. Figure 8 As shown, F1, F2, F3, and F4 represent the thrust of the four propeller units 400, respectively; L X L is the distance between each propeller assembly 400 and the center of rotation along the X-axis; Z The distance between each propeller assembly 400 and the center of rotation along the Z-axis; during takeoff and landing, the four rotors output force uniformly, with thrust F. 3,4 ≈F 1,2 Total thrust = payload × (gravitational acceleration + vertical acceleration) / rotor efficiency (η≥0.75). This process is comparable to the energy consumption of multi-rotor aircraft.

[0048] Transition takeoff phase: rotor thrust F 3,4 >F 1,2 This generates a tilting moment of the frame relative to the crew cabin, causing the frame and propeller to rotate relative to the main cabin 300. Simultaneously, the wings open via the passive mechanical linkage 230. The transition landing phase uses the reverse operation. This process does not use an additional electrical system to drive the frame tilting and wing opening / closing, reducing the total power consumption to 50% of that of aircraft using electric propeller tilting and electric motor wing opening / closing.

[0049] Level flight phase: When the aircraft is in level flight, the lift from the wings offsets the gravity caused by the folded wings, reducing the power requirement for the propeller motors to overcome the tilting moment. The wings provide 80% of the lift, and the propeller assembly provides only 20% of the thrust, reducing the total power consumption to 30% of that of a multi-rotor aircraft.

[0050] The frame tilting and wing deployment are fully synchronized, requiring a takeoff and landing area of ​​≤3.5m×2.5m (compared to ≥10m×10m for traditional compound wings). The takeoff and landing space is roughly equivalent to the size of a small car parking space. The aircraft is equipped with radar around its perimeter. During takeoff and landing, the wings are folded, and the aircraft uses a quadcopter for vertical takeoff and landing. Once the controller detects no obstacles in the surrounding area, it transitions to a transitional takeoff phase.

[0051] It has vertical takeoff and landing capabilities: Take-off and landing area requirements: 0m runway (pure vertical take-off and landing), area size ≤ 3.5m × 2.5m, only the size of a parking lot. For example... Figure 4 As shown, no additional large-scale parking facilities are needed, facilitating commercial operation in urban settings.

[0052] Breakthrough in energy efficiency: Energy consumption is only 14kWh / 100km, equivalent to that of a conventional electric vehicle. This low energy consumption means the aircraft does not rely on breakthroughs in high-energy-density battery technology; conventional lithium-ion batteries (energy density 200Wh / kg) are sufficient, representing a 400% improvement compared to multi-rotor aircraft.

[0053] Simplified structure and reliability: Number of moving parts: <20 (traditional compound wings >500), failure rate reduced to 0.05% / thousand hours.

[0054] In the first embodiment, the aircraft is configured as a single-person electric aircraft with the following power: total motor power of 80kW, total battery energy of 5kWh, and battery energy density of 200Wh / kg. Range: 40km (maximum total flight mass 190kg, cruising speed 95km / h); takeoff and landing area: 3.5m × 2.5m (meeting urban rooftop helipad standards).

[0055] In the second embodiment, the aircraft is configured as a two-person electric aircraft; its structure includes a widened crew cabin to accommodate two people, solar panels on the upper surface of the wings, and a total power of 1.5kW; power source: a total motor power of 120kW, a total battery energy of 25kWh, and a battery energy density of 200Wh / kg; range: 200km (maximum total flight mass of 350kg, cruising speed of 130km / h); takeoff and landing area: 4m×3m (meeting the standards of urban rooftop helipads).

[0056] In the third embodiment, the aircraft is configured as a medium-sized unmanned cargo aircraft, which eliminates the crew cabin and replaces it with a cargo transport cabin (maximum takeoff weight 150kg, maximum cargo weight 50kg); and adopts an automatic cargo center of gravity calibration algorithm based on pressure sensor feedback.

[0057] This application significantly simplifies the structure through an integrated tilting frame and differential thrust control, achieving high reliability and low energy consumption (energy consumption in level flight is reduced to 30% compared to rotor configurations), without relying on breakthroughs in high-energy-density battery technology. Its compact design reduces takeoff and landing space requirements (≤3.5m × 2.5m) to that of traditional compound-wing aircraft.

[0058] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0059] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A vertical takeoff and landing aircraft, characterized in that, include: The main cabin and landing gear, wherein the landing gear is located at the bottom of the main cabin and is used to support the main cabin; The tilting frame is a closed frame structure, which includes two opposing longitudinal members. The two longitudinal members are symmetrically arranged on both sides of the main cabin, and the middle part of either longitudinal member is pivotally connected to the side of the main cabin via a rotating shaft, so that the tilting frame can tilt relative to the main cabin in the vertical plane. At least two propeller units are located on the tilting frame. The at least two propeller units are configured to adjust the angle of the tilting frame relative to the main cabin by adjusting their respective rotational speeds to generate differential thrust, thereby controlling the spatial attitude of the vertical take-off and landing aircraft for vertical take-off and landing, transition and level flight.

2. The vertical takeoff and landing aircraft according to claim 1, characterized in that, Also includes: A pair of folding wings are symmetrically arranged on both sides of the main cabin. Each folding wing is pivotally connected to the outer end of the longitudinal strut on the corresponding side. The folding wings are unfolded or folded relative to the tiltable frame through a wing attitude adjustment system.

3. The vertical takeoff and landing aircraft according to claim 2, characterized in that, The wing attitude adjustment system includes a drive motor; The folding wing is driven by the drive motor to unfold or fold the folding wing relative to the tilting frame.

4. The vertical takeoff and landing aircraft according to claim 2, characterized in that, The wing attitude adjustment system includes a passive mechanical linkage mechanism; The folding wing is connected to the tiltable frame via the passive mechanical linkage mechanism, so that the folding wing can unfold or fold relative to the tiltable frame as the longitudinal rod tilts.

5. The vertical takeoff and landing aircraft according to claim 4, characterized in that, The passive mechanical linkage mechanism includes: The first helical gear is fixed to the side of the main cabin, and its central axis is coaxial with the rotation axis of the tiltable frame; The second helical gear meshes with the first helical gear at one end, and is rotatably connected to the longitudinal rod via a bearing at the other end. The axis of rotation of the second helical gear is parallel to the longitudinal direction of the main cabin. The connector has one end fixed to the rotating shaft of the second helical gear and the other end provided with a sliding element; The lower surface of the folding wing is provided with an arc-shaped slide rail, and the sliding member slides in cooperation with the arc-shaped slide rail; The first helical gear is fixed to the main cabin and remains stationary. When the tiltable frame tilts relative to the main cabin, the tiltable frame rotates synchronously relative to the first helical gear, causing the second helical gear to mesh with the first helical gear and drive the second helical gear to rotate around its own rotation axis. Through the connecting member, the sliding member is driven to slide along the arc-shaped slide rail, so that the folding wing unfolds or folds relative to the tiltable frame.

6. The vertical takeoff and landing aircraft according to any one of claims 1-5, characterized in that, The propeller device is a fixed ducted propeller; The fixed ducted propeller includes a duct, a propeller, and a propeller drive assembly. Both the propeller drive assembly and the propeller are located inside the duct, and the propeller is connected to the duct via the propeller drive assembly. The duct and the corresponding tilting frame are integrally formed.

7. The vertical takeoff and landing aircraft according to claim 6, characterized in that, The closed frame structure also includes two opposing transverse members, and the longitudinal member and the transverse member are connected end to end to form the closed frame structure; The propeller assembly consists of four sets, with one set of the propeller assembly located at each end of the length direction of each transverse member. The four sets of propeller assemblies are symmetrically arranged about the longitudinal center plane of the tilting frame.

8. The vertical takeoff and landing aircraft according to claim 7, characterized in that, The main cabin includes a cabin body and a hatch. The hatch is located on top of the cabin body and is hinged to the cabin body to enable opening and closing.

9. The vertical takeoff and landing aircraft according to claim 8, characterized in that, The main cabin is equipped with at least one manned seat, which is fixed to the bottom of the cabin and located at the center of gravity of the vertical takeoff and landing aircraft; the center of gravity of the vertical takeoff and landing aircraft is located below the rotation center of the rotatable frame.

10. The vertical takeoff and landing aircraft according to claim 6, characterized in that, The closed frame is a rectangular frame, and the tiltable frame is arranged around the outer contour of the main cabin.

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