Compound high-speed helicopter based on tilting tail and retractable wings
By designing a tilting tail thruster and a retractable wing, combined with a differential anti-torsion propeller and a tilting dual-duct tail thruster, the tail boom dynamics problem of the compound helicopter was solved, the rotor control system was simplified, hovering efficiency and high-speed flight performance were improved, and higher hovering efficiency and forward flight speed were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NANJING UNIV OF AERONAUTICS & ASTRONAUTICS
- Filing Date
- 2026-01-16
- Publication Date
- 2026-06-12
AI Technical Summary
Existing compound helicopters suffer from problems such as dynamic issues caused by tail boom structure, high power consumption of tail rotor, low hovering efficiency, insufficient high-speed flight performance, complex structure, and low reliability. Moreover, existing designs have failed to effectively solve the high-speed flight bottleneck of traditional helicopters.
By adopting a tilt-tail thruster and retractable wing design, the cyclic pitch control is eliminated. A differential anti-torsion propeller and a tilt-tail thruster are used, combined with a retractable wing and an independently controlled propeller, to achieve power integration between the main rotor and the propulsion system, simplify the rotor control system, and provide additional lift and thrust through the tilt-tail thruster.
It improves hovering efficiency and stability, simplifies rotor control, reduces system complexity and weight, enhances high-speed flight performance, provides control redundancy and new flight modes, and achieves higher hovering efficiency and forward flight speed.
Smart Images
Figure CN122186392A_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of aircraft technology, specifically relating to a composite high-speed helicopter configuration based on tilt-tail thrust and telescopic wings. Background Technology
[0002] The helicopter industry has long relied on the traditional main rotor plus tail rotor configuration. The tail boom, as a key load-bearing structure, reduces tail rotor size and power consumption by providing a large lever arm, while also achieving flight stability control through the tail plane. To overcome the bottleneck of traditional helicopter horizontal flight speed, the industry has gradually developed two major improvement directions: compound helicopters and thrust-reversing aircraft. The former adds wing surfaces and auxiliary propulsion units to share the lift and propulsion tasks of the main rotor, while the latter uses a tiltrotor as its core, combining the hovering ability of a helicopter with the high-speed cruise performance of a fixed-wing aircraft. Both solutions aim to adapt to diverse mission profile requirements by integrating the technical attributes of fixed-wing aircraft.
[0003] To address the pain points of traditional helicopters, such as main rotor overload and tail boom-induced dynamic problems, existing technological approaches fall into two categories. The first is the thrust-reversing aircraft approach, typically represented by tiltrotor aircraft. This employs a combined wing structure on both sides of the fuselage, with tiltable ductless rotor mechanisms mounted at the wingtips. The rotor provides vertical lift during hovering and horizontal thrust during cruise, achieving a high speed of approximately 400 knots. The second is the compound helicopter approach, subdivided into lift-compound, thrust-compound, and hybrid-compound types. Lift-compound helicopters improve load factor and maneuverability by adding wing surfaces; thrust-compound helicopters utilize horizontal auxiliary propulsion units to share the main rotor's propulsion load; some designs employ a dual propulsion unit design to replace the tail rotor and offset torque; and hybrid-compound helicopters combine wing surfaces and propulsion units, allowing the main rotor to be in a driven or autorotating state during cruise, thus overcoming the dual limits of rotor lift and thrust. Furthermore, some designs attempt to eliminate the tail rotor and coaxial counter-rotating rotor system to further simplify the power structure.
[0004] Exemplary compound helicopters having two wing-mounted propulsion units defining the aforementioned propulsion units are described in patent documents EP2146896A1, EP2690010B1, EP2690011A1, EP3141478B1, EP3486171A1, and US2013 / 0175385A1. These exemplary compound helicopters all have the fixed-wing configuration described below. However, all of the aforementioned compound helicopters have disadvantages when used as high-speed helicopters because their fixed-wing configurations are not optimized for high-speed operation. Furthermore, the aforementioned compound helicopters all feature a tail boom that negatively impacts the overall dynamic performance of the helicopter.
[0005] Document EP3385160B1 describes a helicopter having: a fuselage; a main rotor system connected to the fuselage and configured to rotate in the rotor direction; the helicopter does not include a tail rotor system or a counter-rotating rotor system coaxial with the main rotor system. Roll and yaw control are achieved via flaps on the wing surfaces. This design offers advantages such as structural simplification, reduced drag, and high-speed performance. However, the hovering efficiency of the aircraft is relatively low in hovering conditions.
[0006] Patent documents CN202211073301, CN202111169721, CN201821948364, CN202311332689, and CN201810517681 describe various hybrid unmanned aerial vehicle (UAV) configurations. Among them, fixed-wing / rotor hybrid UAVs typically employ rotatable or adjustable main wing components to achieve transitions between vertical takeoff and landing (VTOL) and level flight modes. However, such configurations generally suffer from structural complexity, significant aerodynamic interference, and poor controllability during mode transitions. Furthermore, they often rely on complex mechanical transmissions and high-precision flight control systems, increasing system weight and the risk of failure. While retractable wing designs can effectively reduce storage space, the wing retraction mechanism often affects the wing's structural strength and aerodynamic shape. In the retracted state, it disrupts the aerodynamic layout, thereby impacting flight stability and safety. The above-mentioned technical solutions suffer from complex system structures, heavy weight, and low reliability; significant aerodynamic interference exists between rotor and fixed-wing systems, and among multiple power units; mode transitions are unstable and lack controllability; flight control systems are complex and highly dependent on sensors and algorithms; and there is an inherent contradiction between the high power required for vertical takeoff and landing and the high aerodynamic efficiency pursued for high-speed cruise. Therefore, there is an urgent need for a new type of composite UAV solution with a simple structure, smooth transitions, high aerodynamic efficiency, and reliable control to further improve its overall performance and practicality.
[0007] Existing technological solutions still have many shortcomings that need to be overcome. The tail boom problem of traditional helicopters has not been completely solved, and most compound helicopters still retain the tail boom structure, resulting in persistent risks of tail flutter, structural fatigue, and ground impact. In addition, heavy detachable joints increase the overall weight and cost of the aircraft. Thrust-reversing aircraft have not optimized their fixed-wing structures for high-speed conditions, and their performance potential has not been fully realized. As for compound helicopters, existing fixed-wing designs are also not adapted to the requirements of high-speed flight; some tail boom-less designs have unreasonable wing surface layouts, with large-span wing surfaces located directly below the main rotor. During hovering, they are subject to severe vibrations caused by the downwash of the main rotor, and long drive shafts or transmission links place extremely high demands on wing surface stiffness. Furthermore, these designs lack sufficient stabilizing surfaces, making it difficult to ensure directional and longitudinal flight stability, thus restricting the improvement of overall aircraft performance. Summary of the Invention
[0008] To address the aforementioned issues, this application provides a composite high-speed helicopter configuration based on tilt-tail thruster and telescopic wing. The aim is to reduce the interference of the fixed wing on the main rotor during hovering through a unique structural design, simplify the main rotor control system, and integrate anti-torque and propulsion functions, thereby achieving higher hovering efficiency and forward flight speed.
[0009] This application provides the following technical solution: a compound high-speed helicopter configuration based on tilt-tail thruster and retractable wing, including fuselage 1, main rotor system, wing system and propulsion system. The main rotor system includes four main rotors 2. The main rotors 2 are only equipped with a collective pitch control structure and do not have a periodic pitch control structure. The wing system consists of a fuselage 1 and a left wing 3 and a right wing 4 respectively connected to both sides of the fuselage 1. Both the left wing 3 and the right wing 4 are wings that can extend and retract along the wingspan direction. The propulsion system includes a differential anti-torsion propeller assembly and a tilting double-ducted tail thruster 8. The differential anti-torsion propeller assembly consists of a left propeller 6 and a right propeller 7. The left propeller 6 is mounted on the left wing 3, and the right propeller 7 is mounted on the right wing 4. The rotational speeds of the left propeller 6 and the right propeller 7 can be independently adjusted to achieve differential operation. The tilting dual-duct tail thruster 8 is installed at the tail of the fuselage 1 and can tilt around the transverse axis. It has two ducted fans arranged side by side inside, and the thrust of the two ducted fans can be controlled independently.
[0010] Furthermore, the left wing 3 and the right wing 4 are connected to the fuselage 1 by a wing-body blending connection.
[0011] Furthermore, the left propeller 6 and the right propeller 7 are respectively installed at the wingtips of the left wing 3 and the right wing 4.
[0012] Furthermore, the tilting action of the tilting double-duct tail thruster 8 is driven by a servo motor or a hydraulic actuator.
[0013] Furthermore, the helicopter also includes a control system connected to a flight control computer, which is configured to: In hovering and low-speed flight, the left wing 3 and right wing 4 are kept in a retracted state, the tilting twin-duct tail thruster 8 is tilted upward, and the rotational speeds of the left propeller 6 and right propeller 7 are differentially controlled to balance the counter-torque generated by the main rotor 2. In high-speed forward flight, control the left wing 3 and right wing 4 to switch to the extended state, and control the tilting twin-ducted tail thruster 8 to tilt forward to provide forward flight thrust.
[0014] Beneficial effects:
[0015] 1. High hovering efficiency: The retractable wing retracts during takeoff and landing, greatly reducing the area obstructing the downwash airflow of the main rotor, allowing more airflow to accelerate downwards, thus improving hovering lift efficiency and stability.
[0016] 2. Simplified operation and high reliability: The main rotor eliminates the complex cyclic pitch control system and retains only collective pitch control, which greatly simplifies the rotor head structure, reduces manufacturing costs and maintenance difficulty, and improves reliability.
[0017] 3. High integration of powertrain and excellent high-speed performance: a. After the wings extend and retract, greater lift is obtained during high-speed forward flight, effectively unloading the main rotor, allowing the main rotor to operate with less thrust, delaying the arrival of shock waves and stall, and breaking through speed limits.
[0018] b. The wingtip propeller has both anti-torsion hovering and auxiliary propulsion forward flight functions, while the tail thruster has both auxiliary lift hovering and main propulsion forward flight functions. The system has a high degree of functional integration and significant weight and drag benefits.
[0019] 4. Control redundancy and new modes: Pitch and roll control can be achieved jointly or selectively by differential propeller thrust to generate roll torque, adjustable horizontal stabilizer if available, and tilt tail thrust to change thrust vector to generate pitch torque, providing control redundancy and potentially enabling new agile flight modes. Attached Figure Description
[0020] Figure 1(a), Figure 1(b), and Figure 1(c) in Figure 1 are respectively a three-dimensional structural schematic diagram of the hovering / take-off and landing state and a partial schematic diagram of the wing retraction and tail thrust tilt in the hovering / take-off and landing state in the embodiment of this application. Figure 2(a) and Figure 2(b) in Figure 2 are respectively a three-dimensional structural schematic diagram of the embodiment of this application in the high-speed forward flight state and a partial schematic diagram of the tail thrust tilted forward in the high-speed forward flight state; Figures 3(a), 3(b), 3(c), and 3(d) in Figure 3 are enlarged schematic diagrams of the connection structure between the wing and the fuselage, respectively. Figure 4 This is a schematic diagram of the tilting double-duct tail thruster in the embodiments of this application; Figure 5 This is a block diagram of the flight control logic in the embodiments of this application; Explanation of the labels in the diagram: 1-Fuselage; 2-Main rotor; 3-Left wing; 4-Right wing; 5-Tail; 6-Left wingtip propeller; 7-Right wingtip propeller; 8-Tilted twin-ducted tail thruster; 81-Left ducted fan; 82-Right ducted fan. Detailed Implementation
[0021] 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.
[0022] As shown in Figures 1(a), 1(b), 1(c) and 2(a), 2(b), this application discloses a composite high-speed helicopter configuration based on tilt-tail thruster and telescopic wing, including a fuselage 1, a main rotor system, a wing system, and a propulsion system. The main rotor system includes four main rotors 2 that are equipped with collective pitch control but not cyclic pitch control; The wing system includes a fuselage 1 and a left wing 3 and a right wing 4 connected on both sides. The left wing 3 and the right wing 4 are wings that can extend and retract along the wingspan direction. The propulsion system includes: The differential anti-torsion propeller assembly consists of a left propeller 6 and a right propeller 7 respectively mounted on the left wing 3 and the right wing 4. The rotational speeds of the left propeller 6 and the right propeller 7 can be independently controlled to achieve differential operation. In hovering and low-speed states, the rotational speeds of the two propellers are changed differentially to generate yaw torque, thereby balancing the counter-torque generated by the main rotor and replacing the function of the traditional tail rotor.
[0023] A tilting dual-ducted tail thruster 8 is installed at the tail of the fuselage 1. It can tilt around the lateral axis and has two independently controllable ducted fans arranged side by side inside. At the tail of the fuselage, there is a tail thruster unit that can tilt around the lateral axis. Two ducted fans are arranged side by side inside this tail thruster unit. In takeoff, landing, and hovering states, the tail thruster unit tilts upward, so that the thrust vector of the ducted fans is upward, providing additional lift or pitch trim moment; in high-speed forward flight, the tail thruster unit tilts forward to a horizontal or near-horizontal position, so that the thrust vector of the ducted fans is forward. As the main propulsion device, the main rotor 2 is installed on the top of the fuselage 1. This rotor system collectively changes lift only by changing the collective pitch of the blades, without cyclic pitch control.
[0024] The left wing 3 and right wing 4 are connected to the fuselage 1 by wing-body blending.
[0025] The left propeller 6 and the right propeller 7 are respectively mounted at the wingtips of the left wing 3 and the right wing 4.
[0026] The helicopter also includes a control system connected to a flight control computer, which is configured to: in hovering and low-speed states, control the left wing 3 and right wing 4 to be in a retracted state, control the tilt-double-ducted tail thruster 8 to tilt upwards, and balance the counter-torque by differentially controlling the rotational speeds of the left propeller 6 and right propeller 7; in high-speed forward flight states, control the left wing 3 and right wing 4 to be in an extended state, and control the tilt-double-ducted tail thruster 8 to tilt forward to provide forward thrust.
[0027] The fuselage 1 is connected to the left wing 3 and the right wing 4 by wing-body fusion. The wings are equipped with an electric motor-driven telescopic mechanism (not shown in the figure), which can extend and retract the entire wing along a rail. Figure 1 shows the retracted state, with the wingspan at its minimum; Figures 2(a) and 2(b) show the extended state, with the wingspan at its maximum.
[0028] The left wingtip propeller 6 and the right wingtip propeller 7 are respectively installed at the wingtips of the left wing 3 and the right wing 4. These two propellers are driven by independent electric motors or through drive shafts, and their differential speeds can be precisely controlled by an electronic control system.
[0029] As shown in Figure 1(a), Figure 1(b), Figure 1(c), Figure 2(a), Figure 2(b) and Figure 4 As shown, a tilting dual-ducted tail thruster 8 is installed at the tail of the fuselage 1. This device is mounted on the fuselage 1 via bearings and can tilt around the lateral tilting axis by a servo motor. Inside, a left ducted fan 81 and a right ducted fan 82 are installed side by side, and their thrust can be adjusted independently.
[0030] Work process: Vertical Takeoff and Landing (VTOL) and Hovering Modes (Figures 1(a), 1(b), and 1(c)): Wings 3 and 4 are retracted to their shortest position. The main rotor 2 provides the primary lift. The left and right wingtip propellers 6 and 7 operate differentially according to the flight control law, generating yaw torque to balance the main rotor's anti-torque and assisting in yaw control. The tilt-tail thruster 8 tilts upward (e.g., vertically upward or slightly forward), and its thrust provides an upward lift component, assisting in lift or pitch trim. Pitch and roll control are mainly achieved by adjusting the thrust difference between the left and right wingtip propellers 6 and 7 (generating roll torque) and adjusting the thrust vector direction of the tilt-tail thruster 8 (generating pitch torque). Transition and high-speed forward flight mode (Figures 2(a) and 2(b)): As airspeed increases, the control system instructs wings 3 and 4 to gradually extend outward to increase the lifting area of the fixed wing. Simultaneously, the collective pitch of the main rotor 2 gradually decreases, and lift is primarily transferred to the fixed wing. The tilt-and-turn thruster 8 gradually tilts forward until the thrust vector is horizontally forward, becoming the primary propulsive force. Wingtip propellers 6 and 7 can switch to uniform speed operation in the same direction or differential speed operation as needed, primarily providing auxiliary propulsion; they can still assist in yaw control during differential operation. Pitch and roll control can transition to being primarily controlled by movable surfaces (such as ailerons and elevators), with other systems playing a secondary role.
[0031] Figure 5 The basic flight control logic is demonstrated: the flight control computer receives control commands and sensor signals, performs comprehensive calculations, and then sends control commands to the main rotor collective pitch mechanism, wing extension mechanism, left / right propeller motors, tail thrust tilt mechanism, and tail thrust left / right fans to collaboratively complete flight attitude and trajectory control.
[0032] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to interchangeably. Each embodiment focuses on its differences from other embodiments. In particular, for the device embodiments, the above descriptions are merely preferred embodiments of the present invention. Since they are fundamentally similar to the method embodiments, the descriptions are relatively simple, and relevant parts can be referred to the descriptions of the method embodiments. The above descriptions are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention, without departing from the principle of the present invention, should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A composite high-speed helicopter configuration based on tilt-tail thruster and telescopic wing, comprising a fuselage (1), a main rotor system, a wing system, and a propulsion system, characterized in that: The main rotor system includes four main rotors (2), and the main rotors (2) are only configured with collective pitch control structure and do not have periodic pitch control structure; The wing system consists of a fuselage (1) and a left wing (3) and a right wing (4) connected to the two sides of the fuselage (1), respectively. The left wing (3) and the right wing (4) are both wings that can extend and retract along the wingspan direction. The propulsion system includes a differential anti-torsion propeller assembly and a tilting double-duct tail thruster (8): The differential anti-torsion propeller assembly consists of a left propeller (6) and a right propeller (7). The left propeller (6) is mounted on the left wing (3), and the right propeller (7) is mounted on the right wing (4). The rotational speeds of the left propeller (6) and the right propeller (7) can be independently adjusted to achieve differential operation. The tilting double-duct tail thrust device (8) is installed at the tail of the fuselage (1) and can tilt around the transverse axis. It has two duct fans arranged side by side inside, and the thrust of the two duct fans can be controlled independently.
2. The composite high-speed helicopter configuration based on tilt-tail thruster and telescopic wing as described in claim 1, characterized in that: The left wing (3), right wing (4) and fuselage (1) are connected by wing-body blending.
3. The composite high-speed helicopter configuration based on tilt-tail thruster and telescopic wing as described in claim 1, characterized in that: The left propeller (6) and the right propeller (7) are respectively installed at the wingtips of the left wing (3) and the right wing (4).
4. The composite high-speed helicopter configuration based on tilt-tail thruster and telescopic wing as described in claim 1, characterized in that: The tilting action of the tilting double-duct tail thruster (8) is driven by a servo motor or a hydraulic actuator.
5. The composite high-speed helicopter configuration based on tilt-tail thruster and telescopic wing according to any one of claims 1 to 4, characterized in that: The helicopter also includes a control system connected to a flight control computer, the control system being configured to: In hovering and low-speed flight, the left wing (3) and right wing (4) are kept in a retracted state, the tilting double-duct tail thruster (8) is tilted upward, and the rotation speed of the left propeller (6) and right propeller (7) is controlled differentially to balance the counter-torque generated by the main rotor (2). In high-speed forward flight, control the left wing (3) and right wing (4) to switch to extended state, and control the tilting double-ducted tail thruster (8) to tilt forward to provide forward flight thrust.