Aircraft with drive propellers below the wings

Description

Field of invention

[0001] The present invention relates to an aircraft suitable for vertical flight and horizontal flight. Background of the invention

[0002] The aircraft shown in disclosures US 1,872,845, DE202017006138U1, DE202019000936U1, DE202019002731U1, and EP21210288.3 have so-called "tilted wings" (i.e., wing sections that can be tilted) and "tiltrotors" (i.e., propellers) attached to each of these, thus enabling a meaningful separation of climb (vertical) and speed flight (horizontal). In the prior art aircraft, for vertical flight (vertical takeoff), all wing sections are tilted from their horizontal position by approximately 90 degrees such that all propellers are located above the wings. The airflow generated by the rotation of the propellers therefore flows towards the ground, resulting in a lift force at each propeller that is directed vertically upwards, i.e., away from the ground.

[0003] When all propellers are arranged above the wings during vertical flight, as in the prior art, and then oriented forward (for the front propellers) and aft (for the rear propellers) for level flight, it is necessary, depending on the flight direction, either to reverse the direction of rotation of the corresponding propeller rotors or to change the blade pitch angle of the corresponding propeller rotors. Otherwise, the airflow caused by the rotation of the front propeller rotors would flow in the opposite direction to the airflow caused by the rotation of the rear propeller rotors. Such opposing airflow would, among other things, cause the aircraft to circle during level flight instead of moving in the desired direction.

[0004] However, reversing the direction of rotation of the propeller rotors or changing the blade pitch angle of the propeller rotors must be precise, rapid, and perfectly timed. This, in turn, requires an additional, high-performance control unit that precisely manages the corresponding steps. Therefore, the transition from vertical to horizontal flight in state-of-the-art aircraft is a complex and safety-critical undertaking. If the reversal of the direction of rotation or the change in the blade pitch angle of the propeller rotors is not controlled with sufficient precision by the control unit (e.g., due to a fault in the control unit), the situation can escalate.(e.g., a malfunction in one of the control processes) can cause the propeller rotors to remain stationary for too long or the driving force to be not optimally directed, which in turn can lead to performance losses in the acceleration of the aircraft, to turbulence such as rotational, rolling, lurching or jerking movements, to an unplanned and sudden drop of the aircraft and / or in the worst case even to a crash of the aircraft. Object of the invention

[0005] It is therefore an object of the invention to provide an aircraft that overcomes the disadvantages of the prior art, particularly in light of simplicity and efficiency.

[0006] Another task is to provide an aircraft that enables a simplified transition from vertical flight to horizontal flight or vice versa.

[0007] Another task is to provide an aircraft with a more efficient and durable propulsion system.

[0008] These problems are solved by realizing at least some of the characterizing features of the independent claims. Features that further develop the invention in an alternative or advantageous way can be found in some of the remaining features of the independent claims and in the dependent claims. Summary of the invention

[0009] The invention relates to an aircraft suitable for vertical and horizontal flight, wherein the aircraft has a transport cabin, in particular a passenger cabin, and two wings arranged on the transport cabin, in particular on a roof of the transport cabin, wherein Each of the two wings has a first and a second wing section, each of the wing sections being attached relative to the remaining wing ("remaining wing" equals "wing" minus "wing sections"), in particular being designed to pivot about a respective pivot axis by up to 90 degrees, each of the wing sections having: at least one propeller which is rotatably mounted in the wing section about an axis of rotation and which is arranged opposite at least a major part of the wing section with respect to the pivot axis, wherein the propeller is substantially perpendicular to a chord line of the wing section, a propeller motor designed for rotating the propeller, and a first gearbox for the operative connection between the propeller and the propeller motor. where the first wing section of the respective wing is pivotable such that, in the pivoted state, the propeller of the first wing section is located above the wing, the second wing section of the respective wing is pivotable such that, in the pivoted state, the propeller of the second wing section is located below the wing, and each wing has at least one pivoting means, wherein the at least one pivoting means can be used to pivot and / or return the pivot of the first and / or the second wing section, wherein the aircraft has two auxiliary wings, one of the two auxiliary wings being arranged on a longitudinal side, in particular on a lower region of the longitudinal side, of the transport cabin. wherein the two auxiliary wings are designed to generate a velocity-proportional counter-moment by means of which an increased air resistance of the aircraft, in particular due to the transport cabin and / or the touch protection, can be compensated, thereby preventing a pitching movement of the front of the aircraft, especially during level flight and thus stabilizing the flight characteristics of the aircraft.

[0010] The aircraft according to the invention has, among other advantages over aircraft of the prior art, that the propeller of the respective second wing section is located below the respective wing during the transition from vertical flight (take-off) to horizontal flight. A reversal of the direction of rotation of the propeller rotors of the respective first wing section or the respective second wing section (depending on which wing section provides the front propeller and which the rear propeller, and depending on the direction of flight), or a change in the blade pitch angle of the propeller rotors and thus the reversal of the direction of the driving force (or lift) of the corresponding propeller, for example by means of a pitch control, can be avoided.

[0011] Due to the inventive arrangement of the respective second wing part below the respective wing, as soon as the position of the wing parts and thus the propellers for level flight has been assumed, the airflows of the airflows caused by the rotation of the propeller rotors of the front propellers are directed in the same direction as the airflows caused by the rotation of the propeller rotors of the rear propellers.

[0012] The aircraft according to the invention can therefore move in a controlled manner in the direction of flight without reversing the direction of rotation or changing the blade pitch angles of the propeller rotors of the respective first or second wing section. This eliminates the need for a powerful control unit and corresponding complex control processes required for precisely controlling the reversal of rotation or the change in blade pitch angle. Consequently, the aircraft according to the invention features both a generally simplified design and a simplified transition from vertical to level flight, which is a significant advantage over the prior art, particularly with regard to efficiency and simplicity.

[0013] In particular, the fact that a control unit and corresponding complex control processes can be dispensed with makes the transition from vertical to level flight less susceptible to disturbances in the aircraft according to the invention. This is of great importance with regard to flight safety, since a disturbance (e.g., an inaccuracy or even a complete failure of the control system) during this step can have significant consequences, as already described. Furthermore, because the airflows caused by the propellers already flow as desired, and thus no unwanted movements of the aircraft occur during the transition from vertical to level flight, further complex flight stabilization measures, which in turn necessitate further complicated control systems, become unnecessary.

[0014] In an exemplary embodiment of the aircraft according to the invention, the at least one pivoting means is designed as a chain drive, wherein the chain drive has a first sprocket and a second sprocket, wherein a movement of a chain of the chain drive can be provided by means of a (rotary) movement of the first sprocket, wherein the second sprocket can be driven by means of the movement of the chain of the chain drive, wherein the pivoting out and / or the return of the pivoting out (pivoting in) of the first and / or the second wing part can be provided by means of the driven second sprocket.

[0015] This embodiment of the aircraft according to the invention has, among other advantages over aircraft from the prior art, the fact that the swiveling device can be designed to be very simple and space-saving.

[0016] In another exemplary embodiment of the aircraft according to the invention, each of the wings has at least one stepper motor designed to drive at least one pivoting device (or chain drive), and / or at least one second drive battery designed to supply the at least one stepper motor with electrical energy, wherein the second drive battery is arranged in or on the wing in such a way that it is replaceable and / or rechargeable there, in particular wherein at least one second gearbox is arranged for the operative connection between the at least one stepper motor and at least one swiveling device (or chain drive).

[0017] In other words, the first sprocket of the chain drive can be driven by a stepper motor, which in turn is operatively connected to a second gearbox. The (rotational) movement of the first sprocket also sets the chain, which is guided over it, in motion. The chain is guided over the second sprocket, which is located at the level of the pivot axis of the corresponding wing section, and thus transfers its kinetic energy to the second sprocket, which is thereby also set into (rotational) motion. The second sprocket then transfers its kinetic energy to a (drive) shaft located on the second sprocket, which in turn is responsible for pivoting the corresponding wing section in or out.

[0018] In another exemplary embodiment, the first gearbox and / or the second gearbox is an eccentric gearbox, in particular a double eccentric gearbox.

[0019] In a further exemplary embodiment, the respective eccentric gear has internal teeth with a tooth difference in the range of 0 to 5 teeth, in particular of one tooth, in particular wherein the tooth shape of the teeth of the respective eccentric gear is such that the respective eccentric gear has oval teeth.

[0020] These embodiments have the advantage that, since an eccentric gear, in particular a double eccentric gear, has low friction losses, increased durability, increased stability even at high speeds, a suitable reduction ratio, etc., the aircraft according to the invention, especially with regard to the first gear, has an efficient and low-wear (and therefore more durable) drive.

[0021] Furthermore, eccentric gearboxes enable the transmission of high torques and high reduction ratios in a compact design with minimal backlash, resulting in high precision throughout their service life (e.g., hysteresis loss of 0.5 to max. 1 arcmin). This high precision also has the added benefit of extremely low transmission error within the gearbox, ensuring a very constant drive speed. The two-stage reduction principle of a double eccentric gearbox also provides excellent dynamic and smooth running characteristics, as well as high repeatability and path accuracy. The gearbox can withstand axial and radial loads and bending moments, contributing to high torsional stiffness and resistance to shock and overload. In emergency stop situations, the eccentric gearboxes can handle up to 500% of the rated torque.This is particularly important for aircraft, as a failure of the propeller gearbox during flight due to a defect can lead to a crash of the aircraft.

[0022] Due to the previously described design of the second gearbox, in particular as a (double) eccentric gearbox, it is possible to transmit a high torque and holding force to the first sprocket of the first chain drive or to the first sprocket of the second chain drive, enabling the respective first sprocket to perform a controlled, stepwise (rotational) movement.

[0023] The second gearbox can be designed such that it can transmit both positive and negative (torque) to the first sprocket of the chain drive. The corresponding torque is transmitted via the chain of the chain drive to the second sprocket and thus (e.g., via a corresponding (drive) shaft) to the corresponding wing component. Therefore, the pivoting mechanism, designed as a chain drive, can perform both the pivoting movement, which, for example, has a positive torque, and the pivoting movement, which, for example, has a negative torque.

[0024] In an exemplary embodiment of the aircraft according to the invention, the first sprocket of the chain drive has a smaller diameter than the second sprocket of the chain drive, in particular wherein the diameter of the first sprocket is smaller by a factor of 2 to 4 than the diameter of the second sprocket.

[0025] Designing the first sprocket with a smaller diameter or area than the second sprocket allows the chain-driven pivoting mechanism to generate a higher torque and holding force at the second sprocket. This increased torque is transmitted via the (drive) shaft attached to the second sprocket to the respective wing section, thus enabling the pivoting of the wing section with a high torque and holding force. Such a high torque and holding force during pivoting is advantageous because it allows the pivoting movement of the wing section to be performed gradually, even under high wind pressure during flight.that the swiveling or pivoting movement can be stopped after reaching a desired tilt angle and the position of the corresponding wing section held at that angle, reliably and with the desired precision (e.g., regarding the tilt angle) and speed. Especially at higher airspeeds, enormous wind pressure acts on the respective wing section, which could impair or even prevent its swiveling or pivoting movement if the torque generated by the corresponding pivoting mechanism (here, the chain drive) during the swiveling or pivoting of the respective wing section were too low. Furthermore, if the holding torque is too low, the wing sections could be forced out of their set angular position by the wind pressure, which would significantly impair the aircraft's flight characteristics.

[0026] In an exemplary embodiment of the aircraft according to the invention, each of the two wings has a first pivoting means and a second pivoting means, wherein the first pivoting means can be used to pivot out and / or return the pivot out (or also pivot in) the first wing part of the respective wing and the second pivoting means can be used to pivot out and / or return the pivot out (or also pivot in) the second wing part of the respective wing.

[0027] In another exemplary embodiment of the aircraft according to the invention, the first pivoting means of the respective wing is designed as a first chain drive and the second pivoting means of the respective wing is designed as a second chain drive.

[0028] In these embodiments, the first and second wing sections of each wing can be independently pivoted outwards or back into their pivoted (or folded) position. Furthermore, each wing section can be pivoted outwards or inwards incrementally to a desired tilt angle and held at that angle, which may differ from, for example, the horizontal or vertical position.

[0029] The first sprocket of the first chain drive and the first sprocket of the second chain drive can each be driven by a stepper motor, which in turn is operatively connected to a second gearbox. In an alternative embodiment, the first sprocket of the first chain drive and the first sprocket of the second chain drive can be driven by a single stepper motor, which in turn is operatively connected to only one second gearbox, wherein this second gearbox can be switched such that either the first sprocket of the first chain drive or the first sprocket of the second chain drive is driven.

[0030] It goes without saying that the first and / or second sprocket does not necessarily have to be circular. In principle, any shape (e.g., polygonal or rectangular) is possible for the corresponding sprocket; the only requirement is that the first sprocket's (rotary) movement sets the chain in motion and thus transmits the torque to the second sprocket. Furthermore, instead of a chain, a rope or rod assembly can be used, for example; the only requirement is that the torque be transmitted from the first sprocket to the second. It would also be possible to design the first and second sprockets as a single unit; the only important thing is that the torque generated by the stepper motor and transmitted by the second gearbox can be transferred to the (drive) shaft that enables the extension or retraction of the respective wing section.Furthermore, the (respective) pivoting mechanism does not necessarily have to be a chain drive. Designs are also possible in which the pivoting mechanism is a cable or chain hoist, with one end of the cable or chain being attached to the corresponding wing section and the other end being attached to a (cable) winch mounted on the wing. By winding or unwinding the cable or chain, the corresponding wing section can then be pivoted in or out.

[0031] The aircraft according to the invention solves, among other things, the technical problem of enabling a simpler, more efficient, and less failure-prone transition from vertical flight to horizontal flight compared to the prior art. Furthermore, the first and / or the second gearbox can be designed as a durable and efficient (dual) eccentric gearbox, thereby enabling more efficient and longer-lasting drives.

[0032] In an exemplary embodiment of the aircraft according to the invention, each of the wing parts has at least a first drive battery configured to supply the propeller motor with electrical energy, wherein the first drive battery is arranged in or on the wing part in such a way that it is replaceable and / or rechargeable there, a communication unit configured to receive control signals, in particular control signals from an external transmitter, a control unit configured, depending on the control signals, to control a swivel angle of the wing part and to control the rotation of the propeller, and / or at least a photovoltaic cell arranged on a surface of the wing part, which is connected to the first drive battery and configured to charge the first drive battery.

[0033] This design has the advantage of allowing for the decentralization of the drive batteries. Instead of a single, large electrical energy source powering the four propellers, the drive battery is distributed among them, thus reducing the energy density of the entire aircraft and minimizing the risk of overheating.

[0034] In another exemplary embodiment, the two wings arranged on the transport cabin, particularly on the roof of the transport cabin, are formed in one piece. This one-piece wing can, for example, be placed on top of the roof and attached there. Alternatively, the two wings can also be attached to the left and right sides of the roof of the transport cabin in such a way that the one-piece wing forms the roof of the transport cabin.

[0035] In another exemplary embodiment, the first wing part is arranged in a front area and the second wing part in a rear area of ​​the respective wing.

[0036] This embodiment has the advantage that, when transitioning from vertical flight to horizontal flight in accordance with the "normal" flight direction intended for the aircraft, no reversal of the direction of rotation or change in the blade pitch angles of the propeller rotors of the respective second wing section is necessary.

[0037] In another exemplary embodiment, each of the wing parts is essentially semicircular in design, such that pivoting out the respective wing part results in a semicircular recess in the rest of the wing, and / or each of the wing parts has a cell structure inside to increase stiffness, wherein the first drive battery is arranged in a cell of the cell structure.

[0038] In another exemplary embodiment, the aircraft according to the invention further features an air cooling circuit, in particular with at least one fan, wherein the air cooling circuit is arranged to cool at least one of: the first drive battery, the second drive battery, the propeller motor, the control unit and the at least one stepper motor, in particular wherein the first and / or second drive battery is configured to supply the at least one fan with electrical energy, and / or a transmitter unit arranged in the transport cabin, wherein the communication unit is configured to receive control signals from the transmitter unit, in particular wherein the transmitter unit is configured to receive at least one of: control signals, anti-collision system warning signals, weather information signals, navigation signals from an external transmitter source.

[0039] In another exemplary embodiment, the transport cabin has a supply battery and the remaining wing has at least one photovoltaic cell on its surface, which is connected to the supply battery and is designed to charge the supply battery.

[0040] In another exemplary embodiment, the first traction battery, the second traction battery, and / or the auxiliary battery Designed as a solid-state battery, rechargeable by an external energy source (e.g., suitable charging stations), in particular via a cable, wherein the charging of the corresponding battery takes place while the corresponding battery is still installed in the aircraft or the battery is at least temporarily removed from the aircraft, and / or as soon as the corresponding battery is discharged (empty), replaceable by a corresponding charged (full) battery.

[0041] In another exemplary embodiment, each of the airfoils has a touch guard, designed to to be arranged on the underside of the wing, to provide a protective wall, in particular a semicircular one, around the propeller of the second wing section which is located below the wing in the swung-out state, and to shield the propeller from physical contact with an area outside the contact protection by means of the protective wall.

[0042] According to the invention, the aircraft has two auxiliary wings, one of which is arranged on a longitudinal side, in particular on a lower region of the longitudinal side, of the transport cabin, the two auxiliary wings being designed to generate a velocity-proportional counter-moment by means of which an increased air resistance of the aircraft, in particular due to the transport cabin and / or the touch protection, can be compensated, thereby preventing a pitching movement of the front of the aircraft, in particular during level flight, and thus stabilizing the flight characteristics of the aircraft.

[0043] In another exemplary embodiment, at least one of the following parts of the aircraft Transport cabin, wing, first wing section, second wing section, propeller, propeller motor, first gearbox, second gearbox, swivel mechanism, auxiliary wing, or contact guard, at least predominantly made of at least one lightweight material, in particular carbon, preferably glass fiber reinforced carbon, Kevlar, titanium and / or aluminum.

[0044] In another exemplary embodiment The main part of the first wing section opposite the propeller is designed such that, in a swung-out state (i.e., during vertical flight), said main part forms a first support for the aircraft (comparable to the landing skids of a helicopter), in particular wherein the first support is located at least approximately at a first end of the transport cabin, and / or (since the second wing section of the aircraft swings out in the opposite direction and standing on the propeller of the second wing section would impair the functionality of the aircraft), the transport cabin has a second (separate) support, in particular on a floor of the transport cabin, in particular wherein the second support is located at least approximately at a second end of the transport cabin opposite the first end of the transport cabin.

[0045] In other words, the invention relates to a universal flying device ("universal" because it can fly vertically and horizontally) with an electric drive and tiltwings, wherein each tiltwing has its own traction system consisting of a propeller blade, eccentric gear, electric motor, pivoting mechanism (e.g., chain drive), traction battery, power electronics, and hinge-like tilt joints, and wherein this traction system can be controlled wirelessly from the cockpit and / or from the ground. In other words, in some embodiments, the electric drive motors for the propellers and the elements for adjusting the pivoting, semicircular wing sections are at least largely housed within the pivoting wing sections themselves, so that their weight generates a stable torque about the axis of rotation of the tiltrotors.In other words, in some embodiments, the adjustability of the tilting wings of a wing is ensured by two chain drives arranged in or on the wing, over whose respective first and second sprockets (or chain sprockets) a chain is guided. The respective first sprockets are rotated by one (or two) electric stepper motor(s) with high holding torque, so that the respective tilt angle of the tilting wings can be precisely set. In contrast to the fixed position of the engines in a conventional fixed-wing aircraft, here the pitch angle of the wings can be determined by the adjustable engines and controlled with considerable force. Therefore, the tail surfaces required at the rear of fixed-wing aircraft are unnecessary. In particular, an eccentric gearbox with, for example, a torque converter is used to provide the necessary torque for the relatively large propellers, approximately 3 meters in diameter, at low speeds.A total gear ratio of i = 36 and a high-speed DC motor with over 25,000 rpm are provided in the tilt wing. With four propellers, the total power output is, for example, 100 kW and the total weight approximately 900 kg.

[0046] Air cooling (or an air cooling circuit) is primarily used for cooling the motors and eccentric gearboxes. The airflow generated during the aircraft's movement passes over the wings and the first and second wing sections (tilt wings), thus cooling their surfaces / outer sides. This cooling of surfaces also cools the propeller motors and eccentric gearboxes located on or within the wing sections. Alternatively, they can dissipate their heat to the surrounding (cooled) components via convection, preventing overheating. Furthermore, structures (e.g.,...) can be located within the wing and / or within the first and second wing sections.Ventilation shafts may be provided through which the resulting airflows can be at least partially directed, in particular wherein the structures may be arranged such that the airflows directed therein are directed onto the propeller motors and / or the eccentric gearboxes (and from the propeller motors and / or the eccentric gearboxes back to the outside) and these can be cooled by the air cooling circuit thus provided. The structures for directing the airflows may also be arranged within the parts of the aircraft in such a way that the airflows can be directed into the passenger cabin (and from the passenger cabin back to the outside), whereby the passenger cabin can be cooled by the air cooling circuit thus provided, for example, to a comfortable room temperature for the passengers or to a significantly lower temperature for refrigerated goods.

[0047] For air transport within the structures, suitable fans (or ventilators) can be used, among other things, whose electric motors can be supplied with electrical energy from the first drive battery, the second drive battery, and / or the supply battery.

[0048] In further embodiments, a metallic-looking layer is applied to the outer skin of at least one of the following: the propellers, the transport cabin, the wing sections, and the remaining wing. This layer prevents electrostatic charging, lightning strikes (Faraday cage), and ice formation. In further embodiments, a gyrocompass in the transport cabin provides an attitude indicator for pitch and roll, as well as an airspeed indicator. In further embodiments, the cockpit includes a status indicator (e.g., charge level, temperature) for the traction battery. Brief description of the drawings

[0049] The aircraft according to the invention is described in more detail below with reference to exemplary embodiments schematically depicted in the figures. Identical elements are marked with the same reference numerals in the figures. The described embodiments are generally not drawn to scale and are not to be understood as limiting. In detail, Fig. 1 : perspective view of an exemplary embodiment of the aircraft according to the invention; Fig. 2 : Top view of an exemplary embodiment of the aircraft according to the invention; Fig. 3 : Side view of an exemplary embodiment of the aircraft according to the invention; Fig. 4A-4C : schematic representation of an exemplary embodiment of the first gearbox; Fig. 5A-5C : schematic representation of an exemplary embodiment of the second gearbox, Fig. 6: View of the arrangement of an exemplary embodiment of the pivoting means on the wing. Detailed description of the drawings

[0050] Figure 1Figure 1 shows a perspective view from an oblique angle of the entire aircraft 1 with the four propellers 2 (also called tiltrotors), the wings 3, 4 extending on both sides of the transport cabin 9, and the first wing sections (semicircular tiltwings) 5, 6 and the second wing sections (semicircular tiltwings) 7, 8. In the embodiment shown, the transport cabin 9 is designed as a passenger cabin, specifically for accommodating at least one person, preferably two or more. If a corresponding radio control system is provided, a human pilot may be unnecessary, allowing for the transport of an additional passenger. Equipped in particular with a longitudinally and laterally oriented gyrocompass, an altimeter, and a satellite-based navigation system, such a universal aircraft can be operated completely autonomously.On the other hand, at least based on a navigation system (e.g., GPS), a pilot in aircraft 1 can be shown approximately how far they are from their destination. A warning (e.g., "Destination reached in 4 km or 2 min") can alert the pilot. The wing sections 5-8 are each mounted in one of the fixed (remaining) wings 3, 4 via a hinge-like joint 10, allowing them to pivot by up to 90 degrees. Their function is to transmit the forces of the rotor propellers 2 to the rest of the system, including the passenger cabin 9. These joints 10 must be highly load-bearing, largely wear-free, and operate reliably with very low frictional resistance for many years. Therefore, they are preferably equipped with roller bearings, especially space-saving needle bearings. They can be lubricated with a lifetime grease filling.The adjustment of the tilt wings (wing sections) 5, 6, 7, 8 is each accomplished by a pivoting device 12, in this case the chain drive 12, which operates in a known manner with a first sprocket 54 and a second sprocket 55. An electric stepper motor 56, operated either from the cockpit or automatically, serves to actuate each chain drive 12. This stepper motor 56 can also have a reduction gear 46 (also referred to as a second gear 46), for example, an eccentric gear, in particular a double eccentric gear. Adjusting each wing section 5-8 by means of such a chain drive 12 represents an ideal solution, as it allows the enormous gyroscopic forces of the high-speed propeller motors to be overcome and the desired tilt angle to be set precisely.

[0051] Figure 2Figure 1 shows the aircraft 1 from above, with the first tiltwings 5, 6 fully extended for vertical flight, thus orienting the front propellers 2 upwards, and the second tiltwings 7, 8 fully extended for vertical flight, thus orienting the rear propellers 2 downwards. The full extension reveals semicircular cutouts or openings 11 in the remaining wing 3, 4.

[0052] Figure 3Figure 1 shows a side view of an exemplary embodiment of the aircraft 1 according to the invention. For level flight, the first and second chain drives 12 retract the wing sections 5, 7 (6, 8 not shown here) flush (shown with solid lines). For vertical takeoff / flight, the first wing section 5 is swung out so that the propeller 2 rotates above the wing 3, while the opposite large section 15 of the first wing section 5 is located below the wing 3 (shown with dashed lines). The second wing section 7 is positioned exactly the opposite way, with the propeller 2 rotating below the wing 3 and the opposite large section 16 of the wing section 7 located above the wing 3. Furthermore, the illustrated embodiment of the aircraft 1 has an auxiliary wing 17 and a protective guard 18.The auxiliary wing 17 is arranged laterally in a lower area of ​​the transport cabin 9, i.e., on a lower area of ​​the longitudinal side of the transport cabin 9. The auxiliary wing 17 ensures that, particularly during level flight, a velocity-proportional counter-moment is generated. This counter-moment compensates for the increased air resistance of the aircraft 1, especially that caused by the transport cabin 9 and / or the contact guard 18. This prevents pitching of the front 19 of the aircraft 1, particularly during level flight, and thus stabilizes the flight characteristics of the aircraft 1. The contact guard 18 is arranged on the underside of the wing 3 and extends from it, with a support structure / mount, approximately as far towards the ground as the second wing section 7.At the end of the support of the contact guard 18 facing the ground, a protective wall extending horizontally, in particular semicircularly, around the propeller 2 of the second wing section 7, which is located below the wing 3 in the swung-out state, is arranged (the contact guard thus has a shape comparable to the letter L when viewed from the side), which shields the propeller 2 from physical contact from an area outside the contact guard 18, among other things to enable passengers to board and disembark safely.

[0053] In the illustrated embodiment, the large portion 15 of the first wing section 5, located opposite the propeller 2, is designed such that, in the extended position (i.e., for vertical flight), it serves as a support foot (comparable to the landing skids of a helicopter). Since the second wing section 7 of the aircraft 1 extends in the opposite direction, and standing on the propeller 2 of the second wing section 7 would impair the functionality of the aircraft 1, the transport cabin 9 has a separate support foot 20 at the end where the second wing section 7 is located (i.e., at the rear of the aircraft 1 in the illustrated embodiment). Because weight reduction plays a crucial role, especially in aircraft, both to ensure flight capability and to optimize energy efficiency during flight (e.g.,(Fuel consumption is also reduced due to a reduced weight of the aircraft), the above-mentioned components in an exemplary embodiment of the aircraft shown 1 can be designed at least predominantly from at least one lightweight material, in particular carbon, preferably glass fiber reinforced carbon, Kevlar, titanium and / or aluminum.

[0054] In particular, when the corresponding components of the aircraft 1 are designed from lightweight materials and battery-powered electric motors are used as propeller motors and / or stepper motors, the corresponding embodiment of the aircraft 1 according to the invention has, among other things, the following further advantages over aircraft from the prior art: Reduced overall weight (e.g., through the use of lightweight materials in the components), increased efficiency (e.g., improved power transmission from the propeller motors to the propellers through the use of efficient, low-wear and low-friction, durable double eccentric gearboxes), increased airspeed (e.g., through improved gear ratios in the first gearbox, which is designed as a double eccentric gearbox), greater range (e.g., through reduced energy consumption due to the reduced weight and / or efficient gearboxes), reduced emissions (e.g., through the use of electric motors (purely electric operation) and / or generally reduced energy consumption), improved flight characteristics / flight stability (e.g., through the auxiliary wings that prevent pitching movements, etc., of the aircraft), simplified design (e.g.,This results in: reduced noise levels (e.g., through the use of space-saving chain drives for the pivoting mechanism), elimination of a separate control unit required to reverse the direction of rotation or change the blade pitch angles of the second wing sections (e.g., via pitch control), and / or elimination of the need for a rotating bearing of the rotor blades in the rotor hub for pitch control; quieter operation (e.g., through the use of electric motors); less maintenance-intensive operation (e.g., through durable double eccentric gearboxes and / or simplified replacement of empty or broken batteries due to easy battery accessibility); more environmentally friendly operation (e.g., through reduced fuel consumption, quieter operation, reduced emissions, etc.); and increased safety (e.g.,This is achieved by using a decentralized arrangement of the batteries, and / or by eliminating the need to reverse the direction of rotation or change the pitch angle of the propellers of the second wing sections, thus avoiding both a temporary interruption of the propulsion forces of these propellers and an additional, potentially failure-prone control unit.

[0055] The transition from vertical to horizontal flight is undoubtedly the most complex and, with regard to flight safety, the most critical phase of such an aircraft 1. Here, the aerodynamic forces are divided into those from the propeller rotors 2 and those from the fixed wings 3,4. They are also divided into vertical and horizontal force components. Furthermore, the airflows have different speed directions, so the effects of the aerodynamic forces are no longer unambiguous. Therefore, these conditions are determined beforehand on the test rig in the wind tunnel and taken into account when controlling the aircraft 1.

[0056] The in Figure 3The arrows shown illustrate the directions of the airflows and the corresponding forces acting upon them during horizontal and vertical flight. During vertical flight, the propeller 2 of the first wing section 5, rotating above the wing 3, rotates in such a direction (for example, clockwise) that the airflow 21 is directed towards the ground 22. The lift force 23 acts against the airflow 21 for this propeller, i.e., in a direction away from the ground 22. The propeller 2 of the second wing section 7, rotating below the wing 4, has the same direction of rotation (for example, also clockwise), so the airflow 24 is also directed towards the ground 22. Therefore, the lift force 25 for this propeller 2 also acts in a direction away from the ground 22.Because the two lift forces 23 and 25 each point vertically upwards (away from the ground 22), a vertical takeoff of the aircraft 1 is made possible. Since the propeller 2 of the second wing section 7 rotates below the wing 3 in the aircraft 1 according to the invention, the airflows 21 and 24 continue to flow in the same direction (opposite the direction of flight 26) during the transition from vertical to horizontal flight and, consequently, during the pivoting of the first and second wing sections 5, 7. Therefore, the driving forces (thrust) 27 and 28 also act in the same direction (in the direction of flight 26) for both propellers 2. As a result, a reversal of the direction of rotation or a change in the blade pitch angle (e.g., by means of a pitch control) of the propeller 2 of the second wing section 7 is no longer necessary in the aircraft 1 according to the invention.This enables a simpler and less fault-prone transition from vertical flight to horizontal flight and vice versa compared to aircraft of the prior art. Due to the shape of the wing 3 and / or the auxiliary wing 17, the aircraft 1 also experiences a lift force 29, 30 during horizontal flight, which acts vertically upwards (away from the ground 22) and thus enables further ascent of the aircraft 1 even during horizontal flight.

[0057] The Figures 4A to 4CFigures 3 and 4 show a schematic representation of an exemplary embodiment of the first gear unit 33, which in the illustrated embodiment is designed as a double eccentric gear unit. For weight reduction purposes, the first gear unit 33, designed as a double eccentric gear unit, can in an exemplary embodiment be made at least predominantly of at least one lightweight material, in particular carbon fiber, preferably glass fiber reinforced carbon fiber, Kevlar, titanium, and / or aluminum. In the illustrated exemplary embodiment, the double eccentric gear unit 33 has internal teeth with a tooth difference of one tooth. In the embodiment shown Figure 4AThe secondary part 34 of the double eccentric gear 33 shown has a ring gear 35 with twenty teeth, each tooth having a height of 5 to 10 millimeters, in particular 7 millimeters, and an angle of 18 degrees between each pair of teeth, starting from the pivot point 36. The cycloidal disk 37 of the secondary part 34 (e.g., made of glass fiber reinforced carbon) has 19 teeth 50 on its outer edge, each tooth 50 having a height of 5 to 10 millimeters, in particular 7 millimeters, which engage in the recesses 51 of the ring gear 35 on one side 38 and rest on the teeth 50 of the ring gear 35 on the opposite side 39. The cycloidal disk 37 (also cycloplate) further has an internal toothing of five, wherein the four teeth 52 of the pinion 40 engage in the corresponding recesses 53 of the inside of the cycloidal disk 37.The teeth 52 of the pinion 40 can be milled from steel, then ground and plasma-nitrided, which preferably makes them as smooth as possible. A lubricant, e.g., a lubricating grease (rolling bearing grease), can be introduced into the cavities created by the tooth differences, ensuring the reliable, smooth, and low-wear operation of the double eccentric gear 33. The double eccentric gear 33 shown has oval teeth. Due to the tooth height of, in particular, 7 to 10 millimeters, this double eccentric gear 33 is also referred to as having a module of 7.0 to 10. Furthermore, it has a gear ratio of 6, which is calculated from the number of teeth of the ring gear 35 and the number of teeth of the pinion 40.

[0058] The in Figure 4BThe primary part 41 of the double eccentric gear 33 shown also has a structure corresponding to that of the secondary part 34 (in particular with regard to the number and size of the teeth of the respective components), however, the cycloidal disk 42 has six circular cutouts 43 into which six rollers / bolts 44 (also referred to as bearing bolts / cycloidal bolts, e.g., made of bearing steel, e.g., 100 Cr 6, with a hardness of at least 60 HRc, induction hardened and ground, embedded or bonded into the cycloidal plate) of a roller disk (as part of the drive shaft) engage (the described arrangement can also be referred to as a rolling bearing). The primary part 41 also has a gear ratio of 6 and is also made of glass fiber reinforced carbon.Since both the primary part 41 and the secondary part 34 have a gear ratio of 6, the double eccentric gearbox used as the first gearbox 33 in the aircraft 1 according to the invention has an overall gear ratio of 36. The first gearbox 33 is operatively connected to the propeller motor (in other words: the power provided by the propeller motor is transmitted via the first gearbox 33 to the propeller 2, causing it to rotate), the propeller motor being an electric motor, in particular a (double) reluctance motor, e.g., a Plusmotor C. Lungu. Such a motor has the advantage that no rare earth elements are required for permanent magnets and that speeds of up to 25,000 revolutions per minute (rpm) are possible. Furthermore, such a motor has a climb power of up to 25 kW and a horizontal power of up to 6.5 kW.

[0059] In Figure 4CFigure 1 shows the arrangement of the primary part 41 (also referred to as the primary stage) and the secondary part 34 (also referred to as the secondary stage) in the first gearbox 33 of the aircraft 1 according to the invention, which is designed as a double eccentric gearbox. The propeller motor, designed as an electric motor, transmits the kinetic energy it provides (approx. 25,000 rpm) to the primary stage 41, which is then set in motion. Because the primary stage 41 is connected to the secondary stage 34, the kinetic energy is transferred to the secondary stage 34. The secondary stage 34 is in turn connected to the propeller shaft 45 (which, for example, has five external teeth and is approximately 2 m long), which is also set in motion by the movement of the secondary stage 34 and thus drives the propeller 2. Due to the overall gear ratio of 36, the propeller shaft 45 has a rotational speed of approximately 700 rpm.In other words, the propeller shaft 45 performs a wobbling motion with the same eccentricity as the cycloidal disk 37 due to the eccentricity of the cycloidal disk 37, only on the side of the secondary stage 34.

[0060] The Figures 5A to 5C Figures 1 and 2 each show a schematic representation of an exemplary embodiment of the second gearbox 46 for the functional connection between the stepper motor 56 and the pivoting device 12 (here a chain drive 12), wherein the second gearbox 46 in the illustrated embodiment is designed as a double eccentric gearbox with the primary stage 47 and the secondary stage 48. For reasons of weight reduction, the second gearbox 46, designed as a double eccentric gearbox, can also, in an exemplary embodiment, be made at least predominantly of at least one lightweight material, in particular carbon, preferably glass fiber reinforced carbon, Kevlar, titanium and / or aluminum. The Figure 5Asecondary part 48 shown and the one in Figure 5BThe primary part 47 of the double eccentric gear 46 shown is fundamentally designed, in particular with regard to the number and size of the teeth, the tooth difference, the materials of the respective components and the transmission ratio, like the primary part 41 of the double eccentric gear 33, wherein in the embodiment shown six bolts 49 (also referred to as bearing bolts / cyclobolts, e.g. made of bearing steel, e.g. 100 Cr 6, with a hardness of at least 60 HRc, induction hardened, ground, plasma nitrided and polished) of a roller disc engage in the secondary part 48. However, unlike the double eccentric gear 33, which is connected to the propeller shaft 45, this roller disc is not connected to a drive shaft, but is designed as part of the first sprocket 54 (also referred to as chain drum 54) of the chain drive 12, which is designed to move a chain 13, 14 by means of a rotary motion.In another embodiment of the double eccentric gear 46 shown, the secondary part 48 can be connected to the drive shaft 57, which is also set in motion by the movement of the secondary part and thus drives the first sprocket 54 of the chain drive 12.

[0061] The second gearbox 46 is operatively connected to the stepper motor 56 (in other words: the force provided by the stepper motor 56 is transmitted via the second gearbox 46 to the first sprocket 54 of the chain drive 12, causing it to rotate and setting the chain 13, 14 in motion), wherein the stepper motor 56 can be an electric motor, in particular a (dual) reluctance motor, e.g., Plusmotor C. Lungu. Since both the primary part 47 and the secondary part 48 also have a gear ratio of six, the double eccentric gearbox used as the second gearbox 46 of the aircraft 1 according to the invention has an overall gear ratio of 36, just like the first gearbox 33.

[0062] In Figure 5CThe arrangement of the primary part 47 (also referred to as the primary stage) and the secondary part 48 (also referred to as the secondary stage) in the second gearbox 46 of the aircraft 1 according to the invention, which is designed as a double eccentric gearbox, is shown. The stepper motor 56, designed as an electric motor, transmits the kinetic energy it provides to the primary stage 47 (approx. 1500 rpm), which is then set in motion. Because the primary stage 47 is connected to the secondary stage 48, the kinetic energy is transferred to the secondary stage 48. The secondary stage 48 is in turn connected to the first sprocket 54 (or chain drum 54) (or to the drive shaft 57, which is in turn connected to the first sprocket 54), which is set into a rotary motion by the movement of the secondary stage 48, thus setting the chain 13, 14 in motion. Due to the overall gear ratio of 36, the first sprocket 54 has a rotational speed of approximately...42 rpm.

[0063] In Figure 6The arrangement of an exemplary embodiment of the first pivoting means 12, designed for pivoting outwards or inwards the first wing section 5 of the wing 4, and the second pivoting means 12, designed for pivoting outwards or inwards the second wing section 7 of the wing 4, is shown on the wing 4. The first pivoting means is designed as a first chain drive 12 and the second pivoting means as a second chain drive 12, wherein the first and the second chain drives 12 each have a first sprocket 54 and a second sprocket 55, wherein in the embodiment shown the diameter of the first sprocket 54 is smaller than the diameter of the second sprocket 55.The respective stepper motor 56, designed as an electric motor, is operatively connected to a respective second gearbox 46, which in turn transmits the energy supplied by the respective stepper motor 56 to the respective drive shaft 57, which in turn sets the respective first sprocket 54 in motion. The movement of the respective first sprocket 54 drives the respective chain 13, 14, which in turn sets the respective second sprocket 55 in motion. The respective second sprocket 55 is connected to the respective shaft 58, which is also set into rotation by the rotational movement of the respective second sprocket 55, thus causing the tilt movement of the wing section 5, 7.

[0064] It is understood that these figures shown only schematically represent possible examples of implementation.

Claims

1. Aircraft (1) suitable for vertical flight and horizontal flight, wherein the aircraft (1) has a transport cabin (9), in particular a passenger cabin, and two wings (3, 4) arranged in each case on the transport cabin (9), in particular on a roof of the transport cabin (9), wherein • each of the two wings (3, 4) has a first and a second wing section (5, 6, 7, 8), • each of the wing sections (5, 6, 7, 8) is designed to be pivotable relative to the rest of the wing (3, 4), in particular by up to 90 degrees, about a respective pivot axis (31, 32), • each of the wing sections (5, 6, 7, 8) comprises ∘ at least one propeller (2) which is mounted in the wing section (5, 6, 7, 8) so as to be rotatable about an axis of rotation and which is arranged in relation to the pivot axis (31, 32) opposite at least a major part (15, 16) of the wing section (5, 6, 7, 8), wherein the propeller (2) is substantially perpendicular to a chord of the wing section (5, 6, 7, 8), ∘ a propeller motor designed to rotate the propeller (2), and ∘ a first gear (33) for the operative connection between the propeller (2) and the propeller motor, • wherein the first wing section (5, 6) of the respective wing (3, 4) can be pivoted out in such a way that, in the pivoted-out state, the propeller (2) of the first wing section (5, 6) is located above the wing (3, 4), • the second wing section (7, 8) of the respective wing (3, 4) can be pivoted out in such a way that, in the pivoted-out state, the propeller (2) of the second wing section (7, 8) is located below the wing (3, 4), and • each of the wings (3, 4) has at least one pivoting means (12), wherein the at least one pivoting means (12) can be used to pivot out and / or return the pivoting out of the first and / or second wing section (5, 6, 7, 8), characterized in that the aircraft (1) has two auxiliary wings (17), wherein one of the two auxiliary wings (17) is arranged in each case on a longitudinal side, in particular on a lower region of the longitudinal side, of the transport cabin (9), wherein the two auxiliary wings (17) are designed to generate a speed-proportional counter-torque by means of which an increased air resistance of the aircraft (1), in particular due to the transport cabin (9) and / or a contact protection (18), can be compensated, whereby a pitching movement of a front (19) of the aircraft (1), in particular during horizontal flight, can be prevented and thus a stabilization of the flight characteristics of the aircraft (1) can be achieved.

2. Aircraft (1) according to claim 1, wherein the at least one pivoting means (12) is designed as a chain drive, wherein the chain drive (12) has a first sprocket (54) and a second sprocket (55), wherein a movement of a chain (13, 14) of the chain drive (12) can be provided by means of a movement of the first sprocket (54), wherein the second sprocket (55) can be driven by the movement of the chain (13, 14) of the chain drive (12), wherein the driven second sprocket (55) provides the pivoting out and / or the return of the pivoting out of the first and / or the second wing section (5, 6, 7, 8).

3. Aircraft (1) according to claim 1 or 2, wherein each of the wings (3, 4) has • at least one stepper motor (56) designed to drive at least one pivoting means (12), and / or • at least one second drive battery designed to supply the at least one stepper motor (56) with electrical energy, wherein the second drive battery is arranged in or on the wing (3, 4) in such a way that it can be replaced and / or recharged there, • in particular wherein at least one second gear (46) is arranged to provide an operative connection between the at least one stepper motor (56) and at least one pivoting means (12).

4. Aircraft (1) according to one of the preceding claims, wherein the first gear (33) and / or the second gear (46) is an eccentric gear, in particular a double eccentric gear.

5. Aircraft (1) according to claim 4, wherein the respective eccentric gear (33, 46) has internal teeth with a tooth difference in the range from 0 to 5 teeth, in particular of one tooth, in particular wherein a tooth shape of the teeth of the respective eccentric gear (33, 46) is such that the respective eccentric gear (33, 46) has oval teeth.

6. Aircraft (1) according to claim 2 and one of claims 3 to 5, wherein the first sprocket (54) of the chain drive (12) has a smaller diameter than the second sprocket (55) of the chain drive (12), in particular wherein the diameter of the first sprocket (54) is smaller than the diameter of the second sprocket (55) by a factor of 2 to 4.

7. Aircraft (1) according to one of the preceding claims, wherein each of the two wings (3, 4) has a first pivoting means (12) and a second pivoting means (12), wherein the pivoting out and / or the return of the pivoting out of the first wing section (5, 6) of the respective wing (3, 4) can be provided by means of the first pivoting means (12) and the pivoting out and / or the return of the pivoting out of the second wing section (7, 8) of the respective wing (3, 4) can be provided by means of the second pivoting means (12).

8. Aircraft (1) according to one of the preceding claims, wherein each of the wing sections (5, 6, 7, 8) has • at least one first drive battery designed to supply the propeller motor with electrical energy, wherein the first drive battery is arranged in or on the wing section (5, 6, 7, 8) in such a way that it can be replaced and / or recharged there, • a communication unit designed to receive control signals, in particular control signals from an external transmission source, • a control unit designed to control a pivot angle of the wing section (5, 6, 7, 8) and to control the rotation of the propeller (2), in each case depending on the control signals, and / or • at least one photovoltaic cell arranged on a surface of the wing section (5, 6, 7, 8), which is connected to the first drive battery and is designed to charge the first drive battery.

9. Aircraft (1) according to one of the preceding claims, wherein the first wing section (5, 6) is arranged in a front region (19) and the second wing section (7, 8) is arranged in a rear region of the respective wing (3, 4).

10. Aircraft (1) according to claim 8, further comprising • an air cooling circuit, in particular with at least one fan, wherein the air cooling circuit is arranged to cool at least one of: the first drive battery, the second drive battery, the propeller motor, the control unit and the at least one stepper motor, in particular wherein the first and / or second drive battery is designed to supply the at least one fan with electrical energy, and / or • a transmission unit arranged in the transport cabin (9), wherein the communication unit is designed to receive control signals from the transmission unit, in particular wherein the transmission unit is designed to receive at least one of: control signals, anti-collision system warning signals, weather information signals, navigation signals from an external transmission source.

11. Aircraft (1) according to one of the preceding claims, wherein the transport cabin (9) has a supply battery and wherein the remaining wing (3, 4) has at least one photovoltaic cell on its surface, which is connected to the supply battery and is designed to charge the supply battery.

12. Aircraft (1) according to one of the preceding claims, wherein each of the wings (3, 4) has a contact protection (18) designed • to be arranged on an underside of the wing (3, 4), • to provide a protective wall, in particular a semicircular protective wall, around the propeller (2) of the second wing section (7, 8) located below the wing (3, 4) in the pivoted-out state, and • to shield the propeller (2) from physical contact from an area outside the contact protection (18) using the protective wall.

13. Aircraft (1) according to one of the preceding claims, wherein at least one of the following sections of the aircraft (1) • transport cabin (9), • wing (3, 4), • first wing section (5, 6), • second wing section (7, 8), • propeller (2), • propeller motor, • first gear (33), • second gear (46), • pivoting means (12), • auxiliary wing (17), or • contact protection (18), is at least predominantly made of at least one lightweight material, in particular carbon, Kevlar, titanium, or aluminum.

14. Aircraft (1) according to one of the preceding claims, wherein • the major part (15) of the first wing section (5, 6) opposite the propeller (2) is designed such that said major part (15) forms a first support foot for the aircraft (1) in a pivoted-out state, in particular wherein the first support foot is formed at least approximately at a first end of the transport cabin (9), and / or • the transport cabin (9), in particular at a floor of the transport cabin (9), has a second support foot (20), in particular wherein the second support foot (20) is arranged at least approximately at a second end of the transport cabin (9) opposite the first end of the transport cabin (9).