Lift module for vertical take-off and landing aircraft and aircraft comprising such module

Abstract

A lift module capable of achieving vertical flight in a fixed-wing aircraft and producing low aerodynamic drag during horizontal flight, the lift module essentially comprising: a structural compartment (40); and two covers (41A) and (41B) hinged to a structural compartment (40) by means of arms (41A-1) and (41B-1), said structural compartment containing at least one drive assembly (43) and at least one rotor (42), said rotor being locked when the lift module (4) is closed during horizontal flight and unlocked when the lift module is open to generate lift by rotation of the rotor.

Description

Technical Field

[0001] The present invention relates to lift modules and, more particularly, to lift modules of the type used to achieve vertical flight in fixed-wing aircraft and to produce low aerodynamic drag during horizontal flight. Background Art

[0002] Vertical take-off and landing aircraft, known as VTOL (vertical take-off and landing) aircraft, can be pure rotary-wing aircraft with one or more rotors, or a combination of rotary and fixed wings known as a hybrid aircraft, which once in vertical flight uses the aerodynamic efficiency of the wings to fly horizontally to achieve greater speed and range than rotary-wing aircraft.

[0003] The present invention belongs to the latter type and, in particular, uses rotors, usually electrically driven, to achieve the vertical thrust required for take-off and wherein, upon transition from vertical to horizontal flight due to the use of a horizontal thrust propulsion system, these rotors or parts thereof are deactivated until reaching the destination point, where they are activated again to achieve a vertical landing at that point.

[0004] They are becoming more widely used because they are very efficient and versatile aircraft, but their aerodynamic efficiency is reduced by the drag of the inactive rotors during horizontal motion of the aircraft.

[0005] In principle, three ways have been developed to reduce the aerodynamic drag of inactive rotors during flight, namely, aircraft with rotors with two fixed blades that are positioned parallel to the flight path; aircraft with rotors with hinged blades that, once retracted, are positioned parallel to the flight path; and aircraft with rotors whose blades (whether fixed or hinged) are positioned within a closed aerodynamic shell to avoid contact with the surrounding airflow.

[0006] The latter system achieves optimal aerodynamic efficiency, as shown in the paper “Impact of liftpropeller drag on the performance of eVTOL lift+cruise aircraft” (ELSEVIER Aerospace Science and Technology, Vol. 109, February 2021, 106429).

[0007] The wind tunnel study showed that for the tested configuration and by retracting the rotors during flight, aerodynamic drag could be reduced by 38%, which could increase the vehicle's cruising speed by 21% or its range by 13% while maintaining the same cruising speed.

[0008] In addition, the following patent documents are known.

[0009] Document EP 3736212 A1 shows the prior art of an aircraft using the first system mentioned, describing an aircraft provided with two propellers positioned in a vertical plane and dedicated to horizontal displacement, and eight two-bladed rotors positioned in a horizontal plane and dedicated to vertical displacement. Once in horizontal flight, the rotor blades are positioned parallel to the flight path to reduce drag, although there is a significant residual drag.

[0010] Document US10994829 B2 shows the prior art of a second type of aircraft, describing an aircraft equipped with a rear propeller positioned in a vertical plane and dedicated to horizontal displacement, and eight three-bladed rotors positioned in a horizontal plane and dedicated to vertical displacement. Once in horizontal flight, the articulated rotor blades of the rotors fold back parallel to the flight path to reduce drag, however maintaining a significant residual drag.

[0011] Document EP 335989 A1 shows a third type of system, describing an aircraft with four articulated arms in the lower part of the fuselage, with two-blade rotors at the ends of the arms. For vertical flight, these arms are deployed and the rotors are then activated by electric motors attached to them. Once in horizontal flight, the rotors are deactivated and their blades are aligned with their respective arms, which in turn are retracted into the fuselage and covered by baffles that isolate the blades from the surrounding airflow. The disadvantage of this system is the complexity of the mechanism, which increases the cost and weight of the aircraft and reduces the available space inside the fuselage.

[0012] Likewise, document EP 3771637 A1 shows an aircraft with four pusher propellers located in front of the leading edge of the wing together with six horizontal rotors for vertical flight, four of which are located behind the trailing edge of the wing and two located in the front of the fuselage, which are retractable during flight so as to be housed inside the fuselage and protected from the surrounding airflow by means of baffles. However, in addition to the complexity of the retraction system for the front rotor, the rest of the rotor still retains a significant residual drag.

[0013] WO 2009 / 149592 A1 shows an aircraft with different propulsion systems and with one or two large folding blade rotors which are housed in a compartment in the upper fuselage when the aircraft has completed the transition and is in horizontal flight. However, the implementation of these solutions involves significant and expensive constructional complications.

[0014] Similarly, US2019 / 0337613 A1 shows an aircraft having a propeller positioned on a vertical tail stabilizer and four horizontal rotors positioned above four aerodynamic volumes, wherein, during horizontal flight, once the rotors are inactive and retracted, cavities beneath the rotors accommodate the rotors, but this requires a mechanism incorporated into each rotor to allow the rotors to be inserted into and removed from the corresponding cavities.

[0015] The structural disadvantages of the above-mentioned systems and the manufacturing costs involved make it necessary to develop a simple, light and easy to manufacture system for vertical take-off and landing of hybrid aircraft.

[0016] In this sense, one of the precedents closest to the present invention is document US2016 / 0236774 A1, in which the rotors are positioned inside longitudinal cylindrical housings located on either side of the fuselage, which have lateral openings that allow the rotors to rotate during vertical flight, and once in horizontal flight, the rotors are deactivated and their blades are positioned parallel to the housing, while a movable cover moves to close the housing opening, without describing a mechanism that allows such closure to be performed. However, the disadvantage is that, due to the dimensional limitations regulated by the openings, this system can only be used for rotors with absolutely rigid blades, since any vertical flexion caused by the aerodynamic loads they must withstand in vertical flight could interfere with these openings.

[0017] Likewise, document US10894599 B1 describes an aircraft with four rotors positioned inside longitudinal pylons located on either side of the fuselage, these rotors having an upper cover which, once raised by a lever mechanism, allows the rotors to rotate during vertical flight, and once in horizontal flight, these rotors are deactivated and their blades are positioned parallel to the stowage device so that subsequently, with the aid of the operation of the lever, the upper cover is lowered and covers the rotors again. This system has the same drawbacks as the previous one and is effective only for rotors with rigid blades that do not have vertical flexion and do not interfere with the pylon covers.

[0018] Therefore, all known systems suffer from a number of problems either related to system complexity or to poor system reliability and performance, as well as problems that limit the use of the system to a limited number of aircraft. Summary of the invention

[0019] The general intended object of the invention is an aircraft lift module according to the claims, and an aircraft comprising an aircraft lift module. In particular, the invention relates to the development of a modular system for vertical propulsion or lifting with reduced aerodynamic drag in horizontal flight, wherein, to achieve this, the rotor blades are housed inside a pod with a cover, which, when opened for vertical flight, exposes the rotor, thereby allowing the rotor to turn without interfering with the pod even if the blades bend due to aerodynamic loads.

[0020] The present invention proposes a modular vertical lift system for fixed-wing aircraft, which is coupled to existing models or integrated into new aircraft specifically designed to use such a system, allowing them to take off and land vertically thanks to the thrust generated by the rotors.

[0021] For a better understanding of the invention, this modular vertical lift system integrating at least one rotor will be called a lift module and its outer surface will preferably be cylindrical, although its cross section may also vary along its longitudinal axis and, if necessary, in a gradual manner. In the case of an aircraft configured with a main wing and stabilizers, the front half-pod positioned in front of the leading edge of the wing is an assembly consisting of a lift module and a nose fairing attached to the front of the lift module, and similarly, the rear half-pod positioned behind the trailing edge of the wing is an assembly consisting of a lift module and a nose fairing attached to the rear of the lift module. The longitudinal junction of the two is called a pod, which is a geometric volume that achieves reduced aerodynamic drag during horizontal flight.

[0022] In addition, it is proposed that the positioning of the pods be symmetrical with respect to the longitudinal axis of the aircraft, with one or more pods on each side. Another feature proposed for the above configuration is that the one or more rotors of the front half of the pod should be equidistant from the one or more rotors of the rear half of the pod with respect to an axis intersecting the center of gravity of the aircraft and perpendicular to the longitudinal axis of the aircraft.

[0023] As in this specific case, as for any other possible aircraft configuration, it is also intended to ensure that the positioning of the rotor relative to the centre of gravity of the aircraft is sufficient to ensure its stability during the vertical flight phase.

[0024] The lift module, which is the main object of the invention, consists of a structural compartment and two covers.

[0025] The structural compartment is located in the lower part of the lift module and has high structural strength, wherein at least one drive assembly consists of at least one motor (preferably an electric motor) that drives at least one rotor attached thereto. The rotor can have fixed blades or retractable blades.

[0026] The cover sits on top of the lift module, and when the cover opens to expose the rotor blades, the rotor blades are driven by their corresponding powerplants, generating the vertical thrust needed to lift the vehicle. Once in the air, thrust from the horizontal propulsion engines accelerates the vehicle to its cruising speed, at which point the wings achieve the lift needed to maintain cruising altitude.

[0027] Once this flight state is achieved, the rotor drive assembly is deactivated and the rotor blades are locked or held in a position parallel to the direction of flight inside the lift module housing the rotor. The cover then closes the contour of the lift module to achieve a completely closed volume and prevent aerodynamic turbulence around the rotor blades, thereby reducing aerodynamic drag.

[0028] For landing, the sequence of operations is performed in reverse, starting with opening the lid in flight and ending with closing the lid once on the ground.

[0029] Only in the case of a rigid rotor without any possibility of bending, the position of the lift modules can be reversed relative to the horizontal plane, with the structural compartment at the top and the cover at the bottom.

[0030] In particular, in order to achieve the object of the invention, these covers are formed by two curved surfaces that are symmetrical with respect to a vertical plane passing through the longitudinal axis of the lift module. The structural module has an outer surface that is also curved and symmetrical with respect to a vertical plane passing through the longitudinal axis of the lift module, so that its combination with the surface of the cover produces a preferably cylindrical surface, the cross section of which will be formed by a closed curve, preferably elliptical or circular.

[0031] Each cover in turn comprises drive means driven by at least one motor, preferably an electric motor, which transmits to the covers such a displacement that allows both covers, in the open position, to be positioned below the plane of rotation of the blades and under the structural compartment without interfering with the rotation of the rotor, even if the blades of the rotor are bent due to aerodynamic loads.

[0032] In other words, in the open position, both covers are located below the plane of rotation of the blade, i.e. substantially below the structural compartment, i.e. almost completely placed below the structural compartment, thereby freeing up the area above the structural compartment and thus avoiding possible interference with the blade when it rotates in a horizontal plane. Furthermore, since both covers are located below the plane of rotation of the blade, they do not cause problems in those situations where the blade flexes vertically upwards due to vertical aerodynamic loads or vertical lift forces, as was the case in the prior art.

[0033] In this way, the aircraft lift module of the invention achieves the dual purpose of achieving perfect aerodynamics in horizontal flight, on the one hand, since the wings or rotor blades are folded in the direction of the longitudinal axis of the aircraft and are completely contained inside the structural compartment, which is conveniently closed by the cover; on the other hand, when the aircraft needs to perform a vertical displacement and the rotor blades are therefore in operation, both covers are positioned below the plane of rotation of the blades and therefore below the structural compartment, in such a way that they do not interfere with the movement of the blades.

[0034] More specifically, as mentioned above, when the aircraft is in horizontal flight, ie without interference from the rotor blades, the rotor blades are housed inside the structural compartment and the structural compartment is suitably closed by a cover, which, however, may be closed in different ways.

[0035] Thus, according to various possible practical realizations that will be explained in detail below, the cover is moved by the drive means and consists of an arched portion with a curved cross section, or in other words, of a surface whose cross section is an arc of a curved cross section, so that when the structural compartment is closed, the cover is dimensioned so that its lower edge overlaps the upper edge of the structural compartment, i.e. there is a certain overlap between the cover and the structural compartment to ensure a correct aerodynamic behavior. In this case, the drive means cause the cover to perform a single downward movement in an opening maneuver, or a single upward movement in a closing maneuver.

[0036] However, in other cases, also described in detail below, it may be desirable that the lower edge of the cover is flush with the upper edge of the structural compartment when closed. In this case, the drive means vary, since in the opening maneuver, the covers or at least their lower edges must first be moved outwards from the lift modules, either by lateral translation or by rotation, so that they can then be moved under the structural compartment. Therefore, during the closing maneuver, the movement is reversed. In other words, both when opening and when closing, the drive means are such that the covers will perform a movement that will be a combination of two movements, one being a translation or a rotation, which helps to get them over the height of the edge of the compartment, and the other being a displacement, which places them under the compartment.

[0037] Finally, as already indicated, the invention also relates to an aircraft comprising a lift module according to the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] To supplement the description herein and to help better understand the features of the invention, a set of drawings is attached hereto as an integral part of said description, in which the following are shown for illustrative and non-limiting purposes:

[0039] Figure 1A schematic perspective view of a VTOL aircraft is shown having engines for horizontal flight and rotors for vertical flight, which are attached to two pylons symmetrical with respect to the horizontal axis of the aircraft.

[0040] Figure 2 A schematic perspective view of a VTOL aircraft is shown, the VTOL aircraft having Figure 1 An architecture similar to the one shown illustrates the improvements obtained with lift modules covered by the invention and which form part of a pod fixed beneath the wing of an aircraft.

[0041] Figure 3 A schematic plan view of a VTOL aircraft as an example of application of the invention is shown, in which lift modules with different numbers of rotors can be seen and the aircraft nacelle is part of the aircraft structure.

[0042] Figure 4 Shown is a perspective view of two closed pod halves, the front pod half and the rear pod half forming a complete pod when joined together.

[0043] Figure 5 A perspective view of a simplified solution of a closed lift module with the rotor in a holding position is shown as an example of an embodiment of the invention.

[0044] Figure 6 A perspective view of a simplified solution of an opened lift module is shown as an example of an embodiment of the invention, with the rotor in a holding position.

[0045] Figure 7 A simplified perspective view of a lift module is shown, showing: a cross section AA where the active arms of the cover are located, and a cross section BB where the passive arms of the cover are located.

[0046] Figure 8 A simplified cross-sectional view of the lift module in section AA is shown, wherein the closed cover can be seen.

[0047] Fig. 9 A simplified cross-sectional view of the lift module in section AA is shown, wherein the open cover can be seen.

[0048] Fig.10 A simplified cross-section of a lift module in section BB is shown, wherein the closed cover can be seen.

[0049] Fig.11 A simplified cross-sectional view of a lift module in section BB is shown, wherein the open cover can be seen.

[0050] Fig.12A simplified cross-sectional view of a lift module according to another possible embodiment of the invention is shown in section AA, in which the closed cover can be seen.

[0051] Fig.13 Shows Fig.12 Simplified cross-section of the lift module in section AA, where the laterally displaced cover can be seen.

[0052] Fig.14 Shows Fig.12 Simplified cross-section of the lift module in section AA, where the open cover can be seen.

[0053] Fig.15 Shown according to Fig.12 Simplified cross-sectional view of the lift module of the illustrated implementation in section BB, in which the closed cover can be seen.

[0054] Fig.16 Shows Fig.15 Simplified cross-section of the lift module in section BB, where the laterally displaced cover can be seen.

[0055] Fig.17 Shows Fig.15 Simplified cross-section of the lift module in section BB, where the opened cover can be seen.

[0056] Fig.18 A simplified cross-sectional view of a lift module according to another possible embodiment of the invention is shown in section AA, in which the closed cover can be seen.

[0057] Fig.19 Shows Fig.18 Simplified cross-section of the lift module in section AA, where the cover can be seen rotated upwards.

[0058] Fig. 20 Shows Fig.18 Simplified cross-section of the lift module in section AA, where the open cover can be seen.

[0059] Fig.21 Shown according to Fig.18 Simplified cross-sectional view of the lift module of the illustrated implementation in section BB, in which the closed cover can be seen.

[0060] Fig. 22 Shows Fig.21 Simplified cross-section of the lift module in section BB, where the cover can be seen rotated upwards.

[0061] Fig.23 Shows Fig.21Simplified cross-section of the lift module in section BB, where the opened cover can be seen.

[0062] Fig.24 A simplified perspective view of a closed lift module according to another possible realization is shown, with the rotor in a holding position, wherein the motor and bearings or bushings located on the axis of the lift module but in different transverse planes can be seen.

[0063] Fig.25 A simplified cross-sectional view of a lift module of the invention, taken in section of the motor-rotor assembly, is shown with the rotor in a holding position, wherein the closed cover can be seen.

[0064] Fig.26 A simplified cross-sectional view of a lift module of the invention, taken in section of the motor-rotor assembly, is shown with the rotor in the deployed position, wherein the open cover can be seen. DETAILED DESCRIPTION

[0065] In the figures provided, identical or similar parts are marked with the same reference numerals. If not indicated otherwise, the positioning axes in space refer to the axes of the aircraft, ie the longitudinal axis X, the transverse axis Y and the vertical axis Z, which are all orthogonal.

[0066] Figure 1 A perspective view of an aircraft 1 for vertical take-off and landing is shown, the lift of which is generated both by fixed wings 2 and by rotors 30 .

[0067] In cruising flight, the aircraft 1 uses the propellers and engines mounted in its fuselage 10 to achieve forward flight along axis X, while the wings 2 provide lift along axis Z. To achieve vertical flight, it uses rotors 30 attached to two pylons 3 symmetrical with respect to the longitudinal axis X of the aircraft 1 and positioned below the wings 2.

[0068] The rotors continue to be exposed to the airflow after take-off and during cruising flight, and although their blades are positioned parallel to the longitudinal axis X of the aircraft, the increase in aerodynamic drag is significant, as described above in the background of the invention.

[0069] Figure 2 The horizontal flight phase is shown. Figure 1 The architecture is similar to the architecture of the aircraft 1 , showing two pods 5 attached to the wings 2 , and the lift modules 4 according to the proposed invention are part of the pods 5 .

[0070] According to this arrangement, since the rotor blades are not exposed to the surrounding airflow, the aerodynamic drag generated by the rotor is relatively small. Figure 1The configuration shown is zero, as described above in the Background of the Invention.

[0071] As examples of applications of the present invention, by way of illustration and not limitation, Figure 3 A plan view of a VTOL aircraft 1 with two pods 5 positioned symmetrically with respect to the longitudinal axis X of the aircraft is shown, in which it can be seen that the lift module 4 has the possibility of accommodating a different number of rotors 42, depending on the characteristics required for the aircraft, such as the maximum weight, the power available to the electric motors, the required level of safety in the event of failure of one or more motors, etc.

[0072] exist Figure 4 , a possible preferred embodiment of providing a lift module 4 with reduced aerodynamic drag in horizontal flight conditions is shown by joining two substantially cylindrical half-pods 51, the front half-pod comprising a nose fairing 52 attached to the front of one lift module 4, and the rear half-pod comprising another lift module 4 with a nose fairing 52 attached to the rear. These half-pods are joined one after the other to form a complete pod 5 as shown in the previous figures.

[0073] Thus, in particular, each lift module 4 comprises:

[0074] - a structural compartment 40 in which is fixed at least one drive assembly 43 driving a rotor 42 and its corresponding blades, the rotor 42 and its corresponding blades defining a plane of rotation when rotating;

[0075] - two covers 41A and 41B movable between an open position and a closed position of the structural compartment 40 ; and drive means for operating said covers 41A and 41B.

[0076] Therein, the drive means are such that, in the open position, both covers 41A and 41B are located below the plane of rotation of the blades so as not to interfere with the rotation of the rotor and, according to the embodiment shown in the figures, at least partially below the structural compartment 40 .

[0077] exist Figure 5 , a possible practical embodiment of the invention is shown in which it can be seen that the lift module 4 is aligned with the aforementioned longitudinal axis X and the structural compartment 40, the covers 41A and 41B of the lift module 4 are closed, and the drive assembly 43 driving the rotor 42 is fixed in the structural compartment 40, the rotor 42 is located above the structural compartment 40 and its blades are aligned with the longitudinal axis X of the lift module 4.

[0078] According to this embodiment, the drive means of the cover 41A and the cover 41B include at least two arms, one for each cover. More specifically, at one end of the arm, the cover 41A is fixed to the upper end of an arm 41A-1 (referred to as the active arm), the lower end of which has a shaft fixed thereto, which is connected or fixed to the shaft of a motor 41A-3 that rotates the cover 41A in a controlled manner.

[0079] However, according to a possible embodiment shown in the figures, the drive means of the covers 41A and 41B may additionally include other arms in order to avoid or reduce as much as possible the vibrations caused by the airflow occurring between the covers and the structural compartment 40. More specifically, the cover 41A is attached to the upper end of another equivalent arm 41A-1' (called the passive arm) at the end opposite to the end at which it is attached to the active arm 41A-1, the lower end of which has a fixed or connecting shaft that rotates freely in a bearing or bushing 41A-4. And in an arrangement structure that is symmetrical with respect to a vertical plane intersecting the longitudinal axis X, the cover 41B is attached to the upper end of the active arm 41B-1, the lower end of which has a shaft attached thereto, which is fixed or connected to the shaft of the motor 41A-3 that rotates the cover 41B in a controlled manner. At the other end, symmetrically, a cover 41B is attached to the upper end of another passive arm 41A-1', the lower end of which has a fixed or connecting shaft that rotates freely in a bearing or bushing 41B-4.

[0080] However, it may even be the case that both arms of each cover are active, in which case the motors driving them should be coordinated to distribute the load, or even that there are more than two arms per cover, combining active and passive arms in a similar manner to that described above.

[0081] on the other hand, Figure 6 Lift module 4 is shown with cover 41A and cover 41B in an open position, showing how both are located below the plane of rotation of the blades and almost completely below structural compartment 40, and also showing that rotor blade 42 can rotate freely without any type of interference.

[0082] Figure 7 The lift module 4 is shown, wherein active arms 41A- 1 and 41B- 1 are located at section AA, and passive arms 41A- 1 ′ and 41B- 1 ′, which are geometrically identical to the active arms, are located at section BB.

[0083] A preferred embodiment of the cover drive system for the present invention can be Figure 8 Seen in Figure 8A simplified schematic diagram of a cross section AA of a lift module is shown, in which active arms 41A-1 and 41B-1 are located, the rotation axes of active arms 41A-1 and 41B-1 being fixedly connected to shafts 41A-2 and 41B-2 of motors 41A-3 and 41B-3, respectively, motors 41A-3 and 41B-3 being fixed to a structural compartment 40 and being located on both sides of the longitudinal axis X of the lift module and equidistant from the longitudinal axis X of the lift module, and preferably being located in the same transverse plane, wherein it can be seen that the curved arcs forming the parts of covers 41A and 41B are in a closed position, their lower edges overlapping the upper edge of the structural compartment 40 on the outside, the cross section of which is formed by another curved arc.

[0084] Fig. 9 A simplified schematic diagram of a cross section AA of a lift module is shown in FIG. Figure 8 The same components described in are located in this lift module, where it can be seen that the active arms 41A-1 and 41B-1 are rotated, which causes the corresponding downward displacement of parts of the covers 41A and 41B until they reach the fully open position, in which, as already mentioned, both are located below the plane of rotation of the blades and almost completely under the structural compartment 40 so as not to interfere with the rotation of the rotor.

[0085] Fig.10 , a simplified scheme of a cross section BB of a lift module is shown, in which a passive arm 41A-1' and a passive arm 41B-1' can be seen, the rotation axes of which are respectively fixed to the axis 41A-2 of a bearing or bushing 41A-4 and the axis 41B-2 of a bearing or bushing 41B-4, which are attached to the structural compartment 40 and are located in the same position as the motor 41A-3 and the motor 41B-3 relative to the longitudinal axis X of the lift module, in which the curved arc forming the part of the cover 41A and the cover 41B can be seen in the closed position, and the lower edges of the cover 41A and the cover 41B overlap the upper edge of the structural compartment 40.

[0086] Fig.11 A simplified schematic diagram of a cross section BB of a lift module is shown in FIG. Fig.10 The same parts described in are located therein, in which the rotation of the passive arm 41A-1 'and the passive arm 41B-1 'can be seen, which, as already mentioned, brings about a corresponding downward displacement of parts of the cover 41A and the cover 41B, until the fully open position is reached, in which, as already mentioned, both are located below the plane of rotation of the blades and practically completely under the structural compartment 40 so as not to interfere with the rotation of the rotor.

[0087] Therefore, as also described above, the covers 41A and 41B are dimensioned so that their lower edges overlap the upper edge of the structural compartment 40 on the outside when the structural compartment 40 is closed, i.e. there is some overlap between the covers and the structural compartment to ensure proper aerodynamic performance.

[0088] However, another possible embodiment of the cover driving system for the present invention is a case where the surfaces of the covers 41A and 41B are flush with the surface of the structural compartment 40, such as Fig.12 As seen in the figure, it shows a simplified scheme of the cross-section AA of the lift module, in which the active arms 41A-1 and 41B-1 are located, and the rotation axes of the active arms 41A-1 and 41B-1 are respectively fixed to the shafts 41A-2 of the motors 41A-3 and 41B-2 of the motors 41B-3, and the rotation axes are located on both sides of the longitudinal axis X of the lift module and are equidistant from the longitudinal axis X of the lift module, and are preferably in the same transverse plane, in which the curved arcs forming the parts of the covers 41A and 41B can be seen in the closed position, their lower edges are flush with the upper edge of the structural compartment 40, and the cross-section of the structural compartment 40 is formed by another curved arc. When motors 41A-3 and 41B-3 are pushed linearly by electric, hydraulic or pneumatic actuators acting on gear racks, worm gears, slides, pistons or any other type of mechanism commonly used to perform such functions, they slide on transverse guides 41A-5 and 41B-5 fixed to the structural compartment 40.

[0089] exist Fig.13 A simplified schematic diagram of a cross section AA of a lift module is shown in FIG. Fig.12 The same parts described in are located therein, where one can see the lateral displacement of the active arms 41A-1 and 41A-1 and therefore of parts of the covers 41A and 41B, so that they are no longer flush with the upper edges of the structural compartments 40, but are separated from them.

[0090] Fig.14 A simplified schematic diagram of a cross section AA of a lift module is shown in FIG. Fig.12 The same parts described in are located therein, where it can be understood that the rotation of the active arms 41A-1 and 41B-1, as already mentioned, brings about a corresponding downward displacement of parts of the covers 41A and 41B until the fully open position is reached, where, as already mentioned, both are located below the plane of rotation of the blades and practically completely under the structural compartment 40 so as not to interfere with the rotation of the rotor.

[0091] exist Fig.15A simplified schematic diagram of a cross section BB of a lift module can be seen in which the axes of rotation / axes of the passive arms 41A-1' and 41B-1' are fixed to the axes 41A-2 and 41B-2 of the bearings or bushings 41A-4 and 41B-4, respectively, and are located in the same relative position with respect to the longitudinal axis X of the lift module as the motors 41A-3 and 41B-3, in which the curved arcs forming part of the covers 41A and 41B can be seen in the closed position, with their lower edges flush with the upper edge of the structural compartment 40. When the bearings or bushings 41A-4 and 41B-4 are pushed linearly by electric, hydraulic or pneumatic actuators acting on gear racks, worm gears, slides, or pistons or any other type of mechanism commonly used to perform such a function, they slide on transverse guides 41A-5 and 41B-5 fixed to the structural compartment 40.

[0092] Fig.16 A simplified schematic diagram of a cross section BB of a lift module is shown in FIG. Fig.15 The same parts described in are located therein, where one can see the lateral displacement of the passive arms 41A-1' and 41A-1' and therefore of parts of the covers 41A and 41B, so that they are no longer flush with the upper edge of the structural compartment 40, but are separated from them.

[0093] Fig.17 A simplified schematic diagram of a cross section BB of a lift module is shown in FIG. Fig.15 The same parts described in are located therein, in which the rotation of the passive arms 41A-1 ′ and 41A-1 ′ can be seen, which, as already mentioned, brings about a corresponding downward displacement of a portion of the cover 41A and a portion of the cover 41B until the fully open position is reached, in which, as already mentioned, both are located below the plane of rotation of the blades and practically completely under the structural compartment 40 so as not to interfere with the rotation of the rotor.

[0094] Thus, as also described above, the covers 41A and 41B are dimensioned so that, when the structural compartment 40 is closed, their lower edges are flush to the same level as the upper edge of the structural compartment 40. In this case, the drive means (i.e., the active arms 41A-1 and 41B-1 and the passive arms 41A-1 ' and 41B-1 ') are first moved laterally outward from the lift modules so that they can then be moved downward to position them below the plane of rotation of the blades, below the structural compartment. Thus, during the closing maneuver, the movement is reversed.

[0095] That is, when opening and closing, the drive means cause the covers to perform a movement that is a combination of two movements, one being a translation or lateral displacement which helps them to overcome the height of the upper edge of the structural compartment 40, and the other being a downward displacement which places them below the plane of rotation of the blades and at least partially under the structural compartment 40.

[0096] Finally, in Fig.18 Another preferred embodiment of the cover drive system for the present invention can be seen in the figure (in this case, the surfaces of the cover 41A and the cover 41B are flush with the surface of the structural compartment 40), which shows a simplified schematic diagram of the cross-section AA of the lift module, in which the active arm 41A-1 and the active arm 41B-1 are located, and the lower ends of the active arm 41A-1 and the active arm 41B-1 have a rotation axis respectively connected to the shaft 41A-2 of the motor 41A-3 and the shaft 41B-2 of the motor 41B-3, and the rotation axis is located on both sides of the longitudinal axis X of the lift module and is equidistant from the longitudinal axis X of the lift module, and is located in different transverse planes, wherein it can be seen that the curved arc forming the part of the cover 41A and the part of the cover 41B is in a closed position, and its lower edge is flush with the upper edge of the structural compartment 40, and the cross-section of the structural compartment 40 is formed by another curved arc. The covers 41A and 41B are articulated with the upper ends of the active arms 41A-1 and 41B-1, respectively, by means of motors 41A-7 and 41B-7, which are fixed to the arms and are located in different transverse planes, and whose axes 41A-6 and 41B-6 are fixed to their corresponding covers. Specifically, according to an exemplary embodiment, in order to move the covers 41A and 41B, the motors 41A-7 and 41B-7 are first actuated simultaneously in a controlled manner, whereby the covers rotate upward and disengage, and then rotate downward in a controlled manner by means of the motors 41A-3 and 41B-3, and are positioned below the plane of rotation of the blades and at least partially below the structural compartment 40.

[0097] Fig.19 A simplified schematic diagram of a cross section AA of a lift module is shown in FIG. Fig.18 The same parts described in are located therein, wherein the active arms 41A-1 and 41B-1 are rotated upwards and thus parts of the cover 41A and parts of the cover 41B are rotated upwards so that they are no longer flush with the upper edges of the structural compartments 40 but are separated from them.

[0098] Fig. 20 A simplified schematic diagram of a cross section AA of a lift module is shown in FIG. Fig.18The same parts described in are located therein, in which the downward rotation of the active arms 41A-1 and 41B-1 can be seen, the corresponding downward displacement of the portion of the cover 41A and the portion of the cover 41B, until the fully open position is reached, in which, as already mentioned, both are located below the plane of rotation of the blades and practically completely under the structural compartment 40 so as not to interfere with the rotation of the rotor.

[0099] exist Fig.21 A simplified schematic diagram of the cross section BB of the lift module can be seen, showing the passive arm 41A-1' and the passive arm 41B-1', the rotation axes of the lower ends of the passive arm 41A-1' and the passive arm 41B-1' are respectively fixed to the shaft 41A-2 of the bearing or bushing 41A-4 and the shaft 41B-2 of the bearing or bushing 41B-4, and are located in the same relative position as the motor 41A-3 and the motor 41B-3 relative to the longitudinal axis X of the lift module, in which it can be seen that the curved arcs forming the part of the cover 41A and the part of the cover 41B are in the closed position, and their lower edges are flush with the upper edge of the structural compartment 40. The covers 41A and 41B are hinged to the upper ends of the passive arms 41A-1' and 41B-1' respectively by means of bearings or bushings 41A-8 and 41B-8, which are fixed to the arms and are located in different transverse planes, and whose axes 41A-6 and 41B-6 are fixed to their corresponding covers, as shown. Fig.21 Specifically, when the cover 41A and the cover 41B rotate by means of the system located in section AA, since the passive arm 41A-1' and the passive arm 41B-1' are supported on bearings or bushings located at the ends of the arms, the ends of the cover 41A and the cover 41B in section BB are dragged and rotated in parallel.

[0100] Fig. 22 A simplified schematic diagram of a cross section BB of a lift module is shown in FIG. Fig.21 The same components described in are located therein, wherein the passive arms 41A-1' and 41A-1' are rotated upwards and thus parts of the cover 41A and parts of the cover 41B are rotated upwards so that they are no longer flush with the upper edges of the structural compartments 40, but are separated from them.

[0101] Fig.23 A simplified schematic diagram of a cross section BB of a lift module is shown in FIG. Fig.21 The same parts described in are located therein, in which the downward rotation of the passive arm 41A-1 'and the passive arm 41B-1 'can be seen, which, as already mentioned, brings about a corresponding downward displacement of a portion of the cover 41A and a portion of the cover 41B, until the fully open position is reached, in which, as already mentioned, both are located below the plane of rotation of the blades and practically completely under the structural compartment 40 so as not to interfere with the rotation of the rotor.

[0102] Thus, as in the previous case, the covers 41A and 41B are dimensioned so that, when the structural compartment 40 is closed, their lower edges are flush to the same height as the upper edge of the structural compartment 40. In this case, the drive means (i.e. the active arms 41A-1 and 41B-1 and the passive arms 41A-1 ' and 41B-1 ') are first rotated upwards so that they can then move downwards so that they are below the plane of rotation of the blades and almost completely under the structural compartment 40. Thus, during the closing maneuver, the movements are reversed.

[0103] That is, when opening and closing, the drive device causes the covers to perform a movement that is a combination of two movements, one movement being an upward rotation to help raise these covers to above the height of the upper edge of the structural compartment 40, and the other movement being a downward movement to place these covers below the structural compartment 40.

[0104] Finally, it should be noted that in all the above-described embodiments, if the distance between motor 41A-3 and motor 41B-3 and the longitudinal axis X of the lift module is very small or even zero, these motors should be located in different transverse planes so as not to interfere with each other, and similarly, bearing 41A-4 and bearing 41B-4 should be located in different transverse planes, such as Fig.24 shown.

Claims

1. A lift module 4 for a vertical take-off and landing aircraft, the lift module comprising: - a structural compartment 40 in which is fixed at least one drive assembly 43 driving a rotor 42 and corresponding blades of said rotor 42 which, when rotating, define a plane of rotation; - a cover 41A and a cover 41B, both of which are movable between an open position and a closed position of the structural compartment 40; as well as - a drive device for actuating the cover 41A and the cover 41B, Characteristically, the drive means are such that, in the open position, both the cover 41A and the cover 41B are positioned below the plane of rotation of the blades so as not to interfere with the rotation of the rotor.

2. The aircraft lift module 4 according to claim 1, characterized in that: The drive means of the cover 41A and the cover 41B are such that in the open position of the cover 41A and the cover 41B both covers are at least partially located below the structural compartment 40 .

3. The aircraft lift module 4 according to claim 1 or 2, characterized in that: The driving device of the cover 41A and the cover 41B includes: at least one active arm 41A-1 attached at its upper end to one of the covers 41A and at its lower end to a shaft connected to a shaft 41A-2 of a motor 41A-3 rotating the cover 41A in a controlled manner; and - at least one active arm 41B-1, which is attached to another cover 41B in the cover at its upper end and has a shaft attached to its lower end, which is connected to the shaft 41B-2 of the motor 41B-3 that rotates the cover 41B in a controlled manner.

4. The aircraft lift module 4 according to claim 3, characterized in that: The rotation axes of the active arm 41A-1 and the active arm 41B-1, which are respectively connected to the shaft 41A-2 of the motor 41A-3 and the shaft 41B-2 of the motor 41B-3, are fixed to the structural compartment 40, and are located on both sides of the longitudinal axis X of the lift module and are equidistant from the longitudinal axis X of the lift module, and are located in the same transverse plane.

5. The aircraft lift module 4 according to claim 3 or 4, characterized in that: The driving device of the cover 41A and the cover 41B includes: at least one passive arm 41A-1', attached at its upper end to one of the covers 41A and having at its lower end a fixed shaft freely rotating in a bearing or bushing 41A-4; and - at least one passive arm 41B-1', which is attached to another cover 41B in the cover at its upper end and has a free-rotating fixed shaft attached to a bearing or bushing 41B-4 at its lower end.

6. An aircraft lift module 4 according to any one of the preceding claims, characterized in that The covers 41A and 41B have curved arc-shaped cross-sections, so that in the closed position, the lower edges of the covers 41A and 41B overlap the upper edge of the structural compartment 40 on the outside, and the cross-section of the structural compartment 40 is formed by another curved arc.

7. The aircraft lift module 4 according to any one of claims 1 to 5, characterized in that: The covers 41A and 41B have curved arc-shaped cross-sections such that in the closed position, the lower edges of the covers 41A and 41B are flush with the upper edge of the structural compartment 40, the cross-section of which is formed by another curved arc.

8. The aircraft lift module 4 according to claim 7, characterized in that: The driving device causes the cover 41A and the cover 41B to perform a combined movement of lateral displacement and another downward displacement during the opening movement of the cover 41A and the cover 41B, wherein the lateral displacement helps the cover 41A and the cover 41B to pass the height of the upper edge of the structural compartment 40, and the other downward displacement places the cover 41A and the cover 41B below the rotation plane of the blade.

9. The aircraft lift module 4 according to claim 8, characterized in that: In order to perform the lateral displacement of the cover 41A and the cover 41B, the aircraft lift module 4 includes a transverse guide 41A-5 and a transverse guide 41B-5 fixed to the structural compartment 40, and the motor 41A-3 and the motor 41B-3 slide on the transverse guide 41A-5 and the transverse guide 41B-5 when they are linearly pushed by the drive device, thereby also causing the lateral displacement of the active arm 41A-1 and the active arm 41B-1 and the lateral displacement of part of the cover 41A and part of the cover 41B.

10. The aircraft lift module 4 according to claim 9, characterized in that: The bearing or bushing 41A-4 and the bearing or bushing 41B-4 slide on the transverse guide 41A-5 and the transverse guide 41B-5 when linearly pushed by the driving device, thereby also causing lateral displacement of the passive arm 41A-1' and the passive arm 41B-1' and lateral displacement of part of the cover 41A and part of the cover 41B.

11. The aircraft lift module 4 according to claim 7, characterized in that: The drive device causes the cover 41A and the cover 41B to perform a combined upward rotation movement and another downward movement during the opening movement of the cover 41A and the cover 41B, wherein the upward rotation movement helps the cover 41A and the cover 41B to pass the height of the upper edge of the structural compartment 40, and the other downward movement places the cover 41A and the cover 41B below the rotation plane of the blade.

12. The aircraft lift module 4 according to claim 11, characterized in that: In order to perform the upward rotation of the cover 41A and the cover 41B, these covers 41A and the cover 41B are respectively hinged to the upper end of the active arm 41A-1 and the upper end of the active arm 41B-1 by means of motors 41A-7 and motors 41B-7, and the motors 41A-7 and the motors 41B-7 are fixed to the arms and are located in different transverse planes, and the axes 41A-6 of the motors 41A-7 and the axes 41B-6 of the motors 41A-7 and the motors 41B-7 are fixedly connected to the covers corresponding to the motors 41A-7 and the motors 41B-7.

13. The aircraft lift module 4 according to claim 12, characterized in that: The cover 41A and the cover 41B are hinged to the upper end of the passive arm 41-A1' and the upper end of the passive arm 41B-1' respectively by means of bearings or bushings 41A-8 and bearings or bushings 41B-8, the bearings or bushings 41A-8 and the bearings or bushings 41B-8 are fixed to the arms and are located in different transverse planes, and the axis 41A-6 of the bearing or bushing 41A-8 and the axis 41B-6 of the bearing or bushing 41B-8 are fixedly connected to the covers corresponding to the bearings or bushings 41A-8 and the bearings or bushings 41B-8.

14. A vertical take-off and landing aircraft, comprising at least one lift module 4 according to any one of claims 1 to 13.

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