Aircraft and its manufacturing process

Abstract

Aircraft and its manufacturing process. The invention relates to an aircraft with the following characteristics: The aircraft has wings (10) with integrated ducted propellers (11-12-13), and these ducted propellers respectively have a ferrule (11) with recesses and a guide grid (12) inserted into the recesses. The invention further relates to a method for manufacturing an aircraft. Figure to be published with the abstract: Fig. 1

Description

Title of the invention: Aircraft and its manufacturing process

[0001] The present invention relates to an aircraft, in particular a fully electric aircraft, capable of vertical take-off and landing (VTOL) and to an advantageous method for manufacturing it.

[0002] In the state of the aerospace art, any aircraft, drone or rocket, in the commonly accepted sense, is described as VTOL, having the ability to take off and then land essentially vertically and without a take-off or landing runway. This generic term is then used in the broad sense, which includes not only fixed-wing aircraft with lifting surfaces, but also rotary-wing aircraft, such as helicopters, gyrocopters and hybrids, such as combined helicopters as well as convertible aircraft. Also included are aircraft having the ability to take off and land over particularly short distances ("short take-off and landing" - STOL), to take off over short distances but to land vertically ("short take-off and vertical landing" - STOVL) or to take off vertically but to land horizontally ("vertical take-off and horizontal landing" - VTHL).

[0003] CN104691751A discloses a safe, triangular-supported, multi-rotor aircraft low weight, with a cone-and-slot structure, consisting of a fuselage, rotors, a flight control module located in the middle of the fuselage, and an integrated wiring harness-type connection. The fuselage comprises a horizontal structural panel and a plurality of lighter vertical structural panels connected by cones and slots to a triangular supporting structure, the outer face of which forms a frame and the inner face of which is supported at an opposite angle. The rotors are arranged at the outermost intersection points of the vertical plates in the vertical direction, while the horizontal plate is connected to the vertical surface of the frame and serves as a fastener. A plurality of rotor holes, which protect the rotors and whose diameters are somewhat larger than those of the rotors, are formed in the horizontal plate, while the rotor drive shafts are used as the centers of the holes.Finally, a plurality of cones is arranged at the point of contact of each vertical plate and the horizontal plate, which is provided with corresponding notches linked to the cones.

[0004] The invention provides an aircraft, in particular a fully electric aircraft, in the sense mentioned above, capable of taking off and landing vertically, as well as a method of manufacturing such a vehicle.

[0005] Thus, the invention relates to an aircraft, characterized by the following features: - the aircraft has wings with integrated ducted propellers and - the shrouded propellers respectively have a ferrule provided with recesses as well as a guide grid introduced into the recesses.

[0006] The approach according to the invention is based on the revelation that a VTOL aircraft usable in an urban environment requires power units in different positions and orientations, which on the one hand are able to cope with each phase of flight (takeoff, transition, cruising flight and landing), but on the other hand do not exceed a manageable number of parts.

[0007] For the thrust of the aircraft, instead of a free-speed rotor, ducted propellers integrated into the supporting surface (known as "ducted fans") are provided, as are known outside aerospace technology, for example in air cushion vehicles or hydrofoils. The cylindrical casing or tubular casing of the air duct (hereinafter referred to as a shell) reduces the thrust losses occurring as a result of turbulence at the blade tips of such a ducted propeller.

[0008] According to the invention, this shell is provided with recesses which allow it to be provided in a modular manner - i.e. according to the principle of a building block or part - with a guide grid (stator) optimized for the design variant and the direction of rotation of the respective drive shaft. The same concept can be used for other design variants, so that specific shells and guide grids can be combined as desired to achieve cost savings.

[0009] The aircraft according to the invention may furthermore have one or more of the following additional characteristics: - the guide grids are introduced by material bonding into the recesses, - the guide grids are glued into the recesses, - the shrouded propellers have different variants of shell construction and the recesses have an identical shape in all construction variants, - the shape is an isosceles trapezoid and the recesses are positioned in pairs at diametrically opposite positions of the ferrule, - the ferrule areas respectively have a peripheral stiffening ring, - the ferrules consist of entry zones and exit zones respectively and the exit zones carry the stiffening rings and have the recesses, - the ferrules have honeycomb struts with inserts and are covered with several layers of carbon fiber reinforced plastic, - the shrouded propellers include an electric motor supported by the grid of guidance.

[0010] The guide grids can therefore be inserted to adhere completely into the recesses, and in particular can be glued there. By using such universal "gluing" on the housings, the specific stator variants can be manufactured inexpensively in different designs and used universally.

[0011] The invention also relates to a method of manufacturing an aircraft of the aforementioned type, characterized in that the guide grids are introduced into the recesses of the ferrules and the faired propellers are mounted in different mounting positions in the wings.

[0012] An exemplary embodiment of the invention is shown in the illustrations and is described further below.

[0013] [Fig.l] shows the isometric view of a wing with partially transparent covering and outer skin.

[0014] [Fig.2] shows the isometric view of a shrouded propeller of the wing without engine.

[0015] [Fig.3] shows a view corresponding to [Fig.2] in elevated perspective.

[0016] [Fig.4] shows the isometric view of a propeller with partially opened inlet and outlet transparent.

[0017] [Fig.5] shows the front view of two fairing parts in two different variants of design.

[0018] [Fig.6] shows the isometric view of a ferrule and a guide grid in a variant according to [Fig.5].

[0019] [Fig.7] shows in detail the butt joint assembly according to the invention of the ferrule and of the guide grid.

[0020] [Fig.8] shows the isometric view of one ferrule and a guide grid in the other variant according to [Fig.5].

[0021] [Fig. 1] illustrates the assembly of a wing (10) for an aircraft which is either fully autonomous or manually controlled, which is subdivided approximately into quadrants by spars and ribs. In three of these quadrants is integrated respectively a shrouded propeller whose guide grid (12) arranged inside the shroud (11) carries a central electric motor (13). The three cylindrical electric motors (13) are radially screwed onto the respective guide grid (12) so that its props made of carbon fiber reinforced plastic (CFRP) allow the electric motor (13) to be supported in an axially and rotationally symmetrical arrangement on opposite sides.

[0022] In the configuration shown, two of the props of each guide grid (12) extend parallel to each other in the direction of inflow of the wing (10) and tangentially flank the corresponding electric motor (13). Respectively two beams joined to these uprights are completed by the beams diametrically opposite the motor (13) of the respective other upright in a St. Andrew's cross and reinforce the electric motor (13) so that the guide grid (12) receives all horizontal forces at the motor. As the illustration allows you to recognize for information purposes, the struts of the guide grid (12) have a width which corresponds approximately to the height of the electric motor (13).

[0023] Figures 2 and 3 show the different construction variants (X, Y) of the ferrule (11). This variant is made possible by the modular system shown in [Fig.4] on the basis of the design variant Y and shown in [Fig.5] by the juxtaposition of the variants X and Y: The ferrule (here: 11, 14) consists of inlet zones (11) and outlet zones (14) reinforced by a ring all around (17, 18, 19 - [Fig.4]).

[0024] [Fig. 6] draws the observer's attention, from an example of a ferrule (here: 11, 14, 19) of the design variant Y, to the fundamental butt joint for the invention of the guide grid (12). The outlet areas (14) of the ferrule (11, 14, 19) of the present embodiment have two pairs of diametrically opposed recesses (20), into which the corresponding guide grid (12) can be introduced from below according to the illustration.

[0025] [Fig.7] illustrates this preparation step in a detailed representation. The indicated recess (20) has - easily recognizable in this view - approximately the shape of an isosceles trapezoid whose base opens onto the lower edge of the outlet zone (14) according to the illustration. The stay of the support grid (12) to be introduced into this recess has a complementary shape which makes it possible to assemble the grid (12) placed under the outlet zone (14) along the median axis of the shell upwards with it and to glue it in its recess (20).

[0026] The advantage of this approach is summarized in [Fig. 8]: Thanks to the common trapezoidal shape of the recesses (20) between all design variants (X, Y), a guide grid (12) can be introduced into the outlet area (14) of a ferrule (11, 14, 19) of variant Y.

[0027] Each ferrule (11, 14) of the propeller may, for example, consist of honeycomb struts with inserts and, as a result, preferably be covered with several layers of CFRP. Below, in this context, composites are to be understood in which carbon fibers are incorporated in a plastic matrix which serves to bind the fibers as well as to fill the intermediate space. As matrix, in addition to a traditional epoxy resin, thermosets or thermoplastics will also be considered here, without departing from the scope of the invention.

[0028] In the present embodiment, the electric motor (13 - [Fig. 1]) is produced with integrated control in the form of an air-cooled inner rotor. It is understood that in an alternative embodiment, an outer rotor or air cooling can be envisaged. liquid propulsion, without departing from the scope of the invention. Other examples of options are published by DUFFY, Michael, et al. “Propulsion scaling methods in the era of electric flight.” 2018 AIAA / IEEE Electric Aircraft Technologies Symposium (EATS). IEEE, 2018. p. 1-23.

[0029] Of course, the invention is not limited to the embodiments described and shown in the attached drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Claims

1. Aircraft, wherein: - the aircraft has wings (10) with integrated ducted propellers (11-20) and - the ducted propellers (11-20) respectively have a shroud (11, 14) provided with recesses (20) as well as a guide grid (12) inserted into the recesses (20) aircraft characterized by the following features: - the shrouds (11, 14) have honeycomb struts with inserts and - the shrouds (11, 14) are covered with several layers of a carbon fiber reinforced plastic.

2. Aircraft according to claim 1, characterized by the following feature: - the guide grids (12) are introduced by material bonding into the recesses (20).

3. Aircraft according to claim 2, characterized by the following feature: - the guide grids (12) are glued into the recesses (20).

4. Aircraft according to any one of claims 1 to 3, characterized by the following features: - the ducted propellers (11-20) have different construction variants (X, Y) of the shroud (11, 14) and - the recesses (20) have an identical shape in all the construction variants (X, Y).

5. Aircraft according to claim 4, characterized by the following features: - the shape is an isosceles trapezoid and - the recesses (20) are positioned in pairs at diametrically opposite positions of the ferrule (11, 14).

6. Aircraft according to any one of claims 1 to 5, characterized by the following feature: - zones of the ferrules (11, 14) respectively have a peripheral stiffening ring (17, 18, 19).

7. Aircraft according to claim 6, characterized by the following feature: - the ferrules (11, 14) are composed respectively of inlet zones (11) and outlet zones (14) and - the outlet zones (14) carry the stiffening rings (17, 18, 19) and have the recesses (20).

8. Aircraft according to any one of claims 1 to 7, characterized by the following feature: - the ducted propellers (11-20) comprise an electric motor (13) supported by the guide grid (12).

9. A method of manufacturing an aircraft according to any one of claims 1 to 8, characterized by the following features: - the guide grids (12) are introduced into the recesses (20) of the ferrules (11, 14), which have honeycomb uprights with inserts and are covered with several layers of a carbon fiber reinforced plastic, and - the ducted propellers (11-20) are mounted in different mounting positions in the wings (10).

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