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 with integrated ducted propellers; and the ducted propellers each have a ferrule (11, 14) consisting of inlet zones (11) and outlet zones (14). The invention further relates to a method for manufacturing an aircraft. Figure to be published with the abstract: Fig. 4

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] As VTOL is described in the state of the aerospace art any aircraft, drone or rocket, in the commonly accepted sense, having the ability to take off and then land essentially vertically and without a takeoff 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] EP 2 193 993 A2 discloses a propeller fairing consisting essentially of annular parts.

[0004] WO 2005 / 032939 A1 proposes manufacturing a propeller fairing in segments according to a modular system.

[0005] US 7,712,701 B1 as well as CN 205770158 U describe propeller fairings manufactured from peripheral segments.

[0006] 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.

[0007] Thus, the invention relates to an aircraft characterized by the following characteristics: - the aircraft has wings with integrated ducted propellers and - the shrouded propellers have a shell composed of inlet zones and outlet zones respectively.

[0008] 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, cruise flight and landing), but on the other hand do not exceed a manageable number of parts.

[0009] For the thrust of the aircraft, instead of a free-speed rotor, there are provided shrouded propellers integrated into the supporting surface ("ducted fans"), as is the case known outside of aerospace technology, for example in hovercraft or hydrofoils. The cylindrical casing of the air duct - hereinafter referred to as the shroud - reduces thrust losses occurring due to turbulence at the blade tips of such a shrouded propeller.

[0010] According to the invention, the propeller fairings have different inlet and outlet areas, designed so that they can be prepared with a common tool but nevertheless of modular design. An advantage of this approach is the reduced cost that is achieved.

[0011] The aircraft according to the invention may furthermore have one or more of the following additional characteristics: - the shrouded propellers have different variants of shell construction and the outlet areas are of identical shapes or mirror images of each other in all construction variants, - the ferrules have honeycomb struts with inserts and are covered with several layers of carbon fiber reinforced plastic, - the shrouded propellers respectively comprise a guide grid and an electric motor supported by the guide grid and the outlet areas have recesses intended for the introduction of the guide grids, - the ferrules each have a peripheral stiffening ring, - the aircraft includes essentially vertical propellers to produce propulsion, - vertical propellers are other ducted propellers, - the electric motors respectively include an integrated control, - the aircraft can be controlled completely autonomously.

[0012] Thus, the outlet areas can be shaped in all design variants in identical or mirror-image shapes. The lower part of the tool can therefore be used universally and only be prepared in conjunction with the corresponding upper part of an individual fairing.

[0013] Finally, the fairings may have honeycomb struts with trims (inserts) covered with several layers of carbon fiber reinforced plastic. The honeycomb struts and inserts may be used several times for different variants.

[0014] The invention also relates to a method of manufacturing an aircraft as described above, characterized in that the shrouds are composed respectively of specific inlet zones and universal outlet zones and the ducted propellers are mounted in different mounting positions in the wings.

[0015] An exemplary embodiment of the invention is shown in the illustrations and is described further below.

[0016] [Fig. 1] shows the isometric view of a wing with partially transparent covering and outer skin.

[0017] [Fig.2] shows the isometric view of a shrouded propeller of the wing without engine.

[0018] [Fig.3] shows a view corresponding to [Fig.2] in elevated perspective.

[0019] [Fig.4] shows the isometric view of a propeller with partially inlet and outlet transparent.

[0020] [Fig.5] shows the isometric view of the honeycomb uprights of two fairings with inserts.

[0021] [Fig.6] shows the front view of two fairing parts in different variants of design.

[0022] [Fig.7] shows a view corresponding to [Fig.5] of the complete fairings with inlet and partially transparent output.

[0023] [Fig.8],

[0024] [Fig.9] and

[0025] [Fig. 10] illustrate the butt joint assembly between the fairing and the guide grid.

[0026] [Fig.l] illustrates the assembly of a wing (10) for an aircraft of the totally optional autonomous or manually controlled, which is roughly subdivided into quadrants by spars and ribs. In three of these quadrants is integrated respectively a shrouded propeller whose guide grille (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 grille (12) so that its carbon fiber reinforced plastic (CFK) struts allow the electric motor (13) to be supported in an axially and rotationally symmetrical arrangement on opposite sides.

[0027] In the configuration shown, two of the struts 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 supplemented 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 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).

[0028] Figures 2 and 3 show the different construction variants (X, Y) of the ferrule (11). This design variant is made possible according to the invention by the modular system shown in [Fig.4] by means of the design variant Y, according to which the ferrule (here: 11, 14) consists of inlet zones (11) and outlet zones (14) which can be prepared in all design variants (X, Y) using a tool with a universal lower part.

[0029] [Fig. 5] illustrates the design of each ferrule (11, 14) from honeycomb uprights (15) with inserts (16) preferably covered with several layers of CFK depending on their composition. 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.

[0030] As illustrated in [Fig.6], this modular approach in the present embodiment is favored by the geometric relationships of the ferrules (11, 14): While each ferrule (11, 14) requires a specific entry area (11), the exit areas (14) in all design variants (X, Y) are geometrically congruent or with the same coverage, and can therefore be moved by parallel shifting, rotation, mirror image or combinations of the aforementioned geometric transformations or movements.

[0031] The ferrules (11, 14) consisting of these specific inlet zones (11) and universal outlet zones (14) can be stiffened by multi-part rings (17, 18, 19) of the type shown in [Fig. 7]. A summary of Figures 8, 9 and 10 illustrates two design variants based on two example ferrules (here: 11, 14, 19), where finally the corresponding guide grid can be introduced therein from below by means of recesses (20) of the outlet zone (14) according to the illustration.

[0032] In the present embodiment, the electric motor (13 - [Fig.l]) 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 liquid cooling can be envisaged, 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

[0033] 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, characterized by the following features: - the aircraft has wings (10) with integrated ducted propellers (11-20) and - the ducted propellers (11-20) respectively have a shroud (11, 14) composed of inlet zones (11) and outlet zones (14), aircraft characterized by the following features: - the ducted propellers (11-20) have different construction variants (X, Y) of the shroud (11, 14) and - the outlet zones (14) are of identical shapes or mirror images of each other in all construction variants (X, Y).

2. Aircraft according to claim 1, characterized by the following features: - the ferrules (11, 14) have honeycomb struts (15) with inserts (16) and - the ferrules (11, 14) are covered with several layers of carbon fiber reinforced plastic.

3. Aircraft according to any one of claims 1 and 2, characterized by the following features: - the ducted propellers (11-20) respectively comprise a guide grid (12) and an electric motor (13) supported by the guide grid (12) and - the outlet zones (14) have recesses (20) intended for the introduction of the guide grids (12).

4. Aircraft according to any one of claims 1 to 3, characterized by the following feature: - the ferrules (11, 14) respectively have a peripheral stiffening ring (17, 18, 19).

5. Aircraft according to any one of claims 1 to 4, characterized by the following feature: - the aircraft comprises essentially vertical propellers to produce propulsion.

6. Aircraft according to claim 5, characterized by the following feature: - the essentially vertical propellers are other ducted propellers (11-20).

7. Aircraft according to claim 3 or any one of claims 4 to 6, as long as they relate to claim 3, characterized by the following feature: - the electric motors (13) respectively comprise an integrated control.

8. Aircraft according to any one of claims 1 to 7, characterized by the following feature: - the aircraft can be controlled as desired in a completely autonomous manner.

9. A method of manufacturing an aircraft according to any one of claims 1 to 8, having wings (10) with integrated ducted propellers (11-20) each having a shroud (11, 14), characterized by the following features: - the ducted propellers (11-20) have different construction variants (X, Y) of the shroud (11, 14), - the shrouds (11, 14) consist respectively of specific inlet zones (11) and universal outlet zones (14) which are of identical shapes or mirror images of each other in all construction variants (X, Y), and - the ducted propellers (11-20) are mounted in different mounting positions in the wings (10).

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