Arrangement for holding an aircraft wing, aircraft and method for mounting a pressure tank

Abstract

An arrangement for supporting an aircraft wing is described. The arrangement comprises a mounting structure with a first and a second support point, and a tubular pressure tank for holding a propellant. The pressure tank is supported longitudinally by the first and second support points and extends beyond the second support point. The arrangement also includes a sliding bearing located at the second support point to support the pressure tank against a lateral force perpendicular to its longitudinal direction. The sliding bearing has an opening with an internal conical structure that tapers towards the first support point. The pressure tank has an external conical structure on its outer surface that corresponds to the internal conical structure of the sliding bearing and tapers towards the first support point.The inner conical structure and the corresponding outer conical structure lie against each other and slide against each other in the longitudinal direction to accommodate changes in circumference and length due to pressure changes in the pressure tank.

Description

Technical field

[0001] The invention relates to an arrangement for holding an aircraft wing. The invention also relates to an aircraft with a wing and an arrangement for holding the wing. Furthermore, the invention relates to a method for mounting a pressure tank in a support structure.

[0002] One way to reduce climate-damaging greenhouse gases is the development of new propulsion technologies. Emission-free propulsion systems play a crucial role in the automotive and aviation industries, for example. Hydrogen, as an energy carrier, represents a promising technology in this regard. The challenge with hydrogen lies in its significantly lower volumetric energy density compared to conventional kerosene. For the same energy, the required volume of hydrogen is approximately four times greater. The energy-equivalent storage densities can be provided within a storage range relevant to mission range, for example, in unprinted cryogenic form, in printed cryogenic form, or as gaseous hydrogen stored in pressurized tanks.

[0003] Pressure storage technologies typically provide the propellant in gaseous form. For example, gaseous hydrogen has a very low volumetric density, making it necessary to store it at high internal pressures to achieve practical storage volumes. Currently used pressure tanks, such as those already employed in the automotive sector, are capable of storing hydrogen at pressures of 350 bar or 700 bar, for instance. Various types of pressure tanks are described in the article "Shape and Size Optimization of an Aerospace Propellant Tank," by Kerem Utku Demir et al., presented at the 12th Ankara International Aerospace Conference (AIAC) in Ankara, Turkey, September 2023.

[0004] The available pressure tanks differ, for example, in the material they are made of and the type and shape of the diffusion barrier. Due to their high potential for lightweight construction, pressure tanks primarily manufactured with fiber-reinforced plastics play a significant role in both the automotive and aerospace industries. The end caps of these pressure tanks are preferably made of metal. Such pressure tanks may, for example, have an inner liner made of polymer materials that serves as a hydrogen diffusion barrier. Alternatively, pressure tanks based on linerless designs can be used; these are, for example, pressure tanks that incorporate suitable resin systems and therefore do not require an inner liner.

[0005] In aircraft, various options and installation spaces are available for storing propellant in pressurized tanks. One possibility is to integrate the pressurized tanks into the aircraft's existing structural spaces. In this case, the tanks can, for example, not only store the propellant but also perform load-bearing functions within the structure.

[0006] Pressure tanks integrated into a wing structure that simultaneously bear structural loads represent an efficient and lightweight structural concept. In this context, it may be particularly necessary to connect the wing with the load-bearing pressure tank tubes to the fuselage via suitable structural elements.

[0007] German patent application DE 29 03 758 A1 describes a support structure for a prestressed cylindrical pressure vessel and a method for its construction. The prestressed cylindrical pressure vessel, preferably made of prestressed concrete, is supported on a foundation by means of an annular retaining wall. Several radially oriented, prestressed bearings, adjustable with respect to force and displacement, are arranged between the pressure vessel and the annular retaining wall and are removable.

[0008] German patent application DE 10 2018 219 559 A1 describes a vehicle with an integrated pressure vessel. The pressure vessel has a cylindrical shell and is supported at axially opposite ends by a first bearing element on the vehicle body and a second bearing element axially spaced from it. In a crash, the two bearing elements, together with the intermediate pressure vessel, are integrated into a load path through which crash energy is transferred to the side of the vehicle facing away from the crash.A motion transmission unit is assigned to the pressure vessel, by means of which, in the event of a crash, a translational crash movement of adjacent vehicle parts is partially converted into a rotational movement that acts on the pressure vessel, so that in the motion transmission unit a division of the load path takes place into a linear load path, in which a linear force component formed in the motion transmission unit acts on the pressure vessel in the crash direction, and in a torsional load path, in which a torsional force component formed in the motion transmission unit acts on the pressure vessel in the circumferential direction and subjects it to torsion with a torsional moment.

[0009] German patent application DE 12 80 079 A describes a mounting system for tanks containing very cold liquids in tank ships, in which the tank bottom rests on a central, upwardly tapered bearing journal and on supports outside of it. A central, upwardly projecting support is provided at the tank top, which engages in a corresponding recess in the ship's deck. The central bearing journal engages in a conical recess in the tank bottom, and the supports each consist of a pair of wedges whose inclination decreases outwards from the central bearing journal, so that despite differing horizontal thermal displacements, the tank experiences uniform vertical displacements at all points.

[0010] The publication EP 1 355 106 B1 discloses a pressure tank for holding a pressurized fluid, comprising a plurality of receiving chambers, each of which includes a receiving space formed between integrally formed chamber walls. Curved chamber walls facing the outside, arranged opposite each other on opposite sides of the pressure tank, are in force-linked contact. A chamber wall of a receiving space facing an adjacent receiving space is planar and transmits an applied tensile stress as a continuous force to the opposite side of the pressure tank. Each planar chamber wall is closed to the outside by a curved chamber wall integrally formed with the corresponding planar chamber walls. The object of the invention is to provide an improved arrangement for holding an aircraft wing.

[0011] The problem is solved by an arrangement for holding an aircraft wing, wherein the arrangement comprises a mounting structure with a first mounting point and a second mounting point, and a tubular pressure tank for holding a propellant. The pressure tank is held longitudinally by the first and second mounting points and extends a section beyond the second mounting point. The arrangement also includes a sliding bearing located at the second mounting point to hold the pressure tank against a lateral force perpendicular to its longitudinal direction. The sliding bearing has an opening with an internal conical structure that tapers towards the first mounting point.The pressure tank has an external conical structure on its outer surface that corresponds to the internal conical structure of the sliding bearing and tapers towards the first support point. The internal conical structure and the corresponding external conical structure are in contact with each other and slide against each other longitudinally to accommodate changes in circumference and length due to pressure changes in the pressure tank.

[0012] According to the embodiments of the invention, it is proposed to hold the pressure tank using conical structures. This makes it possible, for example, to achieve backlash-free mounting in the area of ​​the conical bearing, independent of the internal pressure.

[0013] A conical structure within the meaning of this application is understood to be a conical structure with a tapered outer contour. A conical structure within the meaning of this application includes both conical structures with a linearly tapered outer contour and those with a tapered outer contour that is curved, wherein the outer contour of the conical structure may, in particular, be convex or concave.

[0014] The proposed conical bearing allows, for example, the introduction of tank breathing without loads into the tubular pressure tank. This arrangement enables the tubular pressure tank to expand freely in both axial and radial directions due to the internal pressure resulting from this tank breathing. This avoids, for example, constraint forces caused by radial constriction and / or restrictions on axial expansion. Thus, the bearing and the tank breathing can be decoupled.

[0015] An arrangement according to the embodiments of the invention provides a universal integration concept that makes it possible to mount pressure tanks regardless of the aircraft type. The mounting points, for example, allow for detachable connections and load-adapted dimensioning of the bearing structures. This makes the concept applicable to any aircraft. Furthermore, different tank tube diameters can be implemented. In addition, an arrangement according to the embodiments of the invention makes it possible, for example, to integrate the pressure tank in a removable and thus replaceable manner, enabling replacement and inspection.

[0016] The invention further relates to an aircraft with a wing and an arrangement for holding the wing of the aircraft as described above, wherein the wing is connected to the pressure tank and a fuselage-side support structure in such a way that bending moments at a wing root of the wing can be introduced into the fuselage-side support structure via the pressure tank.

[0017] The invention further relates to a method for mounting a tubular pressure tank in a support structure having a first support point and a second support point, wherein a floating bearing is provided at the second support point, which is designed to hold the tubular pressure tank. The floating bearing has an opening with an internal conical structure having an inner surface that tapers towards the first support point. The tubular pressure tank has an external conical structure on its outer surface that corresponds to the internal conical structure of the floating bearing and tapers towards the first end of the pressure tank. The method comprises inserting the pressure tank with its first end into the opening of the floating bearing until the internal conical structure of the floating bearing and the corresponding external conical structure of the tubular pressure tank are in contact with each other.Furthermore, the procedure includes fixing the first end of the tubular pressure tank to the first holding point.

[0018] Advantageous training and further education programs, which can be used individually or in combination, are the subject of the dependent claims and the following description.

[0019] According to a preferred embodiment, a fixed bearing is provided at the first holding point, which is designed to hold a first end of the pressure tank.

[0020] Preferably, the fixed bearing is mechanically connected to the floating bearing via at least one longitudinal beam.

[0021] Preferably, the fixed bearing is connected to the floating bearing via a box profile structure adapted to the wing cross-section.

[0022] It is advantageous if the fixed bearing is connected to the loose bearing via a load-bearing belt structure and / or via at least one load-bearing longitudinal beam web.

[0023] According to an alternative preferred embodiment, a second loose bearing is provided at the first holding point to hold the pressure tank.

[0024] Preferably, the second loose bearing has an opening with a second inner conical structure having an inner surface that tapers towards the second holding point, wherein the pressure tank has on its outer surface a second outer conical structure corresponding to the second inner conical structure of the second loose bearing, which tapers towards the second holding point, and wherein the second inner conical structure and the corresponding second outer conical structure are in contact with each other.

[0025] According to a preferred embodiment, the outer surface of the external conical structure has a curved contour that is determined by the pressure expansion of the pressure tank in the longitudinal and circumferential directions.

[0026] According to another preferred embodiment, the contour of the outer surface of the external cone structure is linear, wherein the cone angle of the outer surface is given by the linearly approximated ratio of circumferential and length changes of the pressure tank during pressure expansion of the pressure tank.

[0027] It is advantageous if the external conical structure is formed completely around the tubular pressure tank.

[0028] Alternatively, it is advantageous if the external conical structure is formed partially or piecemeal around the tubular pressure tank.

[0029] Preferably, the mounting structure comprises a fuselage-side support structure designed to transfer forces and moments acting on the pressure tank to the fuselage of the aircraft.

[0030] Preferably, the arrangement has a supporting surface attached to it.

[0031] Preferably, the tubular pressure tank is designed for storing pressurized gaseous and liquid propellant. More preferably, the tubular pressure tank is designed to store the propellant at a pressure in the range of 100 bar to 1000 bar.

[0032] According to a preferred embodiment, the tubular pressure tank is made entirely or partially of a fiber composite material and / or of metal.

[0033] It is advantageous if the tubular pressure tank assumes load-bearing properties, in particular acting as a wing spar. Preferably, the loads acting on the tubular pressure tank include one or more of the following: internal pressure, aerodynamic loads, structural loads, weight loads, operating loads, and mooring loads.

[0034] Preferably, the tubular pressure tank is integrated into the cross-section of the wing. More preferably, the arrangement comprises several tubular pressure tanks. Even more preferably, the arrangement comprises several tubular pressure tanks arranged side by side and integrated into the cross-section of the wing.

[0035] It is advantageous if a planar contact is formed between the outer conical structure of the tubular pressure tank and the inner conical structure of the loose bearing.

[0036] According to a preferred embodiment, at least one of the outer cone structure and the inner cone structure is provided with an abrasion-reducing or abrasion-preventing coating, a film, an additive material or a surface treatment.

[0037] Preferably, the support structure comprises a transverse rib to which the first end of the pressure tank is attached. It is advantageous if the pressure tank has a connecting structure at its end, wherein the connecting structure is mechanically linked to the support structure. Alternatively, it is advantageous if the pressure tank has a bossed section at its end, wherein the bossed section is mechanically linked to the support structure. Brief description of the drawings

[0038] Further advantageous embodiments are described in more detail below with reference to exemplary embodiments shown in the drawings, to which, however, the invention is not limited.

[0039] They show schematically: Fig. 1 a wing with integrated tubular pressure tanks; Fig. 2 the hull-side sections of the tubular pressure tanks with external conical structures attached along the circumference; Fig. 3 a longitudinal section through an external conical structure; Fig. 4 the loose bearing with four openings for receiving the tubular pressure tanks; Fig. 5 a section through one of the openings, revealing the internal conical structure; Fig. 6. The interpretation of the cone angles based on a schematic representation of the pressure tank; Fig. 7A a conical bearing in the printed and unprinted state of the pressure tank for a linear conical geometry; Fig. 7B a conical bearing in the printed and unprinted state of the pressure tank for a curved conical geometry; Fig. 8A a conical bearing with a linear conical geometry; Fig. 8B a conical bearing with a curved conical geometry; Fig. 8C a conical bearing with an inverted curved conical geometry; Fig. 9 an arrangement for the connection of the cone bearing to the hull side; Fig. 10A a concept for the realization of a fixed bearing for polar cap connection with separate connection structures; Fig. 10B a cut through the in Fig. Arrangement shown in 10A; Fig. 11 a concept for the realization of a fixed bearing for polar cap connection with bolted boss parts; Fig. 12 a bearing for a pressure tank by means of a first and a second conical bearing. Description of embodiments

[0040] In Fig. Figure 1 shows a schematic representation of an aircraft wing 2 together with four tubular pressure tanks 4-1 to 4-4 integrated into the cross-sectional geometry of the wing 2. The tubular pressure tanks 4-1 to 4-4 extend from the fuselage towards the outer edge of the wing. The number of tubular pressure tanks 4-1 to 4-4 is generally arbitrary. Within the cross-section of the wing profile, the tubular pressure tanks 4-1 to 4-4 can be arranged to make the best possible use of the available space. Various cross-sectional concepts are conceivable. For example, tank tubes with the same or different diameters can be used within the wing profile. In the example of Fig. 1. The pressure tanks 4-1 to 4-4 are designed as circular elongated tube structures, which may be constructed primarily from fiber composite materials, but also from metallic materials.

[0041] Furthermore, in Fig. 1. An arrangement for mounting the wing 2 and the pressure tanks 4-1 to 4-4 can be seen. According to the in Fig. In the embodiment shown in Figure 1, the arrangement comprises a fixed bearing 6 at a first support point and a floating bearing 8 at a second support point spaced apart from the first support point. The fixed bearing 6 is designed to fix the fuselage-side ends of the tubular pressure tanks 4-1 to 4-4. Furthermore, the arrangement includes a fuselage-side support structure 10, which is mechanically connected to the fixed bearing 6 to transfer any loads to the fuselage of the aircraft. If the tubular pressure tanks 4-1 to 4-4 have polar caps at their ends, the polar caps of the pressure tanks 4-1 to 4-4 can be attached to the fixed bearing 6 via suitable connection structures 12-1 to 12-4.

[0042] The loose bearing 8, located at the second support point, is designed as a conical bearing, the construction of which is explained in more detail below. The fixed bearing 6 and the loose bearing 8 are jointly designed to ensure stable support of the tubular pressure tanks 4-1 to 4-4, even when changes in length and circumference of the pressure tanks 4-1 to 4-4 occur due to pressure changes in the propellant stored within them. To ensure stable support, the loose bearing 8 is mechanically connected to the fixed bearing 6 via a belt and longitudinal beam structure 14. The position of the loose bearing 8 along the longitudinal axis of the blades is freely selectable and can be designed according to the specific concept. Fig. In the concept shown in Figure 1, the loose bearing 8 is provided, for example, at a longitudinal position of 800 mm measured from the beginning of the polar caps, with the tubular pressure tanks 4-1 to 4-4 each having a length of 6000 mm.

[0043] The primary function of the pressure tanks 4-1 to 4-4 is to store the propellant under pressure. The propellant can be in liquid or gaseous form. Additionally, the tubular pressure tanks 4-1 to 4-4 can be coupled to form a profile-defining wing cross-section, enabling the transfer of aerodynamic loads to the pressure tanks. The profile-defining wing skin can be mechanically coupled to the tubular pressure tanks 4-1 to 4-4, for example, by bonding or by creating mechanical connections, such as positive-locking connections in the skin area. For a suitable design of the conical bearing 8, it is necessary to consider, for example, whether and to what extent the wing skin assumes load-bearing properties or whether the skin areas primarily have profile-defining properties.In any case, a load component in the form of bending occurs due to the buoyancy distribution. Depending on the connection concept, the bending components must be withstood by the tubular pressure tanks 4-1 to 4-4.

[0044] The following section describes in more detail the loose bearing 8, which is designed as a conical bearing. For this purpose, see in Fig. Figure 2 shows the front section of the tubular pressure tanks 4-1 to 4-4. At the fixed bearing 6, the front ends of the tubular pressure tanks 4-1 to 4-4 are mechanically connected to a transverse rib 16, which in turn is mechanically connected to the fuselage-side support structure 10. For this purpose, the already shown in Fig. The connection structures 12-1 to 12-4 shown in Figure 1 are connected to the transverse rib 16 for the polar caps of the pressure tanks 4-1 to 4-4.

[0045] To implement the conical bearing, an external conical structure 18-1 to 18-4 is attached to each of the tubular pressure tanks 4-1 to 4-4 along the circumference, the outer surface of which tapers towards the fixed bearing 6.

[0046] In Fig. Figure 3 shows a section through the tubular pressure tank 4-3 along section line AA, revealing the geometry of the external conical structure 18-3. The external conical structure 18-3 is located on the outside of the tubular pressure tank 4-3 along its circumference. It can be seen that the outer surface 20-3 of the external conical structure 18-3 tapers towards the first stop point in the direction indicated by arrow 22. The external conical structures 18-1 to 18-4 can be made of different materials, such as fiber composites, metallic materials, plastics, etc. To avoid stress discontinuities, the external conical structures 18-1 to 18-4 can be designed with a tapered geometry to allow a gradual stress transfer from the cone to the free cylindrical tank tube geometry.The position of the external conical structures 18-1 to 18-4 relative to the fixed bearing 6 can be variably designed and is largely determined by the loads to be transferred. When designing the tubular pressure tanks 4-1 to 4-4, the local tube stiffening effected by the external conical structures 18-1 to 18-4 provided along the circumference must be taken into account.

[0047] Fig. Figure 4 shows the loose bearing 8, designed as a conical bearing, which is configured as a counterpart to the external conical structures 18-1 to 18-4. The loose bearing 8 comprises four openings 24-1 to 24-4, which are designed to receive the tubular pressure tanks 4-1 to 4-4. On the inside of each of the openings 24-1 to 24-4, an internal conical structure 26-1 to 26-4 is provided, corresponding to the external conical structures 18-1 to 18-4 on the outside of the pressure tanks 4-1 to 4-4. Fig. Figure 5 shows a section through the opening 24-2 along the section line BB, revealing the geometry of the inner conical structure 26-2. Fig. Figure 5 shows in particular that the inner conical structure 26-2, provided on the inside of the opening 24-2, tapers towards the first stop point in the direction indicated by arrow 28. The loose bearing 8 is located at the same position as the outer conical structures 18-1 to 18-4, so that the outer conical structures 18-1 to 18-4 are completely enclosed by the openings 24-1 to 24-4 and the inner conical structures 26-1 to 26-4. The loose bearing 8 serves to guide the outer conical structures 18-1 to 18-4 along the corresponding inner conical structures 26-1 to 26-4 and to ensure full-surface contact with the respective inner conical structures 26-1 to 26-4, regardless of the tank's internal pressure.The respective inner conical structures 26-1 to 26-4 and the corresponding outer conical structures 18-1 to 18-4 are in contact with each other and can slide against each other longitudinally, in order to accommodate changes in circumference and length of the respective pressure tank 4-1 to 4-4 due to pressure changes. This enables the tubular pressure tanks 4-1 to 4-4 to "breathe" through expansion. Under pressure, no primary forces are exerted on the conical bearing structure.

[0048] The cone bearing 8 can be made of solid material, in particular wood, steel, aluminum, resin, etc., or alternatively of fiber composite material, for example GFK, CFK, AFK, etc.

[0049] According to the proposed bearing concept, during pressure changes within the tubular pressure tanks 4-1 to 4-4, the respective outer conical structure 18-1 to 18-4 slides on the corresponding inner conical structure 26-1 to 26-4. To minimize abrasive wear caused by friction, abrasion-reducing or -preventing coatings, films, additives, or other suitable surface treatments can be used. Furthermore, material pairings can be employed that ensure sliding with minimal structural wear. If the tubular pressure tanks 4-1 to 4-4 are subjected to load due to the lift force on the wing, bending of the tubular pressure tanks 4-1 to 4-4 occurs.In this load condition, the conical bearing, which functions as a loose bearing 8, has the task of transferring the bending moment from the tubular pressure tanks 4-1 to 4-4 via the conical bearing into the hull-side support structure 10 through the full-surface contact of the contact partners in the area of ​​the cones.

[0050] The following discussion will address how to select the geometry of the conical structures. Due to the combination of the conical bearings, which encircle the tubular pressure tanks 4-1 to 4-4 over their entire surface, with a fixed bearing on the hull side in the polar cap region of the pressure tanks, a ratio of circumferential expansion to longitudinal expansion of the respective pressure tank 4-1 to 4-4 results. This ratio defines the conical geometry of the conical structures 18-1 to 18-4 and 26-1 to 26-4 as a function of the tank's longitudinal coordinate. To illustrate the geometric relationships, see Figure 1. Fig. Figure 6 shows a cross-section through one of the tubular pressure tanks 4-1 to 4-4, where the solid line represents the wall 30 of the pressure tank in the unprinted state and the dotted line represents the wall 32 of the pressure tank in the printed state. Furthermore, in Fig. Figure 6 shows the fixed bearing 6. Furthermore, the respective cone angles α, β, γ are shown for various tank longitudinal coordinates.

[0051] A simplified view of the cone reveals that the cone angle varies along the longitudinal direction of the pressure tank as a function of the tank's longitudinal coordinate. Due to the fixed mounting at the hull-side polar cap area, the cone angle decreases from the hull towards the tank's outer surface. The cone angle is calculated from the ratio of the tube expansion in the direction of the tube diameter Δz to the linear expansion Δy of the pressure tank, according to the following equation: tan α=ΔzΔyα>tan β=ΔzΔyβ>tan γ=ΔzΔyγ

[0052] The equation takes into account a constant radial expansion Δz across the entire pressure tank, i.e., in the direction of the tank diameter, assuming that the structural design leads to precisely this uniform circumferential expansion along the entire length of the tank tube due to a constant internal pressure p. In the simplified case considered here, the point on the tank tube at the respective cone apex shifts along the calculated cone angle. If cone lengths are very short relative to the tank tube length in the longitudinal direction, an approximately constant cone angle along the cone can be assumed. Due to the internal pressure acting within the pressure tank, the pressure tank and the external cone structure on it expand circumferentially. Upon reaching the effective internal pressure, the cone angles shift to the values ​​specified in the equation. Fig. 6 positions shown with dashed lines. If changes in the cone angle due to longitudinal expansion of the tank cone are neglected, a constant cone angle results in a first linear approximation in the printed state, such that: α=α'>β=β'>γ=γ'

[0053] In reality, the resulting cone angle must be considered as a function of the tank tube's longitudinal coordinate. Fig. The actual tank cone geometry is schematically represented on the underside of the pressure tank. The cone angle determination begins at an arbitrary first point on the wall of the pressure tank. The required cone angle at this first point can be determined using the ratio given in equation (1). This cone angle has the functional slope m1, which is given in Fig. 6 is shown. If we consider another point in the direction of the tank tube's longitudinal axis, whose longitudinal coordinate y2 is greater than the longitudinal coordinate y1 of the first point, a new cone angle with slope m2 can be determined at this second point. For further points lying in the longitudinal direction of the tank tube, slopes of m3 and m4 are obtained, where the following applies: m1>m2>m3>m4

[0054] This can be taken into account in the geometry of the cone structures. If one considers the point-by-point increases in cone angle along the entire length of the cone structure, in infinitesimally small steps from the beginning to the end of the outer cone structure, a curved cone shape results in this case. This actual cone shape ensures that, when the respective pressure tank is printed, there is always a full-surface connection to an external cone bearing structure with the opposite cone geometry, without any constraint forces being introduced into the cone structure by internal pressure.

[0055] Fig. Figure 7A shows a comparison of the cone bearing in the deformed and undeformed states due to an acting internal tank pressure for the simplified linear cone geometry. For this purpose, in Fig. 7A the outer cone structure 34A in the unprinted state and the outer cone structure 34B in the printed state together with the inner cone structure 36 of the cone bearing for the simplified linear cone geometry are shown.

[0056] In contrast, it shows Fig. 7B for a curved cone geometry, comparing the cone bearing in the deformed and undeformed state due to an acting internal tank pressure. The curved cone geometry can, for example, be a parabolic cone geometry. For this, see in Fig. Figure 7B shows the outer cone structure 38A in the unprinted state, the outer cone structure 38B in the printed state, and the inner cone structure 40 of the cone bearing for the curved cone geometry.

[0057] In the Fig. Sections 8A to 8C show three different cone geometries for comparison. This shows Fig. 8A an outer cone structure 42 and a corresponding inner cone structure 44 for a simplified linear cone geometry. Fig. Figure 8B shows an outer cone structure 46 and a corresponding inner cone structure 48 for a curved cone geometry. In principle, in addition to linear and curved cone geometries, inversely curved cone geometries can also be created. This is conceivable through the use of materials with non-linear material properties and with tank tube stiffeners that are partially considered in the longitudinal direction. Fig. Figure 8C shows an outer cone structure 50 together with a corresponding inner cone structure 52 for the case of such an inversely curved cone geometry. In the Fig. Arrows 54 in 8A to 8C point towards the fuselage side of the aircraft, while arrows 56 point towards the outer wing side.

[0058] To ensure the bending loads of the conical bearing can be reliably transferred, the conical bearing must be attached to the fuselage side in such a way that it maintains its position in the longitudinal wing direction regardless of external loads. One possible embodiment is shown in Fig. 9 shown. The in Fig. The arrangement shown in Figure 9 comprises a fuselage-side support structure 10 with longitudinal girder webs 58 beginning on the fuselage side, on the upper and lower surfaces of which upper chords 60 and lower chords 61 are provided. The longitudinal girder webs 58 can, for example, be configured continuously from the fuselage side to the loose bearing 8 or, for example, in a differential design with connecting elements interrupting in the areas of the fixed bearing 6. Furthermore, the arrangement includes the transverse rib 16, to which the polar caps of the pressure tanks can be attached. The chord and longitudinal girder structure 14 is provided for connecting the fixed bearing 6 to the loose bearing 8. The chord and longitudinal girder structure 14 comprises longitudinal girder webs 62, which extend from the fuselage towards the outer wing surface and are each connected to upper chords 64 and lower chords 66. The chord layers primarily absorb the longitudinal and bending loads, whereas the web structure absorbs shear loads. Fig. 9 The upper chords 64 and the lower chords 66 terminate on the loose bearing 8, which is designed as a conical bearing. The connection between the chords and the conical bearing can be made by bolting, screwing, gluing, co-curing, or with positive-locking connection concepts.

[0059] As an alternative to the one in Fig. In the structural support concept shown in Figure 9, with longitudinal beam webs 62 running between the pressure tanks, self-supporting box-section structures adapted to the airfoil profile are possible for connecting the conical bearing. Furthermore, direct connection concepts of the conical bearing with a self-supporting and load-bearing wing skin are feasible.

[0060] The longitudinal beam webs 58, 62 and the chords 60, 61, 64, 66 can be made of metallic materials such as aluminum or steel, wood-based materials, or fiber composites with glass, carbon, or aramid fibers, etc. The connection between the web sections and the chords can be achieved by bonding, positive-locking plug connections, corner laminates, screws, or bolts. Fig. Figure 9 shows a connection concept using corner laminates 68, where the corner laminates 68 can be made using fiber composites such as glass, carbon, aramid, etc., as well as with metallic angles. The corner laminates 68 can be bonded, riveted, screwed, or positively connected.

[0061] Another concept is the design of the longitudinal beam webs 58, 62 as C, U or L profiles, whereby the upper and lower flange areas of the profiles then serve as a direct connection structure to the flanges 60, 61, 64, 66. With this structural concept, the profiles can be attached directly to the flanges 60, 61, 64, 66 by means of screws, rivets, adhesive bonding or positive locking connection concepts.

[0062] The fixed bearing 6 of the pressure tanks 4-1 to 4-4 encompasses the area around the fuselage-side polar caps. The fixed bearing 6 can be implemented by directly attaching the boss parts of the pressure tanks 4-1 to 4-4 to a fuselage-side structure, or with additional fastening elements on the polar cap.

[0063] In the Fig. 10A and Fig. Figure 10B shows a possible connection method for realizing the fixed support of the polar cap areas, wherein the polar cap areas are fastened by means of the additional connection structures 12-1 to 12-4. Fig. Figure 10A shows the connection of a polar cap area in oblique projection, while in Fig. 10B a longitudinal section along the in Fig. The section line CC shown in Figure 10A illustrates this. The connection structures 12-1 to 12-4, intended for attaching the polar caps, are provided in addition to the boss parts 70-1 to 70-4 of the pressure tanks 4-1 to 4-4. For attaching the polar caps, the connection structures 12-1 to 12-4 are, for example, screwed to the transverse rib 16 using screws 72. Furthermore, bonding, riveting, and form-fit or material-fit direct connections between the connection structures 12-1 to 12-4 and the transverse rib 16 are possible. The transverse rib 16 can, for example, be connected to the longitudinal beam webs 58, the top flange 64, and the bottom flange 66 via corner laminates 68.

[0064] The in the Fig. 10A and Fig. The concept shown in Figure 10B is based on a functional division, whereby the connecting structures 12-1 to 12-4, provided in addition to the boss parts 70-1 to 70-4, establish the connection between the pressure tanks 4-1 to 4-4 and the transverse rib 16, thus realizing the fixed bearing 6. In contrast to the connecting structures 12-1 to 12-4, the boss parts 70-1 to 70-4 are guided through recesses provided for this purpose in the transverse rib 16. In this case, the boss parts 70-1 to 70-4 are always load-free, regardless of the load state of the pressure tanks 4-1 and 4-4 and the wing 2. The connecting structures 12-1 to 12-4 can be made of fiber composite components or of metal. Suitable methods for connecting to the transverse rib 16 include gluing, screwing, riveting, bolting, as well as form-fitting and material-locking connection types, for example through an integral design in the tank manufacturing process.

[0065] An alternative concept that is in Fig. Figure 11 illustrates the direct connection of boss parts 70-1 to 70-4 with the transverse rib 16. In this case, the connecting structures 12-1 to 12-4 can be omitted. In the Fig. In the embodiment shown in Figure 11, a thread is provided on the circumferential surface of each boss part 70-1 to 70-4, which is then guided through a bore in the transverse rib 16 and screwed in on the opposite side by means of a respective central nut 74-1 to 74-4. Fig. In addition, the fuselage-side support structure 10 and the belt and longitudinal support structure 14, which connects the fixed bearing 6 to the floating bearing 8, can also be seen. Generally, the connection between the boss parts 70-1 to 70-4 and the transverse rib 16 can be made by screwing, riveting, gluing, or bolting.

[0066] The existing carrier arrangement on the aircraft according to Fig. Assembly 9 comprises all elements for realizing the fixed bearing 6 and the floating bearing 8. From the outside, the tubular pressure tanks 4-1 to 4-4 are successively inserted through the openings 24-1 to 24-4 of the floating bearing 8 until the outer conical structures 18-1 to 18-4 abut the inner conical structures 26-1 to 26-4. In this installed state, the connecting structures 12-1 to 12-4 provided at the pole caps of the pressure tanks 4-1 to 4-4 are fixed by means of screws from the fuselage-side transverse rib 16. For example, according to a preferred embodiment, the connecting structures 12-1 to 12-4 can each be screwed in place using several screws arranged circumferentially around the respective recess of the transverse rib 18. This completes the installation of the respective pressure tank. This assembly process is repeated sequentially for all pressure vessels 4-1 to 4-4.

[0067] Disassembly is carried out in reverse order, so that after removing the fuselage-side polar cap screw, the pressure tanks 4-1 to 4-4 can be removed towards the outside of the wing through the openings 24-1 to 24-4 of the loose bearing 8.

[0068] In Fig. Figure 12 shows a further embodiment of the invention in which a tubular pressure tank 76 is held by means of a double cone to achieve an indirect fixed / floating bearing arrangement. A first floating bearing 78 is provided at one holding point. Furthermore, a second floating bearing 80 is provided at a further holding point at a predetermined distance from the first floating bearing 78. A first external conical structure 82 is provided on the outside of the tubular pressure tank 76, the outer surface of which tapers in the longitudinal direction of the tank towards the second floating bearing 80. At the further holding point, a second external conical structure 84 is attached to the outside of the tubular pressure tank 76, which has a wedge shape opposite to that of the first external conical structure 82, the outer surface of the second external conical structure 84 tapering in the longitudinal direction of the tank towards the first floating bearing 78.Furthermore, a conical bearing 86 is provided, which is used, for example, in the in . Fig. In the embodiment shown in Figure 12, the conical bearing 86 is designed as a continuous component. It comprises a first inner conical structure 88, which corresponds to the first outer conical structure 82 of the pressure tank 76. Furthermore, the conical bearing 86 comprises a second inner conical structure 90, which corresponds to the second outer conical structure 84. The conical bearing 86 thus replicates the geometry of the tank cones and is connected to a periphery of the longitudinal beam webs and / or the belt supports in such a way that the conical bearing 86 always maintains its position. When the pressure tank 76 is pressurized, it expands in the longitudinal and circumferential directions. The conical structures allow the pressure tank 76 to "breathe," preventing any constraint forces from arising within the pressure tank 76 due to internal pressure.Due to the opposite wedge shape, the two cones of the first loose bearing 78 and the second loose bearing 80 act mutually locking, so that a continuous function transfer with regard to a fixed / loose bearing is created.

[0069] The conical bearing 86 can also be designed in two parts to accommodate the inner conical structures 88, 90. In this case, there are at least two separate bearing areas which must be connected to the longitudinal beam webs and / or the chord beams in such a way that they maintain their relative distance to each other and to the outer conical structures 82, 84 in every load condition.

[0070] In the exemplary embodiment of Fig.Figure 12 shows the conical bearing 86 as a single, continuous component. To ensure ease of assembly, the conical bearing 86 would, in this case, be designed in two parts along the longitudinal axis of the pressure tank. After the pressure tanks are mounted, the conical bearing 86 would act as a clamping ring around the outer conical structures 82 and 84 by means of bolting, bonding, or riveting. Alternatively, the first loose bearing 78 and the second loose bearing 80 can be designed separately. It must be structurally ensured that the conical bearings are always fixed and maintain their position relative to the respective tank cone.

[0071] The features disclosed in the foregoing description, the claims and the drawings can be important for the realization of the invention in its various embodiments, both individually and in any combination. Reference symbol list 2 Wing 4-1 to 4-4 tubular pressure tanks 6 fixed bearings 8 loose bearings 10 fuselage-side support structure 12-1 to 12-4 Connection structures for polar caps 14 Belt and longitudinal beam structure 16 transverse ribs 18-1 to 18-4 external conical structures 20-1 to 20-4 Outer surfaces of the outer cone structures 22 Arrow 24-1 to 24-4 openings 26-1 to 26-4 internal conical structures 28 Arrow 30 Wall of the pressure tank in the unprinted state 32 Wall of the pressure tank in the printed state 34A External conical structure in unprinted state 34B external conical structure in printed state 36 internal conical structure 38A External conical structure in unprinted state 38B external conical structure in printed state 40 internal conical structure 42 external conical structure 44 internal conical structure 46 external conical structure 48 internal conical structure 50 external conical structure 52 internal conical structure 54 arrows pointing towards the side of the fuselage 56 arrows pointing towards the outer wing 58 longitudinal beam webs 60 upper chords 61 lower belts 62 longitudinal beam webs 64 upper chords 66 lower belts 68 corner laminates 70-1 to 70-4 Boss parts 72 screws 74-1 to 74-4 Central nuts 76 Pressure tank 78 first lot 80 second lot 82 first external conical structure 84 second outer cone structure 86 Conical bearing 88 first inner conical structure 90 second inner cone structure

Claims

[1] An arrangement for holding a wing (2) of an aircraft, comprising: - a support structure with a first support point and a second support point, - a tubular pressure tank (4-1 to 4-4, 76) for receiving a propellant, wherein the pressure tank (4-1 to 4-4, 76) is held in its longitudinal direction by the first stop and the second stop and extends with a section beyond the second stop, - a loose bearing (8, 78) provided at the second support point to hold the pressure tank (4-1 to 4-4, 76) against a transverse force in a direction perpendicular to the longitudinal direction of the pressure tank (4-1 to 4-4, 76), wherein the loose bearing (8, 78) has an opening (24-1 to 24-4) with an internal conical structure (26-1 to 26-4, 88) having an inner surface tapering towards the first support point, wherein the pressure tank (4-1 to 4-4, 76) has on its outer surface an outer conical structure (18-1 to 18-4, 82) corresponding to the inner conical structure (26-1 to 26-4, 88) of the loose bearing (8, 78), which tapers towards the first holding point, wherein the inner conical structure (26-1 to 26-4, 88) and the corresponding outer conical structure (18-1 to 18-4, 82) abut each other and slide against each other in the longitudinal direction to accommodate a change in circumference and length due to a change in pressure in the pressure tank (4-1 to 4-4, 76). [2] Arrangement according to claim 1, characterized by , that at the first holding point a fixed bearing (6) is provided which is designed to hold a first end of the pressure tank (4-1 to 4-4, 76). [3] Arrangement according to claim 2, characterized by , that the fixed bearing (6) is mechanically connected to the loose bearing (8, 78) via at least one longitudinal beam (62). [4] Arrangement according to claim 2, characterized by , that the fixed bearing (6) is connected to the loose bearing (8, 78) via a box section structure adapted to the cross-section of the wing. [5] Arrangement according to any one of claims 2 to 4, characterized by , that the fixed bearing (6) is connected to the loose bearing (8, 78) via a load-bearing chord structure and / or via at least one load-bearing longitudinal girder web (62). [6] Arrangement according to claim 1, characterized by , that at the first holding point a second loose bearing (80) is provided to hold the pressure tank (4-1 to 4-4, 76). [7] Arrangement according to claim 6, characterized by , that the second loose bearing (80) has an opening with a second inner conical structure (90) which has an inner surface tapering towards the second holding point, wherein the pressure tank (4-1 to 4-4, 76) has on its outer surface a second outer conical structure (84) corresponding to the second inner conical structure (90) of the second loose bearing (80), which tapers towards the second holding point, wherein the second inner conical structure (90) and the corresponding second outer conical structure (84) are in contact with each other. [8] Arrangement according to any one of the preceding claims, characterized by , that the outer surface of the outer conical structure (46) has a curved contour which is determined by the pressure expansion of the pressure tank (4-1 to 4-4, 76) in the longitudinal and circumferential directions. [9] Arrangement according to any one of claims 1 to 7, characterized by, that the contour of the outer surface of the outer cone structure (42) is linear, wherein the cone angle of the outer surface is given by the linearly approximated ratio of circumferential and length change of the pressure tank (4-1 to 4-4, 76) during pressure expansion of the pressure tank (4-1 to 4-4, 76). [10] Arrangement according to any one of the preceding claims, characterized by , that the outer conical structure (18-1 to 18-4, 82) is formed completely around the tubular pressure tank (4-1 to 4-4, 76). [11] Arrangement according to any one of claims 1 to 9, characterized by , that the external conical structure (18-1 to 18-4, 82) is formed partially or piecewise around the tubular pressure tank (4-1 to 4-4, 76). [12] Arrangement according to any one of the preceding claims, characterized by, that the support structure includes a fuselage-side support structure (10) designed to transfer forces and moments acting on the pressure tank (4-1 to 4-4, 76) to the fuselage of the aircraft. [13] Arrangement according to one of the preceding claims with a support surface (2) attached thereto. [14] Aircraft with a wing (2) and an arrangement for holding the wing (2) of the aircraft according to one of claims 1 to 13, wherein the wing (2) is connected to the pressure tank (4-1 to 4-4, 76) and a fuselage-side support structure (10) in such a way that bending moments at a wing root of the wing (2) can be introduced via the pressure tank (4-1 to 4-4, 76) into the fuselage-side support structure (10). [15] Method for mounting a tubular pressure tank (4-1 to 4-4, 76) in a support structure having a first support point and a second support point, wherein a loose bearing (8, 78) is provided at the second holding point, which is designed to hold the tubular pressure tank (4-1 to 4-4, 76), wherein the loose bearing (8, 78) has an opening (24-1 to 24-4) with an internal conical structure (26-1 to 26-4, 88) having an inner surface that tapers towards the first holding point, wherein the tubular pressure tank (4-1 to 4-4, 76) has on its outer surface an outer conical structure (18-1 to 18-4, 82) corresponding to the inner conical structure (26-1 to 26-4, 88) of the loose bearing (8, 78), which tapers towards the first end of the pressure tank (4-1 to 4-4, 76), and wherein the method comprises the following steps: - Insert the pressure tank (4-1 to 4-4, 76) with its first end into the opening (24-1 to 24-4) of the loose bearing (8, 78) until the inner conical structure (26-1 to 26-4, 88) of the loose bearing (8, 78) and the corresponding outer conical structure (18-1 to 18-4, 82) of the tubular pressure tank (4-1 to 4-4, 76) are in contact with each other, - Fixing the first end of the tubular pressure tank (4-1 to 4-4, 76) at the first holding point.

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