Housing of an electrical device

Abstract

A housing 1 for electrical components 20 has a first part 10 having a bottom wall 100 and preferably two sidewalls 101, 102 and a second part 11 also having a bottom wall 110 and preferably two sidewalls 111, 112. The figure (3) shows the two parts before connection The first and second housing parts 10, 11 are fixed together (See figure 4) such that the sidewalls define a volume above a bottom comprising the two bottom walls arranged to overlap with each other and preferably bolted and / or riveted together to form a double skin floor. At least one part includes mounting holes 140 preferably at corner extensions 14 that are arranged outside the housing volume to allow the housing to be mounted to a vehicle such as an aircraft. The housing preferably provides a high voltage power system receiving battery energy and providing a motor drive output.

Description

Field The present disclosure particularly relates to a housing, to an electrical device, to a power system, to an aircraft and to a method for manufacturing a housing. Background Aircrafts are powered in many different ways. Internal combustion engines, e.g., piston engines or gas turbine engines, enable long ranges and high speeds. Propulsion systems with one or more electric motor(s) enable the use of sustainably generated energy and are often particularly quiet and only require little maintenance compared to, e.g., combustion engines. An important aspect is the distribution of electrical power. In the case of electrically driven aircrafts, a reliable power distribution from an energy source to electric motors is important. In this and other applications a robust housing that can be securely fixed to a structure is needed. Housings for electrical devices can be, e.g., made of machined parts, of composite parts or of sheet metal. Sheet-metal housings are typically made in one piece, wherein sidewalls are welded together at corners. However, for mounting the housing to a structure, in practice typically additional parts such as mounting brackets or the like are bolted or welded on the housing. Particularly welded joints, however, are critical in terms of mechanical integrity and may require complex quality control and inspection. Another possibility to manufacture a housing is deep drawing, but this requires significant tooling costs, is inflexible with respect to changes and imposes limitations on the housing shape. There is a need to provide an improved housing for electric components, or at least a useful alternative to known housings for electric components. Summary According to an aspect, a housing for electrical components comprises a first housing part and a second housing part. The first housing part has a bottom wall and at least or exactly two sidewalls. The second housing part has a bottom wall and at least or exactly two sidewalls. The first and second housing parts are fixed to one another. The first and second housing parts define and divide an inner space from an outside of the housing. The bottom walls of the first and second housing parts overlap with each other. At least one of the first and second housing parts forms mounting holes for mounting the housing to another structure, wherein the mounting holes are arranged on the outside of the housing. This is based on various findings. By the double layer bottom of the housing formed by the two bottom walls of the first and second housing parts, an increased stiffness is provided. Thereby, additional reinforcement may not be necessary what allows to simplify the manufacturing and quality control, even for relatively large housings and for relatively heavy electrical components mounted in the respective housing. Still, the housing allows a relatively low weight because the sidewalls only have half of the thickness compared to the bottom of the housing. Further, by providing the first and second housing parts as described, it becomes possible to provide the mounting holes on robust sections although the housing parts are still simple to manufacture and cost efficient. Furthermore, the housing may be made of a low number of parts. Particularly, each of the first and second housing parts may be made of sheet metal, e.g., steel or aluminum. This allows a very simple manufacturing and a high stability at a low weight. For example, the sidewalls of the first housing part are arranged on opposing sides of the bottom wall of the first housing part and / or the sidewalls of the second housing part are arranged on opposing sides of the bottom wall of the second housing part. By this, a particularly simple design is possible. One or both of the first and second housing parts may have a U-shaped form. For example, one or each of the first and second housing parts may have a U-shaped cross section. For one or both of the first and second housing parts, the sidewalls may be oriented at an angle to the respective bottom wall, e.g., at 100° (e.g., bent by 80°). In one example, for each of the first and second housing parts, the sidewalls are parallel to one another and rectangular to the respective bottom wall. The U-shaped form allows a robust design. For example, the second housing part is inserted into the first housing part. Each of the mounting holes may be arranged on a respective projection of the first housing part. Each of the projections may be formed by a section of the bottom wall and a section of one of the sidewalls of the first housing part. The sections may be connected with one another via a bending between the sections. The sections may be perpendicular to one another. This allows a particularly high stability with a simple design. All mounting holes may be in the same plane. The arrangement of the mounting holes next to the bended sections allows to increase the stiffness in the area of the mounting holes. For example, at least four mounting holes are provided. This allows a secure mounting of the housing to the structure. At least one of the mounting holes may be arranged adjacent to each of four corners of the housing, respectively. Therefore, the mounting holes can be easily accessible for mounting the housing to the structure in a simple manner. For example, the bottom wall of the first housing part faces the outside and / or the bottom wall of the second housing part faces the inner space of the housing. For example, one (major) side of the bottom wall of the first housing part faces the outside and the opposite side faces the bottom wall of the second housing part. One (major) side of the bottom wall of the second housing part may face the inner space and the opposite side faces the first housing part bottom wall. The bottom walls may be adjacent to one another. This allows a high stability and stiffness. The bottom walls of the housing parts may be bolted and / or riveted and / or glued to one another. Alternatively, or in addition, a sealant can be arranged between the bottom walls of the housing parts. The sealant may be in physical contact with each of the two bottom walls. By this, a secure and tight connection is possible. The sealant may seal the housing against dust and liquids. At least one of the first and second housing parts may have openings for electrical inputs and / or electrical outputs of the electrical device having the housing. This allows a convenient connection of the electrical device having the housing. The sidewalls of the first housing part may extend perpendicular to the sidewalls of the second housing part. This provides for a simple design with a low number of parts. The first housing part may be made in one piece. Further, the second housing part may be made in one piece. By this, a simple and fast manufacturing is possible, e.g., by simply cutting and bending each of the housing parts. According to an aspect, an electrical device is provided. The electrical device comprises the housing of any embodiment described herein, and electrical components mounted in the inner space of the housing. Regarding the advantages of the electrical device, reference is made to the description of the housing above. The electrical device may be a (e.g., high-voltage) power distribution unit. The electrical device may comprise at least one input adapted to receive electrical power from at least one energy source. The electrical device may comprise at least one output configured to provide electrical power from the at least one input to at least one electrical load. Power distribution units often contain heavy components which can be safely housed and mounted using the described housing. According to an aspect, a power system, e.g., for an aircraft, is provided. The power system comprises the electrical device of any embodiment described herein. The power system further comprises the at least one energy source (being in electrical connection with the at least one input) and the at least one electrical load (being in electrical connection with the at least one output). Regarding the advantages, reference is made to the description of the housing above. The at least one energy source may comprise a rechargeable electrical battery. Alternatively, or in addition, the at least one electrical load comprises at least a part of an electric motor. According to an aspect, an aircraft comprising the housing and / or the electrical device and / or the power system of any embodiment described herein is provided. Regarding the advantages, again, reference is made to the description of the housing above. According to another aspect, a method of manufacturing a housing is provided, e.g., the housing of any embodiment described herein. The method comprises manufacturing a first housing part with a bottom wall and sidewalls; manufacturing a second housing part with a bottom wall and sidewalls; and fixing the first and second housing parts to one another to define an inner space and an outside of the housing, wherein the bottom walls are arranged so as to overlap with each other, and wherein at least one of the first and second housing parts comprises mounting holes on the outside of the housing for mounting the housing to another structure. Regarding the advantages, again, reference is made to the description of the housing above. Manufacturing of the first and / or second housing parts may comprise cutting and / or bending sheet metal. Brief description of the drawings Exemplary embodiments are now described with reference to the figures, wherein: Figure 1 shows an aircraft in the form of an airplane with a rotor unit; Figure 2 shows a power system for the aircraft of Figure 1, the power system comprising an electrical device in the form of a power distribution unit; Figure 3 shows two parts of a housing of the electrical device according to Figure 2; Figure 4 shows the two parts of Figure 3 mounted to one another; Figure 5 shows the electrical device of Figure 2 with the housing of Figure 4; Figure 6 shows the electrical device of Figure 5 with the housing closed by a lid; and Figure 7 shows a method of manufacturing a housing. The following table lists the reference numerals used in the drawings with the features to which they refer: Ref no. Feature Figure 1 Housing 2456 2 Electrical device 2 56 3 Power system 2 4 Aircraft 1 10 First housing part 3456 11 Second housing part 3456 12 Inner space 4 13 Outside 4 14 Projection 34 15 Sealant 3 16 Lid 6 17 Screw 6 20 Electrical component 2 5 21 Input 5 22 Output 5 40 Energy source 1 2 41 Electrical load 2 42 Fuselage 1 43 Wing 1 44 Rotor unit 1 45 Structure 6 100 Bottom wall 34 101 Sidewall 34 102 Sidewall 34 104A Section 3 104B Section 3 105 Bending 3 106A Opening 3 106B Opening 3 106C Opening 3 107 Hole 3 110 Bottom wall 3 111 Sidewall 34 112 Sidewall 34 113A Opening 3 113B Opening 3 113C Opening 3 114 Bending 3 115 Hole 3 Ref no. Feature Figure 116 Flap 34 117 Mounting element 5 140 Mounting hole 34 400 Battery 2 410 Electric motor 1 411 Inverter 2 412 Electrical lane 2 440 Rotor blade 1 S1 Step 7 S2 Step 7 S3 Step 7 S4 Step 7 Detailed description Aspects and embodiments of the present disclosure will now be discussed with reference to the accompanying figures. Further aspects and embodiments will be apparent to those skilled in the art. Figure 1 shows an aircraft 4 in the form of an airplane having a fuselage 42, wings 43 and a rotor unit 44. The aircraft 4 comprises an electric motor 410 for driving the rotor unit 44. The rotor unit 44 comprises a plurality of rotor blades 440, in this example two rotor blades 440. In the example shown, the rotor blades 440 are mounted on a hub to form a propeller. In alternative embodiments, the aircraft 4 comprises, for example, a fan instead of a propeller and / or a plurality of propellers, fans or the like. The aircraft 4 further comprises one or more energy sources 40. In the present example, the one or more energy sources 40 comprise electric batteries. Alternatively, or in addition, the aircraft 4 may comprise an electric generator and / or a fuel cell as energy source(s). Figure 2 shows a power system 3 of the aircraft 4 of Figure 1. The power system 3 comprises an electrical device 2, at least one, here more than one, namely, two energy sources 40, and at least one, here more than one, namely, two electrical loads 41. The energy sources 40 of the present example each comprise a plurality of electrical batteries 400. The energy sources 40 provide electrical energy to the electrical device 2. Here, the energy sources provide high-voltage electrical power. In the present example, the electrical device 2 is a power distribution unit, more specifically, a high-voltage power distribution unit. The electrical device 2 comprises electrical components 20 such as switches, cables, forks or the like. The electrical device 2 provides electrical power (from the energy sources 40) to the electrical loads 41. Here, each of the electrical loads 41 comprises an inverter 411 and an electrical lane 412. The lanes 412 comprise electrical windings of the electric motor 410. By providing power to the electrical loads 41, the electric motor 410 drives the rotor unit 44. When the aircraft 4 comprises more than one rotor unit 44, each rotor unit 44 may be driven by a separate electric motor 410 powered by the electrical device 2. The electrical device 2 comprises a housing 1 which encloses the electrical components 20 of the electrical device 2. Figure 3 shows two housing parts of the housing 1 of the electrical device 2: a first housing part 10 and a second housing part 11. Each of the first and second housing parts 10, 11 has a U-shaped form. As such, the first housing part 10 comprises a bottom wall 100 and two sidewalls 101, 102. The bottom wall 100 is larger than each of the sidewalls 101, 102. The bottom wall 100 is planar. The sidewalls 101, 102 of this example are planar, too. The sidewalls 101, 102 are arranged on opposing sides of the bottom wall 100. Each sidewall 101, 102 is connected with the bottom wall 100 via a bending 105. The bending 105 is a perpendicular bending. The sidewalls 101, 102 are arranged parallel to one another. The sidewalls 101, 102 of the present example are arranged perpendicular to the bottom wall 100. However, for a better accessibility of the inner space 12 during assembly an angle between the sidewalls 101, 102, 111, 112 and the respective bottom wall 100, 110 of more than 90° can be beneficial (illustrated with dashed lines in Figure 3). As an example, the bending may be 80° (the corresponding angle of the sidewalls 101, 102, 111, 112 to the respective bottom wall 100, 110 can be 100°, e.g., + / - 5°). That is, opposing sidewalls may be at an angle, for example of 20° (e.g., +1-10°), relative to one another. The bottom wall 100 is rectangular and has two opposing longer edges and two opposing shorter edges. The sidewalls 101, 102 are connected with the bottom wall 100 via the longer edges of the bottom wall 100. The sidewalls 101, 102 are substantially rectangular and elongate. Each of the sidewalls 101, 102 comprises two opposing longer edges and two opposing shorter sides. The sidewalls 101, 102 are connected with the bottom wall 100 via a respective one of their longer edges. The first housing part 10 further comprises a plurality of mounting holes 140. Here, the first housing part 10 comprises four mounting holes 140. The first housing part 10 comprises four corners on which the sidewalls 101, 102 are connected with the bottom wall 100. Each one of the mounting holes 140 is arranged on one of the corners. Specifically, each of the mounting holes 140 is arranged on a respective projection 14 of the first housing part 10 formed by a section 104A of the bottom wall 110 and a section 104B of one of the sidewalls 101, 102. The sections 104A, 104B are connected with one another via the bending 105. The projections 14 have an L-shaped cross-section. Therefore, the projections 14 are particularly stiff and robust. The projections 14 are located on four corners of the first housing part 10. Thus, the mounting holes 140 are arranged an each of the four corners of the housing 1. The projections 14 project from the respective edges of the bottom wall 100 and side walls 101, 102. The second housing part 11 comprises a bottom wall 110 and two sidewalls 111, 112. The bottom wall 110 is larger than each of the sidewalls 111, 112. The bottom wall 110 is planar. The sidewalls 111, 112 comprise flaps 116. Besides the flaps 116, the sidewalls 111, 112 are planar, too (in this example). The sidewalls 111, 112 are arranged on opposing sides of the bottom wall 110. Each sidewall 111, 112 is connected with the bottom wall 110 via a (perpendicular) bending 114. The sidewalls 111, 112 are arranged parallel to one another. The sidewalls 111, 112 are arranged perpendicular to the bottom wall 110. The bottom wall 110 of the second housing part 11 is rectangular and has two opposing longer edges and two opposing shorter edges. The sidewalls 111, 112 are connected with the bottom wall 110 via the shorter edges of the bottom wall 110. The sidewalls 111, 112 of the second housing part 11 are rectangular. Each of the sidewalls 111, 112 comprises two opposing longer edges and two opposing shorter edges. The sidewalls 111, 112 are connected with the bottom wall 110 via a respective one of their longer edges. Each of the first and second housing parts 10, 11 comprises a plurality of openings 106A-106C, 113A-113C) in the sidewalls 101, 102, 111, 112. The bottom wall 100 of the first housing part 10 is at least as large as the bottom wall 110 of the second housing part 11. Each of the first and second housing parts 10, 11 is made of sheet metal, e.g., steel. Each of the first and second housing parts 10, 11 is made in one piece. In the present example, each of the first and second housing parts 10, 11 is made my cutting (e.g., stamping) and bending a piece of sheet metal. For manufacturing the housing 1, the first and second housing parts 10, 11 are fixed to one another. In this regard, the housing parts 10, 11 are arranged as shown in Figure 3, i.e., the sidewalls 101, 102 of the first housing part 10 are arranged perpendicular to the sidewalls 111, 112 of the second housing part 11, and the bottom walls 100, 110 are arranged parallel to one another. All sidewalls 101, 102, 111, 112 extend from the bottom walls 100, 110 in the direction. Then, the bottom walls 100, 110 are laid on top of one another. Optionally, the bottom walls 100, 110 are brought in physical contact with one another. In the present example, the bottom walls 100, 110 of the first and second housing parts 10, 11 have the same size. Optionally, as shown in Figure 3, a sealant 15 is disposed on a side of the bottom wall 100 of the first housing part 10 facing the bottom wall 110 of the second housing part 11 (and / or on a side of the bottom wall 110 of the second housing part 11 facing the bottom wall 100 of the first housing part 10). Thus, when mounting the two housing parts 10, 11, the sealant 15 is arranged between the bottom walls 100, 110. In the present example, the sealant is silicone-based. Thus, the housing 1 has a double-layer bottom. Figure 4 shows the housing 1 after connecting the two housing parts 10, 11 to one another. Each of the bottom walls 100, 110 has holes 107, 115 (in this example screw holes) aligned to one another in the assembled state as shown in Figure 4. Further, the sidewalls 101, 102, 111, 112 also have holes 107, 115 (in this example screw holes) aligned to one another in the assembled state as shown in Figure 4. In the case of the second housing part 11, the holes 115 are located on the flaps 116 of the sidewalls 111, 112. The mounted housing 1 has the shape of a rectangular cuboid. The projections 14 project from the rectangular cuboid. Thus, as shown in Figure 4, the housing 1 (which is configured to receive electrical components) comprises the first housing part 10 having the bottom wall 100 and the sidewalls 101, 102, and the second housing part 11 having the bottom wall 110 and the sidewalls 111, 112, wherein the first and second housing parts 10, 11 are fixed to one another defining an inner space 12 and an outside 13 of the housing 1, wherein the bottom walls 100, 110 overlap with each other and wherein at least one of the first and second housing parts 10, 11 (here, the first housing part 10) forms the mounting holes 140, the mounting holes 140 being located on the outside 13 of the housing 1 (i.e., not in the inner space 13 of the housing 1), the mounting holes 140 being configured for mounting the housing 1 to another structure. As becomes apparent from Figures 3 and 4, the bottom wall 100 of the first housing part 10 faces the outside 13 and the bottom wall 110 of the second housing part 11 faces the inner space 12 of the housing 1. Therefore, the first housing part 10 can also be referred to as the outer housing part, and the second housing part 11 can also be referred to as the inner housing part. Figure 5 shows the housing 1 with various electrical components 20 mounted therein. Further, inputs 21 and outputs 22 are mounted on the openings 106A-106C, 113A-113C, such as sockets for plugs. The inputs 21 and outputs 22 are electrically connected to the electrical components 20. Using mounting elements 117, such as screws and / or rivets or the like, the sidewalls 101, 102, 111, 112 are fixed to one another at the holes 107, 115. Similar, using mounting elements 117, such as screws and / or rivets or the like, the bottom walls 100, 110 are fixed to one another at the holes 107, 115. As shown in Figure 6, the housing 1 of the present example further comprises a lid 16 which is mounted on the four sidewalls 101, 102, 111, 112. The lid 16 closes the inner space 12 of the housing 1. Further, Figure 6 shows the housing 1 mounted to the structure 45. For this purpose, screws 17 extend through the mounting holes 140 of the housing 1 and are fixed to the structure 45. In the present example, the structure 45 is a part of the aircraft 4 of Figure 1. As can be seen from Figures 3, 4 and 6, the inner space 12 of the housing 1 is located between the bottom walls 100, 110 of the first and second housing parts 10, 11 and the lid 16. In the inner space 12 of the housing 1, the electrical components 20 may be mounted. Figure 7 shows a method of manufacturing a housing 1, e.g., the housing 1 as described above, and of manufacturing an electrical device. The method comprises the following steps. Step S1: manufacturing a first housing part 10 with a bottom wall 100 and sidewalls 101, 102, e.g., by cutting and bending a piece of sheet metal. Step S2: manufacturing a second housing part 11 with a bottom wall 110 and sidewalls 111, 112, e.g., by cutting and bending a piece of sheet metal. Step S3: fixing the first and second housing parts 10, 11 to one another to define an inner space 12 and an outside 13 of the housing 1, wherein the bottom walls 100, 110 are arranged so as to overlap with each other and wherein at least one of the first and second housing parts 10, 11 forms mounting holes 140 on the outside 13 of the housing 1 for mounting the housing 1 to another structure 45. Step S4: Mounting electrical components 20 in the inner space 12 of the housing 1 to produce an electrical device 1.

Claims

1. A housing (1) for electrical components (20), the housing comprising:a first housing part (10) having a bottom wall (100) and sidewalls (101, 102); anda second housing part (11) having a bottom wall (110) and sidewalls (111, 112);the first housing part (10) and the second housing part (11) being fixed to one another defining an inner space (12) and an outside (13) of the housing (1);wherein the bottom walls (100, 110) overlap with each other, and at least one of the first housing part (10) and the second housing part (10, 11) comprises mounting holes (140) on the outside (13) of the housing (1) for mounting the housing (1) to another structure (45).

2. The housing (1) of claim 1, wherein each of the first housing part (10) and the second housing part (11) is made of sheet metal.

3. The housing (1) of claim 1 or 2, wherein the sidewalls (101, 102) of the first housing part (10) are arranged on opposing sides of the bottom wall (100) of the first housing part (10) and the sidewalls (111, 112) of the second housing part (11) are arranged on opposing sides of the bottom wall (110) of the second housing part (11).

4. The housing (1) of any preceding claim, wherein each of the first housing part (10) and the second housing part (11) has a U-shaped form.

5. The housing (1) of any preceding claim, wherein each of the mounting holes (140) is arranged on a respective projection (14) of the first housing part (10) formed by a section (104A) of the bottom wall (110) and a section (104B) of one of the sidewalls (101, 102), the sections (104A, 104B) being connected with one another via a bending (105) between the sections (104A, 104B).

6. The housing (1) of any preceding claim, wherein at least four mounting holes (140) are provided.

7. The housing (1) of claim 6, wherein at least one of the mounting holes (140) is arranged adjacent to each of four corners of the housing (1).

8. The housing (1) of any preceding claim, wherein the bottom wall (100) of the first housing part (10) faces the outside (13) and the bottom wall (110) of the second housing part (11) faces the inner space (12).

9. The housing (1) of any preceding claim, wherein the bottom walls (100, 110) of the first housing part (10) the second housing part (10, 11) are bolted and / or riveted to one another and wherein a sealant (15) is arranged between the bottom walls (100, 110) of the first housing part (10) and the second housing part (11).

10. The housing (1) of any preceding claim, wherein at least one of the first housing part (10) and the second housing part (11) has openings (106A-106C, 113A-113C) for electrical inputs (21) and / or outputs (22).

11. The housing (1) of any preceding claim, wherein the sidewalls (101, 102) of the first housing part (10) extend perpendicular to the sidewalls (111, 112) of the second housing part (11).

12. The housing (1) of any preceding claim, wherein the first housing part (10) is made in one piece and the second housing part (11) is made in one piece.

13. An electrical device (2) comprising the housing (1) of any preceding claim and electrical components (20) mounted in the inner space (12) of the housing (1).

14. The electrical device (2) of claim 13, the electrical device (2) being a high-voltage power distribution unit and comprising at least one input (21) adapted to receive electrical power from at least one energy source (40) and at least one output (22) configured to provide electrical power from the at least one input (21) to at least one electrical load (41).

15. A power system (3) for an aircraft (4), the power system comprising an electrical device (2) of claim 14, the at least one energy source (40) in electrical connection with the at least one input (21) and the at least one electrical load (41) in electrical connection with the at least one output (22).

16. The power system (3) of claim 15, wherein the at least one energy source (40) comprises an electrical battery (400) and the at least one electrical load (41) comprises at least a part of an electric motor (410).

17. An aircraft (4) including a power system (3) of claim 15 or 16.

18. A method of manufacturing a housing (1), the method comprising the steps of:manufacturing (S1) a first housing part (10) with a bottom wall (100) and sidewalls (101, 102);manufacturing (S2) a second housing part (11) with a bottom wall (110) and sidewalls (111, 112); andfixing (S3) the first housing part (10) and the second housing part (11) to one another to define an inner space (12) and an outside (13) of the housing (1), wherein the bottom walls (100, 110) are arranged so as to overlap with each other and wherein at least one of the first housing part (10) and the second housing part (11) comprises 5 mounting holes (140) on the outside (13) of the housing (1) for mounting the housing (1) to another structure (45).

19. The method of claim 18, wherein manufacturing each of the first housing part (10) and the second housing part (11) comprises cutting and bending sheet metal.10

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