Aircraft equipped with a rain-proof ventilation system for an electric machine

Abstract

The present invention relates to an aircraft (1) equipped with at least one electrical machine (17) housed in a compartment (5) separated by a cowling (10) from an external environment (EXT), said aircraft (1) comprising a ventilation system (30) for conveying air from the external environment (EXT) to the electrical machine (17).The ventilation system (30) includes a duct (35) connected to the electrical machine (17) and extending to a free section (37), the free section (37) being located in said external environment (EXT), the duct (35) passing through a passage (11) in the cowling (10), the duct (35) extending partially into the compartment (5) and partially into the external environment (EXT), a void (12) surrounding the duct (35) in the passage (11) and separating the duct (35) from the cowling (10), the ventilation system (30) including a scoop (50) opposite the free section (37) without obstructing it along a vertical axis (DIRV) when the aircraft (1) is on a horizontal ground (100). Abbreviated figure: Figure 1.

Description

Title of the invention: Aircraft equipped with a rain-proof ventilation system for an electrical machine

[0001] The present invention relates to an aircraft equipped with a rain-proof ventilation system for an electrical machine.

[0002] An aircraft usually includes a propulsion system comprising at least one engine and / or at least one power transmission. For example, a rotorcraft is equipped with at least one engine to drive at least one rotor via a power transmission. This rotor contributes at least partially to the lift and / or propulsion of the rotorcraft.

[0003] The engine(s) may be arranged in an engine compartment separated from the outside of the aircraft by means of cowlings. The term "cowling" may refer to a cowling, a movable structure, a fairing, a streamlined or even partitioned box...

[0004] The engine or engines may be internal combustion engines powered by fuel and air.

[0005] Furthermore, an aircraft may include an electrical machine. An electrical machine may take the form of an electric generator capable of converting mechanical energy into electrical energy, an electric motor capable of converting electrical energy into mechanical energy to drive a mechanical system, or a starter-generator connected to an internal combustion engine to start the internal combustion engine or produce electrical energy as needed. For example, a starter-generator may be kinematically connected to a gas generator of a turboshaft engine.

[0006] Such an electrical machine is likely to overheat during operation. The aircraft may therefore include a ventilation system to cool the electrical machine by drawing in fresh air from outside the aircraft. Although effective, the aircraft may encounter rainy conditions, and unwanted rainwater may eventually reach the electrical machine.

[0007] Some documents are far removed from this issue by describing engine air intakes.

[0008] For example, US document 20200023985 Al describes a system having an air inlet housing a filter and covered by a scoop.

[0009] US document 2362552 A also describes a scoop arranged above an air intake.

[0010] Document FR 3065757 DI describes an air inlet mouth cooperating with a rectifier.

[0011] Documents EP 3560837 Al, US 20190084687 Al, EP 3418183 Al, EP 3403919 Al, FR 3026136 Al, FR 3021994 Al, EP 2880295 A4, EP 2776319 Al, EP 2226473 A3, EP 1828571 Al, US 3208214 A, US 2362552 A, US 2365328 A are also known.

[0012] The present invention then aims to provide an innovative aircraft that makes it possible to overcome the limitations mentioned above.

[0013] The invention relates to an aircraft equipped with at least one electrical machine housed in a compartment of this aircraft, said compartment being separated by a cowling from an external environment, the external environment being located outside the aircraft, said aircraft comprising a ventilation system to convey air from the external environment to the electrical machine.

[0014] The ventilation system comprises a duct connected to the electrical machine and extending to a free section, the free section being located in the external environment, the duct passing through a passage in the cowling, the duct extending partially within the compartment and partially into the external environment, a void surrounding the duct in the passage and separating the duct from the cowling, the ventilation system comprising a scoop opposite the free section without obstructing it. This scoop may be located above the free section without obstructing it along a vertical axis when the aircraft is on a horizontal surface.

[0015] For example, the electrical machine may be an electric generator, an electric motor, or a starter-generator. The electrical machine may optionally be connected to a heat engine that drives a mechanical chain, possibly including at least one rotor. Optionally, the aircraft may be a rotorcraft.

[0016] Therefore, the ventilation system according to the invention can tend to limit the flow of water, for example rainwater, towards the electrical machine.

[0017] In case of rain, water may run down the casing. However, the conduit protrudes into the external environment, with a section extending into this external environment without touching the casing. Therefore, rainwater that may reach the opening by running down the casing does not enter the conduit, but can fall into the gap between the conduit and the edge of the casing that defines the opening. This water thus does not enter the electrical machine.

[0018] Furthermore, the scoop is positioned above the duct. Consequently, the scoop reduces the risk of rainwater falling directly into the duct. The scoop can also facilitate air intake into the duct during aircraft movement.

[0019] The aircraft may also include one or more of the following characteristics, taken alone or in isolation.

[0020] According to one possibility, the scoop and said cowling can provide a corridor extending along an axis of extension from a first surface open to the external environment to a second surface open to the external environment.

[0021] The scoop is thus not only open to the duct but can be traversed completely by air or liquid as the aircraft moves forward. This feature prevents rainwater from accumulating in the scoop and potentially falling into the duct.

[0022] Optionally, the extension axis may be parallel to a roll axis of the aircraft.

[0023] Thus a liquid which enters the corridor through one surface, during the forward movement of the aircraft, can exit through the other surface.

[0024] According to a possibility compatible with the preceding ones, said conduit may include at least one drainage orifice upstream of the electrical machine in a direction going from the external environment towards the electrical machine.

[0025] At least part of the water that would enter the conduit or that would form in the conduit by condensation is thus evacuated through the drainage orifice(s) so as not to reach the electrical machine.

[0026] Optionally the conduit may include an inlet section passing through the casing and an outlet section connected to the inlet section and opening onto the electrical machine, the outlet section extending along an axis of elongation in the extension of the electrical machine, the inlet section extending along an axis in elevation of the outlet section towards the external environment, said drainage orifice being provided in the outlet section.

[0027] The drainage orifice(s) are positioned to optimize water drainage.

[0028] According to a possibility compatible with the preceding ones, said conduit can be connected to a stationary structure in a reference frame of the aircraft by at least one attachment.

[0029] The cover can thus be manipulated independently of the conduit.

[0030] Optionally, the conduit then has a freedom of movement limited to a range of positions relative to the structure.

[0031] Thus, the conduit does not impede any relative movement of the electrical machine with respect to the casing. Indeed, during operation, the electrical machine is likely to move slightly. The fastener allows for such movement.

[0032] For example, the fastener includes a collar that surrounds the conduit, this collar being connected to the structure by a link giving at least one degree of freedom in translation and / or at least one degree of freedom in rotation to the collar.

[0033] According to a possibility compatible with the preceding ones, the passage may have an oblong shape

[0034] The passage may have an oblong annular shape along the axis of extension and allows the conduit to move with the electric machine relative to the casing.

[0035] According to a possibility compatible with the preceding ones, a minimum distance separates said conduit and an edge of the casing delimiting the passage, this minimum distance being between 5 millimeters and 20 millimeters

[0036] The expression "minimum distance" refers to the smallest distance at any given time between the conduit and the edge.

[0037] This minimum distance is sufficient to generate a space between the edge of the passage and the conduit allowing water to be evacuated.

[0038] According to a possibility compatible with the preceding ones, the duct emerges from the casing into the external environment with a minimum height of between 5 millimeters and 20 millimeters

[0039] The expression "minimum height" refers to the smallest distance at any given time between a top of the conduit and the passage.

[0040] This minimum height is sufficient to limit the risks of water ingestion.

[0041] The height of the duct's apex relative to the passage can vary in azimuth. Furthermore, the minimum height may depend on the passage's dimensions.

[0042] According to a possibility compatible with the preceding ones, the scoop can be arranged between the passage and a rotor of said aircraft, said rotor being located in the external environment.

[0043] The passage can thus be arranged on a cowling opposite a rotor, for example on an upper face of an aircraft envelope.

[0044] According to a possibility compatible with the preceding ones, the ventilation system may include at least one protective grille.

[0045] The term "grid" refers to a perforated organ used to limit the ingestion of external bodies.

[0046] Thus, a protective grid can be arranged in the free section.

[0047] The protective grille can completely cover the free section

[0048] As a complement or alternative, a protective grille can be arranged between the scoop and the cowling.

[0049] The protective grille can completely cover a passage area delimited by the scoop and the hood.

[0050] The invention and its advantages will become apparent in more detail in the following description, with illustrative examples given by reference to the accompanying figures, which represent:

[0051] [Fig. 1], a three-dimensional diagram partially illustrating an aircraft according to the invention,

[0052] the [Fig.2], a partially transparent view of the aircraft of the [Fig.1],

[0053] [Fig. 3], a diagram showing a conduit passing through a passage in the cowling in top view, and

[0054] the [Fig.4], a diagram showing the scoop.

[0055] Elements present in several separate figures are assigned one and the same reference.

[0056] Figures 1 to 4 show a reference frame of an aircraft 1 according to the invention. This reference frame comprises three axes X, Y and Z orthogonal to each other.

[0057] The X axis is said to be longitudinal. The term "longitudinal" relates to any direction parallel to this X axis.

[0058] The Y axis is said to be transverse. The term "transverse" relates to any direction parallel to this Y axis.

[0059] Finally, the Z-axis is said to be in elevation. The expression "in elevation" relates to any direction parallel to this Z-axis.

[0060] Figure 1 presents a schematic representation of an aircraft 1 according to the invention. Aircraft 1 is shown only partially so as not to unnecessarily increase the size of Figure 1.

[0061] The aircraft is equipped with a fuselage 2 in which there is at least one compartment 5, such as an engine compartment for example. An electrical machine 17 is housed at least partially in the internal space INT of the compartment 5.

[0062] Compartment 5 is closed in particular by a cover 10, this cover 10 separating an internal space INT of compartment 5 from an external environment EXT located outside the aircraft 1.

[0063] Compartment 5 may be delimited by at least one wall 6, 7, 8, one of the walls comprising the cover 10. The wall(s) 6, 7, 8 may be fire-resistant, for example flame-retardant. Compartment 5 may be divided into several sub-compartments.

[0064] For example, the cowling 10 is located above the electric machine 17 when the aircraft 1 rests on a floor 100. Therefore, the compartment 5 is delimited longitudinally by two longitudinal walls 7, transversely by two transverse walls 8, and vertically by a floor 6 and a wall comprising the cowling 10.

[0065] Furthermore, the electric machine 17 can cooperate with a heat engine 15. This heat engine 15 can include a power shaft 18, connected to a mechanical chain 20, possibly by passing through a longitudinal wall 7. This power transmission mechanical chain 20 can drive at least one rotor 25. For example, the power shaft 18 is connected to a power transmission gearbox 22, which rotates the rotor 25. The rotor 25 has a plurality of blades 26, [Fig. 1] illustrating a single complete blade for convenience. This rotor 25 forms, for example, a rotating wing 2.

[0066] The internal combustion engine 15 is capable of burning fuel to set in motion the power shaft 18. According to one possibility, the heat engine 15 may include an engine block 16 of the turboshaft type or of the piston engine type for example.

[0067] For example, the electric machine can cooperate with the heat engine. The electric machine can include an electric generator, an electric motor, or a starter-generator. For example, the electric machine 17 can operate either as a starter or as an electric power generator. If a turboshaft engine is present, the electric machine can be connected to the turboshaft engine's gas generator.

[0068] Furthermore, the aircraft 1 includes a ventilation system 30 to supply air from the external environment EXT to the electrical machine 17.

[0069] Fig. 2 is a truncated and partially transparent view showing the ventilation system 30. In particular, part of the cover 10 is made transparent.

[0070] The ventilation system 30 includes a duct 35 opening onto the electrical machine 17 and the external environment EXT.

[0071] The conduit 30 has a proximal zone 36 opening onto the electrical machine 17 and extends to a free section 37 open to the external environment.

[0072] The free section 37 is located in the external environment EXT. The conduit 35 extends partially into the external environment EXT and partially into the compartment 5, to be connected to the electrical machine 17. For this purpose, the conduit 35 passes completely through the casing 10. More precisely, the conduit 35 passes through a passage 11 provided in the casing 10. Therefore, the conduit 35 has a section with the free section protruding from the casing 10 into the external environment EXT.

[0073] For example, the duct 35 comprises an outlet section 38 integral with an inlet section 39. The outlet section 38 comprises the proximal zone 36 supplying fresh air to the electrical machine 17 and can extend along an elongation axis AX1 in line with the electrical machine 17. For example, the outlet section has a cylindrical shape with a circular base. The inlet section 39 comprises the free section 37 and can extend along an elevational axis AX2, different from the elongation axis AX1, from the outlet section 38 towards the external environment EXT by passing through the opening 11 of the casing 10.

[0074] Furthermore, the conduit 35 can be attached by one or more fasteners 76 to a structure 75 of the aircraft 1, this structure 75 being stationary in the aircraft's frame of reference. According to the illustrated example, the inlet section 39 is attached to a structure 75, carrying the cowling 10, by a clamp-type fastener 76. This clamp 76 secures a section of the conduit and is then fixed to the structure 75 by a screw-nut system 400 or an equivalent through an oblong hole 401 in the structure 75. According to the example, the structure includes a support having the oblong hole 401, this support being able to be integral with a aircraft traverse. The collar 76 and the conduit 35 can thus be movable in translation relative to the structure 75, within the limits imposed by the oblong hole 401.

[0075] According to a possibility independent of these aspects, the conduit 35 may include at least one drainage orifice 70 upstream of the electrical machine 17. The term "upstream" is to be considered in a sense going from the external environment EXT towards the electrical machine 17.

[0076] One or more orifices 70 may in particular be provided in the lowest area of ​​the conduit 35 when the aircraft rests on a horizontal ground 100. According to the illustrated example, at least one drainage orifice 70 is drilled in the outlet section 38.

[0077] According to another aspect and as illustrated in [Fig.3], the passage 11 is delimited by an edge 13 of the cover 10. The conduit 35 then passes through the passage 11 without coming into contact with the edge 13. A void 12 then surrounds the conduit 35 in the passage 11. This void permanently separates the conduit 35 from the cover 10.

[0078] This passage 11 may have an oblong shape. This passage 11 may allow relative movement, for example translation, between the conduit 35 and the casing 10.

[0079] In addition, a minimum distance 200 separates the conduit 35 and the edge 13 of the casing delimiting the passage 11, this minimum distance 200 possibly being between 5 millimeters and 20 millimeters.

[0080] Furthermore, a protective grid can be attached to the conduit 35. For example, a protective grid 81 is arranged in the free section 37.

[0081] In addition and with reference to [Fig.4], the conduit 35 may protrude from the casing into the external environment EXT by a minimum height of between 5 millimeters and 20 millimeters.

[0082] Furthermore, the ventilation system 30 includes a scoop 50. The scoop 50 is opposite the free section 37 and does not obstruct this free section 37. When the aircraft 1 is on a horizontal surface 100, the scoop 50 is located above the free section 37, without obstructing it, for example along a vertical DIRV axis. In the presence of a rotor 25 as illustrated in [Fig. 1], the scoop 50 can be arranged between the passage 11 and the rotor 25.

[0083] With reference to [Fig. 4], this scoop 50 may include a plate positioned above the free section 37. This plate may be attached to the cover 10 by conventional means, for example by screwing, crimping, gluing, welding, or other means. This plate is curved as illustrated.

[0084] The scoop 50 and the cowling 10 can form a channel 60 between the scoop 50 and the cowling 10. This channel 60 can extend along an axis of extension DIREXT from a first surface 61 open to the external environment EXT to a second surface 62 open to the external environment EXT. This axis of extension DIREXT can be parallel to a roll axis AXROL of the aircraft 1.

[0085] Furthermore, the scoop 50 can be tapered going from the first surface 61 to the second surface 62. The first surface 61 can have a first area greater than a second area of ​​the second surface 62 in order to tend to direct the air towards the duct 35. For example the scoop 50 has a substantially frustoconical shape.

[0086] In addition, a protective grid 82 can be arranged between the scoop 50 and the hood 10, for example in the first surface 61.

[0087] Figure 4 illustrates the operation of the invention. Rain falling on the aircraft along arrow Fl then impacts scoop 50 and does not enter conduit 35.

[0088] The scoop 50 does not obstruct the conduit 35, and does not prevent air from being drawn into the conduit 35.

[0089] Furthermore, if water flows along the casing 10 in the direction of arrow F2, this water enters the channel 60 through the first surface 61 and tends to fall into the empty space 12, without entering the conduit 35, which has a free section 37 projecting above the passage 11 without touching the casing. If water bypasses the passage 11, this water exits the scoop 50 through the second surface 62, and therefore does not risk accumulating in the scoop until it overflows into the conduit 35. Finally, if water flows into the conduit 35, the drainage orifice(s) 70 can discharge it away from the conduit 35.

[0090] Naturally, the present invention is subject to numerous variations in its implementation. Although several embodiments have been described, it is understood that it is not conceivable to exhaustively identify all possible embodiments. It is, of course, conceivable to replace a described means with an equivalent means without departing from the scope of the present invention and the claims.

Claims

Claims

1. Aircraft (1) provided with at least one electrical machine (17) housed in a compartment (5) of this aircraft, said compartment (5) being separated by a cowling (10) from an external environment (EXT), the external environment (EXT) being located outside the aircraft (1), said aircraft (1) comprising a ventilation system (30) for conveying air from the external environment (EXT) to the electrical machine (17), characterized in that the ventilation system (30) comprises a duct (35) connected to the electrical machine (17) and extending to a free section (37), the free section (37) being located in said external environment (EXT), the duct (35) passing through a passage (11) of the cowling (10), the duct (35) extending partially into the compartment (5) and partially into the external environment (EXT), an empty space (12) surrounding in the passage (11) the duct (35) and separating the conduit (35) from the cowling (10),the ventilation system (30) comprising a scoop (50) opposite the free section (37) without blocking it.,

2. Aircraft according to claim 1, characterized in that said scoop (50) and said cowling (10) provide a corridor (60) extending along an extension axis (DIREXT) from a first surface (61) open to the external environment (EXT) to a second surface (62) open to the external environment (EXT).

3. Aircraft according to claim 2, characterized in that the extension axis (DIREXT) is parallel to a roll axis (AXROL) of the aircraft (1).

4. Aircraft according to any one of claims 1 to 3, characterized in that said conduit (35) comprises at least one drainage orifice (70) upstream of the electric machine (17) in a direction going from the external environment (EXT) towards the electric machine (17).

5. Aircraft according to claim 4, characterized in that said duct (35) comprises an inlet section (39) passing through the cowling (10) and an outlet section (38) connected to the inlet section (39) opening onto the electrical machine (17), the outlet section (38) extending along an elongation axis (AX1) in the extension of the electrical machine (17), the inlet section (39) extending along an elevation axis (AX2) of the outlet section (38) towards the external environment (EXT), said drainage orifice (70) being provided in the outlet section (38).

6. Aircraft according to any one of claims 1 to 5, characterized in that said conduit (35) is connected to a structure (75) stationary in a reference frame (X, Y, Z) of the aircraft (1) by at least one attachment (76).

7. Aircraft according to claim 6, characterized in that said conduit (35) has a freedom of movement limited to a range of positions relative to the structure (75).

8. Aircraft according to any one of claims 1 to 7, characterized in that said passage (11) has an oblong shape.

9. Aircraft according to any one of claims 1 to 8, characterized in that a minimum distance (200) separates said duct and an edge (13) of the cowling delimiting the passage (11), this minimum distance (200) being between 5 millimeters and 20 millimeters.

10. Aircraft according to any one of claims 1 to 9, characterized in that said duct (35) emerges from the cowling into the external environment (EXT) with a minimum height of between 5 millimeters and 20 millimeters.

11. Aircraft according to any one of claims 1 to 10, characterized in that the scoop (50) is arranged between the passage (11) and a rotor (25) of said aircraft (1), said rotor (25) being located in the external environment (EXT).

12. Aircraft according to any one of claims 1 to 11, characterized in that the ventilation system (30) comprises at least one protective grille (81, 82).

13. Aircraft according to claim 12, characterized in that said protective grid (81) is arranged in the free section (37).

14. Aircraft according to claim 12, characterized in that said protective grid (82) is arranged between the scoop (50) and the cowling (10).

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