Housing featuring a bidirectional heat sink equipped with fins oriented at a non-zero angle of incidence

Abstract

The housing (5) comprises a heat sink (6) equipped with a plurality of fins (8), each fin having a body projecting from an internal part (10) to an external part (11) between which the heat sink is located. These fins are arranged in a plurality of lines (L) parallel to their axial direction (DA). The heat sink comprises a plurality of separating walls (12), each extending in a plane parallel to their axial direction and delimiting a plurality of flow volumes (13), each comprising at least one line of fins whose body is oriented at an angle of incidence (β) with respect to their axial direction. This angle is non-zero for at least one fin in each flow volume.Within the same line, the angle of incidence of the fins is such that the heat sink can function equally well regardless of whether the airflow is in one direction or the other. Figure to be published with the abbreviation: Figure 20.

Description

Title of the invention: Housing comprising a bidirectional heat sink equipped with fins oriented at a non-zero angle of incidence TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of intelligent electric motors for aircraft.

[0002] The present invention relates to an external housing for an intelligent aircraft electric motor, and in particular a housing having fins projecting outwards.

[0003] The invention finds applications in the aeronautical field, in particular for intelligent motors used in the context of hybrid thermal / electric propulsion systems for aircraft, for converters intended for propulsive applications such as vertical take-off and landing or VTOL aircraft, and for converters of non-propulsive applications such as variable speed constant frequency or VSCF systems. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0004] An example of an aircraft smart motor according to the prior art, or "Smart Motor" in English, is illustrated on [Fig.1] and [Fig.2] and is described in patent FR3091063B1 in the name of the applicant.

[0005] Intelligent motors 1' usually include an electromechanical converter 2' with a polyphase rotor 3' and stator 4', a cylindrical housing 5' equipped with a heat sink 6', and an electronic control unit comprising a plurality of electronic boards 7'.

[0006] During operation, these electronic boards 7' heat up considerably and require cooling to prevent damage. Thus, an essential role of the heat sink 6' is to cool not only the housing 5', but also to cool by conduction the electronic boards 7' which are mounted on the underside of the housing 5'. The heat sink 6' is usually equipped with cooling fins 8' projecting radially outwards. These fins 8' allow the housing 5' and the electronic boards 7' to be cooled by the air flowing through the heat sink 6' when the aircraft is moving. These fins 8' may be surrounded by an outer shroud (not shown), also referred to as a "shroud," which serves primarily to channel the flow and delimit the cooling airflow channels. They usually extend in a radial direction along which extend the rotor 3' and stator 4' of the intelligent motor 1' so that the cooling air flows through the fins 8' in an axial direction.

[0007] In order to produce sufficient cooling, the fins 8' have a significant radial height, which unfavorably results in a large overall size, weight and cost for the intelligent motor 1'.

[0008] There is therefore a need for a heat sink that is less bulky, less heavy and less expensive for a given thermal performance. Summary of the invention

[0009] The invention offers a solution to the problems mentioned above by providing a heat sink whose fins have a considerably reduced radial height compared to those of the prior art, while providing at least the same cooling effect. This result is achieved by adding to at least some of the fins an airflow deflection function in addition to their cooling effect by convection and conduction.

[0010] One aspect of the invention relates to an intelligent engine housing extending along an axis XX, comprising a hollow cylindrical portion defining an axial direction DA, a radial direction DR and a tangential direction DT, said cylindrical portion comprising a cylindrical inner part, a heat sink located on the inner part and thermally connected thereto, and comprising a plurality of fins having a body that rises from the outer face of the inner part and projects outwards, these fins being distributed in a plurality of lines L parallel to their axial direction DA, and characterized in that the heat sink further comprises: • a plurality of separating walls, each extending in a plane P defined by their radial direction DR and their axial direction DA; • a plurality of flow volumes, each delimited by the internal part and two successive separating walls; • at least one line L of fins located in at least one flow volume and comprising three successive parts, namely: • a first part Zi comprising fins 8i, 82, ... 8n whose body is oriented at an angle of incidence [3i, [32, ... [3n relative to their axial direction DA, this angle of incidence [3 being non-zero for at least one fin and such that ipj < l[32l < ... < l[3J; • a second part Z2 comprising fins 8n+i, 8n+2, ... 8m whose body is oriented at an angle of incidence [3n+i, [3n+2, ... [3m] with respect to their axial direction DA, this angle of incidence [3n+i, [3n+2, ... [3m] being non-zero and the same for all the fins of the second part Z2; and • a third part Z3 comprising fins 8m+i, 8m+2, ... 8Z whose body is oriented at an angle of incidence [3m+i, [3m+2, ... [3Z with respect to their axial direction DA, this angle of incidence [3 being non-zero for at least one fin and such that I[3m+iI > l[3m+2l > ... > l[3zl.

[0011] Thanks to the invention, the cooling air flows through the fins in a substantially helical rather than linear motion, as illustrated in [Fig. 15] and [Fig. 16]. Indeed, the airflow is confined in flow volumes where fins oriented with a non-zero angle of incidence impart to it an ideally helical motion with the helix axis substantially parallel to the axial direction, for better heat transfer occurring by radial conduction and convection at the level of the two flanks of the fins.

[0012] Thus, for an equivalent cooling effect, the conductive part of the fin can be reduced by shortening and thinning it. To maintain a satisfactory heat exchange surface, the number of shorter and thinner fins is increased. Convective cooling on the fins is also more efficient near the leading edge, where the cumulative lengths are increased.

[0013] The separating walls are fins which do not participate in the helical movement, but delimit the air flow and can therefore extend over the entire length of the housing, maximizing its filling.

[0014] Furthermore, thanks to the invention, the heat sink can operate bidirectionally, meaning that it can advantageously cool the casing and electronic boards with the same efficiency, regardless of whether the airflow is in one direction or the other. Thus, the same variant of the heat sink can be mounted on two different aircraft configurations: one with direct airflow and the other with reverse airflow.

[0015] According to one aspect of the invention, the fins 8b 82, ... 8n of the first part Zi are such that 0° < ipj < l[32l < ... < l[3nl < 35°, and more preferably such that 0° < ipj < l[32l < ... < l[3nl < 20°.

[0016] According to a further aspect of the invention, the fins 8m+i, 8m+2, ... 8Z of the third part Z3 are such that 35° > l[3m+il > l[3m+2l > ... > l[3zl > 0°, and more preferably such that 20° > l[3m+il > l[3m+2l > ... > l[3zl > 0°.

[0017] According to one aspect of the invention, the fins (8b 82, ... 8n) of the first part Zi are such that 0° < ipj < l[32l < ... < l[3nl < 35°, and more preferably such that 0° < ipj < l[32l < ... < l[3nl < 20°.

[0018] According to another aspect of the invention, the fins (8m+i, 8m+2, ... 8Z) of the third part Z3 are such that 35° > I[3m+iI > l[3m+2l > ... > l[3zl > 0°, and more preferably such that 20° > l|3m+1l > l[3m+2l > ... > l|3zl > 0°.

[0019] According to a further aspect of the invention, the first part Zi and the third Each part Z3 includes the same number of fins.

[0020] According to one aspect of the invention, the first part Zi and the third part Z3 are such that = |3Z, |32 = [3z4, |33 = |3z2, ... , |3n.i = [3m+2, |3n = |3m+1.

[0021] One aspect of the invention also relates to an intelligent engine housing extending along an axis XX, comprising a hollow cylindrical portion defining an axial direction DA, a radial direction DR and a tangential direction DT, said cylindrical portion comprising: • an internal cylindrical part, • a heat sink located on the inner part and thermally connected to it, and comprising a plurality of fins having a body that rises from the outer face of the inner part and protrudes outwards, these fins being distributed in a plurality of lines L parallel to their axial direction DA, and characterized in that: • The heat sink also includes: • a plurality of separating walls, each extending in a plane P defined by their radial direction DR and their axial direction DA; • a plurality of flow volumes, each delimited by the internal part and two successive separating walls; • at least one line L of fins located in at least one flow volume, the body of which is oriented at an angle of incidence [3 with respect to their axial direction DA, said angle of incidence [3 being non-zero for at least one fin of said line L.

[0022] According to one aspect of the invention, the heat sink comprises at least one line L of fins located in at least one flow volume and comprising n fins 8b 82, ... 8n with n > 2, the body of which is oriented at an angle of incidence [3i, [32, ... [3n] with respect to their axial direction DA such that 0° < I [311 < l[32l < ... < l[3nl < 35°, more preferably such that 0° < l[3il < l[32l < ... < l[3nl < 20°, which advantageously allows the air to be progressively deflected in a substantially helical displacement.

[0023] According to another aspect of the invention, the heat sink further comprises at least one line L of fins located in at least one flow volume and whose body is inclined along their tangential direction DT by a non-zero angle of inclination a with respect to their radial direction DR.

[0024] According to a further aspect of the invention, the angle of inclination a is such that 5° < lal < 60°, more preferably such that 10° < lal < 45°.

[0025] The combination of angles a and [3] advantageously generates a satisfactory helical motion for the airflow through the fins without excessively slowing said flow. These angles can advantageously be optimized so that, at cruising speed, the airflow preferentially tiellement approximement between two-thirds and one helix turn over the entire axial length of the heat sink.

[0026] According to one aspect of the invention, the heat sink comprises, in at least one flow volume, at least two lines L of fins, of which at least one line L of fins has a positive angle of inclination α and at least one line L of fins has a negative angle of inclination α.

[0027] According to another aspect of the invention, the heat sink comprises, in at least one flow volume, at least one transverse row R of fins comprising m successive fins with m > 2 whose body is inclined along their tangential direction DT by an angle of inclination ai, a2, ... am such that laj < la2l < ... < laml.

[0028] According to a further aspect of the invention, the heat sink further comprises at least one additional separating wall extending in a plane PS defined by its radial direction DR and its axial direction DA, and which divides a flow volume into two flow sub-volumes. Advantageously, such a wall allows each flow volume to be divided so as to give each flow sub-volume a geometry approaching that of a cylinder with a circular cross-section, which is the most suitable shape for generating airflow along a helical and circular path.

[0029] According to another aspect of the invention, the additional separating wall is equidistant from the two separating walls delimiting the flow volume it compartmentalizes. Such a geometry advantageously allows for the same cooling effect in each sub-volume of flow, and therefore for better control of the overall cooling of the heat sink.

[0030] According to a further aspect of the invention, at least one other line L of fins is located between the two lines L of fins whose fins have a body inclined along their tangential direction DT from one line L of fins to the other line L of fins. This configuration advantageously further promotes the formation of a helical motion in the airflow and fills the space with more fins in a rather homogeneous distribution.

[0031] According to one aspect of the invention, at least one separating wall or an additional separating wall is connected to the outer face of the inner part by a fillet joint. These fillet shapes advantageously give at least a partially rounded contour to the cross-section of each flow volume so as to give it a shape approaching that of a cylinder with a circular cross-section.

[0032] According to a further aspect of the invention, at least one fin has at least one of the following features: • it has raised areas and / or hollows on at least one side; • it has a curved profile; • It has a curved intrados and extrados with different curvatures different; • it exhibits a twist, the angle of incidence of the fin not being constant over its height; • it has a rounded trailing edge; • it has an angular trailing edge; • It has a rounded leading edge; and • It has an angular leading edge.

[0033] These characteristics advantageously increase the heat dissipation effect of the fins by reducing pressure losses.

[0034] According to one aspect of the invention, at least one fin and the internal part form a single piece made of thermally conductive material that is the product of additive manufacturing. Indeed, this manufacturing technique advantageously allows the production of fins with complex geometries.

[0035] According to another aspect of the invention, at least one fin has a downstream trailing edge having at least one notch of substantially triangular shape, this notch makes it possible in particular to minimize the use of support when the fins are made by additive manufacturing from downstream to upstream.

[0036] According to a further aspect of the invention, the cylindrical portion comprises an upstream part and a downstream part which have a different cross-sectional shape, and at least two successive circumferential fins located in an upstream area of ​​the downstream part are connected to each other by a fin whose downstream edge is inclined towards the inner part. This fin advantageously allows the airflow to be redirected towards the fins of the downstream part of the inner part when it encounters an obstacle due to a change in geometry between the upstream and downstream parts of the cylindrical portion.

[0037] According to another embodiment of the invention, the cylindrical portion further comprises an outer cylindrical part concentric with the inner part, the heat sink being located between the inner and outer parts, and the heat sink comprising a plurality of additional cooling fins projecting towards the inner part from an inner face of the outer part. These additional fins advantageously promote the deflection of the cooling airflow, particularly when they have a geometry similar to that of the fins of the inner part.

[0038] Another aspect of the invention relates to an intelligent motor equipped with a housing as described above, which advantageously has a lower weight and size than intelligent motors equipped with a conventional heat sink, for at least an equivalent cooling effect.

[0039] An additional aspect of the invention relates to an aircraft equipped with an intelligent engine as described above.

[0040] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0041] The figures are presented for illustrative purposes only and are in no way limiting of the invention.

[0042] [Fig. 1] is a schematic perspective view of an intelligent motor according to the prior art whose casing does not include an external enclosure.

[0043] [Fig.2] is a view similar to [Fig.1] where the downstream face is open.

[0044] [Fig.3] is a schematic perspective view of an intelligent motor equipped with a housing according to the invention and whose downstream face is open.

[0045] [Fig.4] is a perspective view of a sector of the downstream part of a housing according to the invention, the external part of which is shown to be transparent.

[0046] [Fig.5] is a perspective view of a detail of a sector of the downstream part of the casing of [Fig.4] limited to a single flow volume separated into two half-volumes separated by an additional separating wall and where the external part is not shown.

[0047] [Fig.6] is a downstream side front view of the flow volume of [Fig.5].

[0048] [Fig.7] is an external radial view of the flow volume of [Fig.5].

[0049] [Fig.8] is a cross-sectional view of the flow volume of [Fig.5] in a plane per pendulum to the motor axis.

[0050] [Fig.9] is a cross-sectional view in an axial plane parallel to the driving axis at the base of the fins of the flow volume of [Fig.7] where the fins all have the same angle of incidence [3 within the same line, for example where the helical motion is established.

[0051] [Fig. 10] is a cross-sectional view in an axial plane parallel to the driving axis at the base of the fins of the flow volume of [Fig.7] where the fins have a different angle of incidence [3] within the same line, and increasing as one moves downstream.

[0052] [Fig. 11] is a perspective view of a sector of the upstream and external part of a casing according to the invention seen from the inside, with fillet shapes in the corners of the walls delimiting the flow volumes.

[0053] [Fig. 12] is a view similar to [Fig. 11] where the inner face of the outer part of the housing is equipped with additional fins in the form of folded sheets.

[0054] [Fig. 13] is a perspective view of a flow sub-volume of the downstream part of a casing according to the invention with fillet shapes in the corners for the external part and chamfers for the internal part of the walls delimiting said flow sub-volume.

[0055] [Fig. 14] is a perspective view of a median area of ​​a housing according to the invention where helical movement is established, of which fins are equipped with a fin and where there is a change in the cross-section of the air stream from a cylinder to a flat facet.

[0056] [Fig. 15] is a sectional view similar to [Fig.8], but where the outer part of the housing is shown equipped with additional fins.

[0057] [Fig. 16] is a view similar to [Fig.8] where the substantially helical movement of the cooling air is represented by white arrows.

[0058] [Fig. 17] is a view similar to [Fig. 15] where the substantially helical movement of the cooling air is represented by white arrows.

[0059] [Fig. 18] is a view of a fin profile which has a cambered profile and a greater thickness in the middle.

[0060] [Fig. 19] is a sectional view of an alternative embodiment of a fin in a plane perpendicular to the drive axis

[0061] [Fig.20] is a cross-sectional view in an axial plane parallel to the motor axis at the level from the base of the fins of the flow volume of [Fig.7] where the fins have a variable angle of incidence [3 within the same line, which is increasing, then constant and finally decreasing as we move downstream.

[0062] It should be noted that [Fig. 4] to [Fig. 10] and [Fig. 13] to [Fig. 17] illustrate only the downstream portion of a housing according to the invention. The upstream portion of said housing is, however, very similar to the downstream portion, except that the internal part has a circular cross-section in the upstream portion rather than a polygonal one. DETAILED DESCRIPTION

[0063] Unless otherwise specified, the same element appearing on different figures has a unique reference.

[0064] By convention, in the present application, the terms "upstream" and "downstream" are defined with respect to the direction of air flow E in the intelligent motor, this direction of flow E being represented by white arrows in the figures. This direction of flow E is usually parallel to the axis XX along which the housing according to the invention extends.

[0065] Similarly, the terms "inside" and "outside" and "internal" and "external" are defined radially with respect to the radial direction DR of the housing.

[0066] By "line" of fins, we mean an aligned set or group of fins.

[0067] Finally, the axial direction DA, the radial direction DR, and the tangential direction DT, particularly for a fin, are defined with respect to the external surface of the cylindrical internal part on which said fin is located, this cylindrical internal part being, for example, polygonal, circular, or otherwise cross-sectional. The axial direction DA is parallel to the axis XX. The radial direction DR is a direction passing through the axis of the internal cylindrical part. For additional fins, these directions are defined relative to the internal surface of the external cylindrical part on which these fins are located.

[0068] A tangential direction DT is orthogonal to the axial direction DA and to the axis XX.

[0069] The tangential direction DT of a fin is similar to its circumferential direction when the cylindrical internal part has an external surface with a circular cross-section.

[0070] An intelligent motor 1 equipped with a housing 5 according to the invention is illustrated in [Fig.3]. Its motor shaft extends along the axis XX.

[0071] An intelligent motor 1 consists of an electromechanical converter 2 and its coaxial control electronics. To simplify the industrial diagram, the intelligent motor 1 preferably has its own half-casing, usually cylindrical with a round cross-section, and the electronics have their own half-casing, usually cylindrical with a polygonal cross-section. The two half-casings are usually bolted coaxially to form the casing 5, which encloses the entire intelligent motor 1.

[0072] In a conventional manner, the housing 5 is equipped with a heat sink 6 and contains an electromechanical converter 2 comprising a rotor 3 and a stator 4, and an electronic control unit comprising a plurality of electronic boards 7 located on the underside of the housing 5.

[0073] The housing 5 includes a hollow cylindrical portion 9 with a circular and / or polygonal base, forming a ring defining a radial direction DR and an axial direction DA corresponding to the axis of revolution of the cylinder when it has a circular base, this axis of revolution is preferably identical to the axis XX.

[0074] The cylindrical portion 9 comprises an internal cylindrical part 10, having an internal face 101 equipped with the heat sink 6 and an external face 102. The cylindrical portion 9 may also comprise an external cylindrical part 11, having an internal face 111 and an external face 112. The external part 11 is larger than the internal part 10 and concentric with it so that the heat sink 6 is located between these two parts 10, 11.

[0075] According to one embodiment of the invention, the cylindrical portion 9 comprises an upstream part 9a (see [Fig.3] where the electromechanical converter 2 is preferably housed and a downstream part 9b (see [Fig.4]) where the electronic boards 7 are preferably housed.

[0076] Conventionally, the heat sink 6 comprises a plurality of fins 8 having a cooling function, and having a body that rises towards the outer part 11 in a general direction A from the outer face 102 of the inner part 10 (see [Fig. 5], [Fig. 6] and [Fig. 7]). The fins 8 are arranged in a plurality of rows L parallel to their axial direction DA. Each line L of fins 8 preferentially comprises n fins 8b 82, ... 8n with n > 2.

[0077] Although in the figures the fins 8 are arranged in lines and rows which intersect at right angles, they can also be arranged in a staggered pattern.

[0078] Each fin 8 has a body comprising a foot 85 by which it is positioned on the external face 102 of the internal part 10, a free end 87, located opposite the foot 85, a leading edge 82 located on the upstream side, a trailing edge 81 located on the downstream side and two sides 88 delimited by these four parts 81, 82, 85, 87. The leading edge 82 is preferably straight.

[0079] The heat sink 6 comprises a plurality of separating walls 12, each extending in a plane P, substantially radial, parallel to their axial direction Da. The plane P preferentially passes through the axis XX of the housing 5, it is then defined by the axial direction DA and the radial direction DR of each separating wall.

[0080] The heat sink 6 comprises a plurality of flow volumes 13, each delimited between the inner part 10, the outer part 11 (if present) and two successive separating walls 12.

[0081] According to one embodiment of the invention, the heat sink 6 also comprises a plurality of technical volumes 16, each located between two flow volumes 13, and each delimited by the inner part 10, the outer part 11, and two successive separating walls 12. Each technical volume is preferably occupied by elements enabling the connection of the inner part 10 and the outer part 11.

[0082] The heat sink 6 is characterized in that, in at least one flow volume, it comprises at least one line L of fins 8 whose body is inclined along their tangential direction DT by a non-zero angle of inclination α with respect to their radial direction DR.

[0083] Preferably the angle a is such that 5° < lal < 60°, more preferably such that 10° < lal < 45°.

[0084] According to one embodiment of the invention, the heat sink 6 further comprises at least one additional separating wall 14 which extends in a plane PS defined by its radial direction DR and its axial direction D, and which compartmentalizes a flow volume 13 into two flow sub-volumes 13A, 13B, in particular in order to form flow sub-volumes 13A, 13B whose cross-section approaches a circle as closely as possible.

[0085] When a flow volume 13 has only one additional separating wall 14, this is preferably equidistant from the two separating walls 12 delimiting the flow volume 13 which it compartmentalizes.

[0086] When a flow volume 13 has several supplementary separating walls 14, these and the two separating walls 12 delimiting the flow volume 13 which they compartmentalize are located equidistant from each other. The flow volume 13 is then compartmentalized into more than two sub-flow volumes 13 A.

[0087] It will be noted that a separating wall 12 or an additional separating wall 14 can be considered as a fin which would make the entire axial length of the flow volume 13 and whose plane passes preferentially through the driving axis and more preferably through the axis XX.

[0088] In order to form flow sub-volumes 13A, 13B whose cross-section approximates a circle as closely as possible, according to one embodiment of the invention, at least one separating wall 12 is connected to the outer face 102 of the inner part 10 and / or to the inner face 111 of the outer part 11 by a fillet joint 121, 122 (see [Fig. 11], [Fig. 12] and [Fig. 13]). Similarly, at least one additional separating wall 14 is preferably connected to the outer face 102 of the inner part 10 and / or to the inner face 111 of the outer part 11 by a fillet joint 141, 142.

[0089] By fillet we mean a surface with a partial circular cross-section of concave shape intended to connect two surfaces forming a re-entrant angle.

[0090] Each flow volume 13 or flow sub-volume 13A, 13B preferably comprises several fin lines L, of which at least one fin line L 8 has a positive angle α and at least one fin line L 8 has a negative angle α, that is to say, it preferably comprises at least two opposite fin lines L, where the body of the fins 8 of these L lines is mutually inclined from one L line to another L line.

[0091] Each flow volume 13 or sub-flow volume 13A, 13B preferably comprises at least one transverse row R of fins 8 comprising m successive fins with m > 2, whose body is inclined along their tangential direction DT by an angle of inclination ai, a2, ... am such that laj < la2l < ... < laml, that is to say, within the same row R, the angle of inclination α of the fins 8 evolves, preferably linearly, from one fin 8 to another adjacent fin 8 (see [Fig. 8]). Within the same flow volume 13, within the same row R, the angle of inclination α of the fins 8 evolves preferably uniformly from the outside towards the center of said flow volume 13.

[0092] According to one embodiment of the invention, each flow volume 13 or flow sub-volume 13A, 13B also comprises at least one line L of non-inclined fins 8.

[0093] According to a preferred embodiment of the invention, each flow volume 13 or flow sub-volume 13A, 13B also comprises at least one line L of fins 8 having a body inclined along their tangential direction DT, and located between two other L lines of fins 8.

[0094] The fins according to the invention can not only be inclined tangentially as seen previously, but they can also be oriented with a non-zero angle around their axis A, so that the general direction B of their foot 85 forms an angle of incidence [3 with respect to the axial direction DA (cf. [Fig.9]).

[0095] In the case where the fins are twisted, the angle of incidence of the chord of a fin 8 is not constant over its height. Due to the camber or curvature effect, the angle of incidence of the leading edge 82 and that of the trailing edge 81 differ, so the angle of incidence [3 then designates the average angle of incidence of the fin.

[0096] In addition, this angle of incidence [3 progresses preferentially downstream, from 0° to 35°, preferably from 0° to 20°, so that within the same line L, a fin 8 has an angle of incidence [3 less than or equal to that of the fins 8 downstream of it and greater than or equal to that of the fins 8 upstream of it (cf. [Fig. 10]).

[0097] According to a preferred embodiment of the invention, at least one line L of fins 8 comprises fins 8i, 82, ... 8n whose body is oriented at an angle of incidence [3i, [32, ... [3n] with respect to their axial direction DA such that 0° < l[3J < l[32l < ... < l[3nl] < 35°, more preferably such that 0° < l[3J < l[32l] < ... < l[3nl] < 20°. When this angle of incidence [3] increases from one fin to the next within a line L, this allows a helical displacement to be progressively imposed on the air, while when this angle of incidence [3] remains constant from one fin to the next, this allows this helical displacement to be maintained.

[0098] It should be noted that in the invention, a helical airflow can have a different helix pitch depending on its position within the heat sink 6.

[0099] According to a variant of the invention, the heat sink 6 is bidirectional, that is to say, it can operate with the same efficiency whether the air flows through it in a first direction of flow Ei or in a second direction of flow E2, opposite to the first, these two directions of flow Ei and E2 being preferably parallel to the motor axis and more preferably parallel to the axis XX.

[0100] According to this embodiment, at least one line L of fins 8 is divided into three parts, namely a first part Zb, a second part Z2, and a third part Z3, successively. If the air flows in the first flow direction EB, it passes successively through parts Zb, Z2, and then Z3. Conversely, if the air flows in the second flow direction E2, it passes successively through parts Z3, Z2, and then Zb.

[0101] In its first part Zb, the line L of fins 8 comprises fins 8i, 82, ... 8n whose body is oriented at an angle of incidence [3i, [32, ... [3n] with respect to their axial direction DA, this angle of incidence [3] increasing preferentially from one fin to the next within a line, although two successive fins 8 may have the same angle of incidence. Within this line L, the angle of incidence [3] of the fin 8 is preferably such that 0° < ipj < l[32l < ... < l[3nl < 35°, and more preferably such that 0° < ipj < l[32l < • • • < IPJ < 20°. Within the same line L of the first part Zb it is however preferred that the angle of incidence [3 increases from one fin 8 to the next, so that 0° < ipj < l[32l < ... < l[3nl < 35°, and more preferably such that 0° < I [311 < l[32l < ... < l[3nl < 20°.

[0102] In its second part Z2, the line L of fins 8 comprises fins 8n+i, 8n+2, ... 8m whose body is oriented at an angle of incidence [3n+i, [3n+2, ... [3m] with respect to their axial direction DA, this angle of incidence [3n+i, [3n+2, ... [3m] being the same for all the fins of the second part Z2, that is to say [3n+i = [3n+2 = ... = [3m.

[0103] In its third part Z3, the line L of fins 8 comprises fins 8m+i, 8m+2, ... 8Z whose body is oriented at an angle of incidence [3m+i, [3m+2, ... [3Z] with respect to their axial direction DA, this angle of incidence [3] decreasing preferentially from one fin to the next within a line L, although two successive fins 8 may have the same angle of incidence. Within this line L, the angle of incidence [3] of the fins 8 is preferably such that 35° > [3m+i] > [3m+2] > ... > [3Z] > 0°, and more preferably such that 20° > [3m+i] > [3m+2] > ... > [3Z] > 0°. Within the same line L of the third part Z3, it is however preferred that the angle of incidence [3 decreases from one fin 8 to the next, so that 35° > l[3m+iI > l[3m+2l > ... > l[3zl > 0°, and more preferably such that 20° > l[3m+il > l[3m+2l > ... > l[3zl > 0°.

[0104] According to a preferred embodiment of the bidirectional variant of the heat sink 6, within a line L, the last fin 8n of the first part Zi preferentially has an angle of incidence [3n] identical to the angle of incidence [3n+i] of the first fin 8n+i of the second part Z2.

[0105] Similarly, according to a preferred embodiment of this variant, within a line L, the first fin 8m+i of the third part Z3 preferentially has an angle of incidence |3m+i identical to the angle of incidence [3m of the last fin 8m of the second part Z2.

[0106] According to another preferred embodiment of the bidirectional variant of the heat sink 6, the first part Zi and the third part Z3 are symmetric with respect to the second part Z2, that is to say that [3i = [3Z, [32 = [3zA, [33 = [3Z 2, ... , [3nA = [3m+2, [3n = |3m+b and that the first part Zi and the second part Z2 each comprise the same number of fins 8.

[0107] When the air flows in the first flow direction E1, or in the second flow direction E2 respectively, it first passes through the first part Zb and the third part Z3 respectively, which then act as a helical initiating part of the airflow, progressively imposing a helical displacement on the air, which initially has a substantially rectilinear displacement parallel to the axis XX. The air then passes through the second part Z2, which is a helical displacement maintenance part. Lichoidal of the airflow. Finally, the air ends up passing through the third part Z3, respectively the first part Zb which then acts as a straightening part of the airflow, progressively imposing on the air a substantially rectilinear displacement parallel to the axis XX before its exit from the heat sink 6.

[0108] In [Fig. 20], where an example of the bidirectional variant of the heat sink 6 is illustrated, the first part Zi comprises four fins 8r84, the second part Z2 comprises three fins 85-87, and the third part Z3 comprises four fins 88-8n. In this example, the angle of incidence is such that [3i = [3n, [32 = Pio, P3 = [V and [34 = [35 = Pe = P7 = Ps-. In [Fig. 20], only the foot (or root) of each of the fins 8 is schematically represented.

[0109] It should be noted that when it is not necessary for the heat sink to operate bidirectionally, only the first part Zi may be sufficient—or the third part if the air is to flow in the opposite direction. However, the first part Zi is preferably followed by the second third part Z3 in order to limit pressure losses in the airflow while maintaining the helical airflow.

[0110] According to a preferred embodiment, within the same line L of fin 8, the angle of incidence of the trailing edge 81 of an upstream fin 8n is substantially equal to the angle of incidence of the leading edge 82 of the next downstream fin 8n+i.

[0111] According to a preferred embodiment of the invention, fins 8 may have reliefs and / or hollows on at least one of their flank 88, for example in the form of undulations, sharkskin scales, circular hollows distributed uniformly on the surface in the manner of an outer face of a golf ball, etc.

[0112] According to a preferred embodiment of the invention, at least one fin 8 and the internal part 10 are produced by additive manufacturing. This additive manufacturing is preferably carried out from downstream to upstream, in particular so as to obtain fins 8 whose leading edge 82 is straight. In order to enable this manufacturing, the trailing edge 81 of the fins 8 produced by additive manufacturing preferably has at least one notch 86 of substantially triangular shape.

[0113] According to one embodiment of the invention, fins 8 may have a cambered profile (see [Fig. 18]). The curvature or camber, over a given height of fin 8, designates the angular difference between the angle of incidence at the leading edge 82 and the angle of incidence at the trailing edge 81.

[0114] Fins 8 may also have a greater thickness in the middle to generate the least possible pressure loss, where the lower and upper surfaces are curved with different curvatures (see [Fig. 18]). In addition, fins 8 may exhibit twist, where the angle of incidence of a fin 8 may not be constant along its height. Finally, fins 8 may have a trailing edge and / or a leading edge rounded or angular, with a preferably acute angle. These characteristics, optimized together, each promote the helical movement of the airflow through the fins 8.

[0115] Fins 8 may also have a greater thickness at their base 85, which drains more calories, and a thinner thickness at their free end 87.

[0116] Thus, according to a preferred embodiment of the invention, fins 8 may have a trapezoidal or triangular cross-section. However, since the additive manufacturing of a very thin free end 87 is complicated, fins 8 may have a trapezoidal or triangular cross-section in their portion located on the side of their foot 85 and a portion of constant thickness in their portion located on the side of their free end 87, as illustrated by way of example in [Fig. 19].

[0117] According to one embodiment of the invention, the cylindrical portion 9 comprises an upstream part 9a and a downstream part 9b which have different cross-sectional shapes, for example, an upstream part 9a with a circular cross-section and a downstream part 9b with a polygonal cross-section (see [Fig. 4]), which generates a change of direction for the airflow passing from the upstream part 9a to the downstream part 9b. In order to correct this change of direction, a fin 15 may be provided in the flow volumes 13 or sub-flow volumes 13A, 13B (see [Fig. 14]). This fin 15 is preferably provided at the beginning of the downstream part 9b, that is to say, in an upstream area of ​​the downstream part 9b. It is preferentially carried by two successive fins 8 circumferentially, for example at the level of their free end 87. Each fin is inclined so that its downstream edge is inclined towards the internal part 10.

[0118] According to a preferred embodiment of the invention, the outer part 11 also includes cooling fins, designated as additional fins 80 (see [Fig. 15]). Thus, the heat sink 6 comprises a plurality of additional cooling fins 80 that project towards the inner part 10 from the inner face 111 of the outer part 11.

[0119] The additional fins 80 may have the same characteristics as those of the fins 8, except that they are preferably provided in axial symmetry with respect to the helical center of rotation of the airflow or with respect to the center of the airflow duct. They will therefore not be described further.

[0120] It should be noted, however, that in one embodiment of the invention, the additional fins 80 can be obtained by bending and cutting a sheet of metal (see [Fig. 12]). The external part 11 is itself preferably a tubular sheet. The additional fins 80 are preferably fixed by welding against the inner face 111 of the external part 11, itself preferably a tubular sheet. The Additional fins 80 can also be made in one piece with the heat sink 6 by additive manufacturing (see [Fig. 15]).

[0121] The invention also relates to an intelligent engine 1 equipped with a casing 5 according to the invention, as well as an aircraft equipped with such an intelligent engine 1.

[0122] Although described through a number of examples, variants and embodiments, the casing according to the invention includes various variants, modifications and improvements which will be obvious to a person skilled in the art, it being understood that these variants, modifications and improvements are part of the scope of the invention.

Claims

Demands

1. Intelligent motor housing (5) extending along an axis (XX), comprising a hollow cylindrical portion (9) defining an axial direction (DA), a radial direction (DR), and a tangential direction (DT), said cylindrical portion (9) comprising a cylindrical internal part (10), a heat sink (6) located on and thermally connected to the internal part (10), and comprising a plurality of fins (8) having a body that rises from the outer face (102) of the internal part (10) and projects outwards, these fins (8) being distributed in a plurality of lines (L) parallel to their axial direction (Da), and characterized in that the heat sink (6) further comprises: - a plurality of separating walls (12) each extending in a plane (P) defined by their radial direction (DR) and their axial direction (DA); - a plurality of flow volumes (13) each delimited by the internal part (10) and two successive separating walls (12); - at least one line (L) of fins (8) located in at least one flow volume (13) and comprising three successive parts, namely: • a first part (Zi) comprising fins (8b 8 2, ... 8n) whose body is oriented according to an angle of incidence (pb p2, • • • Pn) with respect to their axial direction (DA), this angle of incidence (P) being non-zero for at least one fin and such that ipj < ip2l < ... < IPJ; • a second part (Z2) comprising fins (8n+i, 8n+2, ... 8m) whose body is oriented at an angle of incidence (Pn+i, pn+2, ... Pm) with respect to their axial direction (DA), this angle of incidence (Pn+i, pn+2, ... pm) being non-zero and the same for all the fins of the second part (Z2); and • a third part (Z3) comprising fins (8m+i, 8m+2, ... 8Z) whose body is oriented at an angle of incidence (Pm+i, pm+2, ... Pz) with respect to their axial direction (DA), this angle of incidence (P) being non-zero for at least one fin and such that l[3m+i 1 > l[3 m+2l> ... >I|3ZI.

2. Carter (5) according to claim 1, characterized in that the fins (8i, 82, ... 8n) of the first part (Zi) are such that 0° < l[3il < l[32l < ... < l[3J < 35°, and more preferably such that 0° < l[3il < l[32l < ... < l[3J <20°.

3. Carter (5) according to claim 1 or 2, characterized in that the fins (8m+i, 8m+2, ... 8Z) of the third part (Z3) are such that 35° > l[3m+il > l[3m+2l > ... > l|3zl > 0°, and more preferably such that 20° > l[3m+il > l[3m+2l > > l[3zl > 0°.

4. Carter (5) according to any one of the preceding claims, characterized in that the fins (8b 82, ... 8n) of the first part (ZJ) are such that 0° < ipj < l[32l < ... < l[3nl < 35°, and more preferably such that 0° < ipj < l[32l < ... < l[3nl < 20°.

5. Carter (5) according to any one of the preceding claims, characterized in that the fins (8m+i, 8m+2, ... 8Z) of the third part (Z3 ) are such that 35° > 1 [3m+i 1 > l[3m+2l > ... > l[3zl > 0°, and more preferably such that 20° > l[3m+il > l[3m+2l > ... > l[3zl > 0°.

6. Carter (5) according to any one of the preceding claims, characterized in that the first part (ZJ) and the third part (Z3) each comprise the same number of fins (8).

7. Carter (5) according to any one of the preceding claims, characterized in that the first part (Zi) and the third part (Z3) are such that — [C [>2 — Pz i» P3 — Pz-2» • • • » (3n i — [im+2. [>n — J3m+i*

8. Intelligent motor (1), characterized in that it is equipped with a housing (5) according to any one of the preceding claims.

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