Electric machine assembly for a motor vehicle, comprising at least one axial flux electric machine and at least one heat exchange device

Abstract

The invention relates to an electric machine assembly (2) for a motor vehicle (1), the assembly comprising at least one axial flux electric machine (3) that comprises a casing (5), a rotor (32), a stator (31) and a sealing membrane (36), wherein the sealing membrane defines a primary compartment (37) for the circulation of a first fluid (F1) and a secondary compartment (38) for the circulation of a second fluid (F2), the assembly (2) comprising a heat exchange device (4) arranged in contact with the casing (5), wherein the casing defines an intermediate compartment (40) for the circulation of the second fluid (F2), so as to allow heat exchange between the fluid and the first fluid (F1) circulating in the primary compartment (37).

Description

Description Title of the invention: Electrical machine assembly for a motor vehicle comprising at least one axial flux electrical machine and at least one heat exchange device

[0001] The invention relates to an electrical machine assembly for a motor vehicle. The invention also relates to a heat exchange device for such an assembly. The invention finally relates to an electric or hybrid motor vehicle equipped with the assembly and / or the heat exchange device.

[0002] Vehicles with electric or hybrid motors typically include at least one electric traction and / or propulsion machine, also known as an electric motor, for moving the vehicle. The electric machine includes, in a known manner, a rotor comprising a shaft and rotating near a stator. Since the rotor moves at a high rotational speed, the electric motor tends to heat up during operation and requires the installation of a cooling system. Such a need increases even more with the vehicle's power requirements.

[0003] In axial flux electrical machines, it is known to cool the stator using oil. However, in order to limit energy losses linked to the rotor splashing in the oil, the latter is conventionally isolated from an oil circulation zone by means of a waterproof membrane glued to the stator and extending partly into the air gap, that is to say in the space present between the stator and the rotor.

[0004] For the most powerful electrical machines, known as high-performance machines, capable of delivering power in the order of a hundred kilowatts, it is also necessary to remove heat from the rotor, particularly at the level of the magnet blocks forming a disc within the rotor. Indeed, at high rotation speeds, particularly around 10,000 rpm, the disc generates significant air shear at the air gap, which tends to heat the disc and the membrane located nearby. It is therefore essential to be able to ensure the cooling of the rotor, on the one hand to reduce energy losses and on the other hand to preserve the integrity of the waterproof membrane attachment.

[0005] Conventionally, it is known to integrate into the electric machine a circuit of an air flow passing at least partly through the rotor and being cooled by means of a heat exchanger, in particular air-water, external to the electric machine, arranged on the front of the vehicle. Such a solution nevertheless has the disadvantage of being very bulky.

[0006] The present invention falls within this context and aims to provide an alternative to known axial flux electric machines allowing the implementation of thermal cooling of the rotor and the stator while avoiding the need to integrate a plurality of external heat exchangers allowing the thermal management of different fluids circulating in the electric machine.

[0007] The invention relates to an electrical machine assembly for a motor vehicle comprising at least one axial flux electrical machine comprising a casing having a plurality of sides delimiting an internal volume, a rotor comprising a hollow shaft extending along a first direction through at least part of the casing, a stator and a sealing membrane fixed in the casing and / or to the stator so as to delimit at least one primary compartment which comprises all or part of the stator and is capable of allowing the circulation of a first fluid and at least one secondary compartment in which the shaft extends and capable of allowing the circulation of a second fluid.The electrical machine assembly also comprises a heat exchange device comprising a plurality of walls delimiting at least in part an intermediate compartment capable of allowing the circulation of the second fluid, said device being arranged in contact with the casing, outside the internal volume, so as to allow a heat exchange between the first fluid circulating in the primary compartment and the second fluid circulating in the intermediate compartment, said device being in fluid connection with the secondary compartment.

[0008] Optionally, the assembly may further comprise a primary channel, arranged in one of the sides of the casing and in fluid connection with the secondary compartment, a supply orifice arranged in the shaft so as to allow the circulation of the second fluid in the hollow of the shaft, and at least one intermediate channel forming a fluid connection between the hollow of the shaft and the secondary compartment, the heat exchange device being in fluid connection with the secondary compartment via the primary channel and in fluid connection with the hollow of the rotor shaft via the supply orifice.

[0009] Notably : - the heat exchange device is made of a metallic material, such as steel, cast iron, aluminum or an aluminum alloy, or of a plastic material; and / or - the heat exchange device is attached and fixed to the casing by means of at least one fixing means, such as a screw.

[0010] According to an exemplary embodiment, the plurality of walls of the heat exchange device comprises a first wall, a second wall, opposite the first wall along the first direction, and at least one end wall connecting the first wall and the second wall between them, the second wall being arranged in contact with the casing delimiting the secondary compartment and the device further comprising at least one primary opening and one secondary opening, arranged in the second wall and in fluid connection, direct or indirect, with the secondary compartment.

[0011] Alternatively, the heat exchange device may be open on one side, facing the housing, and may be tightly mounted on said housing.

[0012] Optionally, the plurality of walls of the heat exchange device may comprise a guide wall delimiting, in the intermediate compartment, a circulation path for the second fluid which is at least partly inscribed in a spiral shape.

[0013] According to an exemplary embodiment, the electrical machine assembly according to the invention may comprise a plurality of axial flux electrical machines, the at least one electrical machine, hereinafter referred to as the first electrical machine, and a second electrical machine of the plurality of electrical machines being arranged on either side of the heat exchange device so that the latter is interposed between the first electrical machine and the second electrical machine along the first direction.

[0014] In particular, the first electrical machine and the second electrical machine may each comprise a casing, called first casing and second casing, delimiting an internal volume which is specific to them, called first internal volume and second internal volume, the assembly further comprising a hollow connection member, configured to ensure a fluid connection between the first internal volume and the second internal volume on the one hand, and the intermediate compartment of the heat exchange device on the other hand.

[0015] In particular, the first electrical machine and the second electrical machine may comprise a rotor shaft common to said electrical machines or the first electrical machine and the second electrical machine may comprise separate rotor shafts connected to each other so as to be moved concomitantly, the heat exchange device comprising at least one central opening configured to allow the passage of the rotor shaft or at least part of the separate rotor shafts.

[0016] The invention extends to a heat exchange device for an electrical machine assembly as previously described, said device comprising a plurality of walls delimiting at least in part an intermediate compartment capable of allowing the circulation of a fluid, said device being configured to be fixed at the level of at least one side of an electrical machine casing so as to allow a heat exchange with a separate fluid circulating in said casing.

[0017] The invention can be extended to a connection member for an electrical machine assembly comprising a plurality of hollow branches and a hollow base, connected to each other and in fluid connection with each other, the branches being configured to be connected to at least one casing of an electrical machine so as to be in fluid connection with an internal volume of said electrical machine, the base being configured to be connected to a heat exchange device so as to be in fluid connection with an intermediate compartment of said device.

[0018] The invention finally extends to a vehicle with an electric or hybrid motor comprising an electric machine assembly and / or a heat exchange device according to the invention.

[0019] Other details, characteristics and advantages will emerge more clearly on reading the detailed description given below, for informational and non-limiting purposes, in relation to the various examples of embodiment illustrated in the following figures:

[0020] [Fig.l] is a schematic representation of an embodiment of a vehicle equipped with an electric machine assembly according to the invention.

[0021] [Fig.2] is a schematic sectional representation of an exemplary embodiment of the electrical machine assembly comprising a single electrical machine.

[0022] [Fig.3] is a schematic perspective representation of an exemplary embodiment of the electrical machine assembly.

[0023] [Fig.4] is an exploded schematic representation of the assembly illustrated in [Fig.3].

[0024] [Fig.5] is a schematic sectional representation of an exemplary embodiment of a heat exchange device of the assembly.

[0025] [Fig.6] is a schematic sectional representation of an exemplary embodiment of the heat exchange device of the assembly.

[0026] [Fig.7] is a schematic sectional representation of an exemplary embodiment of the electrical machine assembly comprising a plurality of electrical machines.

[0027] [Fig.8] is a schematic perspective representation of an exemplary embodiment of the electrical machine assembly comprising a plurality of electrical machines.

[0028] [Fig.9] is a schematic representation of an exemplary embodiment of the heat exchange device of the assembly for the assembly according to [Fig.7] or 8.

[0029] [Fig.10] is a schematic representation of the electrical machine assembly shown in [Fig.9], including a connecting member.

[0030] [Fig.l 1] is a schematic representation of the electrical machine assembly shown in [Fig.10].

[0031] [Fig.12] is a schematic representation of an exemplary embodiment of the heat exchange device of the assembly for the assembly according to [Fig.7], 9, 10 or 11.

[0032] [Fig.l] schematically illustrates an exemplary embodiment of a motor vehicle 1 according to the invention. The vehicle 1 is a vehicle 1 with an electric or hybrid motor. Also, the vehicle 1 can be of any type, for example, a private vehicle, a utility vehicle, a truck or a bus. In particular, the vehicle 1 considered can be a connected and / or autonomous vehicle.

[0033] The vehicle 1 is equipped with an electrical machine assembly 2 according to the invention, comprising, in general, at least one axial-flow electrical machine 3 configured to allow the circulation of a first fluid F1 and a second fluid F2, distinct from each other, and a heat exchange device 4, mounted on said electrical machine 4, configured to allow the circulation of the second fluid F2, separately from the first fluid F1, and to implement a heat exchange between said fluid and the first fluid F1 circulating in at least one electrical machine 3. Also, as further explained below, the electrical machine assembly 2 may comprise a plurality of electrical machines 3, in particular axial-flow electrical machines 3. Also, it is understood that the description below extends to an assembly 2 comprising one or more electrical machine(s).

[0034] Figures 2 to 4 illustrate an exemplary embodiment of a first embodiment of the assembly 2 according to the invention comprising a single electrical machine 3.

[0035] The electric machine 3, also referred to as a traction and / or propulsion electric motor, comprises a casing 5 comprising a plurality of flanks 51 delimiting an internal volume 50. For example, generally the casing 5 is inscribed in a cylindrical or substantially cylindrical shape with a circular base. Here, the term "casing" means a housing or a structural envelope, in particular metallic. In a non-limiting manner, the casing 5 comprises a first flank 51a and a second flank 51b, delimiting the casing 5 along a first direction 100. Also, the casing 5 comprises at least one intermediate flank 51c, connecting the first flank 51a to the second flank 51b.

[0036] The electrical machine 3 comprises a stator 31 and a rotor 32, movable relative to the stator 31. In a known manner, the rotor 32 comprises a shaft 33 movable in rotation extending through at least a portion of the casing 5 along the first direction 100. In particular, the shaft 33 is centered on an axis of rotation 300 parallel or coincident with the first direction 100. The term "axial flux electrical machine" thus means that the direction of the generated magnetic flux is aligned parallel to the axis of rotation 300. The shaft extends, for example, transversely, or even perpendicularly, to the first flank 51a and / or to the second flank 51b of the casing 5. In particular, the shaft 33 is hollow and comprises a bore 34. The shaft 33 is thus capable of allowing the circulation of a fluid. The bore 34 extends over at least a portion of a length of the shaft 33, measured along the first direction 100 between a first end and a second end of the shaft 33, opposite.

[0037] The rotor 32 also comprises a star 32a, in particular made of composite material, connected to the shaft 33 and carrying a plurality of magnets 32b. The different magnets 32b are in particular arranged in blocks so as to fit into a disc shape, or substantially a disc shape, intended to move in rotation concomitantly with the shaft 33.

[0038] The stator 31 is arranged in the internal volume 50, at a distance from the rotor 32. The space separating the stator 31 from the rotor 32 is referred to as the air gap 35. In a known manner, the stator 31 comprises an assembly of teeth and coils, not shown, fixed within the internal volume 50. In this way, the rotor 32 is moved in rotation relative to the stator 31.

[0039] The electric machine 3 is configured to allow the circulation of the first fluid F1 and the second fluid F2. Within the electric machine assembly 2, the first fluid F1 and the second fluid F2 circulate respectively through a first circuit C1 and a second circuit C2, distinct from each other. The first fluid F1 and the second fluid F2 are thus not in direct contact with each other or mixed. The first circuit C1 comprises, for example, a first heat exchanger HX1 arranged at the front of the vehicle 1 and capable of establishing a heat exchange between the first fluid F1 and an external air flow or a separate cooling fluid, such as water or glycolated water.

[0040] In order to allow such separation of the first and second circuits, C1, C2, the assembly 2 comprises at least one sealing membrane 36 arranged so as to delimit at least one primary compartment 37 and at least one secondary compartment 38. In a known manner, the sealing membrane 36 can be fixed to the casing 5 and / or the stator 31, for example by means of an adhesive in order to limit the space generated within the internal volume 50. Note that the assembly 2 can comprise a plurality of sealing membranes 36. The sealing membrane 36 is arranged so as to separate the rotor 32 from all or part of the stator 31. It thus extends at least partly in the air gap 35.

[0041] The primary compartment 37 is arranged in the internal volume 50 so as to comprise all or part of the stator 31 and is capable of allowing the circulation of the first fluid F1 in order to allow the thermal management of said stator 31, particularly its cooling. According to a preferred embodiment, the first fluid F1 is an oil. The casing 5 comprises at least one inlet for the first fluid F1 and one outlet for the first fluid F1, not shown, respectively ensuring the supply and evacuation of said fluid in the primary compartment 37. For example, the inlet and the outlet for the first fluid F1 are arranged in one of the sides 51, in particular the first side 51a or the second side 51b, of the casing 5.

[0042] The secondary compartment 38 delimits, for its part, a compartment in which the rotor 32 extends, in particular at least a portion of the shaft 33, the star 32a and the various magnets 32b. The second fluid F2 thus makes it possible to ensure the thermal management, in particular the cooling, of the rotor 32, in particular the various magnets 32b which it comprises. The secondary compartment 38 allows the circulation of the second fluid F2 separately from the first fluid FL According to an exemplary embodiment, optional but preferred, the second fluid F2 is an air flow.

[0043] For example, said air flow may be the air naturally present in the internal volume 50, particularly in the secondary compartment 38, so as to form a second closed circuit C2 within the electrical machine assembly 2 as illustrated in FIGS. 2 or 7. Alternatively, as further explained below, said air flow may be drawn from an air flow outside the vehicle 1 entering at the front of the vehicle 1, for example through a grille, so as to form a second open circuit C2.

[0044] The present invention thus aims to integrate, by means of the heat exchange device 4, the conventional functions of a heat exchanger within the electrical machine assembly 2, thereby limiting the space requirement generated and without using an external heat exchanger to ensure the thermal management of the second fluid F2.

[0045] In order to ensure the circulation of the second fluid F2, the electrical machine assembly 2 further comprises in particular at least one supply orifice 61 for the second fluid F2, arranged in the shaft 33 and opening into the bore 34 so as to allow the circulation of said fluid in the hollow of the shaft 33. For example, the supply orifice 61 is arranged at the first end of the shaft 33. In particular, the supply orifice 61 is arranged at the end of the shaft 33 closest to the heat exchange device 4. In a non-limiting manner, the shaft 33 contains a single supply orifice 61. Alternatively, the shaft 33 comprises a plurality of supply orifices 61.

[0046] Also, the assembly 2 comprises at least one intermediate channel 62 forming a fluid connection between the hollow of the shaft 33 and the secondary compartment 38. The at least one intermediate channel 62 is thus connected to the bore 34, or hollow, of the shaft 33 and opens at an outer face of the shaft 33, facing the internal volume 50 and the secondary compartment 38. The at least one intermediate channel 62 extends in the shaft 33, transversely, or even orthogonally, to the axis of rotation 300 and / or to the first direction 100. For example, as illustrated, the shaft 33 comprises a plurality of intermediate channels 62. In particular, the intermediate channels 62 are arranged so as to extend on either side of the rotor disc 32. Additionally or alternatively, the intermediate channels are distributed over all or part of the circumference of shaft 33, these extending radially from bore 34 towards the outer surface of the shaft 33, in particular so as to converge towards the axis of rotation 300.

[0047] Finally, the electrical machine assembly 2 comprises at least one evacuation channel 63 for the second fluid F2, arranged in at least one of the sides 51 of the casing 5. The at least one evacuation channel 63 is arranged in fluid connection with the secondary compartment 38 and with the environment outside the casing 5. In other words, the evacuation channel 63 extends from the internal volume 50 of the casing 5, particularly the secondary compartment 38, and passes through at least one of the sides 51 of the casing 5 in order to open towards the environment outside the electrical machine 3.

[0048] The heat exchange device 4 comprises a plurality of walls 41 delimiting at least in part an intermediate compartment 40 capable of allowing the circulation of the second fluid F2. The heat exchange device 4 is arranged in direct contact with one of the sides 51 of the casing 5, for example here the first side 51a, and extends into the environment external to the electrical machine 3, that is to say outside the internal volume 50 delimited by the casing 5. The heat exchange device 4 is configured so as to allow a heat exchange between the first fluid F1 circulating in the primary compartment 37 of the casing 5 and the second fluid F2 circulating in the intermediate compartment 40 of the heat exchange device 4 via the side 51 carrying said device.Thus, the side 51 arranged in contact with the heat exchange device 4 is interposed between the primary compartment 37 and the intermediate compartment 40 along the first direction 100.

[0049] The heat exchange device 4 is also shaped and arranged so as to be in fluid connection with the secondary compartment 38 via the discharge channel 63 and in fluid connection with the hollow of the shaft 33 of the rotor 32 via the supply orifice 61, as further explained below.

[0050] Thus, when the electrical machine assembly 2 is in operation within the vehicle 1, the first fluid F1 circulates in the first circuit C1, it is cooled at the first heat exchanger HX1, then sent to the primary compartment 37, for example via the first sidewall 51a and / or the second sidewall 51b. In the primary compartment 37, the first fluid F1 captures calories from the stator 31, thus allowing it to be cooled. The first fluid F1 is then evacuated via the outlet and returned to the first heat exchanger HX1 at which it gives up calories to the cooling fluid, allowing it to be cooled before it is returned to the internal volume 50 of the casing 5.

[0051] In parallel, the second fluid F2, cold, enters the shaft 33 via the supply orifice 61, passes into the bore 34 then is sent into the secondary compartment 38 via the intermediate channel 62 or the intermediate channels 62. When the shaft 33 of the rotor 32 is rotated, the latter generates a difference pressure between a zone radially close to the shaft 33 and a zone radially more distant. Also, the centrifugal force moves the second fluid F2 towards the sides 51 of the casing 5, in particular towards the at least one intermediate side 51c, thus moving it away from the shaft 33 and sucking the second fluid F2 present in the shaft 33 towards the at least one intermediate side 51c. Such a principle advantageously makes it possible to avoid the need to integrate a pump into the second circuit C2. The second fluid F2, thus passing into contact with the magnets 32b of the rotor 32, captures at least part of their calories and allows them to be cooled. Additionally, the second fluid F2 then circulates in contact with the sealing membrane 36 and advantageously captures part of its calories, allowing it to be cooled. Consequently, such cooling also allows the cooling of the glue holding the sealing membrane 36, thus ensuring its proper fixing.The second fluid F2 then heated leaves the casing 5 through the discharge channel 63 and is directed towards the external environment, more particularly towards the intermediate compartment 40 of the heat exchange device 4 connected to one of the sides 51 of the electrical machine 3 and extending into the external environment. When the second fluid F2 circulates in the heat exchange device 4, it transfers calories to the first fluid F1 circulating in the primary compartment 37 of the casing 5, colder, via the side 51 carrying the heat exchange device 4 before being returned to the cooled shaft 33. Such a principle makes it possible to integrate a space-saving heat exchanger into the assembly 2. The first fluid F1 being evacuated towards the first heat exchanger HX1, the heat exchange thus carried out between the first fluid F1 and the second fluid F2 does not affect the heat treatment of the stator 31 by the first fluid F1.Due to its topology, the axial flux electric machine 3 has first and second flanks 51a, 51b having a large surface area, thus allowing the implementation of the heat exchange between the first fluid F1, arranged on one side of one of said flanks 51, and the second fluid F2, arranged on the other side of this same flank 51, at the level of the environment external to the electric machine 3. The heat exchange thus carried out can be all the more optimized when the flank considered comprises the inlet of the first fluid F1 into the internal volume 50 of the casing 5 or when said inlet is arranged close to said flank 51, the first fluid then being at its coldest at the edges of said flank 51.

[0052] Figures 2 to 5 illustrate different embodiments of the heat exchange device 4 that can be integrated into the assembly 2 comprising a single electric machine 3. When the assembly 2 comprises a single electric machine 3, the heat exchange device 4 is arranged on said electric machine 3 so as to have an extreme position within the assembly 2 along the first direction 100.

[0053] Generally, the heat exchange device 4 comprises a plurality of walls 41 delimiting at least in part the intermediate compartment 40 capable of allowing the circulation of the second fluid F2. The heat exchange device 4 is, optionally but preferably, attached and fixed to the casing 5 by means of at least one fixing means 42, such as a screw. Alternatively, the heat exchange device 4 and at least one side of the casing 5 carrying it are integrally formed.

[0054] The heat exchange device 4 is made of a metallic material, such as steel, cast iron, aluminum or an aluminum alloy, for example an aluminum alloy AlSi9Cu3, in particular when it must also provide a structural function, or of a plastic material, such as polyamide PPA or polypropylene copolymer PPC. Thus, in the case of an assembly 2 such as illustrated in FIGS. 2 to 4 comprising a single electrical machine 3 and not requiring any particular resistance, the heat exchange device 4 can be made of a plastic material by injection.

[0055] According to a first exemplary embodiment, illustrated in [Fig. 5], the plurality of walls 41 of the heat exchange device 4 comprises a first wall 41a, a second wall 41b, opposite the first wall 41a along the first direction 100, and at least one end wall 41c connecting the first wall 41a and the second wall 41b to each other. Said walls 41 thus themselves delimit the intermediate compartment 40. Also, all or part of said walls 41 comprises a plurality of fixing orifices intended to receive the fixing means 42 explained above. Such a heat exchange device 4 is also shown in [Fig. 4], without the first wall 41a in order to make the interior of said device visible.

[0056] Optionally, the heat exchange device 4 is shaped so as to be at least partly complementary in shape to the electrical machine 3. In particular, in the example illustrated in [Fig. 2], the heat exchange device 4 has a stepped structure, a central zone being offset along the first direction 100 so as to accommodate the presence of one end of the shaft 33 extending beyond the internal volume 50 delimited by the casing 5. Alternatively and preferably, as illustrated in FIGS. 3 to 6, the heat exchange device 4 has a cylindrical structure whose first wall 41a and second wall 41b are planar or substantially planar, for example a structure forming a disc, the shaft 33 then being adapted not to extend beyond the internal volume 50 at the flank 51 carrying the heat exchange device 4.Additionally, the heat exchange device 4 is shaped so as to cover all or part of the sidewall carrying it, namely here the first sidewall 51a. In this case, the first wall 41a and the second wall 41b have circular or substantially circular covering shapes. the entirety of the first flank 51a, the second wall 41b being arranged in contact with the first flank 51a.

[0057] In order to ensure the fluid connection with the internal volume 50 of the electrical machine 3, the heat exchange device 4 further comprises, in such an exemplary embodiment, at least one primary opening 43 and at least one secondary opening 44. Said openings are arranged in at least one of the walls 41. The primary opening 43 is arranged so as to be in fluid connection with the secondary compartment 38 via the discharge channel 63, directly or indirectly, while the secondary opening 44 is configured to be in fluid connection with the supply orifice 61.

[0058] In the illustrated example, the second wall 41b is arranged in contact with at least the side of the casing 5 delimiting the secondary compartment 38, also, preferably, the primary opening 43 and the secondary opening 44 are arranged in the second wall 41b. In particular, the primary opening 43 extends at least partly opposite the discharge channel 63, particularly an area of ​​the discharge channel 63 opening towards the environment outside the electrical machine 3, included in the intermediate side 51c and / or in the first side 51a. Similarly, the secondary opening 44 is preferably arranged opposite, or substantially opposite, the secondary opening 44 of the shaft 33 along the first direction 100. For example, the secondary opening 44 has a central position within the heat exchange device 4.

[0059] [Fig. 6] illustrates a second exemplary embodiment of the heat exchange device 4 in which said device is open on one side, said side being configured to face the flank 51 of the electrical machine 3 carrying it. Such a principle makes it possible to minimize the thickness in a manner separating the first fluid F1 from the second fluid F2. For example, when the heat exchange device 4 is inscribed in a cylindrical shape, it then has a “U” or substantially “U” shaped profile. In other words, the heat exchange device 4 uses the principle described previously with reference to the first exemplary embodiment and to [Fig. 5], with the difference that it is devoid of the second wall 41b and that the end wall 41c or the end walls 41c are directly arranged in contact with the flank 51. In such an example, the end wall 41c, or the end walls 41c, form(s) the branches of the “U” while the first wall 41a forms the base of the “U”.The heat exchange device 4 is then mounted in a sealed manner on the side of the casing 5 so that an outer surface of the side 51 of the casing 5 carrying the heat exchange device 4 and said device delimit the intermediate compartment 40. The at least one open side then simultaneously forms the primary opening 43 and the secondary opening 44 described above so as to allow the fluid connection with the channel. discharge 63 on the one hand and the supply orifice 61 of the second fluid F2 on the other hand. The preceding description applies mutatis mutandis to the present embodiment.

[0060] Regardless of the exemplary embodiment implemented, the heat exchange device 4 further optionally comprises at least one guide wall 45. The at least one guide wall 45 is arranged in the intermediate compartment 40 and extends transversely, or even orthogonally, to the first wall 41a and / or to the second wall 41b. It aims to define a circulation path for the second fluid F2 in the intermediate compartment 40, over a portion of the distance separating the discharge channel 63 from the supply orifice 61. The at least one guide wall 45 advantageously makes it possible to optimize the heat exchange implemented by defining a longer circulation path during which the heat exchange with the first fluid F1 can be carried out.In particular, as illustrated in Figures 4 or 8 with dotted arrows, the guide wall 45 is shaped and arranged so that the circulation path of the second fluid F2 is at least partly in a spiral shape. Preferably again, said spiral is oriented so as to minimize the pressure losses at the outlet of the at least one discharge channel 63, that is to say that it extends in the continuity of the direction of circulation of the second fluid F2 leaving said channel.

[0061] Optionally again, independently of the embodiment of the heat exchange device 4 implemented, the latter may comprise at least one regulating member 46 for regulating the pressure passively within the intermediate compartment 40. The regulating member 46 is arranged at the level of at least one of the walls 41 facing the external environment, for example the first wall 41a or the at least one end wall 41c. According to a non-limiting embodiment, the regulating member 46 is a membrane configured to allow the exit of an air flow from the intermediate compartment 40 to the external environment but preventing the entry of a reverse air flow moving from the external environment to the intermediate compartment 40. In particular, said membrane is a “Nitto” membrane.

[0062] Optionally, according to an example not shown, when the second fluid F2 is drawn from an air flow outside the vehicle 1 entering at the front of the vehicle 1, as described above, so as to form a second open circuit C2, at least one of the walls of the heat exchange device 4 comprises an inlet opening for the second fluid F2. For example, the first wall 41a, distant from the side 51 carrying said device, comprises the inlet opening. Optionally, such an opening comprises a filter or a membrane allowing the entry of a portion of the outside air flow.

[0063] Figures 7 to 11 illustrate a second embodiment of the electrical machine assembly 2 according to the invention comprising a plurality of axial flux electrical machines 3. It is understood that the above description applies mutatis mutandis to the present embodiment. The at least one electrical machine 3 as presented above is referred to below as “first electrical machine 3a” and the assembly 2 further comprises a second electrical machine 3b, distinct from the first electrical machine 3a. The plurality of electrical machines 3 is arranged on either side of the heat exchange device 4 so that the latter is interposed between the first electrical machine 3a and the second electrical machine 3b along the first direction 100.It is understood that the invention can also extend to an assembly 2 of electrical machines comprising more than two axial flux electrical machines 3 and / or a plurality of heat exchange devices 4 arranged so as to be interposed between two adjacent electrical machines 3. For example, according to an embodiment not shown, a first heat exchange device 4 can be interposed between the first electrical machine 3a and the second electrical machine 3b while a second heat exchange device 4 has an extreme position, along the first direction 100, as described above.

[0064] It is understood that each of the axial flux electrical machines 3 of the plurality of electrical machines 3 is similar to the electrical machine described above and comprises a casing 5 which is specific to it, comprising a plurality of flanks 51 delimiting an internal volume 50, a rotor 32 comprising a hollow shaft 33 extending along the first direction 100, a stator 31 and at least one sealing membrane 36. In the example illustrated, in a non-limiting manner, the first electrical machine 3a and the second electrical machine 3b are the image of each other by axial symmetry produced along an axis perpendicular to the first direction and passing through the heat exchange device 4. Also the heat exchange device is here arranged in contact with the first flank 51a of said machines.

[0065] Particularly, in figures 7 to 11, the first electric machine 3a and the second electric machine 3b respectively comprise a first casing 5a and a second casing 5b, each delimiting an internal volume 50 which is specific to them, referred to as the first internal volume 50a and the second internal volume 50b. Also, each of said machines comprises at least one supply orifice 61, at least one intermediate channel 62 and at least one discharge channel 63 for the second fluid F2 as described previously. The fixing of the heat exchange device 4 is carried out similarly to what has been explained above, by means of screws, so as to fix it to the first electric machine 3a and to the second electric machine 3b.

[0066] Figures 7 to 12 illustrate different examples of the implementation of devices of heat exchange device 4 which can be implemented in an assembly 2 of electric machines comprising a plurality of electric machines 3. Such heat exchange devices 4 take up the principles set out above with reference to figures 2 to 6.

[0067] Preferably, the heat exchange device 4 is here made of a metallic material in order to have greater structural resistance.

[0068] According to a first exemplary embodiment, not shown, the heat exchange device 4 as shown in [Fig. 5] can be adapted by simply adding at least one primary opening 43 and one secondary opening 44 in the first wall 41a. The first wall 41a, facing one of the sides 51 of the first electrical machine 3a, then makes it possible to ensure the fluid connection with the first internal volume 50a while the second wall 41b, facing one of the sides 51 of the second electrical machine 3b, for example its first side 51a, makes it possible to ensure the fluid connection with the second internal volume 50b.

[0069] In such an example, the discharge channel 63 specific to each electrical machine 3 opens into the side 51 of the casing 5 considered carrying the heat exchange device 4. The primary opening 43 of the first wall 41a is then arranged opposite the discharge channel 63 of the first electrical machine 3a while the primary opening 43 of the second wall 41b is arranged opposite the discharge channel 63 of the second electrical machine 3b.

[0070] Alternatively, as illustrated in Figures 8 to 10, the heat exchange device 4 comprises a single primary opening 43, arranged in the at least one end wall 41c. The discharge channel 63 of each of the electrical machines 3 is then adapted to open into one of the sides 51 of the casing 5 considered adjacent to the side 51 carrying the heat exchange device 4.

[0071] The electrical machine assembly 2 then further comprises a hollow connection member 7, configured to provide a fluid connection between the first internal volume 50a and the second internal volume 50b on the one hand, and the intermediate compartment 40 of the heat exchange device 4 on the other hand. For example, as illustrated in [Fig. 10] or 11, the connection member 7 has a “Y” or “V” shape comprising two hollow branches and a hollow base, connected together and in fluid connection with each other. Within the electrical machine assembly 2, the connection member 7 is mounted on the at least one intermediate flank 51c of each of the electrical machines 3 and on the heat exchange device 4, by screwing or clipping for example.Thus the branches are each arranged at the level of the evacuation channel 63 of one of the electrical machines 3 while the hollow base is mounted at the level of the primary opening 43 of the heat exchange device 4. Optionally, the branches and / or the base of the connection member 7 are curved. In particular, the connection member 7 is made of a plastic material, for example by injection.

[0072] Independently of the exemplary embodiment implemented in the assembly 2 comprising a plurality of electrical machines 3, the heat exchange device 4 optionally comprises an intermediate wall 47 extending into the intermediate compartment 40. The intermediate wall 47 may extend over all or part of a surface of the intermediate compartment 40 and separates the latter into two distinct sub-compartments, separate or in fluid connection with each other.

[0073] Such an intermediate wall 47 may in particular have the function of maintaining F at least one guide wall 45 when the heat exchange device 4 is equipped with it. The heat exchange device 4 may then comprise a single guide wall 45 or a plurality of guide walls 45 forming an identical circulation path in each sub-compartment delimited by the intermediate wall 47. In other words, the at least one guide wall 45 then extends over the entire dimension of the intermediate compartment 40 defined along the first direction 100. Alternatively, the heat exchange device 4 comprises a plurality of guide walls 45, at least one guide wall 45 being arranged in each of the sub-compartments so as to form two circulation paths of similar or distinct shapes.For example, preferably, said guide walls 45 form two separate spirals, each arranged in one of the sub-compartments, said spirals being oriented so as to reduce the pressure losses as a function of the circulation of the second fluid F2 and / or the shape of the connection member 7. The spirals formed by the guide walls 45 on each side of the intermediate wall 47 can then have opposite orientations.

[0074] According to a second exemplary embodiment, illustrated in [Fig.8] or 12 and repeating the principle of the example previously described with reference to [Fig.6], the heat exchange device 4 is open on at least one side, the at least one side being configured to be turned towards the flank 51 of one of the first electrical machine 3a or the second electrical machine 3b carrying it. Such a principle makes it possible to optimize the heat exchange between the first fluid F1 and the second fluid F2 by minimizing a thickness separating them. In particular, as illustrated in [Fig.12], the heat exchange device 4 is open on two opposite sides along the first direction 100.

[0075] In the illustrated example, the at least one end wall 41c defines a contour of the heat exchange device 4. The intermediate wall 47 extends over all or part of the surface of the intermediate compartment 40, delimited by the at least one end wall 41c, and carries the at least one guide wall 45. Similar to what has been explained above, the heat exchange device 4 comprises one or more guide wall(s) delimiting one or more guide path(s) for the second fluid F2. Optionally, the end wall 41c comprises at least one regulating member 46 as described above.

[0076] Optionally, the heat exchange device 4 comprises at least one central opening 48 configured to allow the passage of at least one of the rotor shafts 33 of the rotor 32 of the electrical machine assembly 2. For example, according to the various embodiments set out below, the first wall 41a, the second wall 41b and / or the intermediate wall 47 comprises a central opening 48. When the heat exchange device 4 comprises a plurality of central openings 48, these are aligned and centered on the same axis, for example on the rotation axis 300 of at least one of the shafts 33s of the assembly 2.

[0077] According to an exemplary embodiment not shown, the assembly 2 comprises a rotor shaft 33 32 common to the first electric machine 3a and to the second electric machine 3b or the first electric machine 3a and the second electric machine 3b comprise separate rotor shafts 33 32 connected to each other so as to be moved concomitantly.

[0078] Alternatively and preferably, the first electrical machine 3a and the second electrical machine 3b comprise separate rotor 32 shafts 33, moved independently of each other or not and connected by known means. In such an alternative, as illustrated in [Fig.7], the heat exchange device 4 can then be devoid of the central opening 48.

[0079] The invention thus proposes an electric machine assembly comprising at least one electric machine and a heat exchange device allowing the thermal management of the different parts of said electric machine and integrating the implementation of a heat exchange between two separate fluids at the level of a casing of said machine. The proposed solution is advantageously compact, lightweight, simple to implement and inexpensive. It eliminates the need to integrate a plurality of heat exchangers on the front of the vehicle or to integrate a pump. Furthermore, the invention can be extended to a wide range of axial flux electric motors.

[0080] The present invention cannot, however, be limited to the means and configurations described and illustrated here and it also extends to any equivalent means or configuration and to any technically operative combination of such means insofar as they ultimately fulfill the functionalities described and illustrated in the present document.

Claims

Claims

1. Electrical machine assembly (2) for a motor vehicle (1), comprising: - at least one axial flux electrical machine (3) comprising a casing (5) having a plurality of flanks (51) delimiting an internal volume (50), a rotor (32) comprising a hollow shaft (33) extending along a first direction (100) through at least a portion of the casing (5), a stator (31) and a sealing membrane (36) fixed in the casing (5) and / or to the stator (31) so as to delimit at least one primary compartment (37) comprising all or part of the stator (31) and capable of allowing the circulation of a first fluid (F1) and at least one secondary compartment (38) in which the shaft (33) extends and capable of allowing the circulation of a second fluid (F2); and - a heat exchange device (4) comprising a plurality of walls (41) delimiting at least in part an intermediate compartment (40) capable of allowing the circulation of the second fluid (F2), said device being arranged in contact with the casing (5), outside the internal volume (50), so as to allow a heat exchange between the first fluid (F1) circulating in the primary compartment (37) and the second fluid (F2) circulating in the intermediate compartment (40), said device being in fluid connection with the secondary compartment (38).

2. Assembly (2) according to the preceding claim, further comprising a primary channel, arranged in one of the flanks (51) of the casing (5) and in fluid connection with the secondary compartment (38), a supply orifice (61) arranged in the shaft (33) so as to allow the circulation of the second fluid (F2) in the hollow of the shaft (33), and at least one intermediate channel (62) forming a fluid connection between the hollow of the shaft (33) and the secondary compartment (38), the heat exchange device (4) being in fluid connection with the secondary compartment (38) via the primary channel and in fluid connection with the hollow of the rotor shaft (33) (32) via the supply orifice (61).

3. Assembly (2) according to one of the preceding claims, in which: - the heat exchange device (4) is made of a metallic material, such as steel, cast iron, aluminum or an aluminum alloy, or of a plastic material; and / or - the heat exchange device (4) is attached and fixed to the casing (5) by means of at least one fixing means (42), such as a screw.

4. Assembly (2) according to one of the preceding claims, in which: - the plurality of walls (41) of the heat exchange device (4) comprises a first wall (41a), a second wall (41b), opposite the first wall (41a) along the first direction (100), and at least one end wall (41c) connecting the first wall (41a) and the second wall (41b) together, the second wall (41b) being arranged in contact with the casing (5) delimiting the secondary compartment (38), the device further comprising at least one primary opening (43) and one secondary opening (44), arranged in the second wall (41b) and in fluid connection, direct or indirect, with the secondary compartment (38); or - the heat exchange device (4) is open on one side, facing the casing (5), and is mounted in a sealed manner on said casing (5).

5. Assembly (2) according to one of the preceding claims in which the plurality of walls (41) of the heat exchange device (4) comprises a guide wall (45) delimiting, in the intermediate compartment (40), a circulation path for the second fluid (F2) at least partly inscribed in a spiral shape.

6. Assembly (2) according to one of the preceding claims, comprising a plurality of axial flux electrical machines (3), at least one electrical machine (3), hereinafter referred to as the first electrical machine (3 a), and a second electrical machine (3b) of the plurality of electrical machines (3) being arranged on either side of the heat exchange device (4) so ​​that the latter is interposed between the first electrical machine (3 a) and the second electrical machine (3b) along the first direction (100).

7. Assembly (2) according to the preceding claim, in which the first electrical machine (3a) and the second electrical machine (3b) each comprise a casing (5), called first casing (5a) and second casing (5b), delimiting an internal volume (50) which is specific to them, called first internal volume (50a) and second internal volume (50b), the assembly (2) further comprising a hollow connection member (7), configured to ensure a fluidic connection between the first internal volume (50a) and the second internal volume (50b) on the one hand, and the intermediate compartment (40) of the device heat exchange (4) on the other hand.

8. An assembly (2) according to claim 6 or 7, wherein the first electrical machine (3a) and the second electrical machine (3b) comprise a rotor shaft (33) common to said electrical machines (3) or wherein the first electrical machine (3a) and the second electrical machine (3b) comprise rotor shafts (33) (32) separate connected together so as to be moved concomitantly, the heat exchange device (4) comprising at least one central opening (48) configured to allow the passage of the shaft (33) of rotor (32) or at least part of the shafts (33) of rotor (32) separate.

9. Heat exchange device (4) for an electrical machine assembly (2) according to one of the preceding claims, said device comprising a plurality of walls (41) delimiting at least in part an intermediate compartment (40) capable of allowing the circulation of a fluid, said device being configured to be fixed at the level of at least one side of a casing (5) of an electrical machine (3) so as to allow a heat exchange with a separate fluid circulating in said casing (5).

10. Vehicle (1) with electric or hybrid motorization comprising an assembly (2) of electric machine according to one of claims 1 to 8 and / or a heat exchange device (4) according to claim 9.

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