Stator assembly for an axial flux electric machine, in particular for a motor vehicle, and axial flux electric machine comprising such a stator assembly

Abstract

A stator assembly (3) for an axial flux electric machine (2) comprising a primary compartment (33) and a secondary compartment (34), these being in fluid connection and configured to allow the circulation of a cooling fluid (FR), a plate (5), interposed between said compartments and comprising a plurality of orifices able to allow the circulation of the cooling fluid (FR) and the passage of coils between said compartments, and an interconnection ring (8) arranged in the primary compartment (33) so as to be immersed in the cooling fluid (FR).

Description

Description Title of the invention: Stator assembly for an axial flux electric machine, in particular for a motor vehicle, and axial flux electric machine comprising such a stator assembly

[0001] The invention relates to a stator assembly for an axial flux electric machine, in particular for a motor vehicle. The invention also relates to an axial flux electric machine comprising such a stator assembly. The invention also relates to an electric or hybrid motor vehicle equipped with the stator assembly and / or the electric machine. The invention finally relates to a method for assembling the stator assembly.

[0002] Vehicles with electric or hybrid motors typically comprise at least one electric traction and / or propulsion machine, also referred to as an electric motor, for moving the vehicle. The electric machine comprises, in a known manner, a rotor comprising a steel shaft and a composite star holding at least one rotating magnet in position near a stator. The implementation of high power, particularly greater than 100 kW, involves the use of high-intensity currents and the movement of the rotor at a high rotational speed. As a result, 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.Furthermore, it is essential to implement homogeneous cooling of the stator coils and of the various pads, or teeth, carrying said coils in order to optimize the operation of the electrical machine.

[0003] In axial flux electrical machines, it is known to cool the stator by means of a cooling fluid, in particular an oil, circulating in contact with the stator coils. However, in order to limit the energy losses linked to the rotor splashing in the oil, the latter is conventionally isolated from a cooling fluid 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. Also, the electrical connectors, in particular the interconnection terminal blocks or interconnection bars participating in the electric current supply to the stator, are conventionally arranged outside a volume of the stator so as to be separated from the oil circuit, making the sealing of the zone comprising them complex in terms of implementation and assembly.

[0004] The present invention falls within this context and aims to provide an alternative to known axial flux electric machines allowing the implementation of cooling- optimized thermal distribution of the stator elements, in particular which is homogeneous between the different coils distributed in the stator. The invention also aims to simplify the assembly of said stator and the electrical machine comprising it.

[0005] The invention relates to a stator assembly for an axial flux electrical machine comprising a primary compartment and a secondary compartment, in fluid connection and configured to allow the circulation of a cooling fluid, and a tertiary compartment, separate from the primary compartment and the secondary compartment and configured to receive a rotor.

[0006] The stator assembly further includes: - coils, pads carrying said coils and a support plate for said pads, interposed between the primary compartment and the secondary compartment and comprising a plurality of primary orifices and secondary orifices capable of allowing the circulation of the cooling fluid, the coils extending through the primary orifices; - an interconnection ring arranged in the primary compartment so as to be immersed in the cooling fluid and connected to the coils; - a box connected to the tray and delimiting the primary compartment and the tertiary compartment; - a separation element, comprising walls and a membrane, connected to the tray and separating the secondary compartment from the tertiary compartment.

[0007] In particular, the plate, the housing and the separating element each comprise an opening, for example centered on the same direction, capable of receiving at least part of the rotor.

[0008] In particular, the stator assembly is intended for an axial flux electric machine for a motor vehicle.

[0009] Optionally, the primary compartment comprises a supply gallery, in fluid connection with the secondary compartment via the primary orifices, and an evacuation gallery, separate from the supply gallery and in fluid connection with the secondary compartment via the secondary orifices.

[0010] Notably : - the evacuation gallery is inscribed in a defined shape, in particular circular or annular, and has a variation of at least one dimension along said shape so as to allow the variation of a flow rate of the cooling fluid along said gallery; and / or - the feed gallery is inscribed in a defined shape, in particular circular or annular, and has a variation of at least one dimension along said shape so as to allow the variation of a flow rate of the cooling fluid along said gallery.

[0011] Optionally, the different primary orifices have sections of variable dimensions so as to allow the variation of a flow rate of the cooling fluid through the different primary orifices and / or the different secondary orifices have sections of variable dimensions so as to allow the variation of a flow rate of the cooling fluid through the different secondary orifices.

[0012] Optionally, the stator assembly further comprises a protective member extending through the plurality of primary orifices so as to be interposed between the coils and edges of said orifices.

[0013] According to examples of realization: - the tray is attached and fixed to the housing by means of at least one fixing means, such as a screw; and / or - the separating element is attached and fixed to the plate and / or the housing by means of at least one fixing means, such as a screw.

[0014] Optionally, the stator assembly further comprises a cooling fluid supply pipe and a pipe for discharging said fluid, arranged in fluid connection with at least a portion of the primary compartment, and an electrical connection pipe, comprising at least one cable, the connection pipe and the supply pipe being at least partly common so that a portion of the at least one cable is configured to be immersed in the cooling fluid.

[0015] The invention also relates to an axial flux electric machine, in particular for a motor vehicle, comprising a stator assembly according to the invention and a rotor.

[0016] Optionally, the axial flux electric machine comprises a plurality of primary compartments, secondary compartments, trays, separating elements and interconnecting rings.

[0017] The invention also relates to an electric or hybrid motorized vehicle comprising a stator assembly and / or an electric machine according to the invention.

[0018] The invention finally relates to a method of assembling an electrical machine according to the invention, comprising: - the positioning of the interconnection ring on the board; - positioning the coils so as to connect them to the interconnection ring and wind them around a pad carried by the plate by passing through one of the primary orifices of the plate; - positioning and fixing the separating element on the tray so as to arrange the pads and coils in the second compartment; - the positioning and fixing of the assembly formed by the plate and the fixing element in the housing.

[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. 1] is a schematic representation of an embodiment of a vehicle equipped with an electric machine according to the invention.

[0021] [Fig.2] is a schematic sectional representation of an exemplary embodiment of a stator assembly for an electrical machine.

[0022] [Fig.3] is a schematic cross-sectional representation of a plate of the stator assembly carrying studs.

[0023] [Fig.4] is a schematic cross-sectional representation of the stator assembly plate carrying an interconnecting ring.

[0024] [Fig.5] is a schematic cross-sectional representation of the stator assembly plate carrying studs and coils.

[0025] [Fig.6] is a schematic cross-sectional representation of the assembled stator assembly and coolant galleries thereof.

[0026] [Fig.7] is a top view schematic representation of the stator assembly and a flow of cooling fluid circulating therein.

[0027] [Fig.8] is a schematic sectional representation of the electric machine.

[0028] [Fig.l] schematically illustrates an exemplary embodiment of a motor vehicle 1 according to the invention. The vehicle 1 is a vehicle 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.

[0029] The vehicle 1 is equipped with an axial flux electric machine 2 according to the invention, also referred to as a traction and / or propulsion electric motor, comprising a stator assembly 3 comprising a plurality of pads 31, or teeth, on which coils 32 are wound. The electric machine 2 also comprises a rotor 4, movable relative to the stator assembly 3.

[0030] In a known manner, the rotor 4 comprises a shaft 41 extending through at least a portion of the stator assembly 3 along a first direction 100 and configured to be movable in rotation about an axis of rotation 500 parallel to the first direction 100. The term “axial flux electrical machine” thus means that the direction of the magnetic flux generated within said machine is aligned parallel to the axis of rotation 500. The rotor 4 also comprises a star 42, in particular made of composite material, connected to the shaft 41 and carrying a plurality of magnets 43. The different magnets 43 are in particular arranged in blocks so as to fit into a shape of disc, or substantially disc, intended to move in rotation concomitantly with the shaft 41. The magnets 43 are arranged so as to extend opposite the pads 31 and the coils 32 of the stator assembly 3, as further explained below, at a distance from them. The space separating the rotor 4 from the pads 31 and coils 32 is called an air gap.

[0031] The stator assembly 3 according to the invention generally comprises at least one plate 5 for supporting the coils 32 and pads 31 exposed above, a housing 6 and at least one separating element 7.

[0032] Additionally, the stator assembly 3 according to the invention comprises at least one primary compartment 33 and at least one secondary compartment 34, in fluid connection with each other and configured to allow the circulation of a cooling fluid FR. The cooling fluid FR is configured to ensure the heat treatment, in particular the cooling, of the stator assembly 3, in particular the coils 32 and pads 31 carrying them. In particular, the cooling fluid FR is an oil.

[0033] The stator assembly 3 also comprises a tertiary compartment 35, separated from the primary compartment 33 and the secondary compartment 34 and configured to receive the rotor 4. By “separated” is meant that the tertiary compartment 35 does not allow the circulation of the cooling fluid FR and is not in fluid connection with the primary compartment 33 or the secondary compartment 34. In this way, the cooling fluid FR does not circulate in contact with the rotor 4.

[0034] The plate 5 is a plate that is at least partly flat or substantially flat. The plate 5 has in particular a circular, or substantially circular, shape and comprises a central primary opening 51, configured to receive the shaft 41 of said rotor 4 when the electrical machine 2 is assembled. In particular, the primary opening 51 is centered on a central axis of the stator assembly 3 and configured to be centered on the axis of rotation 500 of the rotor 4. In particular, the plate 5 is made of a metallic material, such as steel or aluminum.

[0035] The plate 5 is arranged so as to be interposed between the primary compartment 33 and the secondary compartment 34 and thus helps to delimit the primary compartment 33 and the secondary compartment 34. In this case, a first face 50a of the plate 5 is turned towards the primary compartment 33 while a second face 50b of the plate 5, opposite the first face 50a, is turned towards the secondary compartment 34.

[0036] The plate 5 carries the plurality of pads 31. In a known manner, not detailed, said pads 31 are arranged to fit into a crown shape surrounding the primary opening 51 so as to form a stator element. Said pads 31 are wound or stacked metal elements arranged and fixed on the second face 50b of plate 5, for example by gluing.

[0037] The housing 6, or casing, is an external structural envelope of the electrical machine 2 and of at least a portion of the stator assembly 3. In particular, the housing 6 is made of a metallic material, comprising for example steel and / or aluminum. The housing 6 delimits an internal volume of the electrical machine 2, in which the primary compartment 33, the secondary compartment 34 and the tertiary compartment 35 are included on the one hand, and in which at least a portion of the rotor 4 extends on the other hand. In particular, the housing 6 directly participates in delimiting the primary compartment 33 and the tertiary compartment 35.

[0038] According to a non-limiting exemplary embodiment, the housing 6 comprises a plurality of flanks which are, for example, at least partly inscribed in a cylindrical or substantially cylindrical shape with a circular base. In this case, the housing 6 comprises a first flank 6a and a second flank 6b, delimiting the housing 6 along the first direction 100. Also, the housing 6 comprises at least one intermediate flank 6c, connecting the first flank 6a to the second flank 6b. Optionally but preferably, the housing 6 comprises two half-housings 6e configured to be assembled so as to form the housing 6. The housing 6 also comprises secondary openings, configured to allow the shaft 41 of the rotor 4 to pass through the stator assembly 3.In particular, the first flank 6a and the second flank 6b each comprise a central secondary opening 6d, centered on the central axis or the axis of rotation 500 of the shaft 41 and extending opposite the primary opening 51 of the plate 5 when the stator assembly 3 is assembled.

[0039] Also, the stator assembly 3, and in particular the housing 6, comprises at least one electrical connection conduit 61 configured to receive electrical connection cables 61a capable of supplying the electrical machine 2 with electrical energy, in particular the coils 32.

[0040] Additionally, the stator assembly 3, and in particular the housing 6, comprises at least one supply line 62 and / or one discharge line 63 for cooling fluid FR, respectively configured to bring the cooling fluid FR into the electrical machine 2 and to discharge the cooling fluid FR from said electrical machine 2. The supply line 62 and the discharge line 63 are thus connected to a circuit 60 for cooling fluid FR, not detailed, conventionally comprising at least one heat exchanger, capable of regulating a temperature of the cooling fluid FR, and a pump, capable of regulating an overall flow rate of the cooling fluid FR. In particular, the supply line 62 and the electrical connection line 61 are adjacent or coincident. Preferably, the connection line 61 and the supply line 63 are at least partly common so that a portion of the cables 61a is configured to bathe in the cooling fluid FR, thus allowing their cooling. Also, in order to limit the space generated, the discharge pipe 63 is close to the supply pipe 62.

[0041] When the stator assembly 3 is assembled, the plate 5 is connected to the housing 6 so that the primary compartment 33 is then included between the housing 6, in particular here the first side 6a and / or one of the half-housings 6e, and the first face 50a of the plate 5. The plate 5 is thus a removable part added relative to the housing 6. Optionally but preferably, the plate 5 is fixed reversibly by means of at least one fixing means 64, such as a screw or a screw-nut assembly.

[0042] The plate 5 comprises a plurality of primary orifices 52 and a plurality of secondary orifices 53 capable of allowing the circulation of the cooling fluid FR. Said orifices 52, 53 are through and extend in the thickness of the plate, between the first face 50a and the second face 50b. In particular, as illustrated in [Fig.6] or 7, the primary orifices 52 are configured to allow the entry of the cooling fluid FR into the secondary compartment 34, i.e. the circulation of the cooling fluid FR from the primary compartment 33 to the secondary compartment 34, while the secondary orifices 53 allow the exit of the cooling fluid FR present in the secondary compartment 34, i.e. the circulation of the cooling fluid FR from the secondary compartment 34 to the primary compartment 33. The primary orifices 52 and the secondary orifices 53 preferably have a circular shape.

[0043] Also, the primary orifices 52 are configured to allow the passage of the coil wires 32. Thus, when the stator assembly 3 is assembled, the coils 32 are arranged so as to each extend through at least one of the primary orifices 52. The cooling fluid FR and the electric current supplying the coils 32 thus circulate simultaneously at the primary orifices 52 when the electrical machine 2 is in operation.

[0044] The primary orifices 52 are arranged in the plate 5 so as to fit into a circular, or annular shape, here a first circle. In particular, such a circle is centered on the central axis and / or the axis of rotation 500 of the rotor 4. Similarly, the secondary orifices 53 are arranged in the plate 5 so as to fit into a circular, or annular shape, here forming a second circle. In particular, such a circle is centered on the central axis and / or the axis of rotation 500 of the rotor 4. Preferably, the primary orifices 52 have a greater proximity to the primary opening 51 than the secondary orifices 53.

[0045] Preferably, the primary compartment 33 comprises a supply gallery 33a for cooling fluid FR and a discharge gallery 33b for the cooling fluid FR. The supply gallery 33a is configured to bring the cooling fluid FR to the secondary compartment 34 while the discharge gallery 33b allows the cooling fluid FR to be discharged from the secondary compartment 34. Preferably, the supply gallery 33a and the discharge gallery 33b are not directly in fluid connection within the primary compartment 33. The secondary compartment 34 is thus interposed between the supply gallery 33a and the discharge gallery 33b of the primary compartment 33 according to the direction of circulation of the cooling fluid FR so that the cooling fluid FR circulates successively through the supply gallery 33a, the secondary compartment 34 so as to be in contact with the coils 32 and the pads 31, then through the discharge gallery 33b.

[0046] As partially illustrated in [Fig. 6], in which the feed gallery 33a and the discharge gallery 33b are shown outside the stator assembly 3 for clarity, or in [Fig. 7], the feed gallery 33a has an annular shape, centered on the central axis and / or the rotation axis 500, and is arranged opposite the primary orifices 52, here forming the first circle. In this way, the primary orifices 52 open into the feed gallery 33a and extend through the plate 5 between the feed gallery 33a and the secondary compartment 34. Similarly, the discharge gallery 33b has an annular shape, centered on the central axis and / or the rotation axis 500, and is arranged opposite the secondary orifices 53, here forming the second circle. The secondary orifices 53 thus open into the evacuation gallery 33b and extend through the plate 5 between the evacuation gallery 33b and the secondary compartment 34.Also, in the example illustrated, preferably, the supply gallery 33a has greater proximity to the primary opening 51 than the evacuation gallery 33b.

[0047] Optionally, the feed gallery 33a is hollowed out in the housing 6, in particular in one of the sides of said housing 6 such as the first side 6a and / or the second side 6b, and / or the feed gallery 33a is hollowed out in the plate 5, in particular at the level of the first face 50a. [Fig. 8] illustrates an exemplary embodiment in which half galleries are formed in the plate 5 and the housing 6, said galleries being configured to extend opposite one another when the stator assembly is assembled in order to form the feed gallery 33a. A similar principle applies mutatis mutandis to the discharge gallery 33b.

[0048] Also, optionally, the supply line 62 opens at the supply gallery 33a so that the supply line 62 and the supply gallery 33a are arranged in fluid connection and the cooling fluid FR supplied by the supply line 62 circulates in said gallery in order to be distributed to the different primary orifices 52. Likewise, option- ally, the discharge pipe 63 opens at the discharge gallery 33b so that these are arranged in fluid connection and the cooling fluid FR leaving the discharge gallery 33b via the secondary orifices 53 is then sent to the discharge pipe 63.

[0049] The stator assembly 3 further comprises an interconnection ring 8, i.e. a conductive element having the function of a connector, for example comprising copper or aluminum, of at least partly annular shape capable of conducting an electric current. Alternatively, such a conductive element has the shape of a curved interconnection bar forming an arc of a circle and / or the stator assembly 3 comprises a plurality of said arcs.

[0050] The interconnection ring 8 is arranged in the primary compartment 33 so as to bathe in the cooling fluid FR when it circulates in the stator assembly 3. In particular, at least a portion receiving electrical connection cables 61a is also bathed in the cooling fluid, at the level of the primary compartment 33. In this way, the stator assembly 3 advantageously makes it possible to optimize the thermal management of the stator assembly 3 and to reduce power losses by Joule effect compared to stators of the prior art by ensuring the cooling of the interconnection ring 8 and a portion of the electrical connectors. Such a principle makes it possible to use larger electrical currents within the electrical machine 2, making it capable of providing more power without causing degradation of its components.

[0051] In particular, the interconnection ring 8 is arranged at the level of the first face 50a of the plate 5, for example in contact with the latter and / or so as to be fixed to the latter. Preferably, the interconnection ring 8 is glued to the first face 50a of the plate 5. Also, the interconnection ring 8 is arranged close to the primary orifices 52 and / or the primary opening 51. The interconnection ring 8 thus surrounds the primary opening 51. In particular, the interconnection ring 8 extends opposite all or part of the primary orifices 52.

[0052] Thus, the wires of the different coils 32 are connected to the interconnection ring 8, pass through the different primary orifices 52 and are then wound around the pads 31 of the stator element. The electrical connection conduit 61 is arranged close to the interconnection ring 8 so as to allow the electrical supply of the wires of the coils 32 via the cables 61a and the interconnection ring 8.

[0053] The separating element 7 is arranged on the plate 5, in particular the second face 50b of the plate 5, and is configured to delimit the secondary compartment 34 and separate the secondary compartment 34 from the tertiary compartment 35.

[0054] The separating element 7 comprises a plurality of walls 71 and at least one membrane 72 connected to said walls 71. For example, said walls 71 are made of a metallic material, such as steel and / or aluminum. The separating element 7 is in particular in an annular, or substantially annular, shape, surrounding a tertiary opening 73 capable of receiving the shaft 41 of the rotor 4. When the stator assembly 3 is assembled, the tertiary opening 73 extends at least partly opposite the primary opening 51 of the plate 5.

[0055] Generally, the separating element 7 comprises at least one internal wall 71a, having a proximal position relative to the central axis and the axis of rotation 500 of the rotor 4 when the electrical machine 2 is assembled, and at least one external wall 71b, having a distal position relative to this same axis. The at least one internal wall 71a thus delimits an internal periphery of the annular shape and delimits the tertiary opening 73 of the separating element 7. The at least one internal wall 71a thus fits into a first circular, or substantially circular, shape. The at least one external wall 71b delimits an external periphery of the annular shape and fits into a second circular shape.

[0056] The separating element 7 comprises an open side, facing the plate 5 when the stator assembly 3 is assembled. The membrane 72 is arranged at a side opposite the open side, distant from the plate 5. Said membrane 72 extends between the at least one internal wall 71a and the at least one external wall 71b so as to connect them together. In this way, when the electrical machine 2 is assembled, the membrane 72 extends opposite the pads 31 and the coils 32 of the stator element included in the secondary compartment 34 on the one hand, and opposite at least one magnet of the rotor 4 arranged in the tertiary compartment 35 on the other hand.

[0057] The separating element 7 thus forms a sealed separation between the secondary compartment 34 and the tertiary compartment 35. Thus, the separating element 7 and the plate 5 delimit the secondary compartment 34, comprising the pads 31 and coils 32 and capable of allowing the circulation of the cooling fluid FR so as to allow the thermal management of said pads 31 and coils 32. The tertiary compartment 35, capable of housing the rotor 4, in particular at least a portion of the shaft 41, the star 42 and the various magnets 43, is fluidically separated from the secondary compartment 34. Optionally, the tertiary compartment 35 is capable of receiving a second fluid, distinct from the cooling fluid FR, such as an air flow, capable of ensuring the thermal management of the rotor 4.The tertiary compartment 35 then optionally allows the circulation of the second fluid separately from the cooling fluid FR, i.e. without mixing or contact between the cooling fluid FR and the second fluid.

[0058] The separating element 7 is attached and fixed to the plate 5 and / or the housing 6. In particular, the fixing carried out is reversible and implemented by means of at least one at least one fastening means 64, such as a screw or a screw-nut assembly.

[0059] Optionally but preferably, the stator assembly 3 further comprises a protective member 9 extending through the plurality of primary orifices 52 so as to be interposed between the wires of the coils 32 and the edges of said orifices. Generally, the protective member 9 is an added part, made of an electrically insulating material, in particular a plastic material, comprising a plurality of hollow cannulas 91 configured to be inserted into the different primary orifices 52 and to receive the wires of the different coils 32 while allowing the circulation of the cooling fluid FR. Thus, the protective member 9 is interposed between the wires of the coils 32, supplied with electric current, and the plate 5 so as to prevent direct contact between them, or too close proximity, and to prevent breakdown phenomena. The protective member 9 thus has a plurality of functions.It provides, on the one hand, the insulating function, and, on the other hand, the guiding function of the wires of the coils 32.

[0060] Figures 2 to 8 illustrate different alternatives for producing the protection member 9.

[0061] According to a first exemplary embodiment, illustrated in Figures 2 to 6, the protection member 9 comprises a base 92 carrying the different cannulas 91. Said base 92 is, for example, an annular part arranged at the level of the second face 50b of the plate 5, the cannulas 91 extending transversely to said base 92. Each cannula 91 then comprises a first segment, configured to extend through one of the primary orifices 52, towards the primary compartment 33, and a second segment, extending into the secondary compartment 34. Here, the term "segment" is understood to mean a portion of a whole. The first segment and the second segment of each cannula 91 then extend on either side of the base 92, they are connected and extend in continuity with each other, forming a channel allowing the passage of the cooling fluid FR and the coil wires 32 from the primary compartment 33 to the secondary compartment 34.

[0062] Optionally, a free end of the cannulas 91, in particular of the second segments of the cannulas 91, comprises an inclined edge 93 so as to limit the wear generated on the wires of the coils 32.

[0063] According to an alternative not shown, the base 92 can be arranged at the level of the first surface of the plate 5, the above description then applies mutatis mutandis.

[0064] According to a second exemplary embodiment, illustrated in [Fig. 8], the protection member 9 comprises, similarly to what has been explained above, a base 92 and cannulas 91. The base 92 is arranged in the primary compartment 33, in particular so as to be connected to the interconnection ring 8 and / or to the first face 50a of the plate 5. Op- tionally, the base 92 is configured to house at least a portion of the interconnection ring 8 and / or the electrical connection cables 61a. The base 92 is inscribed in an annular shape carrying the different cannulas 91. Said cannulas 91 extend through the different primary orifices 52 as explained above with the difference that they comprise a single segment extending towards the secondary compartment 34. Optionally, a free end of said cannulas 91 comprises an inclined edge 93.

[0065] Optionally, the stator assembly 3 is configured to allow a variation in a flow rate of the cooling fluid FR depending on the zones of said stator so as to optimize the homogeneity of the cooling of the different pads 31 and coils 32. Such a principle aims in particular to regulate the flow rates of cooling fluid FR circulating in the different primary orifices 52 and / or secondary orifices 53 in the direction of the different coils 32 in order to compensate for the pressure drops and approach, or achieve, uniform cooling of the different elements.

[0066] According to a first exemplary embodiment, the annular shape of the discharge gallery 33b and / or the annular shape of the supply gallery 33a has(have) a variation of at least one dimension along said annular shape so as to allow the variation of the flow rate of the cooling fluid FR along within the secondary compartment 34 and / or the annular shape considered. For example, the variable dimension considered is a width of the gallery considered, defined along a radial axis originating from the axis of rotation 500 of the rotor 4. In particular, the variation of the dimension considered depends on the position of a part of the gallery considered relative to the position of the supply pipe 62, in the case of the supply gallery 33a, or relative to the position of the discharge pipe 63 in the case of the discharge gallery 33b.Indeed, the flow rate of the cooling fluid naturally tends to be higher near the supply pipe 62 for example, the implementation of a variation in the flow rate within at least one of the galleries advantageously makes it possible to limit, or even compensate for, such a phenomenon.

[0067] Alternatively or additionally, the different primary orifices 52 have circular sections of variable dimensions so as to allow the variation of the flow rate of the cooling fluid FR through the different primary orifices 52 and / or the different secondary orifices 53 have circular sections of variable dimensions so as to allow the variation of a flow rate of the cooling fluid FR through the different secondary orifices 53. For example, the different primary orifices 52 have circular sections of variable dimensions depending on their position, or their angular sector, within the annular shape comprising the primary orifices 52. In particular, such a variation is implemented relative to the position of the supply pipe 62 of the cooling fluid FR. Similarly, optionally, the different secondary orifices 53 have circular sections of variable dimensions depending on their position, or their angular sector, within the annular shape comprising the secondary orifices 53, in particular relative to the position of the evacuation pipe 63 of the cooling fluid FR.

[0068] In the case of the primary orifices 52, optionally crossed by the protection member 9 as described above, the variation of the section of the different primary orifices 52 can optionally be implemented by a variation of section of the different cannulas 91 of the protection member 9 as a function of the position of the primary orifices 52 crossed by said cannulas 91 within the annular shape comprising said orifices. The protection member 9 then comprises a plurality of cannulas 91 comprising sections of variable dimensions so as to allow a variation of the flow rate of the cooling fluid FR as a function of the zones of the stator assembly traveled through so as to optimize the homogeneity of the cooling of the different pads 31 and coils 32.

[0069] In particular, as illustrated in [Fig. 8], the stator assembly 3 according to the invention comprises a plurality of primary compartments 33, secondary compartments 34, plates 5, separation elements 7 and interconnection rings 8 arranged within the housing 6. Optionally, the stator assembly 3 comprises a plurality of protection members 9, supply lines 62, discharge lines 63 and electrical connection lines 61. Indeed, the stator assembly 3 may have a certain symmetry, relative to a median plane 250 of the electrical machine 2 passing through the primary compartment 33 and / or through the star 42 and the magnets 43 of the rotor 4.

[0070] Thus, for the sake of clarity, the elements described above are referred to as the first stator subassembly 3a, comprising a first primary compartment 33', first secondary compartment 34', first plate 5', first separating element 7' and first interconnection ring 8'. The stator assembly 3 according to the invention may then comprise a second stator subassembly 3b, arranged symmetrically to the first subassembly 3a relative to the median plane 250, and comprising in particular a second primary compartment 33”, a second secondary compartment 34”, a second plate 5”, a second separating element 7” and a second interconnection ring 8”. The tertiary compartment 35, in which the rotor 4 extends, thus extends between the first subassembly 3a and the second subassembly 3b, i.e. between the first secondary compartment 34' and the second secondary compartment 34”.Likewise, a first protection member 9' is configured to cooperate with the first plate 5' while a second protection member 9” is capable of cooperating with the second plate 5”.

[0071] Optionally, the stator assembly 3 comprises a first supply line 62' arranged in fluid connection with the first primary compartment 33' while a second supply line 62" is in fluid connection with the second primary compartment 33", in particular with a supply gallery 33a specific to each of said compartments. The same applies to a first discharge line 63' and a second discharge line 63' arranged in fluid connection with the first primary compartment 33' and the second primary compartment 33" respectively, in particular a discharge gallery 33b specific to said compartments. Alternatively, the stator assembly 3 comprises a supply line 62 common to the first primary compartment 33' and to the second primary compartment 33" and / or a discharge line 63 common to the first primary compartment 33' and to the second primary compartment 33".

[0072] Also, each stator subassembly 3a, 3b, in particular each secondary compartment 34', 34”, comprises a subassembly of pads 31 and coils 32 as described previously. The stator assembly 3 then comprises one or more electrical connection conduit(s) 61 capable of supplying the different coils 32 with electrical energy.

[0073] Thus, when the electric machine 2 is assembled and in operation within the vehicle 1, the cooling fluid FR circulates in the cooling fluid circuit 60 arranged in fluid connection with the electric machine 2, in particular here with the first subassembly 3a and the second stator subassembly 3b. The cooling fluid FR is brought to the primary compartment 33', 33" of each of the subassemblies, in particular to the supply gallery 33a of the first primary compartment 33' and second primary compartment 33', via the at least one supply pipe 62. The interconnection ring 8 of each stator subassembly 3a, 3b is then bathed in the cooling fluid FR which is capable of capturing calories from said rings in order to allow them to be cooled.

[0074] The cooling fluid FR is then distributed in the secondary compartment 34 of the different stator subassemblies 3a, 3b via the primary orifices 52. When the cooling fluid FR circulates in the secondary compartment 34, it is able to capture calories from the different coil wires 32 in order to allow their cooling. The cooling fluid FR thus moves from a central zone of the stator assembly 3, close to the primary opening 51 of the plate 5, to a peripheral zone, distal relative to said primary opening 51. The cooling fluid FR is then evacuated from the secondary compartment 34 to the primary compartment 33, in particular to the evacuation gallery 33b of the primary compartment 33, via the secondary orifices 53. The cooling fluid FR is then returned to the cooling circuit via the discharge line 63.

[0075] In parallel, an electric current is brought via the cables 61a arranged in the connecting conduit 61, to the coil wires 32 connected to the interconnection ring 8 at the primary compartment 33. The current flows along the coil wires 32, through the primary orifices 52, concomitantly with the cooling fluid FR, then along the winding of said wires around the different pads 31. The electric current, that is to say a current of electrons, and the flow of cooling fluid FR thus flow in the primary compartment 33 and the secondary compartment 34 of the different stator subassemblies 3a, 3b.

[0076] At the same time, the rotor 4, arranged in the tertiary compartment 35, pivots around the axis of rotation 500. Optionally, as indicated above, a second fluid can then circulate in the tertiary compartment 35 simultaneously with the circulation of the cooling fluid FR in the primary compartment 33 and the secondary compartment 34 of each stator subassembly 3. The second fluid is then supplied by a second circuit and is separated from the cooling fluid FR so that, within the electrical machine 2, the cooling fluid FR and the second fluid are thus not in direct contact with each other or mixed.

[0077] It should be noted that the invention can be extended to an electrical machine assembly comprising a plurality of stator assemblies 3 comprising a common rotor 4 shaft 41 or separate rotor 4 shafts 41.

[0078] The invention extends to a method of assembling an electrical machine 2 according to the invention, comprising, in a first step, the positioning of the interconnection ring 8 on the plate 5. The wires of the coils 32 are then positioned. These are connected to the interconnection ring 8, pulled so as to pass through at least one primary orifice 52 and are wound around a pad 31 carried by the plate 5. The separating element 7 is then positioned and fixed on the plate 5, for example by means of the fixing means 64, so as to arrange the pads 31 and the coils 32 in the secondary compartment 34, delimited by the separating element 7 and the plate 5. Optionally, when the stator assembly 3 comprises at least one protective member 9, the latter can be arranged on the plate 5 before or simultaneously with the positioning of the separating element 7.

[0079] The method finally comprises the positioning and fixing of the assembly formed by the plate 5 and the separating element 7 in the housing 6, in particular in one of the half-housings 6e. The rotor 4 is then arranged in the tertiary compartment 35 of the electrical machine 2 and the housing 6 can be closed, for example by fixing the half-housings 6e together.

[0080] It is understood that, when the stator assembly 3 and the electrical machine 2 according to the invention comprise a plurality of stator sub-assemblies as described above, the steps set out above are applied for each of the stator sub-assemblies considered.

[0081] The invention thus proposes a stator assembly and an electrical machine comprising a plurality of compartments allowing the circulation of a cooling fluid and the thermal management of the active elements of the stator assembly, in particular the coils, and the electrical connectors, in particular an interconnection ring. The proposed solution advantageously makes it possible to optimize the thermal management of the electrical machine, thus making it possible to use more powerful electrical currents within the electrical machine since the interconnection ring and a portion of the cables 61a forming the connector elements are bathed in the cooling fluid. It also makes it possible to simplify the electrical machine and reduce its cost by eliminating the need to seal the storage area of ​​the electrical connectors in order to separate it from the circulation of the cooling fluid.Such a principle also allows for the simplification of the assembly of the electric machine. Furthermore, the invention can be extended to a wide range of axial flux electric motors.

[0082] 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. Stator assembly (3) for an axial flux electrical machine (2) comprising a primary compartment (33) and a secondary compartment (34), in fluid connection and configured to allow the circulation of a cooling fluid (FR), and a tertiary compartment (35), separate from the primary compartment (33) and the secondary compartment (34) and configured to receive a rotor (4), the stator assembly (3) further comprising: - coils (32), pads (31) carrying said coils (32) and a plate (5) for supporting said pads (31), interposed between the primary compartment (33) and the secondary compartment (34) and comprising a plurality of primary orifices (52) and secondary orifices (53) capable of allowing the circulation of the cooling fluid (FR), the coils (32) extending through the primary ports (52); - an interconnection ring (8) arranged in the primary compartment (33) so as to bathe in the cooling fluid (FR) and connected to the coils (32); - a housing (6) connected to the plate (5) and delimiting the primary compartment (33) and the tertiary compartment (35); - a separation element (7), comprising walls (71) and a membrane (72), connected to the plate (5) and separating the secondary compartment (34) from the tertiary compartment (35).

2. Stator assembly (3) according to the preceding claim, in which the primary compartment (33) comprises a supply gallery (33a), in fluid connection with the secondary compartment (34) via the primary orifices (52), and an evacuation gallery (33b), separate from the supply gallery (33a) and in fluid connection with the secondary compartment (34) via the secondary orifices (53).

3. Stator assembly (3) according to the preceding claim, wherein: - the evacuation gallery (33b) is inscribed in a defined shape, in particular circular or annular, and has a variation of at least one dimension along said shape so as to allow the variation of a flow rate of the cooling fluid (FR) along said gallery; and / or - the feed gallery (33a) is inscribed in a defined shape, in particular circular or annular, and has a variation of at least a dimension along said shape so as to allow variation of a flow rate of the cooling fluid (FR) along said gallery.

4. Stator assembly (3) according to one of the preceding claims, in which the different primary orifices (52) have sections of variable dimensions so as to allow the variation of a flow rate of the cooling fluid (FR) through the different primary orifices (52) and / or the different secondary orifices (53) have sections of variable dimensions so as to allow the variation of a flow rate of the cooling fluid (FR) through the different secondary orifices (53).

5. A stator assembly (3) according to any preceding claim further comprising a protective member (9) extending through the plurality of primary orifices (52) so as to be interposed between the coils (32) and edges of said orifices.

6. Stator assembly (3) according to one of the preceding claims in which: - the plate (5) is attached and fixed to the housing (6) by means of at least one fixing means (64), such as a screw; and / or - the separating element (7) is attached and fixed to the plate (5) and / or the housing (6) by means of at least one fixing means (64), such as a screw.

7. Stator assembly (3) according to one of the preceding claims, further comprising a supply pipe (62) for cooling fluid (FR) and a discharge pipe (63) for said fluid, arranged in fluid connection with at least a portion of the primary compartment (33), and an electrical connection pipe (61), comprising at least one cable (61a), the connection pipe (61) and the supply pipe (63) being at least partly common so that a portion of at least one cable (61a) is configured to bathe in the cooling fluid (FR).

8. An axial flux electrical machine (2) comprising a stator assembly (3) according to one of the preceding claims and a rotor (4).

9. Vehicle (1) with electric or hybrid motorization comprising a stator assembly (3) according to one of claims 1 to 7 and / or an electric machine (2) according to claim 8.

10. A method of assembling an electrical machine (2) according to claim 8, comprising: - the positioning of the interconnection ring (8) on the plate (5); - positioning the coils (32) so as to connect them to the interconnection ring (8) and wind them around a pad carried by the plate (5) passing through one of the primary orifices (52) of the plate (5); - positioning and fixing the separating element (7) on the plate (5) so as to arrange the pads (31) and the coils (32) in the second compartment; - the positioning and fixing of the assembly formed by the plate (5) and the fixing element in the housing (6).

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