Stator assembly for axial flux electric machine, particularly for a motor vehicle, and axial flux electric machine comprising such a stator assembly

Abstract

Title: Stator assembly for an axial flux electric machine, particularly for a motor vehicle, and an axial flux electric machine comprising such a stator assembly. Stator assembly (3) for an axial flux electric machine (2) comprising a primary compartment (33) and a secondary compartment (34), in fluidic connection and configured to allow the circulation of a cooling fluid (CF), a plate (5) interposed between said compartments and comprising a plurality of orifices adapted to allow the circulation of the cooling fluid (CF) and the passage of coils between said compartments, and an interconnecting ring (8) disposed in the primary compartment (33) so as to be immersed in the cooling fluid (CF). Abstract figure: Figure 8

Description

Title of the invention: Stator assembly for an axial flux electric machine, particularly 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, particularly for a motor vehicle. The invention also relates to an axial flux electric machine comprising such a stator assembly. The invention further relates to an electric or hybrid vehicle equipped with the stator assembly and / or the electric machine. Finally, the invention relates to a method for assembling the stator assembly.

[0002] Electric or hybrid vehicles typically include at least one electric traction and / or propulsion machine, also called an electric motor, which propels the vehicle. The electric machine comprises, in a known manner, a rotor with a steel shaft and a composite star wheel holding in position at least one magnet rotating near a stator. The implementation of high power outputs, particularly those exceeding 100 kW, necessitates the use of high currents and the rotation of the rotor at a high speed. As a result, the electric motor tends to heat up during operation and requires a cooling system. This need increases 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 electric machines, it is known to cool the stator by means of a cooling fluid, in particular oil, circulating in contact with the stator coils. However, in order to limit energy losses due to the rotor churning in the oil, the rotor is conventionally isolated from the cooling fluid circulation zone by means of a sealed membrane bonded to the stator and extending partially into the air gap, i.e., the space between the stator and the rotor. Also, electrical connectors, in particular the interconnecting terminal blocks or busbars that supply electrical current to the stator, are conventionally located outside a volume of the stator so as to be separated from the oil circuit, making sealing the area containing 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, enabling the implementation of a cooling The invention aims to optimize the thermal dissipation of the stator elements, ensuring homogeneity between the different coils distributed within the stator. It also seeks to simplify the assembly of the stator and the electrical machine comprising it.

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

[0006] The stator assembly further comprises: - 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 and secondary orifices suitable for allowing the circulation of the cooling fluid, the coils extending through the primary orifices; - an interconnection ring positioned in the primary compartment so as to be immersed in the cooling fluid and connected to the coils; - a housing connected to the tray and delimiting the primary compartment and the tertiary compartment; - a separating 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 include an opening, for example centered on the same direction, suitable for receiving at least a 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 includes a supply gallery, in fluidic connection with the secondary compartment via the primary ports, and an evacuation gallery, separate from the supply gallery and in fluidic connection with the secondary compartment via the secondary ports.

[0010] In particular: - the drainage gallery has a defined shape, in particular circular or annular, and exhibits a variation of at least one dimension along said shape so as to allow for the variation of the flow rate of the cooling fluid along said gallery; and / or - the supply gallery is inscribed within a defined shape, in particular circular or annular, and exhibits 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 various primary orifices have sections of variable dimensions so as to allow variation of a flow of the cooling fluid through the various primary orifices and / or the various secondary orifices have sections of variable dimensions so as to allow variation of a flow of the cooling fluid through the various secondary orifices.

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

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

[0014] Optionally, the stator assembly further includes a coolant supply line and a coolant discharge line, arranged in fluidic connection with at least a part of the primary compartment, and an electrical connection line, including at least one cable, the connection line and the supply line being at least partly common so that a part of the at least one cable is configured to be immersed in the coolant.

[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 includes 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 also relates to a method for assembling an electrical machine according to the invention, comprising: - the positioning of the interconnecting ring on the platform; - the positioning of the coils so as to connect them to the interconnecting ring and wind them around a stud carried by the plate by passing through one of the primary orifices of the plate; - the positioning and fixing of the separating element on the tray so as to arrange the blocks and the reels in the second compartment; - the positioning and fixing of the assembly formed by the tray and the fixing element in the housing.

[0019] Other details, features and advantages will become clearer upon reading the detailed description given below, by way of example and not limitation, in relation to the various embodiments 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 cross-sectional representation of an example of an 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 and cooling fluid galleries of said assembly.

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

[0027] Fig. 8 is a schematic cross-sectional representation of the electrical machine.

[0028] Figure 1 schematically illustrates an example of an embodiment of a motor vehicle 1 according to the invention. Vehicle 1 is an electric or hybrid vehicle. Vehicle 1 can also be of any type, for example, a passenger car, a commercial vehicle, a truck, or a bus. In particular, the vehicle 1 in question 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 including a plurality of pads 31, or teeth, on which coils 32 are wound. The electric machine 2 also includes 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 free to rotate about an axis of rotation 500 parallel to the first direction 100. The term "axial flux electric machine" is thus understood to mean 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 various magnets 43 are, in particular, arranged in blocks so as to fit into a shape of A disc, or something similar to a disc, intended to rotate in conjunction with the shaft 41. The magnets 43 are arranged so as to extend at a distance from the pads 31 and coils 32 of the stator assembly 3, as described below. The space separating the rotor 4 from the pads 31 and coils 32 is called the air gap.

[0031] The stator assembly 3 according to the invention generally comprises at least one support plate 5 for the coils 32 and studs 31 described 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, fluidically connected to each other and configured to allow the circulation of a cooling fluid FR. The cooling fluid FR is configured to provide heat treatment, in particular cooling, to the stator assembly 3, including the coils 32 and the pads 31 supporting them. In particular, the cooling fluid FR is an oil.

[0033] The stator assembly 3 also includes a tertiary compartment 35, separate from the primary compartment 33 and the secondary compartment 34 and configured to receive the rotor 4. By "separate" it is understood that the tertiary compartment 35 does not allow the circulation of the cooling fluid FR and is not in fluidic 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 partially flat or substantially flat. In particular, the plate 5 has a circular, or substantially circular, shape and includes 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 platform 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 platform 5 is turned towards the primary compartment 33 while a second face 50b of the platform 5, opposite to the first face 50a, is turned towards the secondary compartment 34.

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

[0037] The casing 6, or housing, is an external structural enclosure of the electric machine 2 and of at least part of the stator assembly 3. In particular, the casing 6 is made of a metallic material, for example steel and / or aluminum. The casing 6 defines an internal volume of the electric machine 2, which includes the primary compartment 33, the secondary compartment 34, and the tertiary compartment 35 on the one hand, and in which at least part of the rotor 4 extends on the other. In particular, the casing 6 directly contributes to defining the primary compartment 33 and the tertiary compartment 35.

[0038] According to a non-limiting embodiment, the housing 6 comprises a plurality of flanks, for example, at least partially inscribed within a cylindrical or substantially cylindrical shape with a circular base. In this case, the housing 6 includes a first flank 6a and a second flank 6b, delimiting the housing 6 along the first direction 100. The housing 6 also includes at least one intermediate flank 6c, connecting the first flank 6a to the second flank 6b. Optionally, but preferably, the housing 6 includes two half-housings 6e configured to be assembled to form the housing 6. The housing 6 also includes secondary openings, configured to allow the passage of the rotor shaft 41 through the stator assembly 3.In particular, the first flank 6a and the second flank 6b each include 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, includes at least one electrical connection conduit 61 configured to receive electrical connection cables 61a suitable for 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, includes at least one supply line 62 and / or one discharge line 63 for coolant FR, respectively configured to supply the coolant FR to the electrical machine 2 and to discharge the coolant FR from said electrical machine 2. The supply line 62 and the discharge line 63 are thus connected to a coolant FR circuit 60, not detailed, conventionally comprising at least one heat exchanger, capable of regulating the temperature of the coolant FR, and a pump, capable of regulating the overall flow rate of the coolant FR. In particular, the supply line 62 and the electrical connection line 61 are adjacent or coincide. Preferably, the connection line 61 and the supply line 63 are at least partially common so that a portion of the cables 61a is configured to be immersed in the FR cooling fluid, thus enabling their cooling. Also, in order to limit the resulting bulk, the drain pipe 63 is located 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 located 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 tray 5 comprises a plurality of primary ports 52 and a plurality of secondary ports 53 adapted to allow the circulation of the cooling fluid FR. Said ports 52, 53 are through-ports and extend through the thickness of the tray, between the first face 50a and the second face 50b. In particular, as illustrated in [Fig. 6] or 7, the primary ports 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 ports 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 preferentially have a circular shape.

[0043] Also, the primary ports 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 that each extends through at least one of the primary ports 52. The cooling fluid FR and the electric current supplying the coils 32 thus circulate simultaneously at the primary ports 52 when the electric machine 2 is in operation.

[0044] The primary orifices 52 are arranged in the plate 5 so as to fit within 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 within 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 are closer to the primary opening 51 than the secondary orifices 53.

[0045] Preferably, the primary compartment 33 comprises a coolant supply gallery 33a and a coolant outlet gallery 33b. FR cooling fluid. The supply gallery 33a is configured to bring the FR cooling fluid to the secondary compartment 34, while the discharge gallery 33b allows the FR cooling fluid to be discharged from the secondary compartment 34. Preferably, the supply gallery 33a and the discharge gallery 33b are not directly connected in fluidic terms 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 flow of the FR cooling fluid, so that the FR cooling fluid flows successively through the supply gallery 33a, the secondary compartment 34 so as to be in contact with the coils 32 and the pads 31, and 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 ports 52, here forming the first circle. In this way, the primary ports 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 ports 53, here forming the second circle. The secondary openings 53 thus open into the evacuation gallery 33b and extend through the platform 5 between the evacuation gallery 33b and the secondary compartment 34.Also, in the illustrated example, preferentially, the supply gallery 33a is closer to the primary opening 51 than the evacuation gallery 33b.

[0047] Optionally, the feed gallery 33a is cut into 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 cut into the plate 5, in particular at the first face 50a. Figure 8 illustrates an example of an embodiment in which half-galleries are formed in the plate 5 and the housing 6, said galleries being configured to extend opposite each other when the stator assembly is assembled to form the feed gallery 33a. A similar principle applies mutatis mutandis to the discharge gallery 33b.

[0048] Optionally, the supply line 62 also opens into the supply gallery 33a so that the supply line 62 and the supply gallery 33a are arranged in fluidic connection and the cooling fluid FR supplied by the supply line 62 circulates in said gallery in order to be distributed to the various primary ports 52. Similarly, optionally- In fact, the drain pipe 63 opens at the level of the drain gallery 33b so that these are arranged in fluidic connection and the cooling fluid FR exiting the drain gallery 33b through the secondary orifices 53 is then sent to the drain pipe 63.

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

[0050] The interconnecting ring 8 is arranged in the primary compartment 33 so as to be immersed in the cooling fluid FR when it circulates through the stator assembly 3. In particular, at least a portion of the electrical connection cables 61a is also immersed in the cooling fluid at the level of the primary compartment 33. In this way, the stator assembly 3 advantageously optimizes its thermal management and reduces power losses due to Joule heating compared to prior art stators by ensuring the cooling of the interconnecting ring 8 and a portion of the electrical connectors. This principle makes it possible to use higher electrical currents within the electrical machine 2, enabling it to deliver more power without causing damage to its components.

[0051] In particular, the interconnecting ring 8 is disposed at the first face 50a of the plate 5, for example in contact with it and / or so as to be fixed to it. Preferably, the interconnecting ring 8 is bonded to the first face 50a of the plate 5. The interconnecting ring 8 is also disposed near the primary ports 52 and / or the primary opening 51. The interconnecting ring 8 thus surrounds the primary opening 51. In particular, the interconnecting ring 8 extends opposite all or part of the primary ports 52.

[0052] Thus, the wires of the various coils 32 are connected to the interconnecting ring 8, pass through the various primary ports 52, and are then wound around the pads 31 of the stator element. The electrical connection conduit 61 is positioned near the interconnecting ring 8 so as to allow the wires of the coils 32 to be supplied with power via the cables 61a and the interconnecting ring 8.

[0053] The separating element 7 is disposed on the tray 5, in particular the second face 50b of the tray 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 annular, or substantially annular, shape surrounding a tertiary opening 73 adapted to receive the shaft 41 of the rotor 4. When the stator assembly 3 is assembled, the tertiary opening 73 extends at least partially opposite the primary opening 51 of the plate 5.

[0055] Generally, the separating element 7 comprises at least one inner wall 71a, having a proximal position relative to the central axis and the axis of rotation 500 of the rotor 4 when the electric machine 2 is assembled, and at least one outer wall 71b, having a distal position relative to this same axis. The at least one inner wall 71a thus delimits an inner periphery of the annular shape and delimits the tertiary opening 73 of the separating element 7. The at least one inner wall 71a thus fits within a first circular, or substantially circular, shape. The at least one outer wall 71b delimits an outer periphery of the annular shape and fits within 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 diaphragm 72 is disposed on a side opposite the open side, away from the plate 5. Said diaphragm 72 extends between at least one inner wall 71a and at least one outer wall 71b so as to connect them. Thus, when the electrical machine 2 is assembled, the diaphragm 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 disposed 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. The separating element 7 and the plate 5 delimit the secondary compartment 34, which includes the pads 31 and coils 32 and is adapted to allow the circulation of the cooling fluid FR so as to enable the thermal management of said pads 31 and coils 32. The tertiary compartment 35, adapted to house the rotor 4, in particular at least a portion of the shaft 41, the star 42, and the various magnets 43, is fluidly separated from the secondary compartment 34. Optionally, the tertiary compartment 35 is adapted to receive a second fluid, distinct from the cooling fluid FR, such as an airflow, suitable for 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 is reversible and implemented by means of less a means of fastening 64, such as a screw or a screw-nut assembly.

[0059] Optionally, but preferably, the stator assembly 3 further comprises a protective element 9 extending through the plurality of primary ports 52 so as to be interposed between the wires of the coils 32 and the edges of said ports. Generally, the protective element 9 is an added component, made of an electrically insulating material, in particular a plastic material, comprising a plurality of hollow nozzles 91 configured to be inserted into the various primary ports 52 and to receive the wires of the various coils 32 while allowing the circulation of the cooling fluid FR. Thus, the protective element 9 is interposed between the wires of the coils 32, which are energized, and the plate 5 so as to prevent direct contact between them, or excessive proximity, and to prevent breakdown phenomena. The protective element 9 thus has a plurality of functions.It provides, on the one hand, the function of insulation, and, on the other hand, the function of guiding the wires of the coils 32. .

[0060] Figures 2 to 8 illustrate different alternative embodiments of the protective element 9.

[0061] According to a first embodiment, illustrated in Figures 2 to 6, the protective element 9 comprises a base 92 carrying the various cannulas 91. Said base 92 is, for example, an annular piece disposed 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, "segment" means a portion of a whole. The first and second segments 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, includes 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 embodiment, illustrated in [Fig. 8], the protective element 9 comprises, similarly to what has been described 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 interconnecting ring 8 and / or to the first face 50a of the tray 5. Op- The base 92 is configured to house at least part of the interconnecting ring 8 and / or the electrical connection cables 61a. The base 92 is annular in shape and carries the various cannulas 91. These cannulas 91 extend through the various primary ports 52 as described above, with the difference that they comprise a single segment extending towards the secondary compartment 34. Optionally, a free end of these cannulas 91 includes an inclined edge 93.

[0065] Optionally, the stator assembly 3 is configured to allow a variation of the cooling fluid FR flow rate according to 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 ports 52 and / or secondary ports 53 towards the different coils 32 in order to compensate for pressure losses and approach, or achieve, a uniform cooling of the different elements.

[0066] According to a first embodiment, the annular shape of the discharge gallery 33b and / or the annular shape of the supply gallery 33a exhibits a variation of at least one dimension along said annular shape so as to allow variation in the flow rate of the cooling fluid FR 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 portion of the gallery considered relative to the position of the supply line 62, in the case of the supply gallery 33a, or relative to the position of the discharge line 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 line 62, for example; implementing a flow rate variation within at least one of the galleries advantageously limits, or even compensates for, such a phenomenon.

[0067] Alternatively or additionally, the various primary orifices 52 have circular cross-sections of varying dimensions so as to allow variation in the flow rate of the cooling fluid FR through the various primary orifices 52 and / or the various secondary orifices 53 have circular cross-sections of varying dimensions so as to allow variation in the flow rate of the cooling fluid FR through the various secondary orifices 53. For example, the various primary orifices 52 have circular cross-sections of varying dimensions depending on their position, or their angular sector, within the annular shape comprising the primary orifices 52. In particular, such variation is implemented relative to the position of the supply line 62 for the cooling fluid FR. Similarly, Optionally, the various secondary orifices 53 have circular sections of varying 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 cooling fluid FR discharge line 63.

[0068] In the case of the primary ports 52, optionally traversed by the protective element 9 as described above, the variation in the cross-section of the various primary ports 52 can optionally be implemented by varying the cross-section of the various cannulas 91 of the protective element 9 according to the position of the primary ports 52 traversed by said cannulas 91 within the annular shape comprising said ports. The protective element 9 then comprises a plurality of cannulas 91 having cross-sections of varying dimensions so as to allow a variation in the flow rate of the cooling fluid FR according to the areas of the stator assembly traversed, in order to optimize the homogeneity of the cooling of the various 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, separating elements 7, and interconnecting rings 8 arranged within the housing 6. Optionally, the stator assembly 3 comprises a plurality of protective devices 9, supply lines 62, discharge lines 63, and electrical connection lines 61. Indeed, the stator assembly 3 may exhibit a certain symmetry with respect 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 first stator subassembly 3a, comprising a first primary compartment 33', first secondary compartment 34', first plate 5', first separating element 7', and first interconnecting ring 8', is 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 interconnecting 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 with respect 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 interconnecting ring 8'. The tertiary compartment 35, in which the rotor 4 extends, thus extends between the first subassembly 3a and the second subassembly 3b, that is, between the first secondary compartment 34' and the second secondary compartment 34'.Similarly, a first 9' protective element is configured to cooperate with the first 5' platform while a second 9" protective element is suitable for cooperating with the second 5" platform.

[0071] Optionally, the stator assembly 3 includes a first supply line 62' arranged in fluidic connection with the first primary compartment 33', while a second supply line 62" is in fluidic 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 fluidic 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 includes a supply line 62 common to the first primary compartment 33' and the second primary compartment 33" and / or a discharge line 63 common to the first primary compartment 33' and 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 above. The stator assembly 3 then comprises one or more electrical connecting conduit(s) 61 suitable for supplying the various coils 32 with electrical energy.

[0073] Thus, when the electric machine 2 is assembled and operating within the vehicle 1, the cooling fluid FR circulates in the cooling fluid circuit 60 arranged in fluidic connection with the electric machine 2, in particular here with the first stator subassembly 3a and the second stator subassembly 3b. The cooling fluid FR is supplied 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 at least one supply line 62. The interconnecting ring 8 of each stator subassembly 3a, 3b is then bathed in the cooling fluid FR, which is capable of absorbing heat from said rings in order to allow their cooling.

[0074] The cooling fluid FR is then distributed into the secondary compartment 34 of the various stator subassemblies 3a, 3b via the primary ports 52. As the cooling fluid FR circulates in the secondary compartment 34, it absorbs heat from the various coil wires 32 to allow their cooling. The cooling fluid FR thus moves from a central area of ​​the stator assembly 3, near the primary port 51 of the plate 5, to a peripheral area, distal to said primary port 51. The cooling fluid FR is then discharged from the secondary compartment 34 to the primary compartment 33, in particular to the discharge gallery 33b of the primary compartment 33, via the secondary ports 53. The FR cooling fluid is then returned to the cooling circuit via the drain line 63.

[0075] In parallel, an electric current is supplied via the cables 61a arranged in the connecting conduit 61, to the coil wires 32 connected to the interconnecting ring 8 at the primary compartment 33. The current flows along the coil wires 32, through the primary orifices 52, concomitantly with the coolant FR, and then along the winding of said wires around the various pads 31. The electric current, i.e. an electron current, and the flow of coolant FR thus circulate in the primary compartment 33 and the secondary compartment 34 of the various stator subassemblies 3a, 3b.

[0076] At the same time, the rotor 4, located 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 brought in 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] Note that the invention can be extended to an electrical machine assembly comprising a plurality of stator assemblies 3 comprising a common rotor shaft 41 or separate rotor shafts 41.

[0078] The invention extends to a method for assembling an electrical machine 2 according to the invention, comprising, firstly, positioning the interconnecting ring 8 on the plate 5. The wires of the coils 32 are then positioned. These are connected to the interconnecting ring 8, drawn through at least one primary orifice 52, and 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 fastening 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 includes at least one protective device 9, this device can be arranged on the plate 5 prior to or simultaneously with the positioning of the separating element 7.

[0079] The method finally includes positioning and fixing 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 placed in the tertiary compartment 35 of the electric 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 subassemblies as described above, the steps set out above are applied to each of the stator subassemblies 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 interconnecting ring. The proposed solution advantageously optimizes the thermal management of the electrical machine, thereby enabling the use of more powerful electrical currents within the electrical machine since the interconnecting ring and a portion of the cables 61a forming the connector elements are immersed in the cooling fluid. It also simplifies the electrical machine and reduces its cost by eliminating the need to seal the area housing the electrical connectors to separate it from the cooling fluid circulation.This principle also simplifies the assembly of the electrical 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 herein 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 this document.

Claims

Demands

1. Stator assembly (3) for an axial flux electric machine (2) comprising a primary compartment (33) and a secondary compartment (34), in fluidic connection and configured to allow the circulation of a cooling fluid (CF), 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 support plate (5) for said pads (31), interposed between the primary compartment (33) and the secondary compartment (34) and comprising a plurality of primary ports (52) and secondary ports (53) suitable for allowing the circulation of the cooling fluid (CF), the coils (32) extending through the primary ports (52);- an interconnecting ring (8) disposed in the primary compartment (33) so as to be immersed 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 separating 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, wherein the primary compartment (33) comprises a feed gallery (33a), in fluidic connection with the secondary compartment (34) via the primary ports (52), and an evacuation gallery (33b), separate from the feed gallery (33a) and in fluidic connection with the secondary compartment (34) via the secondary ports (53).

3. A stator assembly (3) according to the preceding claim, wherein: - the discharge gallery (33b) is 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 variation of the flow rate of the cooling fluid (RF) along said gallery; and / or - the supply gallery (33a) is in a defined shape, in particular circular or annular, and has a variation of at least a dimension along said shape so as to permit variation of a flow rate of the cooling fluid (FR) along said gallery.

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

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

6. Stator assembly (3) according to any one of the preceding claims wherein: - the plate (5) is attached and fixed to the housing (6) by means of at least one fastening 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 fastening means (64), such as a screw.

7. Stator assembly (3) according to any one of the preceding claims, further comprising a coolant (FR) supply line (62) and a coolant (FR) discharge line (63), arranged in fluidic connection with at least a portion of the primary compartment (33), and an electrical connecting line (61), comprising at least one cable (61a), the connecting line (61) and the supply line (63) being at least partly common such that a portion of the at least one cable (61a) is configured to be immersed in the coolant (FR).

8. Axial flux electric machine (2) comprising a stator assembly (3) according to any one of the preceding claims and a rotor (4).

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

10. Method of assembling an electrical machine (2) according to claim 8, comprising: - positioning the interconnecting ring (8) on the plate (5); - the positioning of the coils (32) so as to connect them to the interconnecting ring (8) and wind them around a stud carried by the plate (5) by passing through one of the primary orifices (52) of the plate (5); - the positioning and fixing of the separating element (7) on the plate (5) so as to arrange the pads (31) and the reels (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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