Rotating electrical machine assembly comprising an inverter

Abstract

Rotating electrical machine assembly comprising an inverter Rotating electrical machine assembly (1), comprising: - a rotating electrical machine, - an inverter (2), and - a casing (10) comprising a first casing part (11) covering the electrical machine and a second casing part (12) covering the inverter, the first and second casing parts (11, 12) providing circulation of a cooling fluid, in particular water, to cool the assembly, comprising between them at least one fluid connection (15), the fluid connection (15) comprising a male part (15a) fitting onto a female part (15b), the male part (15a) being made in one piece with the casing (10). Figure for the abstract: Fig. 2b

Description

Title of the invention: Rotating electrical machine assembly comprising an inverter Technical field

[0001] The present invention relates to rotating electrical machines and more particularly to machines comprising an inverter. The invention relates more particularly to rotating electrical machine assemblies, comprising a rotating electrical machine, an inverter and a casing, and to their cooling.

[0002] The invention relates more particularly to synchronous or asynchronous alternating current machines. It relates in particular to traction or propulsion machines for electric (Battery Electric Vehicle) and / or hybrid (Hybrid Electric Vehicle - Plug-in Hybrid Electric Vehicle) motor vehicles, such as individual cars, vans, trucks or buses. The invention also applies to rotating electrical machines for industrial and / or energy production applications, in particular naval, aeronautical or wind power. Prior art

[0003] We know in particular from applications DE 102017 205970, FR 3 091 137 and EP 4 012 901 assemblies comprising an electric machine casing and an inverter casing, but which are devoid of a hydraulic cooling circuit common to the casings of the machine and the inverter, or even which are devoid of a cooling circuit for the inverter casing.

[0004] In US 2020 / 161922, the casing has an axial opening exposing the electrical machine and the inverter to the outside.

[0005] In CN 112448542, the assembly comprises a casing of the electrical machine, which accommodates the electronic components of the inverter, and this casing is closed by a simple cover. The same is true in US 2017 / 232831, US 2006 / 064998, WO 2022 / 068892, CN 111130277 and WO 2020 / 202946. The inverter as such is not supported by the cover.

[0006] In JP 2022081344, an attached sleeve ensures the sealing of the hydraulic connection of the casing.

[0007] There is a need to further improve the cooling of rotating electrical machines comprising an inverter. Summary of the invention

[0008] The invention aims to meet this need and achieves this, according to one of its aspects, by means of a rotating electrical machine assembly, comprising: - a rotating electrical machine, - an inverter, and - a casing comprising a first casing part covering the electrical machine and a second casing part covering the inverter, the first and second casing parts providing circulation of a cooling fluid, in particular water, to cool the assembly, comprising between them at least one fluid connection, the fluid connection comprising a male part fitted onto a female part, the male part being made in one piece with the casing.

[0009] The male part is formed in one piece with the casing, for example machined in it. The absence of an added part is economical and assembly is easier, and also saves space.

[0010] The presence of the male part made in one piece with the casing allows the improvement of the centering of the second casing part on the first casing part, in particular when placing the second casing part on the first casing part. The fluid connection is used to center the two casing parts relative to each other.

[0011] Such a fluid connection according to the invention makes it possible to combine two functions, namely a sealing function in the circulation of the cooling fluid on the one hand, and on the other hand the centering of the two casing parts relative to each other.

[0012] Thanks to the invention, a more precise alignment of the fluid passages between the two housing parts is obtained.

[0013] Good centering also makes it possible to improve the distribution of the forces applied between the two housing parts and to obtain good contact pressure between them with strong and uniform support. This makes it easier to manage the seal between the two housing parts, and makes the design easier.

[0014] The assembly may comprise a single fluid connection between the first and second housing parts. The presence of a single hydraulic connection makes it possible not to stress the seal between the two housing parts.

[0015] The fluid connection may be housed in the housing. The fluid connection may be housed in an interior space of the housing provided by the first housing part and the second housing part when assembled, in which the inverter is housed.

[0016] In one embodiment, the first and second housing portions, when assembled, form the circulation of the cooling fluid. The circulation of the cooling fluid takes place in both the first housing portion and the second housing portion, such that cooling fluid circulates between the first housing portion and the second housing portion.

[0017] A first circulation of the cooling fluid arranged in the first part of the casing and a second circulation of the cooling fluid arranged in The second part of the housing is in fluid communication, which simplifies the configuration of the housing, and improves the sealing between the inverter and the machine. The compactness of the assembly is also improved.

[0018] Furthermore, the assembly of the assembly is facilitated, the necessary operations being simplified. For example, the connection of the circulation of the cooling fluid between the first and second housing parts is made during their assembly. The fluid connection is ensured during assembly, thus with a single operation.

[0019] The number of parts can also be advantageously limited.

[0020] Finally, the configuration according to the invention allows for improved integration of the assembly, with easy distinction between the electrical machine and the inverter, which simplifies manufacturing and after-sales service. For example, changing a defective part can be made easier, in particular by sending only part of the assembly for repair.

[0021] In one embodiment, a fluid connection between a first circulation of the cooling fluid provided in the first part of the housing and a second circulation of the cooling fluid provided in the second part of the housing is housed in the housing.

[0022] By "housing" is meant an enclosure protecting the various internal elements of the assembly, the inverter and the electrical machine, in particular the rotor, the stator and the inverter. The housing may be rigid. This rigidity makes it possible not to generate additional harmonics during vibration tests. The housing may be in one or more parts, in particular in one, two or three parts. The different parts of the housing may be joined together. Alternatively, the housing may be made in a single part. The housing may be an integral part of the chassis of the device, for example of a vehicle, comprising the electrical machine. The housing may carry the main elements of the machine, in particular the stator and the bearings. The housing may carry the active parts of the machine.By "active parts" we mean the electrical elements and the mechanical-magnetic elements, for example the rotor and the stator, converting mechanical energy into electrical energy.

[0023] The casing may be machined or made in a casting. The casing may be made of metal, for example aluminum. Alternatively, the casing may be made of a plastic material.

[0024] The casing may be solid. The weight of the casing may be greater than 2 kg, better still greater than 3 kg, better still greater than 4 kg, being for example of the order of 5 kg or 8 kg or 17 kg. The weight of the casing may be less than 25 kg, better still less than 20 kg, being for example of the order of 5 kg or 8 kg or 17 kg. Statement of the invention

[0025] The male part may comprise a tip, which is in particular a hollow cylinder. It may comprise a wall delimited by an external surface and an internal surface. The internal surface of the hollow cylinder may be cylindrical. The tip may be substantially non-deformable. This ensures good mechanical support of the casing and thus reduces vibrations.

[0026] The male part can be made in one piece with the second housing part. Thus, the centering is directly integrated into the second housing part, on the inverter side. The sealing of the circulation of the cooling fluid is used to position the second housing part. Alternatively, the male part can be made in one piece with the first housing part.

[0027] The female part may be carried by the first housing part. Alternatively, the female part may be carried by the second housing part.

[0028] The female part may comprise a bore formed in the casing part. Alternatively, it may be attached. It may, for example, comprise an attached sleeve. It may, for example, be flexible.

[0029] One of the male part or the female part may carry a seal, in particular an O-ring or a K-ring, in particular the male part carrying a seal, in particular an O-ring or a K-ring. A K-ring ensures good sealing against fluids and dust. It allows good self-centering. The seal obtained may be radial. Such a seal shape may also facilitate centering, by avoiding a loss of load.

[0030] By "K-shaped joint" is meant a joint with a specific cross-sectional shape, in K, which makes it possible to limit assembly and / or fitting forces while guaranteeing a significant sealing line.

[0031] The male part may include an annular groove to receive a seal, in particular an O-ring or K-ring. The presence of this annular groove makes it possible to correctly position the seal and to avoid adding material between the male part and the female part, which makes it possible to improve centering.

[0032] The second housing portion may include a cooling fluid inlet from an external supply, and the first housing portion may include a cooling fluid outlet to an external discharge.

[0033] The second housing portion may have a coolant outlet to the first housing portion and may not have a coolant inlet from the first housing portion.

[0034] The single coolant inlet may be located on the second housing portion and the single coolant outlet may be located on the first housing portion. This configuration is advantageous in that it allows the coolant to be supplied as a priority to the inverter, which may allow for more efficient cooling of the latter.

[0035] Alternatively, the single coolant inlet may be located on the first housing portion and the single coolant outlet may be located on the first housing portion. In this case, the coolant circulation may be configured to conduct the coolant directly to the inverter to allow more efficient cooling thereof, before returning to the machine.

[0036] The cooling fluid inlets and outlets may include one or more seals. This or these seals may be O-rings.

[0037] The assembly may comprise a peripheral seal, the fluid connection being located in particular outside the perimeter of the peripheral seal. The peripheral seal provided by this seal makes it possible to improve the sealing of the interior volume of the casing.

[0038] The hydraulic connection can be made outside the peripheral seal, which can allow two seals between the passage of cooling fluid and the internal volume of the casing, namely the seal provided by the peripheral seal on the one hand and on the other hand the seal provided by the seal of the hydraulic connection mentioned above, carried by the male part or the female part.

[0039] When the hydraulic connection is made outside the peripheral seal, the fluid cannot penetrate into the casing in the event of a leak. The seal is therefore improved.

[0040] The casing may provide an axial opening for the passage of a shaft of the rotating electrical machine. The casing may be devoid of any other axial opening. Said axial opening is provided in the first casing part. In particular, the casing is devoid of an axial opening in the second casing part. The casing only has an axial opening in the first casing part.

[0041] When the assembly is observed in the position of use, for example in an electric vehicle, the second housing part is arranged above the first housing part.

[0042] The inverter may be mechanically supported by the second housing portion. In particular, the inverter may not be mechanically supported by the first housing portion. The second housing portion acts as a mechanical support for the inverter and is not a simple closing cover for the housing.

[0043] The housing is formed by assembling the first housing part and the second housing part. When assembled, the first housing part and the second housing part form an enclosed interior space in which the inverter, including a printed circuit board thereof, is housed.

[0044] The inverter may comprise a printed circuit board housed in the second housing part.

[0045] In the machine according to the invention, all the electronics can be carried by the inverter. The inverter can be mechanically connected to a phase connector.

[0046] The machine may comprise stator winding conductors, at least a portion of the stator winding conductors of the machine, or even a majority of the stator winding conductors of the machine, being in the shape of a U-shaped or I-shaped pin.

[0047] The machine can be used as a motor or as a generator. The machine can be reluctance. It can constitute a synchronous motor or alternatively a synchronous generator. Alternatively, it constitutes an asynchronous machine. The electrical machine need not be an alternator.

[0048] The maximum rotational speed of the machine may be high, for example greater than 10,000 rpm, better still greater than 12,000 rpm, for example of the order of 14,000 rpm to 15,000 rpm, or even 20,000 rpm or 24,000 rpm or 25,000 rpm. The maximum rotational speed of the machine may be less than 100,000 rpm, or even 60,000 rpm, or even less than 40,000 rpm, better still less than 30,000 rpm.

[0049] The invention may be particularly suitable for high-power machines.

[0050] The machine may comprise a single inner rotor or, alternatively, an inner rotor and an outer rotor, arranged radially on either side of the stator and coupled in rotation.

[0051] The stator may comprise teeth defining notches between them. The notches may be at least partially closed. A partially closed notch makes it possible to provide an opening at the air gap, which may be used, for example, for the placement of electrical conductors for filling the notch. A partially closed notch is in particular provided between two teeth which each comprise polar expansions at their free end, which close the notch at least in part.

[0052] Alternatively, the notches may be fully closed. By "fully closed notch" is meant notches that are not open radially towards the air gap.

[0053] In one embodiment, at least one notch, or even each notch, can be continuously closed on the air gap side by a bridge of material made in one piece with the teeth defining the notch. All the notches can be closed on the air gap side by bridges of material closing the notches. The bridges of material can be made in one piece with the teeth defining the notch. The stator mass is then free of any cutout between the teeth and the bridges of material. closing the notches, and the notches are then continuously closed on the air gap side by the bridges of material coming in one piece with the teeth defining the notch.

[0054] Furthermore, the notches can also be closed on the side opposite the air gap by a yoke attached or in one piece with the teeth. The notches are then not open radially outwards. The stator mass can be without a cutout between the teeth and the yoke.

[0055] In one embodiment, each of the notches has a continuously closed contour. By "continuously closed" is meant that the notches have a continuous closed contour when observed in cross-section, taken perpendicular to the axis of rotation of the machine. It is possible to go completely around the notch without encountering a cut in the stator mass.

[0056] The stator may comprise coils arranged in a distributed manner in the notches, in particular having electrical conductors arranged in a row in the notches. By "distributed" is meant that at least one of the coils passes successively through two non-adjacent notches.

[0057] The electrical conductors may not be arranged in the notches loosely but in an orderly manner. They are stacked in the notches in a non-random manner, for example being arranged in rows of aligned electrical conductors. The stacking of the electrical conductors is for example a stacking according to a hexagonal network in the case of electrical conductors of circular cross-section.

[0058] The stator may comprise electrical conductors housed in the notches. At least some electrical conductors, or a majority of the electrical conductors, may be pin-shaped, U-shaped or I-shaped. The pin may be U-shaped (U-pin in English) or straight, being I-shaped (L-pin in English).

[0059] The electrical conductors can thus form a distributed winding. The winding may not be concentrated or wound on teeth.

[0060] In an alternative embodiment, the stator has concentrated winding. The stator may comprise teeth and coils arranged on the teeth. The stator may thus be wound on teeth, in other words with non-distributed winding.

[0061] The stator teeth may have pole shoes. Alternatively, the stator teeth are devoid of pole shoes.

[0062] The stator teeth can be made with a stack of magnetic sheets, each covered with an insulating resin, in order to limit losses by induced currents.

[0063] The invention also relates, according to another of its aspects, independently or in combination with the above, to a vehicle comprising an electric machine assembly as described above, the vehicle being hybrid. The vehicle may for example, include in addition to the electric motor a thermal engine, for example a gasoline engine. Alternatively, the vehicle can be electric. It can then only include an electric machine. Brief description of the drawings

[0064] The invention may be better understood by reading the description which follows, a non-limiting example of its implementation, and by examining the attached drawing, in which:

[0065] [Fig.1a] [Fig.1a] is a schematic and partial perspective view of a rotating electrical machine assembly according to the invention.

[0066] [Fig.lb] [Fig.lb] is an exploded perspective view of the rotating electrical machine assembly of [Fig. la].

[0067] [Fig. 1a] [Fig. 1a] is another exploded perspective view of the rotating electrical machine assembly of [Fig. 1a].

[0068] [Fig.2a] [Fig.2a] is a detailed sectional view of the rotating electrical machine assembly of [Fig.1a].

[0069] [Fig.2b] [Fig.2b] is another sectional detail view of the rotating electrical machine assembly of [Fig.1a].

[0070] [Fig.3] [Fig.3] is a detailed perspective view of the second casing part of the rotating electrical machine assembly of [Fig.1a].

[0071] [Fig.4a] [Fig.4a] is a detailed perspective view of the rotating electrical machine assembly of [Fig.1a].

[0072] [Fig.4b] [Fig.4b] is another detailed perspective view of the rotating electrical machine assembly of [Fig.1a].

[0073] [Fig.5] [Fig.5] is a view similar to [Fig.3] of an alternative embodiment. Detailed description

[0074] In the figures and in the remainder of the description, the same references represent identical or similar elements.

[0075] Figures 1a to 4b illustrate a rotating electrical machine assembly 1 according to the invention.

[0076] The assembly 1 comprises a rotating electrical machine not visible in the figures, an inverter 2 and a casing 10. The casing 10 comprises a first casing part 11 covering the electrical machine and a second casing part 12 covering the inverter 2.

[0077] The first and second casing parts provide a circulation of a cooling fluid, in particular water, provided in the casing 10 to cool the assembly 1. They form, when assembled, the circulation of the cooling fluid. A first circulation of the cooling fluid provided in the first part 11 of the casing 10 and a second circulation of the cooling fluid arranged in the second part 12 of the casing are in fluid communication.

[0078] The assembly 1 comprises for this purpose a fluid connection 15. The fluid connection 15 between the first circulation of the cooling fluid arranged in the first part 11 of the casing 10 and the second circulation of the cooling fluid arranged in the second part 12 of the casing 10 comprises a male part 15a fitted onto a female part 15b.

[0079] The male part 15a is made in one piece with the casing 10. In the example described, the male part 15a is made in one piece with the second casing part 12. Thus, the centering is directly integrated into the second casing part 12, on the side of the inverter 2. The sealing of the circulation of the cooling fluid is used to position the second casing part 12. Thanks to the invention, a more precise alignment of the fluid passages between the two casing parts is obtained, as visible in Figures 2a and 2b.

[0080] In the example described, the male part 15a comprises an annular groove 16 for receiving a K-shaped seal 23. A K-shaped seal ensures good sealing against fluids and dust. Such a seal shape can also facilitate centering, by avoiding a loss of load. The presence of the annular groove 16 allows the seal 23 to be correctly positioned, which improves centering.

[0081] The male part 15a comprises a tip which is in the form of a hollow cylinder. It comprises a wall delimited by an external surface and an internal surface. The internal surface of the hollow cylinder is cylindrical.

[0082] The female part 15b is carried by the first part 11 of the casing. It comprises a bore formed in the part 11 of the casing.

[0083] The assembly also comprises one or more seals arranged between each of the first 11 and second 12 casing parts. This or these seals provide dust-tightness. In the example described, the assembly comprises a peripheral seal 25, as illustrated in [Fig.2b]. The fluid connection 15 is here located outside the perimeter of the peripheral seal 25. The peripheral seal provided by this seal improves the seal of the interior volume of the casing.

[0084] The hydraulic connection can be made outside the peripheral seal, which can allow two seals between the passage of cooling fluid and the internal volume of the casing, namely the seal provided by the peripheral seal 25 on the one hand and on the other hand the seal provided by the seal 23 of the hydraulic connection mentioned above, carried by the part male.

[0085] In the example described, the second casing part 12 has a cooling fluid outlet towards the first casing part 11 and is devoid of a cooling fluid inlet coming from the first casing part 11.

[0086] In this example, the second casing part 12 comprises an inlet 17 for cooling fluid coming from an external supply, and the first casing part comprises an outlet 18 for cooling fluid to an external discharge.

[0087] Thus, the single cooling fluid inlet 17 is located on the second housing part and the single cooling fluid outlet 18 is located on the first housing part. This configuration is advantageous insofar as it allows the cooling fluid to be supplied as a priority to the inverter 2, which allows more efficient cooling thereof.

[0088] When the assembly is observed in the position of use, for example in an electric vehicle, the second housing part 12 is arranged above the first housing part, as illustrated.

[0089] The inverter 2 is mechanically supported by the second casing part 12. The second casing part acts as a mechanical support for the inverter and is not a simple closing cover for the casing, as clearly visible in [Fig. 1c]

[0090] The casing 10 is formed as explained above by assembling the first casing part 11 and the second casing part 12. When assembled, the first casing part and the second casing part form an enclosed interior space in which the inverter 2 is housed.

[0091] [Fig. 5] illustrates an alternative embodiment in which the peripheral seal 25 is positioned outside the fluid connection 15.

Claims

Claims

1. Assembly (1) of rotating electrical machine, comprising: - a rotating electrical machine, - an inverter (2), and - a casing (10) comprising a first casing part (11) covering the electrical machine and a second casing part (12) covering the inverter, the first and second casing parts (11, 12) providing circulation of a cooling fluid, in particular water, to cool the assembly, comprising between them at least one fluid connection (15), the fluid connection (15) comprising a male part (15a) fitting onto a female part (15b), the male part (15a) being made in one piece with the casing (10), one of the male part (15a) or the female part (15b) carrying a seal, in particular an O-ring or K-ring, the seal obtained being radial.

2. Assembly according to the preceding claim, comprising a single (15) fluid connection (15) between the first and second housing parts (11, 12).

3. Assembly according to one of the preceding claims, the fluid connection (15) being housed in the casing (10).

4. Assembly according to one of the preceding claims, the male part (15a) comprising an end piece, which is in particular a hollow cylinder.

5. Assembly according to one of the preceding claims, the male part (15a) being made in one piece with the second part (12) of the casing.

6. Assembly according to one of the preceding claims, the female part (15b) being carried by the first part (11) of the casing.

7. Assembly according to one of the preceding claims, the male part carrying a seal, in particular an O-ring or K-ring.

8. Assembly according to one of the preceding claims, the male part (15a) comprising an annular groove (16) for receiving a sealing gasket (23), in particular toric or K-shaped.

9. Assembly according to one of the preceding claims, the second part (12) of the casing comprises an inlet (17) for cooling fluid coming from an external supply, and the first part (11) of casing comprising an outlet (18) of cooling fluid towards an external discharge.

10. Assembly according to one of the preceding claims, the second casing part (12) comprising a cooling fluid outlet towards the first casing part (11) and being devoid of a cooling fluid inlet coming from the first casing part.

11. Assembly according to one of the preceding claims, comprising a peripheral seal (25), the fluid connection (15) being in particular located outside the perimeter of the peripheral seal.

12. Assembly according to one of the preceding claims, the casing providing an axial opening for the passage of a shaft of the rotating electrical machine and being devoid of any other axial opening.

13. Assembly according to one of the preceding claims, the inverter (2) being mechanically supported by the second part (12) of the casing.

14. Assembly according to one of the preceding claims, the inverter (2) comprising a printed circuit board housed in the second part (12) of the casing.

15. An assembly according to any one of the preceding claims, the machine comprising stator winding conductors, at least a portion of the stator winding conductors of the machine, or even a majority of the stator winding conductors of the machine, being in the shape of a U-shaped or I-shaped pin.

16. Rotating electrical machine assembly (1), comprising: - a rotating electrical machine, - an inverter (2), and - a casing (10) comprising a first casing part (11) covering the electrical machine and a second casing part (12) covering the inverter, the first and second casing parts (11, 12) providing circulation of a cooling fluid, in particular water, to cool the assembly, comprising between them at least one fluid connection (15), the fluid connection (15) comprising a male part (15a) fitting onto a female part (15b), the male part (15a) being made in one piece with the casing (10), one of the male part (15a) or the female part (15b) carrying a K-shaped seal.

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