Axial flux rotating electrical machine

Abstract

The invention relates to an axial flux rotating electrical machine (1) having an axis of rotation (X), comprising:-at least one rotor (3); -at least one stator (2) arranged face-to-face with the at least one rotor in the axial direction forming an air gap, the stator comprising: o a plurality of electrical windings (10) inscribed between a radially inner contour (15) and a radially outer contour (16),-a housing (17) in which the stator (2) is placed,-a distribution chamber (30) for distributing a cooling fluid, in particular a dielectric fluid, the distribution chamber communicates with the housing via at least one injection opening (36) through an annular wall (22) of the housing, the annular wall surrounding a radially outer contour of the electrical winding, the injection opening (36) being configured to inject cooling fluid from the distribution chamber into the housing (17).

Description

Technical Field

[0001] The present invention relates to an axial flux rotating electrical machine, and more particularly to one configured to contribute to the propulsion of an electric vehicle. Background Art

[0002] Patent application US2021288554 discloses an axial flux electrical machine that includes a circulation system for circulating a cooling fluid in an air gap between a stator and a rotor. Summary of the Invention

[0003] The present invention seeks to improve the cooling of an axial flux rotating electrical machine.

[0004] Thus, one subject of the present invention is an axial flux rotating electrical machine having a rotation axis, comprising:

[0005] - at least one rotor,

[0006] - at least one stator, which is arranged facing the at least one rotor in an axial direction, forming an air gap, the stator comprising:

[0007] o a plurality of electrical windings, which are inscribed between a radially inner contour and a radially outer contour,

[0008] - a housing in which the stator is placed,

[0009] - a distribution chamber for distributing a cooling fluid, in particular a dielectric fluid, the distribution chamber being in communication with the housing through at least one injection opening passing through an annular wall of the housing, the annular wall surrounding the radially outer contour of the electrical windings, the injection opening being configured to inject the cooling fluid from the distribution chamber into the housing.

[0010] According to one aspect of the present invention, the distribution chamber is formed between an annular wall of the stator housing and a housing, in particular a gearbox housing.

[0011] Thus, the present invention enables the axial flux rotating electrical machine to be cooled by injecting fluid. A distribution chamber for distributing a flow of cooling fluid (such as oil) is provided between the inner wall of the gearbox and the outer wall of the stator housing. The present invention enables compact components to be provided while providing better heat dissipation due to the injection of the fluid.

[0012] According to one aspect of the present invention, the distribution chamber has an annular shape.

[0013] According to one aspect of the present invention, the distribution chamber is axially delimited by at least one seal, in particular two seals positioned such that they are offset along the rotation axis.

[0014] According to one aspect of the present invention, these seals bear against the wall of the housing on the one hand and against the annular wall of the housing on the other hand.

[0015] For example, the seal is silicone-based.

[0016] According to one aspect of the invention, one or more seals are of the O-ring type.

[0017] As a variant, one or more seals are of the flat washer type.

[0018] According to one aspect of the invention, the distribution chamber communicates with the housing through a plurality of injection openings.

[0019] According to one aspect of the invention, these injection openings are arranged around the circumference of the housing, in particular with a regular spacing between them.

[0020] According to one aspect of the invention, at least in some cases, the injection openings lead to the housing between two circumferentially adjacent windings of the stator.

[0021] If necessary, at least in some cases, the injection openings lead to the housing on the circumferential surface of one of the stator windings.

[0022] According to one aspect of the invention, the stator housing is formed by a housing body that includes a plurality of supports, on each of which a tooth carrying one or more stator windings is supported.

[0023] According to one aspect of the invention, the supports are positioned around the axis of rotation, in particular evenly.

[0024] According to one aspect of the invention, each tooth is axially interposed between the support of the housing body and the support of an independent support member.

[0025] According to one aspect of the invention, each support is bounded by two radial branches of the housing body.

[0026] According to one aspect of the invention, each tooth is circumferentially positioned between two adjacent radial branches.

[0027] According to one aspect of the invention, the branches extend linearly in the radial direction.

[0028] According to one aspect of the invention, the housing body includes an inner annular wall and an outer annular wall, and the radial branches defining the supports extend radially between the inner annular wall and the outer annular wall.

[0029] According to one aspect of the invention, the support for each tooth includes at least one support area on which the tooth, in particular the end of the tooth, is supported.

[0030] According to one aspect of the invention, an injection opening for injecting a cooling fluid is arranged to be vertically aligned with a branch of the housing body.

[0031] Thus, the cooling fluid is ejected into the space between two adjacent teeth.

[0032] According to one aspect of the invention, at least one branch includes a baffle configured to divide the flow of the cooling fluid from the ejection opening into two flows directed towards two windings located on either side of the branch.

[0033] According to one aspect of the invention, the deflector is formed by a protrusion of the branch, in particular in the form of a rib.

[0034] According to one aspect of the invention, the distribution chamber includes a coolant inlet formed in the housing, and the inlet particularly includes a connector fitting configured to connect a coolant supply pipe.

[0035] According to one aspect of the invention, the housing includes a coolant outlet formed in the housing defining the stator housing.

[0036] According to one aspect of the invention, the coolant outlet includes a groove in the housing.

[0037] Another subject of the invention is an assembly comprising an axial flux rotating electric machine as described above and a gearbox provided with a housing, the axial flux rotating electric machine being received in a housing portion of the housing. Description of the Drawings

[0038] With reference to the accompanying schematic drawings, further features, details and advantages of the invention will become more apparent by reading the detailed description given below and by way of non-limiting illustration by means of a plurality of exemplary embodiments, wherein:

[0039] Figure 1 is a schematic perspective view of an axial flux rotating electric machine received in a gearbox housing according to an exemplary embodiment of the invention;

[0040] Figure 2 is Figure 1 a schematic side view of the axial flux rotating electric machine;

[0041] Figure 3 is Figure 1 a schematic front view of the axial flux rotating electric machine;

[0042] Figure 4 is Figure 1 a schematic partial perspective view of the housing of the axial flux rotating electric machine;

[0043] Figure 5 is Figure 1 a schematic partial cross-sectional view of the assembly. Detailed Description

[0044] Described already is an axial flux rotary electric machine 1 of the permanent magnet type having a rotational axis X, comprising a stator 2 and two rotors 3, the rotors 3 being placed on each side of the stator 2 and axially facing the stator 2. The stator 2 and the rotors 3 are visible in a Figure 5 cross-sectional view.

[0045] In the example described, the axial flux electric machine 1 is configured to operate in motor mode and in generator mode. In this case, it is a permanent magnet synchronous motor for electric vehicle propulsion.

[0046] Figure 1 Shown is an assembly 100, which includes the axial flux rotary electric machine 1 and a gearbox 110 provided with a housing 111, the axial flux rotary electric machine 1 being received in a housing portion 112 of the housing 111.

[0047] As is known, each rotor 3 includes a plate carrying a plurality of permanent magnets, the permanent magnets having a substantially sector-shaped profile.

[0048] The stator 2 includes a plurality of electrical windings 10, a plurality of teeth 50 carrying these electrical windings 10. The housing 12 is configured to support the plurality of teeth 50.

[0049] The windings 10 on the teeth 50 together form the integral winding of the stator, for example a winding of the three-phase type. These windings 10 are produced by multiple turns of wire wound around each tooth.

[0050] Each tooth 50 includes radially stacked grain-oriented electrical steel laminations.

[0051] As a variant, each tooth is made of a soft magnetic composite material (SMC), in particular obtained by sintering.

[0052] The windings 10 are configured to be powered so as to generate a magnetic field capable of producing an output torque together with the rotors 3 of the axial flux electric machine 1.

[0053] A resin, in particular an epoxy resin, can be deposited on the turns of the windings 10.

[0054] The electrical windings 10 are inscribed between a radially inner profile 15 and a radially outer profile 16.

[0055] The housing 12 forms a casing 17 for receiving the stator 2 and the rotors 3.

[0056] As Figure 5 shown, a distribution chamber 30 for distributing a dielectric cooling fluid is formed between an annular wall 22 of the housing 12 and the housing 111.

[0057] The distribution chamber 30 communicates with the casing 17 via injection openings 36 and 37 passing through the annular wall 22 of the casing 17, the annular wall 22 surrounding the radially outer profile 16 of the electrical windings 10.

[0058] These injection openings 36 and 37 are configured to inject the cooling fluid from the distribution chamber 30 into the housing 17.

[0059] The distribution chamber 30 has an annular shape around the housing 12.

[0060] The distribution chamber 30 is axially delimited along the axis X by two annular seals 38, which are positioned such that they are offset along the axis of rotation X.

[0061] These seals 38 bear against the inner wall 115 of the housing 111 on the one hand and against the annular wall 22 of the housing 12 on the other hand.

[0062] For example, the seals 38 are silicone-based.

[0063] The injection openings 36 and 37 are arranged around the periphery of the housing 17 with a regular spacing between them.

[0064] The housing 12 includes a plurality of supports 40, on each of which a tooth 50 carrying the stator winding 10 is supported.

[0065] These supports 40 are evenly arranged around the axis of rotation X.

[0066] Each tooth 50 is axially interposed between a support 40 of the housing 12 and a similar support of a support member (not shown) on the other side of the tooth.

[0067] Each support 40 is delimited by two radial branches 41 of the housing 12. Each tooth 50 is circumferentially positioned between two adjacent radial branches 41.

[0068] The branches 41 extend linearly in the radial direction.

[0069] [[ID=3?]]The housing 12 includes an inner annular wall 43 and an outer annular wall 22, and the radial branches 41 defining the supports extend radially between the inner annular wall 43 and the outer annular wall 22.

[0070] Each support 40 of a tooth 50 includes at least one support area on which the end of the tooth 50 is supported.

[0071] Two sets of injection openings 36 and 37 are distinguishable, and these two sets of injection openings 36 and 37 are respectively arranged in two rows axially offset along the axis X, as Figure 2 shown.

[0072] In the case of the injection openings 36, these injection openings lead to the housing 17 on the circumferential surface 39 of each stator winding 10.

[0073] As for the injection openings 37, they lead to the housing 17 between two circumferentially adjacent stator windings 10.

[0074] Each of the cooling fluid injection openings 37 is arranged to be vertically aligned with one of the branches 41 of the housing 12.

[0075] Thus, the cooling fluid is injected into the space between two adjacent teeth 50.

[0076] The branch 41 includes a baffle 44 configured to divide the flow of the cooling fluid from the injection opening 37 into two flows directed towards two windings 10 located on either side of the branch 41.

[0077] The baffle 44 is formed by a protrusion in the form of a rib of the branch 41.

[0078] The distribution chamber 30 includes a coolant inlet 47 formed in the housing 111, in the form of a connector fitting, which is configured for connection to a coolant supply pipe.

[0079] The outer housing 17 includes a coolant outlet 48 formed in the housing 12, in the form of two kidney-shaped slots 49. As Figure 3 shown, these slots 49 are adjacent to the outer periphery of the housing 12 at a low point to facilitate the discharge of the cooling fluid.

[0080] The fluid discharged from the outer housing 17 via these slots 49 is then discharged via a pipe 51 on the housing 111.

[0081] The slots can have different shapes and / or different numbers. The slots can be a single slot instead of two slots.

[0082] The openings 36 and 37 can be circular or alternatively elliptical. Their number can vary and they can also be arranged in different numbers of rows.

Claims

1. An axial flux rotating electrical machine (1) having a rotational axis (X), comprising: - at least one rotor (3); - at least one stator (2) which is arranged facing the at least one rotor in the axial direction, forming an air gap, the stator comprising: o a plurality of electrical windings (10) which are inscribed between a radially inner contour (15) and a radially outer contour (16), - a housing (17) in which the stator (2) is placed, - a distribution chamber (30) for distributing a cooling fluid, in particular a dielectric fluid, which is in communication with the housing via at least one injection opening (36, 37) passing through an annular wall (22) of the housing, the annular wall surrounding the radially outer contour of the electrical windings, the injection opening (36, 37) being configured to inject the cooling fluid from the distribution chamber into the housing (17).

2. The electric machine according to the preceding claim, wherein, The distribution chamber (30) is formed between an annular wall (22) of the stator housing and a housing (111) of a gearbox (110).

3. The electric machine according to any one of the preceding claims, wherein, The distribution chamber (30) is axially delimited by at least one seal (38), in particular two seals which are positioned such that they are offset along the rotational axis (X).

4. The electric machine according to any one of the preceding claims, wherein, The distribution chamber (30) is in communication with the housing (17) via a plurality of injection openings (36, 37).

5. The electric machine according to the preceding claim, wherein, These injection openings (36, 37) are arranged around the housing (17), in particular with a regular spacing between them.

6. The electric machine as claimed in the previous claim, wherein, At least in some cases, the injection openings lead into the housing between two circumferentially adjacent windings of the stator.

7. The electric machine according to any one of the preceding claims, wherein, The stator housing is formed by a casing (12) which comprises a plurality of supports (40), on each of which a tooth (50) carrying one or more stator windings is supported.

8. The electric machine according to the preceding claim, wherein, Each support (40) is delimited by two radial branches (41) of the casing.

9. The electric machine according to the preceding claim, wherein, One of the injection openings (37) for injecting the cooling fluid is arranged to be vertically aligned with one of the branches (41) of the casing.

10. The electric machine according to the previous claim, wherein, At least one branch comprises a baffle (44) which is configured to divide the flow of the cooling fluid from the injection opening into two flows which are directed towards two windings located on either side of the branch.

11. An assembly (100) comprising an axial flux rotating electrical machine (1) according to any one of the preceding claims, and a gearbox (110) provided with a housing (111), the axial flux rotating electrical machine being received in a housing part (112) of the housing.

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