STATOR FOR A ROTATING ELECTRICAL MACHINE

Abstract

A rotary electric machine includes a stator housed in a housing, the stator having a stator body formed by a stack of stator laminations, the laminations are generally non-circular and being angularly offset with respect to each other, so as to form spaces with the housing, the housing having ducts for the flow of a coolant, and said spaces also being used for the flow of the coolant.

Claims

1. The rotary electric machine, comprising a stator housed in a housing, the stator comprising a stator body formed by a stack of stator laminations, the laminations being generally non-circular and being angularly offset with respect to each other, so as to form spaces with the housing, the housing comprising ducts for the flow of a coolant, and said spaces also being used for the flow of the coolant.

2. The machine according to claim 1, wherein the laminations are substantially polygonal.

3. The machine according to claim 2, wherein the laminations having truncated corners.

4. The machine according to claim 1, wherein the laminations of the stator body being coated with a protective coating.

5. The machine according to claim 1, wherein the housing comprises an exterior sleeve and an interior sleeve between which are formed ducts for the coolant.

6. The machine according to claim 1, wherein the coolant is glycol water.

7. The machine according to claim 1, wherein the stator comprises a winding embedded in resin.

8. The machine according to claim 7, wherein a part of the winding facing the rotor and furthest from a central plane of the machine, perpendicular to the axis of rotation, not being coated in the resin.

9. The machine according to claim 7, further comprising a conductive ring positioned between the winding of the stator and the housing.

10. The machine according to claim 7, further comprising a separating liner positioned between the stator winding and the rotor.

11. The machine according to claim 1, further comprising at least one circuit forming a passage for the coolant around the winding.

12. The machine according claim 11,wherein the circuit comprises at least one fin configured to send a cooling gas towards a rotor of the machine.

13. The machine according to claim 1, wherein the housing forms an interior space of the machine, configured to be pressurized.

14. The machine according to claim 13, wherein the machine comprises an inner fan, which is positioned on a shaft of the machine or on the rotor, on one side of the stator and the rotor, in the interior space of the machine.

15. The machine according to claim 1, wherein the machine comprises a rotor forming an interior cooling circuit with at least one delivery passage and at least one return passage, through which a cooling gas can pass.

16. The machineMachine according to claim 1, further comprising at least one end flange, or two end flanges, at least one flange comprising passages for the flow of a coolant.

17. The machine according to claim 16, wherein the end flange comprises the passages for the flow of a coolant, comprising a plate of material for redirecting the cooling gas coming from the delivery passage of the rotor towards the return passage of the rotor.

18. The machine according to claim 17, wherein the machine comprises a diffuser insert fastened to the end flange comprising the passages for the flow of a coolant, configured to guide the cooling gas coming from the delivery passage of the rotor towards the plate of material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0078] The invention will be better understood on reading the following detailed description of non-limiting exemplary embodiments thereof, and from examining the appended drawing, in which:

[0079] FIG. 1 is a partial schematic longitudinal cross-sectional view of a machine according to the invention,

[0080] FIG. 2 is a partial schematic transverse cross-sectional view of the machine in FIG. 1,

[0081] FIG. 3 is a similar view to FIG. 1 of a variant embodiment,

[0082] FIG. 4 is a partial schematic transverse cross-sectional view of the machine in FIG. 3,

[0083] FIG. 5 is a similar view to FIG. 1 of a variant embodiment,

[0084] FIG. 6 is a similar view to FIG. 1 of a variant embodiment,

[0085] FIG. 7 is a partial schematic transverse cross-sectional view of the machine in FIG. 6.

DETAILED DESCRIPTION

[0086] In the description hereinafter, identical elements or identical functions have the same reference sign. For the sake of concision, they will not be described with respect to each of the figures, and only the differences between the embodiments will be described. For the sake of clarity, the figures do not always show the actual proportions.

[0087] FIG. 1 shows a first example of a rotary electric machine according to the invention. The machine 1 comprises a rotor 40, a stator 10 and a housing 20 extending along a longitudinal axis X of rotation of the machine. It is cooled by the flow of a coolant.

[0088] The housing 20 forms an interior space inside which the stator 10 and the rotor 40 are accommodated. The housing comprises an exterior sleeve 21 and an interior sleeve 22 between which are formed ducts 25 for the coolant. In this example, the coolant is glycol water.

[0089] The stator 10 comprises a stator body 11 formed by a stack of stator laminations 12, the laminations 12 of the stator 10 being generally non-circular and angularly offset with respect to each other, so as to form spaces 15 with the housing, as can be seen in FIG. 1.

[0090] The laminations can be offset one by one or, as a variant, in groups of two or more laminations. The groups can comprise two laminations or more than two laminations.

[0091] Despite the staggered arrangement of the laminations of the stator body 11, it is also ensured that the slots of the stator also remain correctly aligned with each other, as illustrated in FIG. 2.

[0092] In addition, the laminations 12 are coated with a protective coating, in particular a lacquer or an adhesive, which makes it possible to prevent any risk of corrosion, in particular due to contact with the coolant, and to ensure satisfactory sealing between the laminations, and prevent any leaking of coolant towards the rotor, through the stator, and in particular between the laminations 12.

[0093] The spaces 15 of the stator 10 are also used for the flow of the coolant. The coolant can thus flow in the housing 20, in particular in the ducts 25 thereof provided to this end, and between the housing 20 and the stator body 11, in the spaces 15 formed between the housing 20 and the laminations 12.

[0094] Such flow is sealed. Sealing can be obtained by a sealed closure between the housing and the stator body.

[0095] In addition, the stator comprises a winding 17 embedded in resin.

[0096] The machine also includes conductive ring 30, here made from aluminium, positioned between the stator winding 17 and the housing 20, which makes it possible to promote heat conduction between the winding 17 and the housing 20, and thus improve the heat rejection produced in the stator winding. In addition, the conductive ring 30 also makes it possible to promote the sealing of the coolant flow, and prevent leaks towards the winding 17.

[0097] The machine also comprises an insulating plate 35 positioned between the conductive ring 30 and the winding 17. This is electrical insulation.

[0098] Finally, the machine comprises a separating liner 37 positioned between the stator winding and the rotor, fastened to the stator. This separating liner 37 makes it possible to prevent potential leaks towards the rotor, as well as leaks of lubricating oil.

[0099] The resin coating the winding can also close the spaces between the stator body and the housing, and thus ensure that it is sealed and prevent any leaking of coolant, as illustrated in the embodiment in FIGS. 3 and 4.

[0100] In the embodiment in FIGS. 3 and 4, the winding is not completely coated in the resin. There is one uncoated part, namely the part of the winding facing the rotor and furthest from a central plane of the machine, perpendicular to the axis of rotation X. This part of the winding can remain exposed to a gas present in the machine, in particular exposed to a cooling gas that will be described hereinafter.

[0101] As a variant, as illustrated in FIG. 5, the winding is completely coated in the resin.

[0102] In the example in FIGS. 3 and 4, the interior space of the housing is configured to be pressurized. Conversely, in the example in FIG. 5, the housing forms an interior space that is not pressurized. It can in particular be placed at ambient pressure. The interior space of the machine can in particular be filled with air.

[0103] In the two examples in FIGS. 3, 4 and 5, the machine comprises an inner fan 60, which is in positioned on a shaft of the machine, at a distance from the rotor 40, on one side of the stator and the rotor, in the interior space of the machine. The inner fan 60 allows the cooling gas to flow in the interior space of the machine.

[0104] In addition, in the example described in FIG. 4, the laminations are substantially polygonal, in the shape of a square, with four straight sides 12a, and four truncated corners 12b, which have an arc-shaped outline. The arc is centred on the axis of rotation of the machine. Here, the radius of the arc is the same for each corner of a lamination and for all of the laminations of the stator body.

[0105] For each corner of the laminations, the radius of the arc is substantially greater than the radius of the circle geometrically inscribed in the square perimeter of the laminations. In addition, this radius is sufficiently small so that on any two consecutive laminations, the corresponding arcs continue on from each other or are superposed and form a substantially continuous arc in an axial view of the stator, that is, when projected in a plane perpendicular to the axis of rotation of the machine, as can be seen in FIG. 4.

[0106] In addition, the laminations of the stator body are connected to each of the two adjacent laminations 12 by weld beads 19, in order to improve the holding thereof and strengthen the structure of the stator body 11. In the embodiment in FIGS. 3 and 4, the weld beads are 12 in number, every 30°, for a 48-slot stator.

[0107] FIGS. 6 and 7 show another variant embodiment, in which the conductive ring 30 has a reduced thickness, so as to leave space to accommodate a circuit 50 forming a passage 51 for the coolant around the winding 17. This circuit 50 is formed level with the winding overhangs, in order to further improve the cooling of the stator winding.

[0108] The circuit 50 also comprises static fins 52, configured to send a cooling gas towards the rotor 40 of the machine. The fins 52 make it possible to ensure that heat is exchanged between a cooling gas and the coolant, and thus promote the general cooling of the machine.

[0109] In addition, as illustrated in FIGS. 6 and 7, the machine comprises a rotor 40, forming an interior cooling circuit with delivery passages 41 and return passages 42 through which a cooling gas can pass. The cooling gas can be air.

[0110] In this example, the inner fan 60 comprises fins 61 positioned on an end plate of a rotor body of the rotor.

[0111] The machine also comprises two end flanges 71, 72 placed at the axial ends of the housing 20.

[0112] In this example, the end flange 71 comprises passages 75 for the flow of the coolant. The flow in the flange 71 is in fluid communication with the ducts 25 of the housing 20, as illustrated.

[0113] The other flange 72 is without such passages. The flange 72 without passages is situated on the same side of the stator as the fins 61 of the fan 60, and the flange 71 comprising the passages 75 is situated on the opposite side of the stator.

[0114] The flange 71 comprising the passages 75 for the flow of the coolant also comprises a static plate of material 77 for redirecting the cooling gas coming from the delivery passage 41 of the rotor towards the return passage 42 of the rotor.

[0115] Finally, the machine comprises a static diffuser insert 80, fastened to the flange 71 comprising the passages 75, configured to guide the cooling gas coming from the delivery passage 41 of the rotor towards the plate of material 77.

[0116] The cooling gas can be sucked into the return passage 42 of the rotor through the action of the fan 60 situated on the other side of the rotor.

[0117] The invention is not limited to the examples that have just been described.

[0118] In particular, the housing can be a different shape, for example square, hexagonal or octagonal.

[0119] The stator can comprise a different number of ducts, for example between 2 and 200.