STATOR FOR A ROTATING ELECTRICAL MACHINE

Abstract

A stator for a rotary electric machine, having a stator mass that has slots in which electrical conductors introduced axially into the slots are housed, each of the slots having a continuously closed contour.

Claims

1. A rotary electric machine having a stator and a permanent magnet rotor, the stator having a stator mass that has slots in which electrical conductors introduced axially into the slots are housed, each of the slots having a continuously closed contour.

2. The machine of claim 1, wherein the stator mass comprises teeth formed between the slots, which are connected to one another on a side of an air gap by bridges of material and on an opposite side by a yoke.

3. The machine of claim 2, wherein the bridges of material comprise at least one localized narrowing formed by at least one groove.

4. The machine of claim 1, wherein the electrical conductors are disposed in the slots in a distributed manner.

5. The machine of claim 1, wherein the electrical conductors comprise a transverse section of a rectangular overall shape.

6. The machine of claim 1, wherein each slot comprises two to eight electrical conductors.

7. The machine of claim 1, wherein the electrical conductors comprise pins that are U-shaped or I-shaped.

8. The machine of claim 1, wherein at least one slot comprises mutually parallel radial edges.

9. The machine of claim 1, wherein at least one slot comprises a transverse section of rectangular or hexagonal shape.

10. The machine of claim 1, further comprising at least one tooth having a transverse section of trapezoidal overall shape.

11. The machine of claim 1, wherein the stator mass comprises stacked magnetic laminations, with the slots formed in the stator mass by cutting the magnetic laminations of the stator mass.

12. The machine of claim 1, wherein the stator mass is produced at least partially by an additive manufacturing technique.

13. A stator for a rotary electric machine, having a stator mass that has slots in which electrical conductors introduced axially into the slots are housed, each of the slots having a continuously closed contour, at least one slot having a transverse section of hexagonal shape.

14. The rotary electric machine having a stator as claimed in claim 13 and a rotor.

15. A method for manufacturing a stator for a rotary electric machine, wherein electrical conductors are disposed in the slots of a stator mass of the stator by introducing them into the corresponding slots via one or both axial ends of the machine.

16. The method of claim 15, wherein either a single U-shaped electrical conductor is disposed in two different non-consecutive slots of the stator mass of the stator, or two I-shaped electrical conductors previously introduced into two different non-consecutive slots of the stator mass of the stator are connected to one another.

Description

DETAILED DESCRIPTION

[0107] The invention will be better understood on reading the following detailed description of nonlimiting exemplary embodiments thereof, and on studying the appended drawing, in which:

[0108] FIG. 1 is a partial and schematic perspective view of a stator produced in accordance with the invention,

[0109] FIG. 2 is a top view thereof, along the arrow II,

[0110] FIG. 3 is a partial and schematic perspective view of the electrical conductors of the stator in FIGS. 1 and 2, considered individually,

[0111] FIG. 4 shows a partial and schematic view in cross section of the stator mass of the stator according to the invention,

[0112] FIG. 5 partially and schematically shows a portion of the stator mass of the stator in FIG. 1,

[0113] FIG. 6 is a partial and schematic view in cross section of the stator, and

[0114] FIG. 7 illustrates a variant embodiment.

[0115] FIGS. 1 to 6 illustrate a stator 2 of a rotary electric machine 1 also having a rotor that is not shown. The stator makes it possible to generate a rotary magnetic field for driving the rotor in rotation, in the context of a synchronous motor, and, in the case of an alternator, the rotation of the rotor induces an electromotive force in the electrical conductors of the stator.

[0116] The examples illustrated below are schematic and the relative dimensions of the various constituent elements have not necessarily been respected.

[0117] The stator 2 has electrical conductors 22, which are disposed in slots 21 formed between teeth 23 of a stator mass 25. The notches 21 are closed, i.e. a complete circuit can be made around each slot 21 without meeting a cut in the stator mass. The slots 21 are closed on the side of the air gap by bridges of material 27, each connecting two consecutive teeth of the stator mass 25, and on the opposite side by a yoke 29. The latter and the teeth 23 are in one piece. The yoke 29 may be equipped if appropriate with semicircular longitudinal ribs 31 intended to house ducts for the circulation of a cooling liquid.

[0118] The electrical conductors 22 are disposed in the slots 21 in a distributed manner. They may be I-shaped or U-shaped.

[0119] The electrical conductors 22 are disposed in the slots 21 in an arranged manner, in one or more rows of aligned electrical conductors.

[0120] The electrical conductors may have a transverse section of rectangular overall shape, in particular with rounded corners. In the example described, they are radially superposed in a single row. The circumferential dimension of an electrical conductor corresponds substantially to the width of a slot. Thus, the slot has only a single electrical conductor in its width. It may have a plurality of electrical conductors in its radial dimension.

[0121] The electrical conductors 22 are made of copper or another conductive material that is enameled or coated with any suitable insulating coating.

[0122] In the example described, a slot has at least two electrical conductors with different phases. In the variant embodiment in FIG. 7, a slot has four electrical conductors.

[0123] Each electrical conductor 22 is surrounded by a sheet 37 of insulation that makes it possible to insulate the electrical conductors from the walls 33 and 36 of the slot and the electrical conductors 22 of different phases, as is visible in FIG. 6.

[0124] The slots 21, in the example described, have mutually parallel radial edges 33 and, in section in a plane perpendicular to the axis of rotation X of the machine, are substantially rectangular in shape.

[0125] The bottom 35 of the slots 21 has a shape that is substantially complementary to that of the electrical conductors 22, with the exception of a groove or a localized crushing 40. Below, reference will be made only to a groove, but it should be clearly understood that a localized crushing is also possible instead of the groove.

[0126] The bottom 35 of the slots 21 is connected to the radial edges 33 by rounded portions 38. The groove 40 of each slot 21 is centered on the bottom of the slot 35 and extends along the axis of rotation X of the machine. In a variant embodiment that is not illustrated, it is possible for the groove not to be centered, or the bottom 35 could have a plurality of grooves.

[0127] The grooves 40 have, in section in a plane perpendicular to the axis X, a curved shape that is in particular substantially semicircular. They have a depth p of between 0.2 mm and 1 mm, for example equal to 0.42 mm.

[0128] The grooves 40 form a localized narrowing of the bridges of material 27. Such a narrowing allows magnetic saturation of the lamination by a lower magnetic flux along the bridge 27, thereby limiting the passage of the magnetic flux.

[0129] The smallest width l of the bridges of material 27 is preferably between 0.3 mm and 0.6 mm, for example equal to 0.4 mm.

[0130] The stator mass 25 is formed of a pack of magnetic laminations that are stacked along the axis X, the laminations being, for example, identical and exactly superposed. They may be held together by clipping, by adhesive bonding, by rivets, by tie rods, by welds and/or by any other technique. The magnetic laminations are preferably made of magnetic steel. The teeth 23 of the stator mass 25 may have complementary reliefs on the surface allowing the various laminations that make up the stator mass 25 to be clipped to one another. As a variant, the stator mass may also be formed of one or more sheet-metal strips that are cut out and wound on themselves.

[0131] The stator may be obtained by means of a manufacturing method in which the electrical conductors 22 are inserted into the slots 21 via one or both axial ends of the stator, by sliding into the slots 21 along an axis parallel to the longitudinal axis X.

[0132] Of course, the invention is not limited to the exemplary embodiments that have just been described, and the rotor associated with the stator described may be a wound rotor or a permanent magnet rotor.

[0133] The expression “having a” should be understood to be synonymous with “comprising at least one”.