FR2830994A1 - Winding for rotary electrical machine and stator using the winding, uses windings with tapered rectangular cross section for easier fitting into stator slots - Google Patents

Abstract

The winding is a hollow rectangle in plan view. The long sides of the rectangle are joined by the short sides of the rectangle. The interior faces (5a,5b) of the short sides and the interior faces (4a,4b) of the long sides are non-parallel, although they are each symmetric about a median plane. The convergent faces simplify fitting the winding into the stator slots.

Description

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 The present invention relates to rotating electrical machines and more particularly, but not exclusively, coils intended to be used in such machines and produced independently of the magnetic core on which they will be engaged.

 Such coils, also called individual coils, may in particular be arranged on the teeth of a stator magnetic circuit of a rotating machine having a concentric rotor and stator.

 There is a need to benefit from a coil which can be easily manufactured and whose mounting on the stator and the connection to the electrical conductors of current collection or supply can be performed easily, especially when the stator teeth have a section transverse which decreases towards their free end.

 The invention aims in particular to meet one or more of these needs.

 The subject of the invention is therefore a new coil for a rotating electrical machine, comprising at least one winding of at least one electrical conductor, this winding forming a plurality of turns, this coil having two large opposite inner faces united by two small inner faces. opposed, the coil being characterized in that the small inner faces are non-parallel.

 The presence of these non-parallel faces is advantageous especially when the coil is intended to be engaged on a tooth having a decreasing cross section towards its free end, and that the large opposite inner faces converge towards one side of the coil. In this case, by making the coil so that the small inner faces converge towards the opposite side, it is possible to wind the electrical conductor from the opposite side to that towards which the large inner faces converge, without fearing that the thread does not slip on the shape of the winding. It is thus easier to make a coil in which the end of the nearest electrical conductor, in the radial direction of the tooth, that is to say the end, has been used as a starting point for Winding operation, is on the side of the base of the tooth, that is to say the bottom of a notch and not the side of its free end. Thus, the electrical connection of the coil can be facilitated. In particular, it is possible to avoid having to pass the electrical conductor inside the turns and the length of the coil may be reduced. The machine can

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risque d'être abîmés par les outils utilisés pour le réusinage. On obtient facilement. grâce t > à l'invention, des bobines dont les deux extrémités de raccordement sont situées du côté de la base de la dent, ce qui facilite les connexions électriques. then present a smaller footprint. Moreover, in case of reworking of the stator after installation of the coils, the electrical conductors of the coils are less exposed to

may be damaged by tools used for re-machining. We get easily. Thanks to the invention, coils whose two connection ends are located on the side of the base of the tooth, which facilitates the electrical connections.

 In a particular embodiment, the small inner faces may be symmetrical with respect to a median plane of the coil, perpendicular to the large inner faces. The small and large interior faces defining an interior space, the cross section of this space can be substantially rectangular, for example.

 In a particular embodiment, the large inner faces may be non-parallel.

 The large inner faces may be symmetrical with respect to a median plane of the coil, perpendicular to the small inner faces.

 The large inner faces can converge to one side of the coil and the small inner faces converge to the opposite side.

 In a particular embodiment, the coil having an insertion side on a stator tooth and an opposite side, the small inner faces may converge towards the insertion side and the large inner faces converge towards the opposite side.

 The coil may be formed by the winding of a single-stranded electrical conductor, of circular section for example, or by the winding of a multi-stranded electrical conductor, for example with seven strands of circular section, or with several parallel strands.

 The coil may have several concentric layers, including an even number of layers.

 The invention further relates to a rotating electric machine stator. characterized in that it comprises at least one coil as defined above.

 The subject of the invention is also a stator of a rotating electrical machine comprising a magnetic circuit comprising teeth and coils disposed on said teeth, each having connection ends, one of these connection ends corresponding to a radially located electrical conductor. on the inner side of the winding and the side of the tooth base, and the current collection or supply conductors, electrically connected to the electrical connection ends of the coils.

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 these conductors having reliefs for positioning the electrical connection ends of the coils.

 These reliefs may each have a general shape of L lying or U; in the latter case, the groove defined by the two branches of the U may be adapted to receive an electrical connection end of a coil.

 The collection conductors or current lead may each have a generally annular shape, possibly interrupted.

 In a particular embodiment, the stator comprises six current collection or supply conductors, each in the form of a ring portion. these six conductors being concentric. In general, the number of conductors may be twice the number of phases or at once the number of phases plus one.

 Each conductor for collecting or delivering current may present, for example over a major part of its length, a generally rectangular cross section. In such a cross section, the two long sides may be oriented parallel to the axis of the rotor or perpendicular to the axis of the rotor. When the long sides are oriented parallel to the axis of the rotor, the manufacture of the machine can be facilitated, as this can avoid bending the electrical connection ends of the coils.

 The aforementioned reliefs are for example formed in one piece with the rest of the conductor for collecting or supplying current, for example by cutting a sheet or a flat.

 Each collection or current supply conductor may comprise a connection lug made in one piece with the rest of the conductor. This connection lug may comprise, for example, a hole for fixing a lug of a power supply or current collection cable or two lateral extensions brought inwards by the crimping of a power cable or of current collection.

 In a particular embodiment, half of the conductors may comprise substantially straight connection tabs and the other half of the angled connection tabs. The substantially straight connecting tabs may be angularly offset and said bent tabs may also be angularly offset, with substantially the same angular offset as the substantially straight connecting tabs. Two legs belonging to two adjacent drivers

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 can be angularly offset by an angle close to that existing between two consecutive teeth.

 The teeth may have a non-constant width, and each tooth may have, for example, two opposite sides diverging away from the rotor, over at least a major part of their length, measured from the free end of the tooth, the teeth being devoid of polar blooms, still called horns.

 The teeth may have, near their free end, notches for the assembly of locking wedges of the reels engaged on the teeth.

 The invention further relates to a rotating electrical machine, characterized in that it comprises a stator as defined above.

 Such a machine may constitute a motor, or alternatively, a generator. or both.

 The invention further relates to a method of manufacturing a coil. characterized in that it comprises the following steps: - providing a form for winding, having a generally rectangular or trapezoidal cross section, having small faces. converging to a first side, - winding at least one conductive wire on said shape starting to perform the first turn of the first side of the form.

 In such a method, the form used for the winding may have two large non-parallel faces, converging towards a second side opposite the first.

 The form used for the winding, when it generally comprises a first pair of opposite faces which converges towards a given side, and a second pair of opposite faces which converges towards the opposite side, is advantageously achieved in at least two parts, to allow the extraction of the coil. These two parts may be contiguous for example along a separation plane to allow winding, such a separation plane extending for example obliquely to the axis of the coil and extending transversely to the long sides of shape. The form for winding may also have more than two parts. for example three parts. The different parts of the shape can be placed between two removable plates, in order to carry out the winding. The two plates can be connected by at least one rod, for example two or three rods, this or these rods passing through

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 said parts. At least one of the stems may pass through both a hole made in one of the parts of the shape and a hole made in another part of the shape.

 The invention also relates to a set of conductors for collecting and supplying current, usable with coils other than those defined above. which can be characterized in that it comprises a plurality of curved bent strips, each provided with reliefs for connecting connection ends of the coils.

 Other characteristics and advantages of the present invention will emerge on reading the following detailed description of non-limiting examples of implementation of the invention and on examining the appended drawing, in which: FIG. 1 schematically represents, in perspective, a coil made according to an exemplary embodiment of the invention; FIG. 2 is a schematic and partial view of an exemplary form that can be used for the operation of FIG. FIG. 3 is a section along III - III of FIG. 2; FIG. 5 is a sectional view of the magnetic circuit of a stator, FIG. the teeth are intended to receive the coils, - Figure 6 shows a detail of Figure 5, - Figure 7 schematically shows the complete stator, seen along its axis, - Figure 8 is a schematic perspective view of the stator of Figure 7, - FIG. 9 is a diagrammatic cross-sectional view along IX-IX of FIG. 7; FIG. 10 is a diagrammatic, perspective view of a current supply or current collection conductor; FIGS. 13 show various details of embodiment of the conductor of FIG. 10, - FIG. 14 represents, in isolation, all the conductors serving to supply the coils or to collect the current, FIG. 15 is an enlarged view of detail XV of FIG. FIG. 14; FIG. 16 shows in perspective the detail XVI of FIG. 14,

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- la figure 19 représente un détail de réalisation du conducteur de la figure 18. r~l
On a représenté sur la figure 1 une bobine 1 réalisée conformément i l'invention. FIG. 17 represents an alternative embodiment of the connection tabs used to connect the collection or current supply cables; FIG. 18 represents a variant embodiment of a conductor for collecting or supplying the current, and

FIG. 19 represents a detail of embodiment of the conductor of FIG. 18.
FIG. 1 shows a coil 1 made according to the invention.

 This coil 1 is manufactured, in the example described, by winding an electrical conductor constituted by an enameled copper wire 2, on a form 10 shown in FIGS. 2 to 4, this form 10 connecting two parallel plates 11 a and 11 b.

 The shape 10 is shown separately in plan view in FIG. 2 and between the plates 11a and 11b in longitudinal section in FIG. 3 and transverse in FIG.

 The coil 1 has an interior space 3 intended to allow its mounting on a tooth of a stator, as will be explained below, this space 3 having a geometry related to that of the form 10 used during winding, being delimited by two large inner faces 4a, 4b and two small inner faces 5a, 5b.

2 comprise par exemple entre environ 0, 2 et environ 5 mm2. It is not beyond the scope of the present invention when the wire 2 is replaced by a multi-stranded electrical conductor or of other than circular section, in particular flat or square, the passage section offered to the current by the electrical conductor being

2 for example between about 0.2 and about 5 mm 2.

 Adhesive strips 6 hold the turns of the coil waiting for its mounting on the stator.

 The X axis of the coil 1 is substantially coincident with the axis of the tooth which is intended to receive it. This axis X is also substantially perpendicular to the facing faces of the plates 1a and 1b and parallel to a normal Y to them.

 The shape 10 has, in a sectional plane perpendicular to the Y axis, a generally rectangular cross-section, being delimited by two large flat lateral faces 13a and 13b which are non-parallel and which converge in the direction of the plate 1 lb and by two small flat side faces 14a and 14b which are non-parallel and which converge towards the plate 11a.

 In FIGS. 2 to 4, the slopes of the lateral faces 13a, 13b, 14a and 14b of the

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 form 10 have been exaggerated, for the sake of clarity of the drawing. In practice, for example, the angle h that is made in the plane of Figure 4 each large side face 13a or 13b with the Y axis in the plane of Figure 3 may be between about 00 and about And the angle k that each small side face 14a or 14b makes with the Y axis may be, for example, between about 0 and about 20. The angle h is for example chosen equal to the angle made by the corresponding faces of the tooth intended to receive the coil with the axis of the tooth.

 The angle k may for example be equal to or greater than a few degrees at the angle h.

 The inclination given to the small lateral faces 14a and 14b makes it possible to wind the wire 2 starting with an end 7a placed in the corner formed by the small lateral face 14a and the plate 11a without fearing a sliding of the wire 2 on the form 10 slip that would occur if the slopes of the small side faces 14a and 14b were parallel to the Y axis, given the inclination of the large side faces 13a and 13b.

 Several concentric layers 1a, 1b, ..., Id can be wound on the form 10 by making round-trips between the plates 11a and 11b, as illustrated in FIGS. 3 and 4.

 If the number of concentric layers is even, that is to say that we made only round trips on the form 10 from the plate 11a, the second electrical connection end 7b can be located for example on the same side of the coil 1 as the end 7a.

 To allow removal of the coil of the form 10, the latter is made for example in at least two parts, for example two parts 10a and 10b as in the example shown.

 These two parts 10a and 10b are separated by a plane 10c which extends obliquely transversely to the long sides of the shape.

 The portion 10a is traversed by two bores 10d and 10e and the portion 10b is crossed by two bores 10fet 10g. Bores 10e and 10f are aligned. Two rods not shown are engaged in the bores 10d, 10g and a third rod is engaged in the bores 10e and 10g.

 These rods make it possible to ensure the cohesion and the relative positioning of the parts 10a, 10b and the maintenance of the plates 11a and 11b during the winding operation and

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 then allow the separation of these different elements to remove the coil. The form 10 shown in Figures 2 to 4 is only an example and can for example be realized in more than two parts, for example in three parts, the middle part can be removed once winding is complete .

 The coil 1 shown in Figure 1 has small inner faces 5a.

5b whose respective slopes converge to the same side (that which is apparent in Figure 1) of the coil that where are the connection ends 7a and 7b. This side is also the side by which the coil 1 is introduced on a tooth 21 of the stator 20, shown in FIGS. 7 to 9.

 The length of the large faces 13a and 13b at the plate 1a may for example be greater than a few millimeters to the dimension of the corresponding tooth measured along the axis of the rotor. The length of the large faces 13a and 13b may for example be greater than 5 mm approximately to the size of the tooth, which is relatively low and provides a compact machine.

 The fact of starting to wind on the side of the plate 11a, that is to say on the side of the tooth which is positioned in the bottom of the notches located on either side of the tooth on the stator, makes it possible to simplify the electrical connection of the coil. Indeed. if the winding was carried out starting from the plate 11b, the starting end of the wire is located, when the coil is made and placed on the stator tooth, radially inward with respect to the turns and on the side of the free end of the tooth.

 Such an end is then difficult to connect to an electrical conductor supply or collection of current, and may require to lengthen the coils to the detriment of the compactness of the machine, and / or to follow the wire a path that exposed to damage during the manufacture of the stator.

 In the example shown, the end 7a which is radially innermost with respect to the turns is located on the side of the coil which is placed in the bottom of the notches, and the aforementioned problem no longer exists. The other end 7b is radially outer, relative to the turns, and does not pose difficulties when connected. even if it is located on the side of the free end of the tooth, or in an intermediate position between the plates 1a and 11b at the end of the winding operation.

 The magnetic circuit of the stator 20 is constituted for example by a stack of magnetic sheets such as those shown in FIG. 5, this stack being

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 possibly housed in a magnetic envelope 23a or not. The teeth 21 of the magnetic circuit of the stator 20 may each be made with notches 25 in the vicinity of their free end, these notches being shown in dashed lines in FIG. 6, to allow the assembly of blocking wedges of the coils, not shown.

 The teeth 21, like the individual sheets used for the manufacture of the stator, have non-parallel sides 21a and 21b, as can be seen in FIG. 5, converging radially inwards. The angle between the sides 21a and 21b may for example be between about 0 and about 15, preferably being the same as the angle between the large inner faces 4a and 4b of the spool 1. The base of the door teeth reference 2 on the drawing, and their free end 21 d.

 The coils 1 are intended to be electrically connected to a plurality of conductors 30 for collecting or supplying the current.

 An example of these conductors 30 is shown separately in FIG.

 This conductor 30 is formed for example from a copper plate or flat formed by stretching, cutting and / or bending, the cutting operation to achieve reliefs 32 distributed along a strip 31 and a tab 33. The band 31 is bent for example on each side of the tab 33 to form an open ring having a broken area 38, as shown in Figure 10.

 The tab 33 comprises for example an end portion 34 which is folded back on itself, in order to double its thickness.

 In the example shown, half of the conductors 30 is made with a tab 33 forming two elbows 35 and 36, as can be seen in Figure 16, these two elbows being at right angles, one directed radially towards the outside and the other directed in the opposite direction to the band 31. Each lug 33 further comprises a hole 37 for fixing a power lug in the case of a motor or current collection in the case of a generator.

 It will be noted in FIG. 14 that the interrupted zones 38 of the various conductors 30 are angularly offset from one another, which makes it easier to give the set of conductors 30 a rigid shape.

 The conductors 30 are offset angularly relative to each other, so that the reliefs 32 are angularly positioned at the corresponding coils. Since there are twenty-four teeth in the illustrated example, the

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 angular offset is about 150. The tabs 33 which are bent and which belong to the three radially outermost conductors, are offset relative to each other by about 150, and the three non-bent tabs belonging to the three radially innermost conductors, are offset by compared to others of about 150. A non-bent tab is located substantially at the same angular position as a bent tab, being separated by two strips 31, as can be seen in Figure 16 in particular.

 The reliefs 32 each have, in front view, a U-shape for example, the two branches of the U defining a groove 39 whose width substantially corresponds to the diameter of the wire 2. The reliefs 32 could also have, for example, a shape L lying down. When the set of conductors 30 is in place on the stator, the reliefs 32 are grouped in pairs, two reliefs 32 of a pair belonging to different conductors 30, the spacing between two reliefs 32 of a pair corresponding substantially to the spacing between the connection ends 7a and 7b of a coil 1.

 The magnetic sheets are then assembled to form the magnetic circuit of the stator. Then the conductors 30 are reported on the magnetic circuit and the coils 1 placed on the teeth 21. Their connection ends 7a and 7b are then welded to the corresponding reliefs 32. Cables are, possibly before coating, electrically connected to the legs 33 and the assembly is then coated or impregnated with insulating resin according to the usual manufacturing techniques. The cables could also be connected after impregnation or resin coating.

 Of course, the invention is not limited to the implementation example which has just been described.

 In particular, the coil may have an interior space having a section other than generally rectangular, in particular an internal section of trapezoidal shape, particularly in the case of a discoid machine, the bases of the trapezium then corresponding to the inner small faces 5a and 5b of the example described above.

 The invention applies to the production of synchronous or asynchronous electric machines, motor and / or generators, with a magnetic circuit constituted by a stack of magnetic sheets or by molding a powder of a magnetic material, the supply current coils and / or generated by the latter may have a number

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 any of the phases.

 The teeth of the magnetic circuit of the stator can be made in one piece with a magnetic yoke or reported on the latter. The magnetic circuit may also be constituted by the assembly of sectors each having one or more teeth. The stator can be inside or outside.

 The supply or current collection conductors may comprise, for example, tabs for connecting electrical power supply or power collection cables which have a shape different from that shown in FIG.

 The legs can be bent or not. They may for example be made with two lateral extensions 33a and 33b bent so as to define a housing for receiving and crimping the end of an electric cable for collecting or delivering the current, as shown in FIG. 17.

 The supply or current collection conductors may be made by bending a strip 31 parallel to its plane, as illustrated in FIGS. 18 and 19. In such an example, the reliefs 32 serving to connect the electrical connection ends coils have radially directed grooves, which can avoid to bend at right angles the son of the coils to engage in said grooves.

 The stator can be embedded in an insulating resin after its manufacture.

Claims (29)

1. Coil for rotary electric machine having two large opposite inner faces (4a; 4b) joined by two small opposite inner faces (5a; 5b), characterized in that the small inner faces (5a; 5b) are non-parallel.  2. Coil according to claim 1, characterized in that the small inner faces are symmetrical with respect to a median plane of the coil, perpendicular to the large inner faces.  3. Coil according to claim 1 or 2, the small and large inner faces defining an interior space (3), characterized in that the cross section of said space (3) is substantially rectangular.  4. Coil according to any one of the preceding claims, characterized in that the large inner faces (4a, 4b) are non-parallel.  5. Coil according to the preceding claim, characterized in that the large inner faces (4a, 4b) are symmetrical with respect to a median plane of the coil perpendicular to the small inner faces (5a, 5b).  6. Coil according to any one of the preceding claims, characterized in that the large inner faces (5a, 5b) converge towards one side of the coil and in that the small inner faces (4a, 4b) converge towards the opposite side.  7. Coil according to any one of the preceding claims, the coil having an insertion side on a tooth (21) of a stator (20) and an opposite side, characterized in that the small inner faces (5a; 5b) converge towards the insertion side and in that the large inner faces (4a; 4b) converge towards the opposite side.  8. Coil according to the preceding claim, characterized in that an electrical connection end of the coil corresponds to a conductor which is radially inner, relative to all of the turns, and which is located on the insertion side.  9. Coil according to any one of the preceding claims, characterized in that it is formed by the winding of a single strand (2).  10. Coil according to any one of claims 1 to 8, characterized in that it is formed by the winding of a multi-stranded conductor.  11. Coil according to any one of the preceding claims, characterized <Desc / Clms Page number 13>  in that it has several concentric layers (la; 1b; le; Id).  12. Coil according to claim 11, characterized in that it comprises an even number of layers (la; 1b; lc; ld).  13. Stator of rotating electrical machine, characterized in that it comprises at least one coil (1) as defined in any one of the preceding claims.  14. Stator of rotating electrical machine comprising a magnetic circuit comprising teeth (21) and coils (1) as defined in any one of claims 1 to 12 disposed on said teeth, each having connection ends (7a; 7b), one of these connecting ends corresponding to an electrical conductor located on the radially inner side of the winding and on the side of the base (21c) of the tooth, and electrically connected conductors at the ends (7a; 7b). electrical connection of the coils (1), these conductors having reliefs (32; 32 ') for positioning the electrical connection ends (7a; 7b) of the coils (1).  15. Stator according to claim 14, characterized in that said reliefs (32; 32 ') each have a general shape of L lying or U, in the latter case the groove (39) defined by the two branches of the U being adapted to receive an electrical connection end (7a; 7b) of a coil.  16. Stator according to claim 14 or 15, characterized in that said conductors (30) each have a generally annular shape, possibly interrupted.  17. Stator according to any one of claims 14 to 16, characterized in that it comprises six concentric conductors (30), each in the form of a ring portion.  18. Stator according to any one of claims 14 to 17, characterized in that each conductor (30) has over a major part of its length a generally rectangular cross section, with two long sides oriented parallel to the axis of the rotor .  19. Stator according to any one of claims 14 to 17, characterized in that each conductor has on a major part of its length a generally rectangular cross section, with two long sides oriented <Desc / Clms Page number 14>  perpendicular to the axis of the rotor.  20. Stator according to any one of claims 14 to 19, characterized in that said reliefs (32; 32 ') are formed integrally with a strip (31; 31') of the conductor (30).  21. Stator according to any one of claims 14 to 20, characterized in that each conductor (30) comprises a connecting lug (33) formed integrally with a strip (31; 31 ') of the electrical conductor. .  22. Stator according to claim 21, characterized in that two connecting tabs belonging to two adjacent conductors (30) are angularly offset by an angle close to that existing between the axes of two consecutive teeth.  23. Stator according to any one of claims 14 to 22, characterized in that the teeth (21) have a non-constant width.  24. Stator according to the preceding claim, characterized in that each tooth (21) has two opposite sides (21a; 21b) which diverge away from the rotor, over at least a major part of their length, measured from the free end (2 Id) of the tooth.  25. Stator according to any one of claims 14 to 24, characterized in that the teeth have, near their free end (21d), notches (25) for mounting the blocking wedges of the coils engaged on the teeth.  26. Rotating electrical machine, characterized in that it comprises a stator as defined in any one of claims 14 to 25.  27. A method of manufacturing a coil, characterized in that it comprises the following steps: - providing a form (10) for the winding, having a generally rectangular or trapezoidal cross section, having small faces (14a; ) non-parallel, - wind at least one conductive wire (2) on said form (10), starting to perform the first turn of the side (lla) of the form (10) to which said faces (14a; 14b) converge.  28. Method according to the preceding claim, characterized in that the shape has two large faces (13a; 13b) non-parallel, converging towards the side (lib) opposite that (11a) to which converge said small faces (14a; 14b). ). <Desc / Clms Page number 15>  29. The method of claim 27 or 28, characterized in that the shape (10) is formed in at least two parts (10a; 10b).