FR3045232A1 - ROTATING ELECTRIC MACHINE STATOR WITH WIND INSULATION INSULATION - Google Patents

Abstract

The invention relates mainly to a stator (9) of rotating electrical machine comprising: - a stator body (16), in particular in the form of a bundle of sheets, having an axis (X), - said stator body ( 16) comprising a yoke and teeth distributed angularly along an inner periphery of said yoke, - a coil (17) comprising at least one coil (50), characterized in that said stator (9) comprises at least one cheek (61) having a first axial end face (611) disposed against an end face of said stator body (16) and a second axial end face (612) opposite said first face, said flange (61) having at least one an interface structure (69), said interface structure (69) having first and second electrically conductive connection pads (75, 76) for electrically connecting respectively to said input end portion (58); ) and said portion of outlet end (59) of said coil (50).

Description

ROTATING ELECTRIC MACHINE STATOR WITH A JOUE

The invention relates to a stator of a rotating electrical machine provided with a coil insulating cheek. The invention finds a particularly advantageous, but not exclusive, application with electric motor vehicle compressors.

In known manner, the rotating electrical machines comprise a stator and a rotor secured to a shaft. The rotor may be integral with a driving shaft and / or driven and may belong to a rotating electrical machine in the form of an alternator, an electric motor, or a reversible machine that can operate in both modes.

The rotor comprises a body formed by a stack of sheets of sheet metal held in pack form by means of a suitable fastening system. The rotor has poles formed by permanent magnets housed in cavities in the rotor body.

Furthermore, the stator is mounted in a housing configured to rotate the shaft for example by means of bearings. The stator comprises a body consisting of a stack of thin sheets forming a crown-shaped yoke whose inner face is provided with notches open towards the inside to receive phase windings.

In a distributed corrugated type winding, the windings are obtained for example from a continuous wire coated with enamel or from conductive elements in the form of pins connected together by welding. Alternatively, in a "concentric" type winding, the phase windings are constituted by closed coils on themselves which are wound around the teeth of the stator. These windings are polyphase windings connected in star or delta whose outputs are connected to a control electronics.

Rotating electrical machines are known that are coupled to a shaft of an electric compressor. This electric compressor makes it possible to compensate, at least in part, for the loss of power of the reduced-displacement heat engines used on many motor vehicles in order to reduce their consumption and the emissions of polluting particles (so-called "downsizing" principle in English). For this purpose, the electric compressor comprises a turbine disposed on a duct upstream or downstream of the heat engine to allow the air to be compressed in order to optimize the filling of the cylinders of the heat engine. The electric machine is activated to drive the turbine in order to minimize the torque response time, in particular during the transient phases during acceleration, or in the automatic restart phase of the engine after a standby ("stop and start" operation in English).

However, given the small dimensions of the electrical machine, the interconnection between the ends of the coils and Γinterconnecteur is difficult to achieve industrially because of the need to maintain the ends of the coils in position during welding while the latter have some elasticity. In addition, in the case where the stator body is poorly electrically isolated vis-à-vis its environment, there is significant risk of short circuit between the winding and the stator body. The invention aims in particular to remedy these drawbacks by proposing a stator of a rotating electrical machine comprising: a stator body, in particular in the form of a bundle of sheets, having an axis, said stator body comprising a cylinder head and teeth distributed angularly along an internal periphery of said yoke, - a coil comprising at least one coil, said coil comprising: - a portion wound around a tooth, - an inlet end portion, - a portion of output end, characterized in that said stator comprises: - at least one cheek having a first axial end face disposed against an end face of said stator body and a second axial end face opposite said first face, said cheek comprising at least one interface structure, said interface structure comprising first and second electrically conductive connection tabs intended to be e respectively electrically connected to said input end portion and said output end portion of said coil. The invention thus makes it possible to guarantee effective electrical insulation of the stator body while ensuring, due to the fixed positions of the connection tabs, positioning under control of the input and output end portions of the coils during the production. electrical connections with an interconnector ensuring the coupling of the coils to form the different phases of the electric machine.

In one embodiment, the cheek is overmolded on the connection tabs.

According to one embodiment, the tabs project, in particular axially, with respect to the second axial end face.

According to one embodiment, said interface structure comprises: a first means for holding the input end portion of said coil, and a second means for holding the output end portion of said coil; said holding means being arranged to each hold one of the end portions of the spool during winding of the spool.

This facilitates the hooking of the wires during the winding operation so that it is possible to make all the coils in a single pass.

According to one embodiment, each holding means is disposed at a first height relative to the first face, a second height axially separating the first and second faces, the first height being strictly lower than the second height. In other words, the holding means is set back from the second face.

In one embodiment, each holding means projects radially relative to the cheek.

According to one embodiment, said first and second holding means each comprise a hook. Alternatively, the holding means are formed by lugs or anchor pads.

According to one embodiment, said hooks are made of an electrically insulating material.

According to one embodiment, each hook is made of material with a corresponding connecting tab.

According to one embodiment, said interface structure comprises a first guide element of the input end portion of said coil, and - a second guide element of the output end portion of said coil, - said elements guide means being arranged to guide each one of the end portions of the coil during welding of said end portions to the respective connector tabs.

According to one embodiment, said first and second guide elements each comprise a guide groove extending axially along an axis parallel to the axis of said stator body. Alternatively, the guide elements may be formed by guide lugs, in particular protruding radially relative to the cheek, pairs of pins, an elastic clamp, or a plastic form V-shaped.

According to one embodiment, said cheek comprises isolation means for isolating the coil relative to the stator body.

In one embodiment, this insulation is obtained by walls covering the internal faces of a notch resulting from a plastic extrusion. Alternatively, this insulation can be achieved by a paper insulation, less optimal for the manufacturing process of the machine. Alternatively, the insulation can be provided by overmolding the sheet package.

According to one embodiment, said interface structure comprises first and second thinned portions positioned on the farthest side of said stator body, said first and second thinned portions being intended to respectively receive said input end portion and said portion. output end of said coil.

This makes it possible to prevent the input and output end portions from protruding radially from the interface structure when these end portions are electrically connected to a corresponding tab or when the wire is bent so as to cooperate with a corresponding holding means.

According to one embodiment, each holding means is disposed at a corresponding thinned portion.

In one embodiment, each holding means protrudes axially relative to the base of the thinned portion.

In one embodiment, said cheek comprises an annular portion positioned along a circumference of said cylinder head.

In one embodiment, said cheek comprises at least one arm positioned along an end face of a tooth.

According to one embodiment, said annular portion and said arm are made of an electrically insulating material.

According to one embodiment, said stator comprises a plurality of coils each mounted around a corresponding tooth of the stator body.

According to one embodiment, said cheek comprises as many interface structures as coils, each interface structure being associated with a single corresponding coil. The invention also relates to an assembly characterized in that it comprises: - a stator as defined above, and - an interconnector comprising electrical terminals, - each end portion of the input or output of the coils being positioned between a connecting tab of said cheek and an electrical terminal of said interconnector.

According to one embodiment, each end portion of the input or output of the coils is soldered to a connecting tab of said cheek and to a corresponding electrical terminal of said interconnector. The subject of the invention is also a stator of a rotating electrical machine comprising: - a stator body, in particular in the form of a bundle of sheets, having one axis, - said stator body comprising a yoke and teeth distributed angularly according to an inner periphery of said yoke, - a coil comprising at least one coil, said coil comprising: - a portion wound around a tooth, - an input end portion, - an output end portion, characterized in that said stator comprises: at least one cheek disposed against an end face of said stator body, said cheek comprising at least one interface structure, said interface structure comprising: a first guiding element the input end portion of said coil, and a second guide element of the output end portion of said coil. said guide elements being arranged to guide each one of the end portions of the coil during the welding of said end portions to the respective connection tabs. The invention further relates to a stator of a rotating electrical machine comprising: - a stator body, particularly in the form of a bundle of sheets, having an axis, - said stator body having a yoke and teeth angularly distributed according to a internal periphery of said yoke, - a coil comprising at least one coil, said coil comprising: - a portion wound around a tooth, - an input end portion, - an output end portion, characterized in that said stator comprises: at least one cheek disposed against an end face of said stator body, said cheek comprising at least one interface structure, said interface structure comprising: a first means for maintaining the input end portion of said coil, and second means for holding the output end portion of said coil, said holding means being arranged to each maintain one of the extr Moth the coil during a coil winding.

According to one embodiment, each end portion of the input or output of the coils is soldered to a connecting tab of said cheek and to a corresponding electrical terminal of said interconnector.

According to one embodiment, said machine comprises a rotor provided with buried permanent magnets for example four in number.

According to one embodiment, said rotor body has an outer periphery delimited by a cylindrical face of external diameter between 20 mm and 50 mm, in particular between 24 mm and 34 mm, and preferably of the order of 28 mm.

According to one embodiment, said machine has a response time of between 100 ms and 600 ms, in particular between 200 ms and 400 ms, for example being of the order of 250 ms to go from 0 or 5000 to 70,000 revolutions / min.

In one embodiment, plating elements are interposed between the rotor body and each permanent magnet. The invention will be better understood on reading the description which follows and the examination of the figures which accompany it. These figures are given for illustrative but not limiting of the invention.

Figure 1 is a sectional view of an electric compressor comprising a rotary electric machine according to the present invention;

Fig. 2 shows a perspective view of the stator body of the rotating electrical machine according to the present invention;

Figure 3 is a perspective view illustrating the positioning of the cheek installed on one end of the stator body;

Figure 4 is a perspective view of the insulating cheek according to the present invention alone;

Figures 5a, 5b, and 5c are views illustrating the different steps for coupling between coil ends and terminals of an interconnector;

Figure 6 shows a perspective view of the rotor of the rotating electrical machine according to the present invention;

Fig. 7 is a cross-sectional view of the rotor of the rotating electrical machine according to the present invention.

Identical, similar or similar elements retain the same reference from one figure to another.

FIG. 1 shows an electric compressor 1, comprising a turbine 2 equipped with fins 3 able to suck, via an inlet 4, uncompressed air coming from an air source (not represented) and to repress the compressed air via the outlet 5 after passing through a volute referenced 6. The output 5 may be connected to a distributor (not shown) located upstream of the engine to optimize the filling of the cylinders of the engine. In this case, the suction of the air is performed in an axial direction, that is to say along the axis X1 of the turbine 2, and the discharge is carried out in a radial direction perpendicular to the axis X1 of the turbine 2. Alternatively, the suction is radial, while the discharge is axial. Alternatively, the suction and the discharge are made in the same direction relative to the axis of the turbine (axial or radial). For this purpose, the turbine 2 is driven by an electric machine 7 mounted inside the housing 8. This electric machine 7 comprises a stator 9, which may be polyphase, surrounding a rotor 10 with the presence of an air gap 11. This stator 9 is mounted in the housing 8 configured to rotate a shaft 12 through bearings 13. The shaft 12 is rotatably connected to the turbine 2 and the rotor 10. The stator 9 is preferably mounted in the housing 8 by hooping.

In order to minimize the inertia of the turbine 2 during an acceleration request from the driver, the electric machine 7 has a short response time of between 100 ms and 600 ms, in particular between 200 ms and 400 ms. , for example being of the order of 250ms to go from 0 or 5000 to 70000 revolutions / min. Preferably, the operating voltage is 12V or 48V. Preferably, the electric machine 7 is able to provide a current peak, that is to say a current delivered over a continuous period of less than 3 seconds, between 150 A and 300 A, in particular between 180 A and 250 A These current values are valid for a voltage of 12V.

Alternatively, the electric machine 7 is able to operate in alternator mode, or is a reversible type electric machine.

As can be seen in FIG. 3, the stator 9 comprises a body 16 and a coil 17. The X-axis stator body 16 consists of an axial stack of plane sheets. More precisely, as is better seen in FIG. 2, the stator body 16 is delimited radially by an internal cylindrical face 21 and by an outer cylindrical face 22. The body 16 is moreover defined axially by end faces 23 and 24.

The body 16 has teeth 27 distributed angularly in a regular manner on an inner periphery of a yoke 28. These teeth 27 delimit notches 29, so that each notch 29 is delimited by two successive teeth 27. The yoke 28 thus corresponds to the solid outer annular portion of the body 16 which extends between the bottom of the notches 29 and the outer periphery of the stator 9.

The notches 29 open axially into the axial end faces 23, 24 of the body 16. The notches 29 are also radially open in the internal cylindrical face 21 of the body 16.

The teeth 27 of the stator 9 are preferably with parallel edges, so that the internal faces facing each other of the notches 29 are inclined with respect to each other.

Preferably, the stator 9 is provided with toothed feet 34 on the side of the free ends of the teeth 27. Each tooth root 34 extends circumferentially on either side of a corresponding tooth 27.

The stator 9 is an unsegmented piece made of laminated sheets of magnetic material. In addition, the teeth 27 come from material with the yoke 28. Alternatively, the stator 9 may however be segmented, that is to say that it is made from several angular segments assembled together. Alternatively, the stator may be monobloc (non-laminated).

The stator body 16 is preferably formed by an axial stack of sheet-metal sheets 37 each extending in a radial plane perpendicular to the axis X. The sheets 37 are held by fixing members 41 for forming a set manipulable and transportable. For this purpose, a plurality of fixing holes 40 are made in the stator body 16 to allow each passage of a fastener 41 of the sheets of the stator body 16. In this case, the fixing holes 40 are preferably through, that is to say that they open axially on each of the axial ends 23, 24 of the stator body 16, so that it is possible to pass inside each fixing hole 40 a rod 41 provided with a head or not 42 at one of its ends and whose other end or both will be (are) deformed (s) for example by a method of pegging to ensure the axial retention of the package of sheets. Alternatively, the sheets may be held together by buttoning, or bonding, or laser welding.

As can be seen in FIG. 3, to form the winding 17 of the stator 9, a plurality of phase windings are formed by coils 50, here six in number, each mounted around a tooth 27. Each coil 50 is formed starting from an electrically conductive wire 51. In this case, the winding 17 is of the three-phase type, each phase being in particular made by two diametrically opposed coils 50.

More specifically, each coil 50 comprises a wound portion 57 around a tooth 27, an inlet end portion 58, and an outlet end portion 59. The electrical insulation between the plate pack 16 and the coils 50 is provided in particular by an insulating cheek 61 having a first axial end face 611 disposed against an end face of said stator body 16 and a second axial end face 612 opposite to said first face 611.

As can be seen in FIGS. 3 and 4, the flange 61 has an annular portion 62 intended to be positioned along a circumference of the yoke 28, and a plurality of arms 65 intended to be positioned each along a side of the yoke. end of a tooth 27. The annular portion 62 and the arms 65 are made of an electrically insulating material. The arms 65, each positioned between an end face of a tooth 27 and a corresponding coil 50, thus provide electrical insulation between a coil 50 and the stator body 16. The arms 65 are preferably each provided with a flange 66 extending on the side of their free end intended to cooperate with a corresponding tooth root 34. The arms 65 may also be extended by insulating walls 67 clearly visible in FIG. 4 intended to cover the inner faces of the teeth 27 delimiting the notches 29. The walls 67 have a U-shape intended to fit into a corresponding notch 29 . Alternatively, the cheek 61 is devoid of insulating walls 67, the insulation of the interior of the notches 29 then being provided by insulating paper. Alternatively, the insulation can be provided by overmolding the stator body 16.

The flange 61 also includes a plurality of interface structures 69 each having a body 71 projecting from the annular portion 62. Each interface structure 69 is associated with a single corresponding coil 50. Each interface structure 69 is positioned on the side of the end of a corresponding arm 65 coming from the annular portion 62. The annular portion 62, the arms 65, and the bodies 71 of the interface structures 69 preferably form a single piece obtained by molding.

In this case, the body 71 of each interface structure 69 comprises a first guide element 72 of the inlet end portion 58 of the coil 50, and a second guide element 73 of the end portion. the first and second guide members 72, 73 are each constituted by a guide groove extending axially along an axis parallel to the axis X of the stator body 16.

Alternatively, the guide elements 72, 73 may be formed by guide tabs, in particular protruding radially relative to the cheek, pairs of pins, a resilient clip, or a plastic form V-shaped.

The interface structure 69 also comprises a first electrically conductive tab 75 and a second connection pad 76 intended to be electrically connected respectively to the input end portion 58 and to the output end portion 59 of the coil. 50. The body 71 of the interface structures 69 is made of an insulating material overmolded on the corresponding connection tabs 75, 76. The tabs 75, 76 project, in particular axially, with respect to the second face 612 of axial end.

A first 77 and a second 78 hooks are made of material each with a connecting lug 75, 76 corresponding. These hooks 77, 78 are intended to respectively maintain the inlet end portion 58 and the outlet end portion 59 of the spool 50 during a winding operation.

As illustrated in FIG. 4, each hook 77, 78 is disposed at a first height H1 relative to the first face 611, a second height H2 axially separating the first and second faces 611, 612, the first height H1 being strictly lower than the second height H2. In other words, the hooks 77, 78 are set back with respect to the second face 612. Each hook 77, 78 projects radially relative to the body of the interface structure 69. Each hook 77, 78 is arranged at the level of a corresponding thinned portion 81, 82. Each hook 77, 78 protrudes axially relative to the base of the thinned portion 81, 82 corresponding. Alternatively, the holding means 77, 78 are formed by lugs or anchor pads around which can be wound an end portion 58, 59 of a coil wire 51. Alternatively, the hooks 77, 78 may be made of an electrically insulating material.

During a winding operation, one of the end portions 58, 59 is held by one of the hooks 77, 78 in order to have an anchor point during the winding operation of the thread 51 around the corresponding tooth 27 during the winding operation. Then once the coil 50 is formed, the other end portion 58, 59 is held by the other hook 77, 78 (see Figures 3 and 5a). Prior to the welding operation, the end portions 58, 59 are straightened so as to be positioned in the grooves 72, 73 and pressed against the tabs 75, 76, as shown in FIG. 5b.

Then, as shown in FIG. 5c, an interconnector 86 is positioned in such a way that each end portion 58, 59 is positioned between a connection tab 75, 76 and an electrical terminal 85 belonging to said interconnector 86. end 58, 59 is then welded to a connecting lug 75, 76 and a corresponding electrical terminal 85, by means of welding electrodes coming to pinch each end portion 58, 59 between these two elements. This ensures, because of the fixed positions of the connection tabs 75, 76, a positioning under control of the input end portion 58 and the output portion 59 when the electrical connections are made with the interconnector 86 ensuring the coupling of the coils 50 between them to form the different phases of the electric machine.

In addition, a first 81 and a second 82 thinned portions of the body 71 are positioned in each interface structure 69 on the farthest side of the stator body 16. The thinned portions 81, 82 are intended to receive respectively the portion of the inlet end 58 and the outlet end portion 59 of the spool 50. This prevents the inlet end portion 58 and the outlet end portion 59 from protruding radially from the interface structure 69 when these portions end 58, 59 are each electrically connected to a corresponding lug 75, 76 or when the wire 51 is bent so as to cooperate with a corresponding holding means 77, 78, in particular when an end portion 58, 59 is positioned in the space delimited by a hook 77, 78.

On the other hand, the rotation axis rotor Y shown in detail in FIGS. 6 and 7 is permanent magnets. The rotor body 91 comprises a sheet package consisting of an axial stack of sheets. The rotor body 91 can be rotatably connected to the shaft 12 in various ways, for example by force-fitting the splined shaft 12 into the central opening 92 of the rotor 10, or using a keyed device.

The rotor 10 of the buried magnet type 93 comprises a plurality of cavities 96 in each of which is housed at least one permanent magnet 93. The magnets 93 are radially magnetized, that is to say that the two parallel faces the one relative to one another having an orthoradial orientation are magnetized so as to be able to generate a magnetic flux in a radial orientation with respect to the Y axis.

As is clearly visible in FIG. 7, where the letters N and S respectively correspond to the North and South poles, the magnets 93 located in two consecutive cavities 96 are of alternating polarity.

Furthermore, the magnets 93 do not completely fill the cavities 96, so that there are two empty spaces 97 on either side of a given magnet 93 in a orthoradial direction. The volume of air delimited by all the spaces 97 of the rotor makes it possible to reduce the inertia of the rotor 10 and to optimize the magnetic flux.

The magnets 93 are preferably made of rare earth in order to maximize the magnetic power of the machine 7. Alternatively, however, they can be made of ferrite according to the applications and the desired power of the electric machine 7. Alternatively, the magnets 93 can be of different shades to reduce costs.

In addition, plating elements 98 are interposed between the rotor body 91 and each magnet 93, to ensure the maintenance of each permanent magnet 93 inside the corresponding cavity 96. The plating elements 98 are positioned on the side of the Y axis of the rotor 10. In a variant, the plating elements 98 could be positioned on the side of the gap 11 of the electric machine.

Each plating element 98 is constituted by an elastically deformable curved spring blade. Alternatively, the plating element 98 is constituted by a pin, a spiral spring, or a spring mounted compressed by crushing along its height between the rotor body 91 and the permanent magnets 93.

Of course, the foregoing description has been given by way of example only and does not limit the scope of the invention which would not be overcome by replacing the different elements by any other equivalent.

Claims (15)

1. Stator (9) of rotating electrical machine comprising: - a stator body (16), in particular in the form of a bundle of sheets, having an axis (X), - said stator body (16) comprising a cylinder head (28) and teeth (27) angularly distributed along an inner periphery of said yoke, - a coil (17) comprising at least one coil (50), said coil (50) comprising: - a wound portion (57) around a tooth (27), an inlet end portion (58), an outlet end portion (59), characterized in that said stator (9) comprises: - at least one cheek (61) ) having a first axial end face (611) disposed against an end face of said stator body (16) and a second axial end face (612) opposite said first face (611), - said flange ( 61) having at least one interface structure (69), said interface structure (69) having a first and a second connecting lugs (75, 76) el electrically conductive means for electrically connecting respectively to said inlet end portion (58) and said outlet end portion (59) of said spool (50). 2. Stator according to claim 1, characterized in that the cheek (61) is overmolded on the connecting tabs (75, 76). 3. Stator according to claim 1 or 2, characterized in that the tabs (75, 76) project, in particular axially, relative to the second face (612) axial end. 4. Stator according to any one of claims 1 to 3, characterized in that said interface structure (69) comprises: - first holding means (77) of the input end portion (58) of said coil (50), and - a second holding means (78) of the output end portion (59) of said coil (50), - said holding means (77, 78) being arranged to each maintain a end portions (58, 59) of the spool (50) during winding of the spool (50). 5. Stator according to claim 4, characterized in that each holding means (77, 78) is disposed at a first height (H1) relative to the first face (611), a second height (H2) separating axially the first and second faces (611, 612), the first height (H1) being strictly lower than the second height (H2). 6. Stator according to any one of claims 1 to 5, characterized in that said interface structure comprises a first guide element (72) of the input end portion (58) of said coil (50) and a second guide element (73) for the output end portion (59) of said coil (50), said guide elements (72, 73) being arranged to guide each of the end portions (58, 59) of the spool (50) during welding of said end portions (58, 59) to the respective connector lugs (75, 76). 7. Stator according to claim 6, characterized in that said first and second guide elements (72, 73) each comprise a guide groove extending axially along an axis parallel to the axis (X) of said body stator (16). 8. Stator according to any one of claims 1 to 7, characterized in that said cheek comprises isolation means (67) for isolating the coil relative to the stator body. 9. Stator according to any one of claims 1 to 8, characterized in that said interface structure (69) comprises a first (81) and a second (82) thinned portions positioned on the farthest side of said stator body (16), said first and second thinned portions (81, 82) being adapted to respectively receive said input end portion (58) and said output end portion (59) of said spool (50). 10. Stator according to any one of claims 1 to 9, characterized in that said flange (61) comprises an annular portion (62) positioned along a circumference of said yoke (28). 11. Stator according to any one of claims 1 to 10, characterized in that said flange (61) comprises at least one arm (65) positioned along an end face of a tooth (27). 12. Stator according to claims 10 and 11, characterized in that said annular portion (62) and said arm (65) are made of an electrically insulating material. 13. Stator according to any one of claims 1 to 12, characterized in that it comprises a plurality of coils (50) each mounted around a corresponding tooth (27) of the stator body (16). 14. Stator according to claim 13, characterized in that said flange (61) comprises as many interface structures (69) as coils (50), each interface structure (69) being associated with a single coil (50). ) corresponding. 15. An assembly characterized in that it comprises: - a stator (9) as defined according to any one of claims 1 to 14, and - an interconnector (86) comprising electrical terminals (85), - each portion of input end (58) or output (59) of the coils (50) being positioned between a connecting tab of said cheek (61) and an electrical terminal (85) of said interconnector (86).