FR3056350A1 - STATOR SEGMENT FOR ROTATING ELECTRIC MACHINE AND METHOD FOR PRODUCING CORRESPONDING COIL STATOR - Google Patents

Abstract

The invention relates mainly to a rotary electric machine stator comprising a plurality of segments (10) assembled together, each stator segment (10) being formed by a stack of sheets (11) and comprising at least one tooth (12). and a yoke portion (13), characterized in that said laminations (11) of the stator segments (10) are held by at least one axial holding member (16) advantageously positioned at said yoke portion (13) said stator segments (10).

Description

Holder (s): VALEO ELECTRIC EQUIPEMENTS MOTOR Simplified joint-stock company.

Extension request (s)

Agent (s): VALEO EQUIPEMENTS ELECTRIQUES MOTOR Simplified joint-stock company.

STATOR SEGMENT FOR A ROTATING ELECTRIC MACHINE AND METHOD FOR PRODUCING A CORRESPONDING COIL STATOR.

FR 3 056 350 - A1

The invention relates mainly to a rotary electric machine stator comprising a plurality of segments (10) assembled together, each stator segment (10) being formed by a stack of sheets (11) and comprising at least one tooth (12) and a cylinder head portion (13), characterized in that said sheets (11) of the stator segments (10) are held by at least one axial retaining member (16) advantageously positioned at said cylinder head portion (13) said stator segments (10).

STATOR SEGMENT FOR A ROTATING ELECTRIC MACHINE AND METHOD FOR PRODUCING A CORRESPONDING COILED STATOR

The present invention relates to a stator segment for a rotary electrical machine as well as to the method for producing a corresponding wound stator.

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

The rotor has poles formed for example by permanent magnets housed in cavities made in the magnetic mass of the rotor. Alternatively, in a so-called salient pole architecture, the poles are formed by coils wound around the rotor arms.

The stator comprises a body formed by a stack of sheets of metal sheets held in the form of a package by means of a suitable fixing system. The stator is mounted in a casing configured to rotate the shaft, for example by means of bearings. The stator comprises a body provided with a plurality of teeth defining notches, and a winding inserted in the notches of the stator.

The documents US8127430 and JP2014050236 describe a process for producing a wound stator according to which a winding is preformed before insertion of segments inside the spaces of the winding. More precisely, the preformed winding of generally cylindrical shape comprises interlaced conductors to form the various phase windings of the machine.

The conductors have axial portions intended to be inserted inside the notches. The axial portions are spaced angularly between them by a regular pitch. The conductors further include connecting portions extending in a circumferential direction and ensuring a connection between the ends of the axial portions.

A set of stator segments each provided with two teeth and a cylinder head portion are positioned around the winding. The segments are then brought radially inwardly towards the winding, so that the axial portions of the winding penetrate inside the notches defined by two successive teeth of the stator segments.

Maintaining the segments can then be ensured by means of a ring installed by shrinking around the external periphery of the body of the wound stator îo thus formed. The use of such a ring however requires the implementation of a complex and expensive assembly step.

The invention aims to effectively remedy this drawback by proposing a stator of a rotary electrical machine comprising a plurality of segments assembled together, each stator segment being formed by a stack of sheets and comprising at least one tooth and a portion of cylinder head, characterized in that said sheets of the stator segments are held by at least one axial holding member advantageously positioned at the level of said yoke portion of said stator segments.

The invention thus makes it possible, due to the use of at least one axial holding member, to facilitate the production of the wound stator by eliminating the use of the hooped ring. In addition, the various segments of the stator can be assembled using tools that are simple to handle to ensure the insertion of the retaining members.

According to one embodiment, said holding member consists of two half-25 rivets.

According to one embodiment, said holding member is a molding.

According to one embodiment, each stator segment comprises either rivets, or bulbs or a combination of the two.

According to one embodiment, said cylinder head portion of each stator segment has one end having a shape of cut substantially complementary to that of the other end of said cylinder head portion.

According to one embodiment, the cutting of the ends of the breech portion is asymmetrical with respect to a median plane of the tooth.

According to one embodiment, at least one sheet is positioned in the stack inversely with respect to the rest of the sheets.

According to one embodiment, the sheets are stacked alternately in a front direction and a back direction.

According to one embodiment, each stator segment is formed by at least two bundles of sheets, one of the bundles being constituted by a first stack of sheets in a recto direction, and the other bundle being constituted by a second stack in a verso direction.

According to one embodiment, each stator segment is formed from two packets of sheets having substantially the same axial height.

According to one embodiment, the holding members are positioned in assembly zones between two adjacent stator segments.

According to one embodiment, each stator segment is a one-piece assembly produced by gluing or any other mechanical fixing means.

According to one embodiment, each stator segment has at least two teeth.

According to another aspect, the subject of the invention is a method for producing a wound stator, characterized in that it comprises the following steps:

a step of producing a preformed winding from a set of interleaved conductors to form different phase windings, said conductors comprising axial portions intended to be inserted inside notches, and connection portions s 'extending in a circumferential direction and ensuring a connection between the ends of said axial portions,

a step of positioning stator segments around said preformed winding, each stator segment being formed by a stack of sheets and comprising at least one tooth and a cylinder head portion,

a step of radial insertion of the teeth of the stator segments inside spaces extending between two successive axial portions of said preformed winding, and

a step of inserting axial retaining members into corresponding openings made at the level of said yoke portion of said stator segments in order to axially hold said sheets of said adjacent stator segments.

The invention will be better understood on reading the description which follows and on examining the figures which accompany it. These figures are given only by way of illustration but in no way limit the invention.

Figure 1 shows a perspective view of a stator segment of an electric machine according to the present invention;

Figure 2a is a schematic representation of a two-part rivet used for the assembly of the stator segments according to the invention;

Figure 2b is a schematic representation of an assembly area between two adjacent stator segments;

Figure 3 is a schematic top view illustrating the cutting of the sheets forming the stator segment according to the present invention;

Figure 4 is a perspective view of a segment of stator teeth according to the present invention;

Figure 5 is a perspective view of a preformed winding used to make a wound stator according to the present invention;

FIG. 6 is a partial schematic view illustrating the insertion of the stator segments inside the spaces of the preformed winding;

FIG. 7 is a perspective view of the wound stator according to the invention obtained after the step of inserting the segments of FIG. 6.

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

As illustrated in FIG. 1, a stator segment 10 is formed by a stack of sheets 11 and comprises a tooth 12 and a corresponding cylinder head portion 13. The sheets 11 of the segments 10, in this case two adjacent segments 10, are held together by at least one axial holding member 16 advantageously positioned at the level of the cylinder head portion 13 of the segments 10.

The axial holding member 16 may be constituted by a rivet, or two half-rivets 17, 18 with a male half-rivet 17 cooperating with a female half-rivet 18 of corresponding shape, as shown in FIG. 2a.

The axial retaining member 16 may also take the form of a molding made up of male and female shapes made in the sheets 11. Each stator segment 10 may include either rivets, or molding, or a combination of the two.

In an exemplary embodiment, the breech portion 13 of each segment 10 has one end having a shape of cut substantially complementary to that of the other end of the breech portion 13. The cutting of the ends of the breech portion 13 is preferably asymmetrical with respect to a median plane Pm of tooth 12.

In order to obtain such a configuration, all the sheets 11 have the same shape in which each sheet 11 has a lateral projection. It will be possible to take advantage of this shape to limit the loss of material during cutting by nesting the shapes of two adjacent sheets 11 one inside the other as illustrated by FIG. 3.

At least one sheet 11 is positioned in the stack inversely with respect to the rest of the sheets 11, that is to say that at least one of the sheets 11 is positioned on the back side while the other sheets are positioned from the front side. If the so-called front face referenced 21 corresponds to the main extension face of the sheet 11 lying in the plane of the sheet of drawings in FIG. 3, the so-called back face corresponds to the opposite face referenced 22. The direction of so-called front stacking therefore corresponds to the placing of a sheet in the stack by its front side and the direction of said back stacking corresponds to the placing of a sheet in the stack by its back side. In other words, at least one of the sheets 11 has been pivoted 180 degrees along the axis of the tooth 12 relative to the other sheets 11 of the stack. Of course, the teeth 12 of all the sheets 11 of the stack forming a segment 10 are oriented radially in the same direction.

According to the embodiment of Figure 1, the sheets 11 are stacked alternately in a front direction and a back direction. Thus, the end of a cylinder head portion 13 can nest by form cooperation in the end of an adjacent cylinder head portion 13. Indeed, the sheets 11 projecting from one of the cylinder head portions 13 can be inserted into the corresponding spaces between two sheets 11 of the adjacent cylinder head portion 13.

In the exemplary embodiment of FIG. 4, each segment 10 is formed by at least two packets of sheets 101, 102. One of the packets 101 consists of a first stack of sheets 11 in a recto direction, and the other packet 102 is constituted by a second stack of sheets 11 in a reverse direction. In this case, the two packets of sheets 101, 102 have substantially the same axial height.

As illustrated in FIG. 2b, the holding members 16 can be positioned in the assembly zones 25 between two adjacent segments 10. To this end, the axial opening 26 produced in a cylinder head portion 13 is located axially in the extension of the corresponding axial opening 26 produced in the adjacent cylinder head portion 13. It is then possible to have inside of these openings 26 facing one another a retaining member 16 of rivet type or equivalent passing axially right through the ends of the cylinder head portions 13 of two adjacent segments 10 superimposed relative to each other.

The following describes, with reference to FIGS. 5 to 7, the method for producing a wound stator 30 according to the present invention. According to a first step, a preformed winding 31 having a generally cylindrical shape is produced from a set of interlaced conductors 32 to form the various phase windings of the machine, as shown in FIG. 5.

The conductors 32 comprise axial portions 35 intended to be inserted inside the notches 38 of the stator. The axial portions 35 are angularly spaced apart from one another by a regular pitch. The conductors 32 further comprise connecting portions 36 extending in a circumferential direction and ensuring a connection between the ends of the axial portions 35.

As illustrated in FIG. 6, a set of segments 10 i angularly spaced apart from each other in a regular manner are arranged around the coil 31 at a distance greater than that of the external diameter of the coil 31. Each segment 10 having the shape as above described could be a one-piece assembly made by gluing or any other mechanical fixing means.

The segments 10 are then brought together radially towards the inside of the winding, so that the teeth 12 penetrate inside the spaces 37 extending between two successive axial portions 35 of the winding. In order to facilitate the insertion of the segments 10 inside the spaces 37, the teeth 12 are advantageously devoid of tooth foot.

When the ends of the adjacent cylinder head portions 13 overlap each other by form cooperation, the axial holding members 16 are inserted into the corresponding openings 26 in order to hold the adjacent segments 10 together.

As illustrated in FIG. 7, once the stator 30 has been assembled, the teeth 12 of the segments 10 delimit two by two of the notches 38 in which the axial portions 35 of the winding 31 are positioned, while the cylinder head portions 13 are brought to end at the end form the yoke corresponding to the full external annular part of the stator body which extends between the bottom of the notches 38 and the external periphery of the stator 30.

As a variant, each segment 10 has two or more teeth 12 as described in particular in document US8127430.

Of course, the foregoing description has been given by way of example only and does not limit the scope of the invention from which one would not depart by replacing the various elements with any other equivalent.

Furthermore, the various features, variations, and / or embodiments of the present invention can be combined with one another in various combinations, insofar as they are not incompatible or mutually exclusive of each other.

Claims (14)

1. Stator (30) of a rotary electrical machine comprising a plurality of segments (10) assembled together, each stator segment (10) being formed by a stack of sheets (11) and comprising at least one 5 tooth (12) and a cylinder head portion (13), characterized in that said sheets (11) of the stator segments (10) are held by at least one axial retaining member (16) advantageously positioned at the level of said cylinder head portion (13) of said stator segments (10). 2. Stator according to Claim 1, characterized in that the said holding member (16) consists of two half-rivets (17, 18). 3. Stator according to claim 1, characterized in that said holding member (16) is a molding. 4. Stator according to any one of claims 1 to 3, characterized in that each stator segment (10) comprises either rivets (17, 18), 15 either bulbs or a combination of the two. 5. Stator according to any one of claims 1 to 4, characterized in that said yoke portion (13) of each stator segment (10) has one end having a shape of cut substantially complementary to that of the other end of said portion of cylinder head 20 (13). 6. Stator according to claim 5, characterized in that the cutting of the ends of the yoke portion (13) is asymmetrical with respect to a median plane (Pm) of the tooth (12). 7. Stator according to claim 5 or 6, characterized in that at least one sheet (11) is positioned in the stack in an inverted manner relative to the rest of the sheets (11). 8. Stator according to any one of claims 5 to 7, characterized in that the sheets (11) are stacked alternately in a front direction and a back direction. 9. Stator according to any one of claims 5 to 8, characterized in that each stator segment (10) is formed by at least two bundles of sheets (101, 102), one of the bundles (101) being constituted by a first stack of sheets (11) in a recto direction, and the other package (102) 5 being constituted by a second stack in a reverse direction. 10. Stator according to claim 9, characterized in that each stator segment (10) is formed of two packets of sheets (101, 102) having substantially the same axial height. 11. Stator according to any one of claims 1 to 10, îo characterized in that the holding members (16) are positioned in assembly zones (25) between two adjacent stator segments (10). 12. Stator according to any one of claims 1 to 11, characterized in that each stator segment (10) is a one-piece assembly produced by gluing or by mechanical fixing means. 15 13. Stator according to any one of claims 1 to 12, characterized in that each stator segment (10) comprises at least two teeth (12). 14. Method for producing a wound stator, characterized in that it comprises the following steps: 20 - a step of producing a preformed winding (31) from a set of interleaved conductors (32) to form different phase windings, said conductors (32) comprising axial portions (35) intended to be inserted into the interior of notches (38), and connecting portions (36) extending in a circumferential direction and 25 ensuring a connection between the ends of said axial portions (35), a step of positioning stator segments (10) around said preformed winding (31), each stator segment (10) being formed by a stack of sheets (11) and comprising at least one tooth (12) and a portion of cylinder head (13), A step of radial insertion of the teeth (12) of the stator segments (10) inside spaces (37) extending between two axial portions (35) successive of said preformed winding (31), and a step of inserting axial retaining members (16) into corresponding openings (26) formed at the level of said yoke portion (13) of said stator segments (10) in order to axially hold said sheets (11) of said segments stator (10) adjacent. 1/3