WO2019011759A1 - Rotary electric machine provided with a stator with hairpin winding - Google Patents

Abstract

The invention relates to a rotary electric machine including a rotor and a stator, the stator (100) including a stator body (110) that is provided with laminations and a plurality of slots (111) and a winding comprising: - a plurality of hairpins (121) that are connected to one another so as to form a plurality of phase windings, a central portion of the hairpins being housed in the plurality of slots, a collateral portion (124) of said hairpins being arranged outside the slots (111) in order to form a winding overhang (125) protruding from an axial end face (114) of the stator body; and - a plurality of inverting hairpins (130), each electrically connecting two distinct hairpins (121) that are housed in two distinct slots, the inverting hairpins (130) being positioned such that a greatest height (l) of each of said inverting hairpins (130) with respect to the axial end face (114) of the stator body (110) is smaller than or equal to a greatest height (L) of the winding overhang (125) with respect to said axial end face of the stator body.

Description

 ROTATING ELECTRIC MACHINE WITH A STATOR A

PIN WINDING

TECHNICAL AREA

The present invention relates to a rotating electrical machine whose stator comprises a pin winding. The invention finds applications in the field of rotating electrical machines for motor vehicles and, in particular, in the field of alternators, alternator-starters and e-machines.

STATE OF THE ART

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 alternator-type machine that can operate in the two modes.

 The stator is mounted in a housing configured to rotate the shaft on bearings by bearings. 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 comprises poles formed for example by permanent magnets housed in cavities formed in the magnetic mass of the rotor. Alternatively, in a so-called "salient" pole architecture, the poles are formed by coils wound around rotor arms.

 As shown in Figures 1 and 2, the stator 100 comprises a body 1 10 constituted by a stack of thin sheets forming a ring, the inner face is provided with notches 1 1 1 open radially inward to receive windings 120. These phase windings 120 pass through the notches 1 1 1 of the stator body and form a bun 125, 126 on either side of the stator body 1 10. The phase windings 120 are connected polyphase windings in star or delta, whose phase inputs / outputs 123 are connected to an electrical control module.

The phase windings 120 are obtained from conductive elements in the form of pins 121 interconnected electrically. Two pins 121 of a same winding are interconnected directly, for example by welding. Two phase windings 120 are interconnected by means of reversing pins 130, each reversing pin electrically connecting the last pin 121a of one windings with the first pin 121b of the other winding.

 A pin 121 has two branches connected by a curved head, or collateral portion, and whose intermediate rectilinear portions, or central portions, are placed in two different notches angularly offset from each other by a predetermined angle. The heads of the pins 121 are twisted and form the upper bun 125 - namely the bun provided with phase inputs / outputs, located upstream of the winding. The free ends of the branches are interconnected, for example by welding, and twisted to form the lower bun 126 - namely the bun downstream of the winding.

 Generally, the reversal pins 130 are located above the upper bun, that is to say in the axial extension of the winding, so as to connect two windings respectively having a first and a last pins positioned at a distance. one of the other. This axial location of the reversing pins 130 has the effect of substantially increasing the axial size of the coil.

The method of making a pin winding stator requires twisting the pins so as to tilt the ends of the pins forming the buns. For this, the heads of the pins positioned so as to form together an annular ring are twisted. After this first twisting pin heads, the crown is inserted into the stator body and the free ends of the pin branches are twisted. However, the twisting of the free ends of the pins, called second twisting, requires the use of a specific tool and wedges to maintain the pinheads without damaging the reversing pins. FIG. 3 represents an example of an upper bun 125 against which the specific tool and the wedges come to bear in order to allow the second twisting of the free ends forming the lower bun. This FIG. 3 shows, in particular, the line ZA which is the support zone on which the specific tool and the ZC housings which constitute the wedging zones into which the wedges are inserted so as to avoid damaging the bun. upper 125 during the second twisting. It will be understood that the use of this specific tool and holds only a difficulty of implementation, but also a significant cost both in the purchase of tools and labor.

SUMMARY OF THE INVENTION

To meet the aforementioned problems of axial space and difficult implementation, the applicant proposes a rotating electrical machine in which the reversing pins are positioned radially around the bun, on its inner periphery or on its outer periphery, so that they do not protrude axially from the bun.

 The stator region is referred to as the "inner periphery" of the stator, the area of the stator containing the cylindrical face directed towards the axis of rotation of the machine and located facing the rotor. The "outer periphery" of the stator is called the zone of the stator containing the cylindrical face furthest from the axis of rotation of the machine and opposite to the internal cylindrical face. By analogy, the inner periphery of the bun is the part of the bun located above the inner periphery of the stator and the outer periphery of the bun is the part of the bun located above the outer periphery of the stator.

 According to a first aspect, the invention relates to a rotating electrical machine comprising a rotor and a stator, the stator comprising a stator body provided with a bundle of sheets and a plurality of notches and a coil comprising:

 a plurality of pins connected together so as to form a plurality of phase windings, a central portion of the pins being accommodated in the plurality of notches, a collateral portion of said pins being arranged out of the notches to form a bun in protrusion on an axial end face of the stator body, and

 a plurality of reversing pins each electrically connecting two separate pins housed in two separate notches, the reversing pins being positioned such that a greater height of each of said reversing pins relative to the face axial end of the stator body is less than or equal to a greater height of the bun relative to said axial end face of the stator body.

The bunches are those portions of the pins that are not wedged into the stator slots and form a ring on the axial end faces of the stator. stator. The bun located upstream of the winding, called upper bun, is formed of pinheads. This upper bun is traversed by the reversing pins and the winding ends connected to the stator control module.

 The configuration of the reversing pins proposed in the invention makes it possible to reduce the height of the upper bun and thus reduce the overall size of the machine. It also makes it possible to simplify the second twisting operation of the bun pins since it avoids the use of specific tools and wedges.

 Advantageously, along a radius of the stator passing to the axis of a notch and centered on an inversion pin, the stator comprises in an orderly way a notch, the sheet bundle and the reversing pin.

 The term "centered" means that the radius of the stator is measured in the middle of a pin, in a plane orthogonal to the axis of rotation of the rotor.

 The rotary electrical machine according to the invention can comprise one or more of the following characteristics:

 - Each reversing pin is mounted in a radially outer region of the bun.

 - Each reversing pin is disposed in an area facing the axial end face of the stator body, so that the reversing pins are confined in the circumferential size of the stator.

 - The winding comprises a plurality of winding end pins, each of said end pins being mounted in a radially inner region of the bun.

 - Each reversing pin has two arms at least partially engaged in two separate notches and a central body connecting the two arms.

 the central body of each reversing pin is bent along a progressive radius of curvature.

 the central body of each reversing pin is disposed axially at a distance from the axial end face of the stator body or, on the contrary, close to the axial end face of the stator body.

in a plane parallel to the axial end face of the stator body, the largest width of a head of each reversing pin is less than the greater width of the collateral portions of the pins forming the hair bun.

 - Each reversing pin extends out of the notch, along a plane inclined relative to the plane in which the pins forming the bun extend.

the maximum height of each reversing pin with respect to an axial end face of the stator body is substantially equal to the height of the reversing pin. In other words, the space located axially between the stator body and the reversing pin is less than the height of the reversing pin.

 - The pins forming the bun have a U-shaped having two branches connected by a head.

 the inversion pins have a U-shaped shape comprising two arms connected by a head inclined with respect to the arms, so that the head is in a plane different from the plane containing the two arms,

 at least one reversing pin, in particular each reversing pin, comprises two portions of rectangular section each housed in a notch of the stator and at least one portion of rounded section between the two portions of rectangular section.

According to another aspect, the invention relates to a rotating electrical machine comprising a rotor and a stator, the stator comprising a stator body provided with a bundle of sheets and a plurality of notches and a coil comprising:

 a plurality of pins connected together so as to form a plurality of phase windings, a central portion of the pins being accommodated in the plurality of notches, a collateral portion of said pins being arranged out of the notches to form a bun in protrusion on an axial end face of the stator body, and

 a plurality of reversing pins each electrically connecting two separate pins housed in two separate notches and each comprising at least two sections of different shapes, at least a portion of each reversing pin having a rectangular section, a portion at least each reversing pin having a rounded section.

The configuration of the reversing pins proposed here makes it possible, on the one hand, to simplify the second operation of the bobbin pins by avoiding the use of specific tools and wedges and, on the other hand, to simplify the manufacture. of the reversing pins by limiting the folds generated during the bending of the electrical conductor.

 Advantageously, each reversing pin comprises two portions of rectangular section each housed in a notch of the stator and at least one portion with a rounded section between the two portions of rectangular section.

 Advantageously, each reversing pin comprises two arms and a central body connecting the two arms, each arm having one of the rectangular section portions, the central body having the round section portion. The rectangular section of the arms allows their wedging in the notches of the stator body. The rounded section of at least a portion of the central body allows a reduced bulk of the stator.

 The rotating electrical machine according to this other aspect of the invention may comprise one or more of the following features:

 - The portion of rounded section is flattened, for example by stamping, over a portion of a length of the central body.

 the reversing pins are positioned so that a greater height of each of said reversal pins with respect to the axial end face of the stator body is less than or equal to a greater height of the bun compared to said axial end face of the stator body. - Following a stator radius passing to the axis of a notch and centered on an inversion pin, the stator comprises in an orderly way a notch, the package of sheets and the reversing pin. The term "centered" means that the radius of the stator is measured in the middle of a pin, in a plane orthogonal to the axis of rotation of the rotor.

 - Each reversing pin is mounted in a radially outer region of the bun.

 each inversion pin is disposed in an area facing the axial end face of the stator body.

 - The winding comprises a plurality of winding end pins, each of said end pins being mounted in a radially inner region of the bun.

the central body of each reversing pin is bent along a progressive radius of curvature. in a plane parallel to the axial end face of the stator body, the largest width of a head of each reversing pin is less than the greater width of the collateral portions of the pins forming the bun.

 - Each reversing pin extends out of the notch, along a plane inclined relative to the plane in which the pins forming the bun extend.

- The pins forming the bun have a U-shaped having two branches connected by a head.

 - The reversing pins have a U-shaped having two arms connected by a head inclined relative to the arms, so that the head is in a plane different from the plane containing the two arms.

BRIEF DESCRIPTION OF THE FIGURES

Other advantages and characteristics of the invention will appear on reading the description, illustrated by the figures in which:

 - Figure 1, already described, schematically shows a perspective view of the stator of a machine according to the prior art;

 FIG. 2, already described, schematically represents a view of the upstream portion of the stator of a machine according to the prior art;

 - Figure 3, already described, shows a view of the upstream portion of the stator of Figure 2 on which are indicated the support zones and wedge insertion during the second twisting operation;

 FIGS. 4A and 4B show views, in perspective and from above, of the upstream portion of the stator of a rotating electrical machine according to one embodiment of the invention;

 FIG. 4C is a perspective view of a stator reversing pin of FIGS. 4A-4B;

 FIGS. 5A and 5B show views, in perspective and from above, of the upstream portion of the stator of a rotating electrical machine according to another embodiment of the invention;

 FIG. 5C is a perspective view of a stator reversing pin of FIGS. 5A-5B;

FIGS. 6A and 6B show views, in perspective and from above, of the upstream portion of the stator of a rotating electrical machine according to another embodiment of the invention;

 FIG. 6C shows a perspective view of a stator reversing pin of FIGS. 6A-6B. DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT

An exemplary embodiment of a rotating electrical machine, wherein the reversing pins are positioned radially around the bun, on its inner periphery or on its outer periphery, is described in detail below, with reference to the accompanying drawings. This example illustrates the features and advantages of the invention. However, it is recalled that the invention is not limited to this example.

 In the figures, the identical elements are identified by identical references. For questions of readability of the figures, the size scales between elements represented are not respected.

 The electrical machine according to the invention comprises a polyphase stator of axis X corresponding to the axis of the machine. The stator surrounds a rotor rotatably mounted on a shaft, as described in the state of the art. The stator 100, a portion of which is shown in FIGS. 4A-4B, 5A-5B and 6A-6B, comprises a body 1 10 formed of a bundle of sheets and a coil passing through the body 1 10. The body 1 10 is delimited by an inner periphery 1 12, or inner cylindrical face, an outer periphery 1 13, or outer cylindrical face, and two axial end faces. Only the upper axial end face 1 14 - upstream of the winding - is visible in Figures 4A - 6B. The body 1 10 is provided on its inner periphery 1 12, teeth 1 15 extending radially towards the rotor and delimiting pairs of notches January 1 for mounting the winding. Two successive slots 1 1 1 are separated by a tooth 1 15. The notches January 1 1 open axially in the axial end faces and radially in the inner cylindrical face 1 12 of the stator body 1 10.

The coil comprises a plurality of phase windings inserted into the notches January 1. Each phase winding has ends 123, called winding ends, which correspond to a phase winding input, a phase winding output or, in some configurations, a neutral point. The phase windings pass through the notches 1 1 1 and form, on each axial end face, a bun 125 extending projecting from both sides of the stator body 1 10.

 In the machine according to the invention, the phase windings are obtained from conductive elements in the form of pins, electrically connected to each other, for example by welding. Each pin has two branches connected by a head and having a U-shape. The free ends of the pin-branches are connected to the free ends of the preceding and following pin-branches and are twisted so as to form a lower bun projecting from the lower axial end face of the stator body, or downstream face. The pin heads 124 are also twisted and form the upper bun 125 protruding from the upper axial end face 1 14 of the stator body 1 10, or upstream face.

 Two phase windings are electrically connected to each other by means of an inverting pin 130. This reversing pin connects the last pin 121a of a phase winding with the first pin 121b. another phase winding. In the machine according to the invention, each reversing pin 130 is positioned radially along a portion of the bun 125, at the inner periphery or at the outer periphery of the bun. The reversal pins positioned at the outer periphery of the bun are wedged at the bottom of the notches 1 1 1 of the stator. The reversal pins positioned at the inner periphery of the bun are wedged at the mouth of the slots 1 1 1 of the stator. The reversal pins 130 are positioned at the periphery of the bun 125 so that the greatest height of each reversing pin 130 relative to the upper axial end face 14 is less than or equal to the greatest height of the bun greater than 125 relative to said upper axial end face 1 14. Each reversing pin 130 is therefore positioned next to the pin heads 124 and not above said pinheads, which allows not only facilitate the second twisting operation, but also to achieve a winding whose total height is equal to the distance between the upper bun 125 and the lower bun, the winding ends 123 are not included in the bun since they constitute connections to the stator control module.

Each inversion pin 130 has a U-shape with two arms 131 connected by a head 133, the head being inclined relative to the arms 131 so as to be positioned in a plane different from the plane containing the two arms 131. Fig. 4A, which shows a partial perspective view of the stator of the machine according to some embodiments of the invention, and Fig. 4B, which shows a top view of the stator portion of Fig. 4A, show a pin. inversion 130 radially offset relative to the pins forming the bun 125, on the outer periphery 1 13 of the stator body. Thus, according to a radius R of the stator passing to the axis of a notch January 1 and centered on the reversing pin 130, the stator comprises in an orderly way the notch, the package of plates and the pin of 'inversion.

 According to some embodiments, the reversing pin 130 is positioned facing the axial end face 1 14 of the stator body and comprises two arms 131 connected by a central body 132. Each reversing pin 130 is made by folding an electrical connector of rectangular section and predetermined length. Folding an inversion pin gives said pin oriented areas in different directions. Thus, the two arms 131 of each reversing pin are oriented axially. The two arms 131, substantially parallel to each other, are at least partially engaged in two separate notches 1 1 1. The arms 131 are each connected, for example by welding, to the central portion of one of the pins 121 forming the bun 125, for example to the pins 121a and 121b. The central body 132 comprises a head 133, oriented in a circumferential direction, and at least first and second elbows 134, 135 which each connect the head 133 to one of the arms 131. The elbows 134 and 135 may be identical or, conversely, different from each other, each of the elbows having curvatures adapted to connect the head 133 to an arm 131 while skirting the heads 124 of the pins 121 forming the bun 125.

 The bent shape of the central body 132 allows each reversing pin 130 to have rectilinear arms 131, mounted axially in the notches January 1, and a head 133 positioned radially around a portion of the bun 125, without the reversing pin is in electrical contact with the bun.

 In the embodiments of Figures 4A-4C, the central body 132 includes a first double-elbow 134 and a second double-elbow 135, each connecting the head

133 to one of the arms 131. In the example of FIGS. 4A-4C, the first double-elbow

134 has an internal elbow 134a connecting one of the arms 131 to an intermediate portion 134b positioned in the twisting direction of the pins 121 of hair bun. It furthermore comprises an external bend 134c connecting the intermediate section 134b to the head 133. This external bend 134 comprises a double-curvature associating a radial bend and a tangential curvature to enable the head to be tied in a circumferential direction with the intermediate section 134b. in the twisting direction. The radii and directions of curvature of each of the elbows are adapted to the shape and dimensions of the bun 125. In the embodiments of Figures 4A-4C, the second double-bend 135 is substantially identical to the first double-bend 134.

 In these embodiments, the reversing pin 130 is positioned at a distance from the axial end face 1 14 of the stator body 1 10. In other words, the head 133 of the reversing pin 130 is positioned at a height, with respect to the plane containing the axial end face 1 14, substantially equal to or slightly smaller than the plane containing the end of the heads 124 of the bun pins 121.

 Other embodiments of the reversing pin 130 are shown in FIGS. 5A-5C. In these embodiments, the reversal pin 130 is positioned at the outer periphery of the bun 125, close to the axial end face 1 14, or even in contact with said axial end face 1 14 of the stator body. 10. In these embodiments, as in the embodiments just described, each reversing pin 130 comprises two arms 131, substantially parallel, at least partially engaged in two separate notches January 1, both arm 131 being connected by a central body 132. In the embodiments of FIGS. 5A-5C, the central body 132 of each reversing pin 130 has a head 133 and two elbows 134, 135 with substantially similar curvatures. The elbow 134 and the elbow 135 are both external elbows which each directly connect the head 133 with one of the arms 131. This form of reversal pin 130 has the advantage of being relatively simple to machine since each reversing pin 130 is a U-shaped pin whose end near the head 133 is folded radially. Such an inversion pin also offers a gain in winding resistance due to its shorter length than that of the other embodiments.

Other embodiments of the reversing pin 130 are shown in FIGS. 6A-6C. In these embodiments, the reversing pin 130 is positioned at the outer periphery of the bun 125, at a distance from the end face axial 1 14, that is to say at a height, relative to the plane of the axial end face 1 14, substantially equal to or slightly smaller than the heads 124 of the bun pins 121. In these embodiments, as in the embodiments which have just been described, each reversing pin 130 comprises two arms 131, substantially parallel, at least partially engaged in two distinct notches 1 1 1, the two arms 131 being Connected by a central body 132. In the embodiments of Figures 6A-6C, the central body 132 of each reversing pin 130 has a head 133 and two elbows 134, 135 having progressive radii of curvature. These progressive radii of curvature allow a progressive folding of the central body 132 so as to pass from the axial direction of the arms 131 to the circumferential direction of the head 133 by limiting the number of folds and by deflecting the direction of the intermediate sections 134b with respect to twisting direction of the bun. In these embodiments, each bend 134, 135 has an outer bend, respectively 134c, 135c, and an inner bend 134a, 135a whose radii of curvature are smaller than in the embodiments of Figures 4A-4C. In particular, the outer bends 134c, 135c comprise a single bend, or fold. These embodiments have the advantage of limiting the risk of demagnetization at the folds of the reversal pins 130.

 In the embodiments described above, the reversing pins 130 are described in the case where they are positioned on the outer periphery of the bun 125. Those skilled in the art will understand that the reversing pins 130 can also be positioned on the inner periphery of the bun 125, the radii and directions of curvature of the bends then being adapted so that the heads 133 of the reversing pins are radially offset from the bun towards the inside of the stator.

Whatever the embodiments of the invention, the winding ends 123 - for example the phase inputs, the phase outputs and / or the neutral points - are set so as not to interfere with the reversing pins. 130. Indeed, the winding is carried out in the machines according to the invention, so that the winding ends 123 do not come out in the vicinity of the arms 131 of the reversal pins 130. For example, some of the winding ends 123 - or all winding ends if necessary - can be positioned so as to exit the bun 125 in an area between the two arms 131 of an inversion pin or between two arms 131 of two successive reversing pins. In another example, some of the winding ends 123 - or all winding ends if necessary - are positioned in the inner area of the bun 125 (i.e. on the opening side of the notches 1 1 1 ) when the reversing pins 130 are positioned in the outer area of the bun 125 or, conversely, in the outer area of the bun 125 (i.e. the bottom side of the notches 1 1 1) when the pins inversion 130 are positioned in the inner area of the bun 125.

 Although described through a certain number of examples, variants and embodiments, the rotary electrical machine according to the invention comprises various variants, modifications and improvements which will become obvious to the person skilled in the art, it being understood that these variants modifications and improvements are within the scope of the invention.

Claims

1. A rotating electrical machine comprising a rotor and a stator, the stator (100) having a stator body (1 10) provided with a bundle of plates and a plurality of notches (1 1 1) and a coil comprising:  a plurality of pins (121) connected together to form a plurality of phase windings, a central portion of the pins being accommodated in the plurality of notches, a collateral portion (124) of said pins being disposed out of notches (1 1 1) for forming a bun (125) projecting from an axial end face (1 14) of the stator body, and  a plurality of reversing pins (130) each electrically connecting two separate pins (121) housed in two separate notches, the reversing pins (130) being positioned so that a larger height (I) of each of said reversing pins (130) relative to the axial end face (1 14) of the stator body (1 10) is less than or equal to a greater height (L) of the bun (125) relative to at said axial end face of the stator body. Rotary electric machine according to claim 1, characterized in that, along a radius of the stator (100) passing on the axis of a notch (1 1 1) and centered on an inversion pin (130), the stator comprises an ordered notch, the plate package and the reversing pin. Rotary electric machine according to claim 1 or 2, characterized in that each reversing pin (130) is mounted in a radially outer zone (1 13) of the bun (125). 4. A rotary electric machine according to any one of claims 1 to 3, characterized in that each reversing pin (130) is disposed in a zone facing the axial end face (1 14) of the stator body. . 5. Rotating electric machine according to claim 4, characterized in that the coil comprises a plurality of winding end pins (123), each of said end pins being mounted in a radially inner region (1 12) of the bun. 6. rotary electrical machine according to any one of claims 1 to 5, characterized in that each reversing pin (130) comprises two arms (131) at least partially engaged in two separate notches (1 1 1) and a body central (132) connecting the two arms. 7. A rotary electric machine according to claim 6, characterized in that the central body (132) of each reversing pin is bent along a progressive radius of curvature. 8. rotary electric machine according to claim 6 or 7, characterized in that the central body (132) of each reversing pin is disposed axially away from the axial end face (1 14) of the stator body. 9. rotary electric machine according to claim 6 or 7, characterized in that the central body (132) of each reversing pin is disposed near the axial end face (1 14) of the stator body. 10. Rotating electric machine according to any one of claims 1 to 9, characterized in that, in a plane parallel to the axial end face (1 14) of the stator body (1 10), the largest width of the one head of each reversal pin is smaller than the largest width of the collateral portions of the pins forming the bun. 1 1. Rotary electric machine according to any one of claims 1 to 10, characterized in that each reversing pin (130) extends out of the notch, in a plane inclined relative to the plane in which extend the pins forming the bun.