FR3069111A1 - ROTATING ELECTRIC MACHINE HAVING A PINK WINDING STATOR - Google Patents

Abstract

A rotating electrical machine having a rotor and a stator, the stator (100) having a stator body (110) having a package of plates and a plurality of notches (111) 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 said plurality of notches notches (111) for forming a bun (125) projecting from an axial end face (114) of the stator body, and - a plurality of reversing pins (130) each electrically connecting two pins ( 121) housed in two distinct notches and each comprising at least two sections (131, 132) of different shapes, at least one portion (131) of each reversing pin having a rectangular section, a portion (132) at least of each inver pin with a rounded section

Description

ROTATING ELECTRIC MACHINE PROVIDED WITH A STATOR A

PIN COIL

TECHNICAL AREA

The present invention relates to a rotary 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 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 rotary electric machine in the form of an alternator, an electric motor or a reversible machine of the alternator starter type which can operate in both modes. .

The stator is mounted in a housing configured to rotate the shaft on bearings by means of bearings. The rotor 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 rotor has 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 the rotor arms.

As shown in FIGS. 1 and 2, the stator 100 comprises a body 110 constituted by a stack of thin sheets forming a crown, the inner face of which is provided with notches 111 open radially inward to receive phase windings 120 These phase windings 120 pass through the notches 111 of the stator body and form a bun 125, 126 on either side of the stator body 110. The phase windings 120 are polyphase windings, connected in star or in triangle, 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 electrically connected to each other. Two pins 121 of the same winding are connected together directly, for example by welding. Two phase windings 120 are connected to each other by means of reversing pins 130, each reversing pin electrically connecting the last pin 121a of one of the 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 connected together, for example by welding, and twisted to form the lower bun 126 - namely the bun downstream of the winding.

Generally, the reversing 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 having respectively a first and a last pins positioned at a distance from the one of the other. This axial location of the reversing pins 130 has the effect of substantially increasing the axial size of the winding.

The method of manufacturing a pin winding stator requires double twisting of 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 crown are twisted. After this first twist of the pin heads, the crown is inserted into the stator body and the free ends of the pin branches are twisted. However, twisting the free ends of the pins, called the second twist, requires the use of a specific tool and shims to hold the pin heads 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 to allow the second twist of the free ends forming the lower bun. This figure 3 shows, in particular, the line ZA which is the support zone on which the specific tool comes to rest and the housings ZC which constitute the wedging zones in which the wedges are inserted so as not to damage the bun upper 125 during the second twist. It will be understood that the use of this specific tool and of the shims generates not only a difficulty of implementation, but also a non-negligible cost both in terms of purchasing the tool and in terms of labor.

SUMMARY OF THE INVENTION

To respond to the above-mentioned problems of axial size and delicate implementation, the applicant proposes a rotary electrical machine in which the reversing pins are positioned radially around the bun, on its internal periphery or on its external periphery, so that they do not protrude axially from the bun.

The stator "internal periphery" is the area of the stator containing the cylindrical face directed towards the axis of rotation of the machine and located opposite the rotor. The stator "outer periphery" is the area of the stator containing the cylindrical face furthest from the axis of rotation of the machine and opposite the internal cylindrical face. By analogy, the internal periphery of the bun is the part of the bun situated above the internal periphery of the stator and the external periphery of the bun is the part of the bun situated above the external periphery of the stator.

According to a first aspect, the invention relates to a rotary electrical machine comprising a rotor and a stator, the stator comprising a stator body provided with a pack of sheets and a plurality of notches and a winding comprising:

- A plurality of pins connected together so as to form a plurality of phase windings, a central portion of the pins being housed in the plurality of notches, a collateral portion of said pins being disposed outside 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 one portion of each reversing pin having a rectangular section, a portion at least of each reversing pin having a rounded section

The portion of the pins which are not wedged in the notches of the stator and form a crown on the axial end faces of the stator is called a bun. The bun located upstream of the winding, called the upper bun, is made up of pin heads. This upper bun is crossed 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 as well as the radial size of the machine. It also makes it possible, on the one hand, to simplify the operation of second twisting of the bun pins by avoiding the use of specific tools and shims and, on the other hand, to simplify the manufacture of the pins. inversion by limiting the folds generated during the folding of the electrical conductor.

Advantageously, each reversing pin has 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.

Advantageously, each reversing pin has two arms and a central body connecting the two arms, each arm comprising one of the portions of rectangular section, the central body comprising the portion of rounded section. The rectangular section of the arms allows their setting in the notches of the stator body. The rounded section of at least part of the central body allows a reduced space requirement of the stator.

The rotary electrical machine according to the invention may include one or more of the following characteristics:

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

the reversing pins are positioned so that a greater height of each of said reversing pins relative to the axial end face 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.

- along a radius of the stator passing through the axis of a notch and centered on a reversing pin, the stator comprises in an orderly manner a notch, the pack of sheets and the reversing pin. "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 external area of the bun.

- each reversing pin is arranged in a zone opposite 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 internal 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 largest width of the collateral portions of the pins forming the bun.

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

- The pins forming the bun have a U shape comprising two branches connected by a head.

- the reversing pins have a U-shape comprising 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;

- Figure 2, already described, schematically shows a view of the upstream part of the stator of a machine according to the prior art;

- Figure 3, already described, shows a view of the upstream part of the stator of Figure 2 on which are indicated the areas of support and insertion of shims during the second twist operation;

- Figures 4A and 4B show views, in perspective and from above, of the upstream part of the stator of a rotary electrical machine according to an embodiment of the invention;

- Figure 5 shows a perspective view of a reversing pin of the stator of Figures 4A-4B.

DETAILED DESCRIPTION OF AT LEAST ONE EMBODIMENT

An exemplary embodiment of a rotary electrical machine, in which the reversing pins are positioned radially around the bun, on its internal periphery or on its external periphery, is described in detail below, with reference to the accompanying drawings. This example illustrates the characteristics and advantages of the invention. It is however recalled that the invention is not limited to this example.

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

The electric machine according to the invention comprises a polyphase stator of axis X corresponding to the axis of the machine. The stator surrounds a rotor mounted in rotation on a shaft, as described in the state of the art. The stator 100, a portion of which is shown in FIGS. 4A-4B, comprises a body 110 formed of a pack of sheets and a coil passing through the body 110. The body 110 is delimited by an internal periphery 112, or internal cylindrical face , an external periphery 113, or external cylindrical face, and two axial end faces. Only the upper axial end face 114 - upstream of the winding - is visible in FIGS. 4A - 4B. The body 110 is provided, on its internal periphery 112, with teeth 115 extending radially towards the rotor and delimiting two by two of the notches 111 for mounting the winding. Two successive notches 111 are therefore separated by a tooth 115. The notches 111 open axially in the axial end faces and radially in the internal cylindrical face 112 of the stator body 110.

The winding comprises a plurality of phase windings inserted in the notches 111. 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 111 and form, on each axial end face, a bun 125 extending projecting on either side of the stator body 110.

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 substantially 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 projecting lower bun. on 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 projecting from the upper axial end face 114 of the stator body 110, or upstream face.

Two phase windings are electrically connected to each other by means of an inversion pin 130. This inversion pin connects the last pin 121a of a phase winding with the first pin 121b of another phase winding. In the machine according to the invention, each reversing pin 130 is positioned radially along a part of the bun 125, on the inner periphery or on the outer periphery of the bun. The reversing pins positioned at the outer periphery of the bun are wedged at the bottom of the notches 111 of the stator. The reversing pins positioned at the inner periphery of the bun are wedged at the mouth of the notches 111 of the stator. The reversing 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 114 is less than or equal to the greatest height of the upper bun 125 relative to said upper axial end face 114. Each reversing pin 130 is therefore positioned next to the pin heads 124 and not above said pin heads, which makes it possible not only to facilitate the 'second twist operation, but also to produce a winding whose total height is equal to the distance between the upper bun 125 and the lower bun, the winding ends 123 not being included in the bun since they constitute the connections to the stator control module. The reversing pins 130 can be positioned at a greater or lesser distance from the axial end face 114: they can be positioned at substantially the same height as the pin heads 124 (that is to say at a distance from the axial end face) or near the axial end face 114 (that is to say at a short distance from said face 114) or at any distance between these two distances.

Each reversing pin 130 has a U shape comprising 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 represents a partial perspective view of the stator of the machine according to certain embodiments of the invention, and FIG. 4B, which represents a top view of the stator part of FIG. 4A, show a pin reversal 130 offset radially relative to the pins forming the bun 125, on the outer periphery 113 of the stator body. Thus, along a radius R of the stator passing to the axis of a notch 111 and centered on the reversing pin 130, the stator comprises in an orderly manner the notch, the sheet pack and the reversing pin .

In the examples of FIGS. 4A-4B, the reversing pin 130 is positioned opposite the axial end face 114 of the stator body 110, at a distance from said axial end face. In other words, the inversion pin 130, like all the inversion pins of the stator, is positioned at a height relative to the plane containing the axial end face 114, substantially equal to or slightly less than the plane containing the high end of the heads 124 of the bun pins 121.

Each reversing pin has two arms 131 connected by a central body 132. The arms 131 and the central body 132 of each reversing pin 130 are produced by folding an electrical connector of predetermined length, this folding giving said pin inversion zones oriented in different directions. According to the invention, the reversing pin 130 has at least two sections of different shapes. It comprises, in particular, at least one portion of rectangular section and at least one portion of round or rounded section. According to the example of FIG. 5, the two arms 131 of the reversing pin 130 are of rectangular section and the central body 132 is of round section. The entire central body 132 may be of round section or only a part. The portions of different cross-section can be obtained by folding a multi-section electrical conductor or an electrical conductor with a round / rounded section, certain portions of which are stamped to make them rectangular.

The two arms 131 of each reversing pin 130 are oriented axially substantially parallel to one another. The two arms 131 both have a rectangular section of dimensions adapted to the dimensions of the notch 111 so as to be housed in two distinct notches 111. Each arm 131 is connected on either side to the central body 132. 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 a arms 131. The elbows 134 and 135 may be identical or, on the contrary, different from each other, each of the elbows having radii and directions of curvature adapted to the shape and dimensions of the bun 125, to connect the head 133 to an arm 131 while bypassing 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 straight arms 131, mounted axially in the notches 111, and a head 133 positioned radially around a portion of the bun 125, without the reversing pin is not in electrical contact with the bun.

In certain embodiments, the central body 132 can comprise, for example, internal bends and / or external bends having a double curvature associating, for example, a radial curvature and a tangential curvature or an axial curvature and a tangential curvature . The central body 132 may comprise, for example, a first and a second double-elbow each connecting the head 133 to one of the arms 131. Each of the first and second double-elbows has an internal elbow connecting one of the arms 131 to an intermediate section positioned in the twisting direction of the bun pins 121 and an external elbow connecting the intermediate section to the head 133. The external elbow may have a double curvature associating a radial curvature and a tangential curvature to allow the head to be linked in a circumferential direction with the intermediate section in the twist direction.

In certain other embodiments, the central body 132 may comprise only a first and a second external elbow which each connect, directly, the head 133 with one of the arms 131. In these embodiments, the reversing pin 130 is positioned near the axial end face 114, or even in contact with said axial end face 114 of the stator body 110.

In embodiments shown in Figures 4A-4B and 5, the two elbows 134, 135 have progressive radii of curvature. These progressive radii of curvature allow 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 deviating the direction of the intermediate sections 136, 137 by relative to the direction of twist of the bun. In these embodiments, each elbow 134, 135 has an outer elbow and an inner elbow each having a single curvature, or fold. Such a progressive radius of curvature makes it possible to limit the risks of enameling at the elbows of the reversing pins 130.

Whatever the curvatures of the central body 132, said central body 132 can be made, in part or in whole, in an electrical conductor of round or rounded section. In the embodiment of Figure 5, the entire central body 132 (that is to say the head 133, the intermediate sections 136, 137 and the elbows 134, 135) is of round section. Such a rounded / round section makes it possible to limit the deformation brought to the conductor during folding. Indeed, a round / rounded section is easier to handle and its folding generates fewer folds than a rectangular section. A round / rounded section also makes it possible to reduce the radial size of the reversing pins - compared to a uniform rectangular section - and therefore to reduce the radial size of the protruding elements of the stator body 110.

To further reduce the radial size, it is possible to stamp a portion of the central body, for example the head 133, so that the portion of the reversing pin formed along the bun 125 has a rectangular section, the greatest width is positioned axially along the bun. Each reversing pin 130 then comprises three portions of rectangular section, namely the two arms 131 and the head 133, and portions of round / rounded section, namely the elbows 134, 135 and intermediate sections.

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 internal periphery of the bun 125, the radii and directions of curvature of the elbows then being adapted so that the heads

133 of the reversing pins are offset radially from the bun towards the inside of the stator.

Whatever the embodiments of the invention, the winding ends 123 - for example phase inputs, phase outputs and / or neutral points - are set so as not to interfere with the reversing pins 130. In fact, the winding is produced, 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 reversing pins 130. For example, some of the winding ends 123 or all of the winding ends if necessary - can be positioned so as to exit from the bun 125 in an area located between the two arms 131 of a reversing pin or between two arms 131 of two successive reversing pins. In another example, some of the winding ends 123 - or all of the winding ends if necessary - are positioned in the internal zone of the bun 125 (that is to say on the side of the opening of the notches 111) when the reversing pins 130 are positioned in the external zone of the bun 125 or, on the contrary, in the external zone of the bun 125 (that is to say on the bottom side of the notches 111) when the reversing pins 130 are positioned in the internal area of the bun 125.

Although described through a certain number of examples, variants and embodiments, the rotary electric machine according to the invention includes various variants, modifications and improvements which will be obvious to those skilled in the art, it being understood that these variants , modifications and improvements are part of the scope of the invention.

Claims (12)

1. Rotating electric machine comprising a rotor and a stator, the stator (100) comprising a stator body (110) provided with a pack of sheets and a plurality of notches (111) and a winding comprising: - A plurality of pins (121) connected together so as to form a plurality of phase windings, a central portion of the pins being housed in the plurality of notches, a side portion (124) of said pins being disposed outside the notches (111) to form a bun (125) projecting from an axial end face (114) of the stator body, and - A plurality of reversing pins (130) each electrically connecting two separate pins (121) housed in two distinct notches and each comprising at least two sections (131, 132) of different shapes, a portion (131) at the less than each reversing pin having a rectangular section, at least one portion (132) of each reversing pin having a rounded section. 2. Rotating electric machine according to claim 1, characterized in that each reversing pin (130) comprises two portions (131) of rectangular section each housed in a notch (111) of the stator and at least one portion (132) to rounded section between the two rectangular section portions. 3. Rotating electric machine according to claim 2, characterized in that each reversing pin comprises two arms (131) and a central body (132) connecting the two arms, each arm comprising one of the rectangular section portions, the central body comprising the portion with rounded section. 4. Rotating electric machine according to claim 3, characterized in that the portion with rounded section is flattened over a part (133) of a length of the central body. 5. rotary electric machine according to any one of claims 1 to 4, characterized in that the reversing pins (130) are positioned so that a greater height (I) of each of said reversing pins relative to to the axial end face (114) of the stator body is less than or equal to a greater height (L) of the bun relative to said axial end face of the stator body. 6. Rotating electric machine according to any one of claims 1 to 5, characterized in that, along a radius of the stator (100) passing through the axis of a notch (111) and centered on an inversion pin ( 130), the stator comprises in an orderly manner a notch, the sheet pack and the reversing pin. 7. Rotating electric machine according to any one of claims 1 to 6, characterized in that each reversing pin (130) is mounted in a radially external zone (113) of the bun (125). 8. Rotating electric machine according to any one of claims 1 to 7, characterized in that each reversing pin (130) is arranged in a zone opposite the axial end face (114) of the stator body. 9. rotary electric machine according to any one of claims 1 to 8, characterized in that the winding comprises a plurality of winding end pins (123), each of said end pins being mounted in a radially internal zone (112) of the bun. 10. Rotating electric machine according to claim 9, characterized in that the central body (132) of each reversing pin is bent along a progressive radius of curvature. 11. Rotating electric machine according to any one of claims 1 to 10, characterized in that, in a plane parallel to the axial end face (114) of the stator body (110), the greatest width of a head of each reversing pin is less than the greatest width of the collateral portions of the pins forming the bun. 12. Rotating electric machine according to any one of claims 1 to 11, characterized in that each reversing pin (130) extends, out of the notch, along a plane inclined relative to the plane in which the pins forming the bun extend.