FR2838883A1 - CONDUCTIVE ELEMENTS FOR A STATOR OF A ROTATING ELECTRIC MACHINE AND ROTATING ELECTRIC MACHINE PROVIDED WITH SUCH CONDUCTIVE ELEMENTS - Google Patents

Abstract

The invention relates to a conductive hairpin element for a stator of a rotary electric machine. The conductive elements (14) are of the type comprising a U-shaped head portion (14c) and two branch portions (14a, 14b), substantially parallel to each other. The element (14) is characterized in that one (14b) of the two branches (14a, 14b) of the hairpin conductive element (14) is offset from its position of symmetry with respect to the other branch (14a), relative to the axis of symmetry of the pin, by a distance slightly greater than the thickness (d) of a branch (14a, 14b). The invention can be used for rotating electrical machines.

Description

characterized by the fact that its power is greater than or equal to 500

kW.

  The invention relates to a rotary electrical machine, in particular for a motor vehicle, of the type comprising a rotor mounted to rotate inside a stator comprising a cylindrical body and a winding with several phases each formed by a plurality of electrically conductive elements mounted. in series along the periphery of the stator between an input and an output, the cylindrical body comprising in its radially internal face radial notches for receiving at least two pads of phase conductive elements which wind juxtaposed in the notch the radial direction to form at least four layers of conductive elements, each conductive element having the shape of a pin comprising a U-shaped head portion seen in the peripheral direction and two branches received in two different notches, the free ends of the branches being each electrically connected to a free end of a

  branch of another conductive element.

  The invention also relates to a hairpin conductive element for a rotating electrical machine, of the type comprising a U-shaped base part. 314 780 a stator winding of the type defined above, in which the two conductors of each pad have different widths so that the narrower conductor is placed inside the wider conductor, the parties then forming unequal U concentric. During the formation of the pins, the branches wind closer in their straight portion than at the level of the head so that these backs constitute

  bulges in relation to the branches.

  The configuration of the pins according to the US patent has the disadvantage that due to the different width of the pins of each padre, it is necessary at least two possibilities of forming specific pins, equipped with different tools. In addition, there is a risk of alteration of the protective mail in the head area of pins with greater curvature. In addition to these drawbacks, the wide feasts of the pins, which constitute the bun, cause an increase in the external diameter of the latter, annoying

when mounted in the bearing.

  The object of the invention is to overcome the drawbacks

  which have just been announced from the state of the art.

  To achieve this object, a conductive element according to the invention is characterized in that one of the two branches of the conductive hairpin clement is offset from its position of symmetry with respect to the other branch, with respect to the axis of symmetry of the pin, a distance slightly greater than the width of a branch. According to a characteristic of the invention, the distance between the two parallel branches of the conductive element corresponds substantially to twice the width

  of a branch of conductive element increased by one set.

  According to a characteristic of the invention, the above-mentioned offset branch is bent at its birth in the direction of the other branch, then bent to be parallel to this behind at the predetermined distance. According to a characteristic of the invention, the two conductive elements of a pad of conductive elements

  have substantially identical shapes.

  Thus advantageously, a pad of conductive elements is produced economically by the

  manufacture of a single type of conductive element.

  On the other hand, a rotary electrical machine, in particular for a motor vehicle, of the type comprising a rotor mounted for rotation inside a stator comprising a cylindrical body and a winding with several phases each formed by a plurality of electrically conductive elements mounted in series along the periphery of the stator between an input and an output, the cylindrical body comprising in its laterally internal face radial notches for receiving at least two pads of phase conducting elements, which wind juxtaposed in their notch in the radial direction to form at least four layers of conductive elements, each conductive element having the shape of a pin having a U-shaped head portion seen in the peripheral direction, and two branches received in two notches different, the free ends of the branches being each electrically connected to a free end of a branch of another conductive element, the fe your pins have a side of the cylindrical stator body forming a bun is characterized in that it comprises pads of conductive elements according to

the invention.

  According to another characteristic of the invention, the pads of conductive elements wind implanted in the notches of the stator so that the non-offset branches of the two conductive elements are in a notch and the two offset branches mentioned above in a

another notch.

  According to an advantageous characteristic of the invention, the pads of wind conducting elements implanted in the notches of the stator so that in the inner layer of a first notch is the straight branch of a first pin, the other bent branch of this first pin being in the third layer of the other notch and in that in the second inner layer of the first notch, is the bent branch of the second pin, the other straight branch of this second pin being in the fourth

layer of the other notch.

  According to yet another characteristic of the invention, the total width of the conductive elements of a pad of conductive elements, in a view along the periphery of the stator, is substantially constant over any radial extension of the pad of conductive elements . According to yet another characteristic of the invention, the outside diameter of the bun is substantially equal to the outside diameter on the

conductors in the notches.

  The invention will be better understood and other aims, characteristics, details and advantages thereof

  will appear more clearly in the description

  Explanatory which will follow made with reference to the accompanying schematic drawings given solely by way of example illustrating an embodiment of the invention and in which: - Figure 1 is an axial sectional view of a type of rotary electric machine which the invention is applicable; - Figure 2 is a perspective view of the stator of a rotating electrical machine according to Figure 1; - Figure 3 is a cross-sectional view showing the device of the conductive elements in a notch of the stator; - Figure 4 is a top view of a stator of a machine according to Figure 1; - Figure 5 is a schematic view illustrating the implantation of padre of conductive elements in a stator, in accordance with the invention; - Figure 6 illustrates a pad of conductive elements in pins according to the invention; - Figure 7 illustrates a conductive element according to the invention, of a particularly advantageous configuration; - Figure 8 illustrates a padre of conductive elements in pins, according to the invention, having the configuration according to Figure 3; - Figure 9 is a schematic representation of a mode of implantation of the conductive elements according to the invention in two consecutive notches of the same phase; - Figure 10 is a schematic representation of an advantageous mode of implantation of pads of conductive elements in pins according to Figure 8 in the stator

of a rotating electrical machine.

  We will first describe with reference to Figure 1 the general structure of a rotating electrical machine, here an alternator for a motor vehicle, to which

  the invention is likely to apply.

  The alternator comprises, going from left to right of FIG. 1, that is to say from front to rear, a drive pulley 1 secured to the front end of the shaft 2, the rear end of which carries slip rings (not shown) belonging to a manifold 3. The axis of the shaft 2 constitutes the axis of

machine rotation.

  Centrally, the shaft carries the rotor 4 for fixing, provided with an excitation winding 5, the wind ends of which are connected by electrical connections to the collector 3. The rotor 4 is here a claw rotor comprising two front and rear pole wheels 6, 7 each carry a front fan 8 and a rear fan respectively 9. References 11 and 13 designate the front bearings and

back of the machine.

  Fans create cooling air flows such as, for example, indicated by

arrowed lines.

  The rotor 4 is mounted coaxially and rotatable inside a stator 10 of the hexaphase type, comprising in the example shown in FIG. 2 a cylindrical body 12 of axis XX 'and two series of phase trotters P1 to P3 and P4 to P6, therefore, known per se. Each phase P1 to P6 is formed by a plurality of electrically conductive elements 14 mounted in series along the periphery of the stator 10 between an input, respectively E1 to E6 and an output respectively S1 to S6, to form at least one winding of phase. As shown in FIG. 2, the cylindrical body 12 also called a deck of soles comprises in its radially internal face radial notches L for receiving at least four phase conductive elements 14. The conductive elements are juxtaposed in the notch L in the radial direction to form at least four layers of conductive elements C1 to C4 as shown in Figures 3 and 5. The four conductive elements engaged in a notch constitute two pads

of conductive elements.

  Figure 6 shows a padre of conductive elements 14 each of which has the shape of a pin having two substantially parallel branches 14a and 14b. It can be seen that the radii of curvature of the

  parties 14c of the two identical wind pins.

  Referring to Figure 5 we see that each conductive element pin 14 extends between two notches L, L 'each of which receives a branch 14a or 14b, the two branches being in the two notches L, L' in different layers. This arrangement of the conductive elements is obtained by twisting the pins as shown in FIG. 4, with the parties 14c being located on the same axial side 12a of the stator 12 and forming a bun 16. The free ends of the branches 14a and 14b of each element pin conductor 14 protrude from the second axial side 12b of the body 12 and wind electrically connected each to the free end of another pin conductor element, forming

thus a second bun 18.

  FIG. 6 schematically illustrates the arrangement of the two pads of conductive hairpin elements in their two receiving notches, designated L and L '. It can be seen that, for example, the branches 14a of the conductive elements 14 of a pad are in the notch L in the radially successive internal layers C1 and C2 and the branches 14b of the conductive elements of this pad are placed in the notch L ' in both

  successive radially external layers C3 and C4.

  The configuration of the two conductive elements 14 of each pad, as shown in FIG. 6 thus has the advantage that there is no longer any need for two pins for forming pins equipped with different tools, as in the state of the technical, because the pins have the same radius of curvature. This avoids the aforementioned risk of alteration of

  the protective email at the level of the curvature.

  Figures 7 and 8 show a particularly advantageous configuration of the two elements

pin conductors of a padre.

  Indeed, loreque one constitutes a padre pins, in accordance with Figure 6, there remains a clearance J between the two inner branches of the padre. During the twisting operation of the pins and the insertion in the stator, this clearance will be reduced to a value close to zero in the right part of the branches inserted in

the notches.

  Figure 7 illustrates an advantageous configuration

of each pin.

  The pin conductive element 14 of FIG. 7 has the particularity with respect to the pins according to FIG. 6, that the bending at the level of the head 14c is carried out so that the curvature goes beyond an angle of 180 so that the portion of the branch 14b close to the curvature is no longer parallel to the branch 14a but inclined in the direction of the latter at a predetermined angle. Then at a certain distance of curvature or head 14c, in 20, the branch 14b is bent so that it again sits parallel to the branch 14a. So the gap between the two branches is smaller in their

  portion of parallelity only at the level of the head 14c.

  The offset of the branch 14b thus produced corresponds substantially to the width d of such a branch 14b and the distance between the branches 14a and 14b corresponds to the width of a branch plus a certain clearance. FIG. 8 shows that by having the two conductive elements 14 so that their curved branches 14b are adjacent, it is possible to obtain an overall configuration of the two pins in which the width of the assembly is practically constant over the entire length of the pins while having reduced practically to zero the deviation J of the two adjacent branches 14b. So the total width of a padre

  of pins does not exceed that of a single pin.

  Figures 9 and 10 illustrate two possibilities for installing pads of conductive elements in

pin 14 in stator 12.

  In the case of FIG. 9, the pins 14 are placed so that their straight branches 14a are juxtaposed in a notch, for example in the two radially internal layers of the notch L and the two bent branches 14b in the notch L 'in the two radially outer layers. It can be seen that a bun 16 is thus obtained having an outside diameter DCH greater than the outside diameter DE defined by the outside branches 14b. In other words, the bun has swelling which could hinder its proper assembly.

  in the bearing of the rotating electrical machine.

  FIG. 9 shows that this swelling towards the outside of the bun can be avoided when the pins 14 are implanted in the manner illustrated in FIG.> 3, that is to say in place, ant in the same notch L in radially successive radial layers the straight branch 14a of a pin and the bent branch 14b of the other pin and, in the other notch L ', in the third layer the bent branch 14b of the pin whose straight branch 14a is found in the radially inner layer of the first notch L. The other straight branch 14a of the pad will then occupy in the notch L 'the radially outer layer. More precisely, the pads of conductive elements 14 wind implanted in the notches L, L 'of the stator 10 so that in the inner layer C1 of a first notch L is the straight branch 14a of a first pin, the other bent branch 14b of this first pin being in the third layer C3 of the other notch L 'and in that in the second inner layer C2 of the first notch L, is the bent branch 14b of the second pin, the other straight branch 14a of this second pin being in the fourth layer C4 of

the other notch L '.

  Thus the outside diameter DCH of the bun 16 is reduced and substantially identical to the outside diameter DE of the branches of the pins on the other axial side 12b of the stator body 12, that is to say the outside diameter

  on the conductors in the notches.

  It should also be noted that, in the case of FIG. 8, one could of course let the parties 14c take an inclined position during the twist and thus reduce the outside diameter of the bun. But this inclination would tend to bring the circles of the two padres of consecutive pins closer together, at the risk of creating a

  electrical contact and thus a short circuit.

  The configuration according to Figure 10 eliminates any risk of dangerous point contact at the crossing of

  two sets of consecutive pins.

Claims (9)

RESELL I CAT I ONS   1. Pin conductor element for a stator of a rotating electric machine, of the type comprising a part forming a U-shaped head and two parts forming branches, substantially parallel to each other, characterized in that one (14b ) of the two branches (14a, 14b) of the conductive pin element (14) is offset from its position of symmetry with respect to the other branch (14a), relative to the axis of symmetry of the pin, a distance slightly greater than the width (d) of a branch (14a, 14b).   2. Conductive element according to claim 1, characterized in that the distance between the two parallel branches (14a, 14b) of the conductive element (14) corresponds substantially to twice the width of a   conductor branch increased by one clearance (J).   3. Conductive element according to claim 2, characterized in that the above-mentioned offset branch (14b) is curved at its birth in the direction of the other branch (14a), then bent to be parallel to   this behind the predetermined distance.   4. Rotating electrical machine, in particular for a motor vehicle, of the type comprising a rotor mounted for rotation inside a stator comprising a cylindrical body and a winding with several phases each formed by a plurality of electrically conductive elements mounted in series on along the periphery of the stator between an input and an output, the cylindrical body comprising in its laterally internal face radial notches for receiving at least two pads of phase conductive elements, which wind juxtaposed in their notch in the radial direction to form at least four layers of conductive elements, each conductive element having the shape of a pin comprising a U-shaped head portion seen in the peripheral direction, and two branches received, received in two different notches, the free ends of the branches being each electrically connected to a free end of a branch of another conductive element, the fetes des épi ngles provided with a side of the cylindrical stator body forming a chignon, characterized in that the conductive elements (14)   elements according to one of claims 1 to 3.   5. Machine according to claim 4, characterized in that the two conductive elements (14) of a pad of conductive elements have substantially identical shapes. 6. Machine according to claim 5, characterized in that the pads of conductive elements (14) wind implanted in the notches (L, L ') of the stator (10) so that the non-offset branches (14a) of the two conductive elements are in a notch (L) and the two above-mentioned offset branches (14b) in another notch (L ').   7. Machine according to claim 5 characterized in that the pads of conductive elements (14) wind implanted in the notches (L, L ') of the stator (10) so, con that in the inner layer (C1) of a first notch (L) is the straight branch (14a) of a first pin, the other bent branch (14b) of this first pin being in the third layer (C3) of the other notch (L ') and in that in the second inner layer (C2) of the first notch (L) is the bent branch (14b) of the second pin, the other straight branch (14a) of this second pin being in   the fourth layer (C4) of the other notch (L ').   8. Machine according to claim 7, characterized in that the total width of the conductive elements (14) of a pad of conductive elements (14), in a view along the periphery of the stator, is substantially constant over any extension padre radial of conductive elements.   9. Machine according to claim 8, characterized in that the outside diameter (DCH) of the bun (16) is substantially equal to the outside diameter (DE) on the conductors in the notches.