Rotor of rotating electrical machine and associated fabrication process

1. A rotor of a rotary electric machine, comprising:

a body comprising a cylindrical central core and a circumferential plurality of arms extending radially out from the cylindrical central core, the body being mounted with an ability to move about an axis of rotation;

a coilset produced by windings of turns and forming at least one series of coils,

a coil comprising a predetermined number of turns around at least two arms of the body, two adjacent coils of a series being angularly offset from one another with a partial overlap; and

at least one additional retaining turn wound around at least two arms of which at least one is common to the arms around which is wound the last coil, situated radially outermost, of at least one series and of which at least one is distinct from the arms around which the said last coil is wound, so that the at least one additional retaining turn partially overlaps the turns of the said last coil,

wherein the rotor comprises two series of coils arranged at 180° with respect to one another and with respect to the axis of rotation,

wherein the two series of coils each comprises the at least one additional retaining turn, and each of the at least one additional retaining turn extends from one series of the two series of coils to the other series of the two series of coils.

2. The rotor according to claim 1 , in which one single series of coils comprises at least one additional retaining turn partially overlapping the turns of the last coils of the two series of coils.

3. The rotor according to claim 1 , in which the at least one additional retaining turn of at least one series of coils is produced between a plurality of arms, the plurality of arms comprising:

a first arm around which the last coil of the series is wound, and

a second arm around which the last coil of another series of coils is wound, the at least one additional retaining turn of the series of coils partially overlapping the turns of the last coils of the series of coils.

4. The rotor according to claim 1 , in which the at least one additional retaining turn extends in a direction substantially equal to an angle of 360° divided by a number of poles of the rotary machine with respect to the direction of the turns of the last coil of a series.

5. The rotor according to claim 1 , configured to collaborate with a stator of the rotary electric machine comprising a number of poles greater than or equal to four.

6. The rotor according to claim 5 , in which an angle covered by the arms around which a coil is wound is substantially equal to 360° divided by the number of poles of the stator of the rotary electric machine.

7. The rotor according to claim 1 , comprising a slip-ring provided with a plurality of terminals and configured to supply power to the coils of the rotor and wherein the additional retaining turn is a connecting wire connecting two terminals of the slip-ring.

8. A method of manufacturing a rotor of a rotary electric machine comprising a body having a cylindrical central core and a circumferential alternation of arms extending radially out from the cylindrical central core, the body being intended to be mounted with an ability to move about an axis of rotation, the method comprising:

a succession of steps of winding a predetermined number of turns of a coilset around at least two arms of the body to form at least one series of coils, the winding steps being performed in such a way that two adjacent coils of a series are wound around at least one common arm and at least one distinct arm, two adjacent coils of a series being angularly offset from one another with a partial overlap,

an additional step of winding at least one additional retaining turn of the coilset around at least two arms of the body, of which arms at least one is common to the arms around which is wound the last coil of a series, situated radially outermost, and the other arm is distinct from the arms around which the last coil of a series is wound, the said at least one additional retaining turn partially overlapping the turns of the said last coil,

wherein the rotor comprises two series of coils arranged at 180° with respect to one another and with respect to the axis of rotation,

wherein the two series of coils each comprises at least one additional retaining turn, and each additional retaining turn extends from one series of the two series of coils to another series of the two series of coils.

9. The method of manufacture according to claim 8 , in which the successive winding steps are performed in duplicate and simultaneously at a first place on the body and at a second place on the body that is diametrically opposite the first place so as to form two series of coils which are symmetric about the axis of rotation.