Method of winding a conductor in double pancake

Abstract

A method of winding a conductor in double pancake, including a first pancake and a second pancake, a reel initially containing the conductor, the method including: a first step in which the reel is placed on a tensioner and a first portion of the conductor is wound around a storage volume; a second step in which a first part of the conductor is inserted in a winding mandrel to change the layer; a third step in which a second portion of the conductor is wound around a first part of the storage volume so as to form a first pancake; a fourth step in which the first portion of the conductor is unwound from the storage volume and is wound around the reel; and a fifth step in which the first portion of the conductor is wound around a second part of the storage volume to form a second pancake.

Claims

1. A method of winding a conductor in double pancake, said double pancake comprising a first pancake and a second pancake, a reel initially containing said conductor, said method comprising: placing the reel on a tensioner and winding a first portion of the conductor around a storage volume; inserting a first part of the conductor in a winding mandrel in order to change a layer between the first portion of the conductor and a second portion of the conductor; winding the second portion of the conductor around a first part of the winding mandrel so as to form the first pancake; unwinding the first portion of the conductor from the storage volume and winding the first portion of the conductor around the reel, and winding the first portion of the conductor around a second part of the winding mandrel so as to form the second pancake.

2. The method according to claim 1, wherein, in said placing of the reel on the tensioner and winding the first portion of the conductor around the storage volume, the reel is placed at a first part of the tensioner, the reel possibly being moved between the first part of the tensioner and a second part of the tensioner; wherein the first portion of the conductor is wound between a first part of the storage volume and a second part of the storage volume in a first rotation direction due to displacement of the reel between the first part of the tensioner and the second part of the tensioner.

3. The method according to claim 2, wherein the inserting is done once the reel has reached the second part of the tensioner, the winding mandrel being placed at the second part of the storage volume.

4. The method according to claim 2, wherein in said winding of the second portion of the conductor around the first part of the winding mandrel so as to form the first pancake, the second portion of the conductor is wound in the first rotation direction, the reel remaining fixed at the second part of the tensioner.

5. The method according to claim 2, wherein in said unwinding of the first portion of the conductor from the storage volume and winding the first portion of the conductor around the reel, the reel is initially put into position on the tensioner at the first part of the tensioner and the first portion of the conductor is unwound from the storage volume in the first rotation direction by displacement of the reel between the first part of the tensioner and the second part of the tensioner.

6. The method according to claim 1, wherein in said winding of the first portion of the conductor around the second part of the mandrel so as to form the second pancake, the first portion of the conductor is wound in a second rotation direction above the first pancake.

7. The method according to claim 1, wherein in the inserting, the second part of the conductor is inserted in a groove of the winding mandrel.

8. The method according to claim 1, wherein in said winding of the second portion of the conductor around the first part of the winding mandrel so as to form the first pancake, the conductor is held in position by means of a system of axial and radial pressure rollers.

9. The method according to claim 1, wherein in said unwinding of the first portion of the conductor from the storage volume and winding the first portion of the conductor around the reel, the conductor is held in position by means of a system of axial and radial pressure rollers.

10. The method according to claim 1, wherein in said unwinding of the first portion of the conductor from the storage volume and winding the first portion of the conductor around the reel, the tensioner is offset in the radial direction.

11. The method according to claim 1, wherein in said unwinding of the first portion of the conductor from the storage volume and winding the first portion of the conductor around the reel, the reel is turned back on a tensioner axis of the tensioner.

12. The method according to claim 1, wherein in said winding of the second portion of the conductor around the first part of the winding mandrel so as to form the first pancake, the conductor forming the first pancake is clamped once the first pancake has been formed.

13. The method according to claim 1, further comprising, prior to winding the first portion of the conductor around the second part of the winding mandrel so as to form the second pancake, positioning an insert above the first pancake to be inserted between the first pancake and the second pancake.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) Other characteristics and benefits of the invention will become clear after reading the following description with reference to the appended figures that show:

(2) FIGS. 1 to 5, diagrammatic views of the different steps of a winding method according to an embodiment of the invention.

(3) For more clarity, identical or similar elements are marked by identical reference signs in all the figures.

DETAILED DESCRIPTION

(4) FIGS. 1 to 5 show the same elements, namely a winding table 1 on which there is a winding machine tray 2 and the cylinder 8 acting as the storage volume. This storage volume may be either cylindrical or conical to reduce the total height and/or to increase the radius of curvature of the conductor. It also shows a tensioner 4 comprising a support axis 5 on which there is a reel 6. The reel is a support on which conductors/wires are wound. The tensioner is a motor fitted with a brake to tension and rewind the conductors. The arrow 15 shown in FIGS. 1 to 5, shows the rotation direction of the conductor winding or unwinding.

(5) FIG. 1 shows a first step in the winding method. The reel 6 is put into position on the support axis 5 of the tensioner 4 at a first part of the tensioner, in this case the upper end of the support axis 5 of the tensioner 4. The reel may be moved between the upper end of the support axis 5 of the tensioner and the lower end of the support axis 5 of the tensioner, the second part of the tensioner. A first portion of the conductor 7 is wound around the storage volume 8 also referred to as the spare solenoid. This first step is a step that corresponds to splitting the conductor, and unlike in prior art, it is now done directly on the winding machine. The conductor 7 placed on the reel includes the required quantity for winding the complete double pancake. The reel is initially at the upper end of the tensioner support axis 5, a first end of the conductor 7 is unwound from the reel and is attached to the storage volume 8. The conductor 7 is then tensioned using the tensioner 4 and a first portion of the conductor is then wound around the storage volume as far as the winding mandrel 3 moving the reel down along the tensioner axis 5, i.e. by moving the reel between the first part of the tensioner and the second part of the tensioner. The first conductor portion thus wound around the storage volume will be used for winding the second pancake of the double pancake.

(6) FIG. 2 shows a second step in a winding method. A first part of the conductor is inserted in a groove (not visible) in a winding mandrel 3 so that the layer change 9 between the first portion of the conductor and a second portion of the conductor can be made. The layer change is made when the reel reaches the second part of the tensioner. The winding mandrel is placed at the second part of the storage volume, in this case the lower part of the storage volume. The layer change 9 may be made with or without tension. If it is made with tension, the reel displacement speed on the tensioner is adjusted to index the angular position of the conductor at the exit from the spare cylinder so that the layer change can then be made.

(7) FIG. 3 shows a third step in a winding method. This third step is the step in which the first pancake of the double pancake is wound. When the reel 6 reaches the lower end of the support axis 5 of the tensioner, the second part of the tensioner, and the layer change has been made, a second portion of the conductor is wound in a first rotation direction 15, around a first part of the mandrel so as to form the first pancake 11. The reel is kept fixed in its position so that the first pancake 11 can be wound. Axial and radial pressure roller systems 10 are added to keep the conductor in position while the first pancake is being wound.

(8) FIG. 4 shows a fourth step in a winding method that corresponds to recovery of the first portion of the conductor from which the second pancake will be formed ready for winding above the first pancake. Once the first pancake has been wound and the conductor has been clamped, the tensioner 4 is shifted in the radial direction and the empty reel 12 is returned to the first part of the tensioner, i.e. the upper end of the tensioner axis. The first portion of the conductor is then unwound from the storage volume and is wound around the empty reel in the first rotation direction moving the reel from the first part of the tensioner towards the second part of the tensioner, i.e. by moving the reel down as far as the exit from the layer change 9.

(9) FIG. 5 shows a fifth step in a winding method that corresponds to winding the second pancake 13. The first conductor portion is wound around a second part of the mandrel. This winding takes place in a second rotation direction, i.e. by reversing the rotation direction from the previous steps. The second pancake is wound above the first pancake 11. An insert 14 can be seen in FIG. 5. This insert is placed between the first pancake 11 and the second pancake 13 and acts as the winding plate for the second pancake 13 and electrical insulation. A system of axial and radial pressure rollers 10 is installed to keep the second pancake 13 in position during winding.

(10) The invention is not limited to the embodiments disclosed above with reference to the figures and variants could be envisaged without going outside the scope of the invention.