JPH0466088B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to superconducting coils, such as racetrack type and saddle type, used as field coils of superconducting rotating electrical machines.

[Technical background of the invention and its problems]

In superconducting coils, elements that cause quenching, such as grinding heat generated by misalignment of wires and joule heat generated from connections between wires, must be minimized as much as possible. Therefore, the coil has a structure that can be firmly fixed, and long wires are continuously wound to reduce the number of connections. In addition, in a coil where multiple layers of conductors overlap to form a coil for one pole, the wire is bent at the part where it crosses between each layer; This part is difficult to fix, and tends to become a point where quenching occurs, such as stress from the formation remaining or the filament within the wire easily breaking. Therefore, it is necessary to bend the bent portion of the wire smoothly.

Figure 1 is a perspective view of a general spiral coil.
4 is a number indicating each side of the coil, a indicates the lower layer of the coil, and b indicates the upper layer of the coil. Now, the developed diagrams of each layer of this coil are shown in FIGS. 2 to 4. In these figures, for the sake of simplicity, the number of strands arranged horizontally is six, and the widths of the strands are drawn extremely thick.

In FIG. 2, the coil of the first layer starts winding from the lower layer a side in FIG. 1 toward the inner circumferential side from point S, and crosses from the first layer to the second layer at point E. Note that in order to wind from the outer circumferential side toward the inner circumferential side, guides such as slots are provided on the sides 1 and 3, and the winding is performed. Figure 3 shows the second
This shows the winding state of the layer, starting from point S continuing from the first layer, winding toward the outer periphery and crossing to the third layer at point E.
Note that there is a curved part on side 4 for crossing side by side. FIG. 4 (extremely drawn in the figure) shows the third layer, which continues from the second layer and winds toward the inner circumference from point S, and reaches the fourth layer at point E. Note that, as in FIG. 3, there is a curved portion on side 4 for crossing side by side. (The figure shows an extreme case.) By repeating the above steps, a coil for one pole is completed.
Figure) There is a method of first passing the strands from the outermost circumference to the innermost circumference, and then always winding from the inner circumference, but since the crossing part becomes thicker, the overall thickness of the coil becomes thicker.

Now, in the conventional coil as described above, each layer has many horizontal transition parts, but since the positions differ depending on the layer, the bending operation must be performed at different positions for each layer. In addition, the coil is wound with a long continuous wire to reduce the number of connections that can easily cause quench.
Each time it is wound, it is necessary to bend it horizontally.

Furthermore, since the transition between layers must be made over a short distance, bending operations are required. However, as described above, such bent portions tend to become points where quench occurs, and the bending work must be performed carefully so as not to damage the strands. or,
In particular, superconducting wires with a low copper ratio are hard, making bending the wires a labor-intensive task.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a superconducting coil that has few bent portions that are likely to cause quenching and is easy to wind.

[Summary of the invention]

In a rectangular superconducting coil formed by coaxially stacking a plurality of unit coils, the present invention collects the parts that cross between each unit coil on one coil side, and moves the strands from the outer circumference to the inner circumference. Bending that is likely to cause quenching by winding alternately layer by layer from the periphery to the outer periphery, and by making the number of strands forming the coil side with a crossover part greater than the number of strands lining the other coil side. Reduce the number of parts and simplify the winding work.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 2 and 5.
This will be explained with reference to FIGS.

Although FIG. 2 is a developed view of the lowermost layer of the conventional hollow-shaped coil, the lowermost layer of the coil according to the present invention is also the same as the conventional one. That is, in Figure 2,
Starting from point S, it is wound toward the inner circumferential side and passes from the first layer to the second layer at point E. Next, the wire that has passed to the second layer moves to point S in FIG. 5, and is wound from the inner circumferential side to the outer circumferential side, contrary to the first layer. What is characteristic here is that the number of horizontally arranged strands on coil side 4 is 7,
This point is that the number of horizontally arranged strands is greater than 6 on side 2, which is the coil end on the opposite side. Therefore, in the present invention, it is possible to cross between layers over a long distance as shown by hatching near S and E in FIG.
The bending radius can be increased. In addition, since there is no need for a bending part for horizontal transition, the shape is extremely simple.

Now, after winding the second layer as shown in Figure 5,
The third layer is as shown in FIG. That is, the transition part from the second layer becomes the hatching part near S, and then the third layer is wound from the outer circumference toward the inner circumference, contrary to the second layer, and the fourth layer is connected to the hatching part near E. It passes to. In Fig. 6, the number of horizontally arranged strands on coil side 4 is 7, and side 2 on the opposite coil end.
The number of transitions between layers is longer as shown by the hatching, and there is no need for a bending portion for horizontal transition, resulting in a very simple shape.
By repeating the above steps, a coil for one pole according to the present invention is completed.

As described above, in the present invention, the number of horizontally arranged strands of the coil end having a transition section between layers is made larger than the number of horizontally arranged strands of the other coil end, so that the transition between layers becomes gentler, and the number of horizontally arranged strands of the coil end having a transition section between layers is made larger. No bending part is required. Therefore, the number of bent parts that are likely to cause quenching is greatly reduced, and the amount of careful and labor-intensive bending work is reduced, making the coil winding work more efficient.

It should be noted that the present invention is not limited to the illustrated and described embodiments, and can be applied to, for example, coils with a large number of strands, coils directly wound in slots, race track coils, etc. It goes without saying that various modifications can be made without changing the gist.

〔Effect of the invention〕

As explained above, in the present invention, the parts that cross each layer are collected on one coil side, and the coil is wound layer by layer alternately from the outer circumference to the inner circumference and from the inner circumference to the outer circumference. Since the number of strands of strands constituting the coil side that rotates and has a transition section is greater than the number of strands of strands that constitute the coil side of the other coil side, the bending section of the transition section between layers becomes gentler, and the bending section for crossing to the side-by-side This eliminates the need for bent parts that can easily become a source of quench, and has the effect of simplifying the winding work.

[Brief explanation of the drawing]

Figure 1 is a perspective view of a general saddle-shaped coil, Figure 2
4 through 4 are developed diagrams showing the winding state of a conventional wedge-shaped coil, and FIGS. 5 and 6 are developed diagrams showing the winding state of the wedge-shaped coil according to the present invention. a...Coil lower layer side, b...Coil upper layer side,
1, 2, 3, 4...Each side of the coil, S...The starting point of the coil, E...The ending point of the coil.

Claims (1)

[Claims] 1. In a rectangular superconducting coil formed by coaxially stacking multiple layers of unit coils, the parts that cross between each unit coil are collected on one coil side, and the wires are moved from the outer circumference to the inner circumference. What is claimed is: 1. A superconducting coil in which the coils are alternately wound layer by layer toward the outer periphery, and the number of strands on the coil side having a transition portion is greater than the number of strands on the other coil sides.