US3274414A - Electrical windings - Google Patents

Description

Sept. zo, 196e R. A. BEDARD 3,274,414

ELECTRICAL WINDINGS Filed oct. 4, 1963 2 sheets-sheet 1 Sept. 20, 1966 R, A, BIDARD 3,274,414

ELECTRICAL WINDINGS Filed OCL. 4, 1963 2 Sheets-Sheet 2 INVENTOIL RENE HLP/ 50 loflfd) HffonLNE/S United States Patent O 1 s claims. (Cl. 31o-26s) In some electric machines hav-ing flat rotors and/or stators, that is to say in which the windings are formed of bare lamellar conductors disposed flat on both sides of a thin and flat support made of insulating material, this being achieved as a result of the so-called printed circuit technique or by any other means, and in which the currents are relatively high, it may happen that the conductors become too wide in the radial (or almost radial) portion, thus occasioning losses by excessive eddy currents, whether the current be directed or alternating.

It is therefore necessary to split each basic conductor into ltwo or more partial conductors in parallel and to choose the positions of these partial conductors suitably so as to avoid circulation currents between them.

Here, however, a diiiiculty arises owing to the fact that the said conductors are placed flat on the insulating support, covering the two faces thereof practically completely, and that, moreover, not being insulated, they can form only a single layer on each face of the sa-id support.

The present invention has for its object to remedy this diiculty.

The invention is described hereinafter with the aid of various diagrams and figures given by way of nonlimitative example, the said support being assumed to be a disc.

FIG. l is a fragmentary perspective view of a conventional flat winding formed of lamellar conductors.

FIG. la is a fragmentary section taken across the insulating support and showing a few conductors on each side.

FIG. 2 is a diagrammatic plan View of an embodiment of the present invention.

FIG. 2a is a fragmentary section ysimilar to that of FIG. la, but applicable to the embodiment of FIG. 2.

FIGS. 3-7 illustrate, in schematic fragmentary plan views, various alternative embodiments.

The conventional flat winding illustrated 4in FIGS. 1 and la comprises an insulating support 4, for example in the shape of a disc, bearing on its two faces bare lamellar conductors 1; outgoing ones A and return ones B on opposite sides, interconnected by means of connections 5 extending through the thickness of the disc 4.

The present invention, as illustrated in FIGS. 2 and 2a, consists in dividing each initial basic conductor 1 into two partial conductors 2 and 3, the Width of which is half that of the initial conductor, and in disposing one of these on one face of the thin insulating support 4 and the other on the other face right opposite the previously mentioned partial conductor, while taking advantage of the space left free in this way between the partial conductors on one face, which have 'become half as wide, and to do the same with those on the other face.

Connections 5 extend through the support 4 at the ends of the partial conductors 2 and 3 and connect them in parallel. Since -these conductors are exactly back to back they encompass no magnetic flux and therefore, no circulation current between them is to be feared.

Holes are to be provided in the support for the connections 5. They may all be located on two concentric circles or disposed in staggered arrangement about such circles as shown in FIG. 2.

Only a few conductors have been shown, but in reality 3,274,414 Patented Sept. 20, 1966 the two faces of the support 4 are entirely covered with conductors; the partial conductors 3 are exactly opposite the partial conductors 2.

If a further subdivision of the conductors is required the invention provides that the initial conductor 1 be replaced by partial conductors placed this time side by side and that there be formed in this way half loops which are joined by electrical connections so as to avoid circulation currents. Various arrangements are possible, the diagrams of the principle of which are shown in FIG- URES 3 to 7 inclusive. In these gures, there is shown each time an outgoing conductor A, in linear form for simplicity.

In FIGURE 3, the initial conductor 1 is divided therein into four partial conductors 6, 7, 8, 9 forming two half loops which are to encompass the same linx, thus determining a suitable relation between the division radius Rd, the permutation radius Rp and the reconnection radius Rr.

It may happen that if the initial conductor has a width which is still acceptable in the inner region of the beginning of the straight or radical portions, the subdivision need only be started at a radius Rd greater than the commencing radius R1 of the straight portions, in which case the arrangement will be that shown in FIGURE 4.

More generally still, it is possible to subdivide the conductor first into two, then into four, then into eight, etc. partial conductors, as the radius increases. There will then be obtained an arrangement with a principle similar to that of FIGURE 5, which is drawn for the case of a double subdivision.

In the latter case, it will be necessary, in order to comply with the condition of equality of iiuxes encompassed by all the closed circuits obtained by following the conductors connected in parallel, that a relation similar to the foregoing one be observed between the division rad-ii Rdl and Rdz, the permutation radii R111, Rpz and the reconnection radii Rrl and Rrz of each stage of subdivision.

It may then happen that the spacing of the various radii in an order such as that shown in FIGURE 5. In this case, lin order to have regard both for the correct radii Rd for the subdivisions and the condition of ux which iixes the permutation position, that is to say the radii Rp,

it may be necessary to permute the conductors in pairs in accordance with the basic principle diagram of FIG- URE 6.

In most instances, however, this complicated arrangement may be avoided, while paying regard to the condition of flux, by modifying the subdivision radi-i Rd (that is to say by making these subdivisions a little sooner or a little later).

Finally, whatever the number of subdivisions, it may be advantageous, in some case, to effect in the outer curved portions of windings reconnections of the partial conductors. A case of this kind is shown by way of example in the diagram of FIGURE 7, in which only the outer portion of the windings is illustrated.

Various solutions are possible for the material realisation of a simple subdivision accompanied by permutation, that is to say for a single stage of subdivision of the partial conductors in accordance with one or other of the basic principle diagrams described above, but it is clearly understood that these solutions are applicable to every subassociated portions of reduced width, half of said portions of each conductor extending over the opposite faces of said support, means extending from one face of said insulating support to the other face thereof for connecting said conductors to each other vat the ends thereof, and means extending through said insulating support for electrically interconnecting said associated portions of each respective conductor to minimize eddy current losses in operation.

2. The winding assembly as claimed in claim 1, wherein the associated portions of each respective conductor are positioned substantially back to back and are interconnected therethrough in parallel.

3. The winding assembly as claimed incla-im 1, wherein lthe associated portions of each respective conductor comprise pairs of segments positioned side by side on a same face of saidsupport, said pairs being connected in series in a cross-like manner.

4. The winding assembly as claimed in claim 3, Wherein each respective conductor comprises a pair of segments on one face of the insulating support and a pair of segments on the other face thereof, said pairs of segments being connected in a cross-like manner.

5. The winding assembly as claimed in claim 3, wherein each respective conductor comprises two pairs of segments on a same face of the insulating support a conductor section of small length on the other face thereof, and two connections therethrough to interconnect in a crosslike manner said segments through said conductor section.

References Cited by the Examiner UNITED STATES PATENTS 3,109,114 10/1963 Henry-Baudet a B10-168 3,159,760 12/1964 Olofsson B10-268 X I MILTON O. HIRSHFIELD, Primary Examiner.

J. J. SWARTZ, Assistant Examiner.

Claims (1)

1. AN ELECTRICAL WINDING ASSEMBLY COMPRISING A THIN SUPPORT OF INSULATING MATERIAL HAVING TWO SUBSTANTIALLY PLANAR PARALLEL FACES, A MULTIPLICITY OF BARE LAMELLAR ELECTRIC CONDUCTORS EXTENDING FLAT ON SAID FACES, AT LEAST A LENGTHWISE PORTION OF EACH CONDUCTOR BEING DIVIDED INTO ASSOCIATED PORTIONS OF REDUCED WIDTH, HALF OF SAID PORTIONS OF EACH CONDUCTOR EXTENDING OVER THE OPPOSITE FACES OF SAID SUPPORT, MEANS EXTENDING FROM ONE FACE OF SAID INSULATING SUPPORT TO THE OTHER FACE THEREOF FOR CONNECTING SAID CONDUCTORS TO EACH OTHER AT THE ENDS THEREOF, AND

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