US2502068A - Insulator for wound core structures - Google Patents

Description

March 28, 1950 e. R. ANDERSON INSULATOR FOR WOUND CORE STRUCTURES 2 Sheets-Sheet 1 Filed May 26, 1947 INVENTOR GORDON R. ANDERSON lair} ll ATTOR N EY March 28, 1950 R. ANDERSON 2,502,068

INSULATOR FOR WOUND CORE STRUCTURES Filed May 26, 194'? 2 Sheets-Sheet 2 FIG. 3

FIG. 2

FIG. 4

INVENTOR GORDON R. ANDERSON ATTORNEY Patented Mar. 28, 1950 INSULATOR FOR WOUND CORE STRUCTURES Gordon R. Anderson, Beloit, Wis., assignor to Fairbanks, Morse & (30., Chicago, 111., a corporation of Illinois Application May 26, 1947, Serial No. 750,531

(01. I'll-252) 7 Claims. 1

This invention relate to improvements in insulators for separating coil windings of magnetic core and winding structures for electrical machines and the like, and has particular reference to improved insulators of unitary character, for separating the phase windings in plural phase core assemblies.

It has been the general practice heretofore in the application of a plurality of phase windings to a slotted core structure, to insert separate pieces or strips of insulation in the slots between coil legs of different phase coils, and between the adjacent sides of such coils. Experience with this practice has shown that unless the insulator pieces are firmly placed in position between the coil sides, some or all of them eventually work loose and fall away from the assembly, particularly when the core and winding assembly is given frequent and rough handling. Moreover, the insertion of a great number of separate insulator strips according to the prevailing practice, is a comparatively slow and tedious process, resulting from labor alone, in appreciably high manufacturing assembly costs.

Accordingly, it is the principal object of this invention. to obviate the foregoing disadvantages, by the provision of an insulator of unitary character, for physically separating and electrically insulating the coils of adjacent phase windings in a magnetic core assembly for electric motors and the like, wherein the insulator is so constructed as to facilitate ready and rapid application and positive retention thereof in place in the core assembly.

Another object is to provide an insulator of the character and for the purpose above indicated, which is suitable in particular, for use in stator core assemblies of the form employed in electrical machines of the axial air gap type.

ther objects and advantages of the invention will appear from the description of a preferred embodiment thereof, illustrated in the drawing, wherein:

Fig. 1 is a fragmentary view in plan, of a wound core structure of circular extent, embodying insulators provided according to the present invention;

Fig. 2 is a fragmentary, developed view at the outer side of a circular core structure having some of the windings and insulators in place thereon. the latter being relatively widely spaced in order better to illustrate the relationship of the insulators to the phase windings;

Fig. 3 is a sectional elevation, transversely of 2 the core assembly, as viewed from line 3-3 in Fig. 1;

Fig. 4 is a fragmentary section of the core assembly, a taken along the line 4-4 in Fig. 3;

Fig. 5 is a fragmentary sectional view of the assembly, as taken along the line 5-5 in Fig. 2;

Fig. 6 is a sectional view similar to Fig. 5, but taken from the line 6-6 in Fig. 2;

Fig. 7 illustrates in plan elevation, one form of insulator according to the invention, and

Fig. 8 illustrates in plan elevation, a modified form of insulator.

Referring to the drawing, Fig. 1 illustrates in fragmentary part a stator core assembly for axial air gap type motor or the like. The assembly includes an annular magnetic core is pref-- erably of laminated construction, providing generally radially directed coil slots ll subtending the planar role face l2, each slot opening to the inner and outer circular core sides l4 and respectively. Each slot by preference, is lined with an insert l6 (Figs. 3 and 4) of suitable insulating material, and seated in and. through the slots are the leg portions l8 of coil windings l9, each coil spanning a given number of slots as indicated in Fig. 2, with the opposite slot-spanning coil sides 2i! and 2! exposed along the core sides M and i5 respectively (Figs. 1, 5 and 6). The stator sembly as shown, is of plural phase winding character wherein the coils are arranged in two or more phases. For example, (see Fig. 2) the coils 23 and 24 may be in one phase winding, whilev the adjacent set of coils 26 and 28 are in. another phase winding, and the next adjacent set of coils 3| and 32 either in the first mentioned phase, or in a third phase winding, such alter phase arrangement of the coil sets obtaining around the circular core. Moreover and as appears in Figs. 1 and 2, the exposed sides of one set of phase coils and the sides of the adiacent set of phase coils, are relatively overlapping along the opposite core sides, this overlapping relationship obtaining substantially uniformly around the core. While in the core assembly illustrated, each slot contains one coil leg portion N3 of each of two coil l9, more than two coil legs may be included in each slot as may be required in am cordance with a given coil arrangement and the number of different phase windings desired.

It is the purpose of the present invention as heretofore indicated, to provide an improved phase separator and insulator device for separating the'exposed sides of the coils in adjacent coil sets of differing phase, as well as the coil legs in the slots. Referring to Fig. 7, one form of the device now provided comprises a one-piece skeleton-like member 40 formed from suitable, relatively stiff sheet material of insulating character. The finished member which may be obtained by stamping or other cutting process, provides opposite elongate surface portions 4| and 42 each greater in width than the average diameter of the coiLc, 19. The surface portion 4| is generally arcuate, while the surface element 42 is arcuate along its inner margin, as shown. In adaptation of the member for application to the radial slot, axial air gap type core structure, the portion 4! is of appreciably longer arcuate length than the portion 42, since in core assembly the former extends along the outer side i5 of the core while the latter extends along the inner core side l4. structurally uniting the portions 4| and 42 are narrow portions or rib 44, each joining the portion 41 somewhat rearwardly of the terminal end 45 of the latter, and similarly joining the portion 42 rearwardly of the terminal end 46 thereof. The ribs 44 are directed substantially radially of the arcuate portion 4| and are relatively spaced such that in application of the device to the core, each rib will seat in and through a core slot.

The dimensional factors of the insulator, in respect to the length and width of the surface portions 4i and 42, and the relative spacing of the ribs 44, are determined for a given stator winding structure, so that in insulator placement between the coils of adjacent phase windings, which may be effected as the coils are applied to the core, the insulator portions 4! and 42 located respectively, along the inner and outer sides of the core, will overlap the coil sides spanning the core slots as such appears in Figs. 1 and 2. Thus the insulator serves effectively, to separate and insulate the adjacent phase windings, while the ribs 44 seated in certain of the core slots, provide assembly retention of the insulator to the core structure, effecting what may be called a locked-in mounting of the insulator.

As appears from Figs. 2 through 6, a plurality of the insulators All are applied about the core, these appearing in staggered relation in effecting the insulating separation of each pair of coils. The arrangement as illustrated, is such that in each alternate slot, as the slots 1 la, i la, He, etc., (Fig. 2) there will be a rib 44 of each of two insulators. In final core assembly, the two ribs will be compressed between the upper and lower coil legs l8 (Fig. 3) in the assembly securement of the latter by the pegs 53, thus effecting thereby an insulating phase separation of the coil legs. On the other hand, in using insulators of the form shown. by Fig. 7 in the arrangement according to the several figures, ribs 44 of the insulator elements will not appear in the alternate intermediate slots as lib, lld, etc., between the coil legs therein. However, if in these slots the coils are in the same phase, the absence of insulator elements between the slot legs of the coils may not be objectionable, although it is preferred in the interest of uniformity of slot-coil assembly and a complete insulation of all coils, to insert here between the otherwise non-separated coil legs, insulator pieces such as that shown at 5| in Fig. 4.

Where the coil legs in the alternate intermediate core slots as above indicated, are included in coils of different phase windings, the separating insulation elements. 5| will be required. While pieces 5| may be formed separately and inserted as the winding proceeds, such may be provided as parts of integral insulators according to the present invention. Fig. 8 shows an insulator 52 similar generally, to the described insulator 40, but including ribs 53 additional to ribs 54, the latter corresponding to ribs 44 of the element ac cording to Fig. 7. Consequently, utilizing insulating separators of the form shown by Fig. 8, in the core-winding assembly of Figs. 1 to 6, each and every core slot will have two ribs between the coil legs therein.

From the foregoing, it will appear now that an integral insulating separator of the improved character shown, may be provided to have an even or an odd number of connecting ribs, to adapt the same to a given character of phase winding assembly, so that all portions of coils of differing phase, ma be adequately insulated one from another. Moreover, and importantly to the present invention, the insulators by reason of the integral structures thereof including ribs extending through the core slots, will be firmly and securely locked in assembly to the core structure.

While the insulator device is herein shown and described as adapted for use in wound core structures of planar pole face character, for use in electric motors and the like, of the axial air gap type, it will be appreciated that the improved insulator may be modified readily, for use in core assemblies of the form provided for conventional circular air gap type electric machines. Such modification would provide for example, an integral insulator such as the insulator 40 of Fig. 7, wherein the surface portions 4| and 42 would be of rectilinear extent and equal in length, and the ribs 44 would be in parallel relation.

Having now described and illustrated a presently preferred form of the invention, what I desire to claim and secure by Letters Patent is:

1. In a core and winding structure for electrical machines, a magnetic core having relatively spaced winding slots therein, a plurality of phase windings in said slots, said windings including exposed coil sides spanning certain of the slots, and insulating members separating the windings of differing phase, said members each providing surface portions between the coil sides of one phase winding and the coil sides of an adjacent phase winding, and strip portions uniting said surface portions and seated in certain of the core slots to retain the member in assembly to the core and winding structure.

2. In a core and winding structure for electrical machines, a magnetic core having winding slots therein, a plurality of phase windings in said core slots, adjacent phase windings having slotsp-annin'g coil sides exposed along the opposite sides of the core, and an insulator for separating the coil sides of adjacent phase windings, said insulator comprising a one-piece member of relatively stiff insulating material, providing surface portions extending between the coil sides of adjacent phase windings, at the opposite sides of the core, and relatively narrow portions structurally connecting said surface portions, each of said narrow portions being extended through a core slot.

3. In a core and winding structure for electrical machines, a circular magnetic core having substantially radially directed slots therein, a plurality of phase windings in said core slots, adjacent phase windings having slot-spanning coil sides exposed along the inner and outer curved sides of the core, and an insulator for separating the coils of adjacent phase windings, said insulator comprising a skeleton-like sheet member of relatively stiff insulating material, providing a portion of appreciable surface area extending along the outer side of the core between the exposed coil sides of adjacent phase windings, a similar portion of less surface area extending along the inner side of the core between the opposite exposed coil sides of said adjacent phase windings, and at least two relatively spaced strips structurally connecting said surface portions, each of said strips extending through a core slot.

4. In a core and winding assembly for electrical machines, a magnetic core having slots therein, at least two phase windings including coils arranged in the slots such that each slot contains at least two coil legs, the coils further being arranged in overlapping relationship and such that the coils in each adjacent overlapping pair are of different phase, and insulating separators for the adjacent pairs of coils, each separator comprising a unitary member of insulating material providing surface portions between the opposite overlapping sides of an adjacent pair of coils, and elements bridging the surface portions, each of said bridging elements extending through a core slot between the coil legs therein.

5. In a core and winding structure for electrical machines of the axial air gap type, a circular magnetic core providing a planar pole face and substantially radially directed slots therein, a plurality of phase windings each comprising at least one coil having coil legs in certain of the core slots and coil sides exposed along the opposite circular core sides, the coils being arranged onthe core such that the coil sides of one phase winding overlap the coil sides of another phase winding, and insulator means for separating the overlapping coil sides, said insulator means comprising a member of relatively stiff insulating material, formed to provide surface portions adapted to extend along the opposite curved sides of the core between the overlapping coil sides, and strip portions uniting said surface portions, extending through certain of the core slots, said strip portions serving thereby, to retain the insulator member in assembly to the core and winding structure. v

6. An insulator for a coil wound radially slotted core, comprising a one-piece flat member of relatively stiff insulating material, formed to provide relatively spaced surface portions each of a predetermined appreciable width and one thereof being of arcuate trend, and rib portions each of a width materially less than the width of said surface portions, bridging said surface portions, each of said rib portions being directed radially 10f said surface portion of arcuate trend and adapted for placement in a radial slot of the core. 7. A combined separating, insulating, and retaining'member for the slotted core structure of an electrical machine having at least two phase windings, said member being made of a unitary piece of insulating material and being formed to include spaced end surface portions to separate and insulate adjacent phase windings protruding from each side of the slotted core structure and to include connecting ribs of predetermined width between the spaced portions for insertion into the slots to insulate and retain the coil windings in the slots of the core.

GORDON R. ANDERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Name Date Holbrook Sept. 14, 1926 Number

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