US3414746A - Dynamoelectric machine field core winding and method of construction - Google Patents

Description

Dec. 3, 1968 R. J. MELVIN DYNAMOELECTRIC MACHINE FIELD CORE WINDIN AND METHOD OF CONSTRUCTION Filed April 1, 1966 INVENT'fiZ FaY J. MELVIN W,Mv m

Afrorzhgyg United States Patent 3,414,746 DYNAMOELECTRIC MACHINE FIELD CORE WINDING AND METHOD OF CONSTRUC- TION Roy J. Melvin, Waterford, Wis., assignor to MSL Industries, Inc., Racine, Wis., a corporation of Minnesota Filed Apr. 1, 1966, Ser. No. 539,459 9 Claims. (Cl. 310-42) This invention relates to a field core winding and method of construction.

The invention is shown as applied to the field of a universal A.C.-D.C. motor having its coil mounted on the core assembly by an automatic coil winding equipment.

The core assembly is conventionally made by rive-ting together prefabricated laminations of desired form. Con ventionally, special tooling has been used to support the winding turns until the winding has been completed and its leads and end turns taped or clamped to the core.

In the preferred practice hereinafter described, the prefabricated laminations are assembled with straps having central portions offset to fit about the laminations (preferably in channels formed therein) and held in the assembly by the rivets which pass through the laminations to constitute the core.

It is contemplated that the straps will be electrically insulated either by coating them or sleeving tubes of electrical insulation over the ends of the straps or, as is preferred, by spraying the straps with an insulating coating such as epoxy resin. conventionally, such a coating is applied to the field core upon assembly of the laminations to constitute such a core. Accordingly, it is preferred that the coating be applied both to the core and to the straps after the straps are attached by the rivets.

The laminations are desirably notched to provide the core with channels to receive the offset portion of the straps. The ends of the straps are left projecting out wardly and serve as guides about which the successive turns of the coil winding are supported and located in passing about the core from one set of poles to another. When the winding is complete, the straps are folded down about the winding to anchor the several turns and the leads.

It will be noted that once the coil is complete and the straps folded about the turns, it is no longer necessary that the straps be anchored to the core, since they are held in place by the winding. Hence, a variation in the foregoing procedure is possible, wherein the traps could be temporarily attached to the core by means intended to be removed when the winding is complete and the ends of the straps are folded thereabout. However, the method first described is better and less expensive and is preferred.

In the drawings:

FIG. 1 is a view in perspective showing a field core having one of the turn-positioning and retaining straps applied to the laminations and another one illustrated in outwardly spaced position in readiness for application when the remaining rivet is applied to hold the laminations in assembly.

FIG. 2 is a view showing the completed core in end elevation with the winding fragmentarily illustrated and retaining straps still projecting.

FIG. 3 is a view taken in section on the line 3-3 of FIG. 2 showing the assembly more advanced, the projecting ends of the strap at one side having been folded down over the winding and the projecting ends of the strap at the other side being in readiness for this final step.

FIG. 4 is a view of a modified embodiment on an enlarged scale and shown in cross section taken at the 3,414,746 Patented Dec. 3, 1968 "ice position indicated at 4-4 in FIG. 1, the insulation having the form of a tube sleeved over the projecting end of the strap.

The several laminations 6 of the magnetic core 8 are prefabricated in any desired manner. It is conventional to stamp these of magnetic iron to provide the poles shown at 10, 12, 14 and 16. They are provided with registering holes 18 to receive rivets 20 for connecting them together unitarily. In accordance with the present invention, the several laminations have registering notches which form slots 24 to receive the anchor straps contemplated for the practice of this method. By holding the laminations in temporary assembly in a jig, the channels 24 may be machined in the laminations so positioned. However, it is preferred that the notches for forming these channels be stamped in the respective lamination as shown in FIG. 1.

Separately prefabricated are the straps 26 which are conveniently made of steel sufficiently stiff to support the coil while it is being wound and yet sufficiently llexible so that the strap ends can readily be folded about the end turns and terminal leads. Each such strap is prefabricated to provide a centrally offset portion 28 dimensioned to embrace the assembled laminations and adapted to seat in one of the channels 24 and having projecting ends 30 which act as winding forms and, ultimately, as clamps. Intermediate the ends and the offset portion 28 each strap has a portion 32 designed to seat against an end face of the core and apertured at 34 to receive a rivet 20.

The prefabricated straps may be rendered dielectric by being insulated either by coating or by applying an insulating sleeve such as is shown at 36 in FIG. 4. An epoxy resin such as is conventially applied to field cores is an example of an appropriate coating. The applied insulation shown at 36 may conveniently be made by cementing insulation to the strip or by using extruded nylon or other synthetic resin in the form of a prefabricated sleeve slipped over the end of the strip. Since the core has to be insulated in any event, and since this is conventionally done by spray coating, it is preferred that the uninsulated strips be attached to the laminations by the rivet 20 in the assembly of the core and the entire unit may then be insulated by spray coating with epoxy resin or the like.

The coil is now wound turn by turn in situ, each turn passing about one pole and then passing about the outstanding end 30 of the respective form strip before passing the next pole. This procedure continues until the winding is complete. At the left in FIG. 3, the otherwise complete winding is shown at 40 before the ends 30 of the guide strip have been folded about it in the manner indicated by the arrows. At the right in FIG. 3, the ends 30 are shown folded over the winding 40 to confine the turns and to locate permanently and with precision the projecting leads 42.

This completes the field assembly. The ends which originally served as guide for-ms in the winding of the turns now remain as clamps and as permanent parts of the field. Use of special tooling of separate preformed clamps in the manner of previous practice has been eliminated.

Mechanically, the field difiers from conventional practice in having channels in the laminations within which the said offset portions 28 of the guide and clamp elements 26 are recessed. Since these elements remain as permanent parts of the assembly, it is significant that they hold the coils and leads more securely and more neatly than heretofore.

In terms of the method, it is advantageous to use as coil winding forms elements which subsequently become clamps as above described, each turn being located accurately by winding it in situ against a guide strip end which is then folded about the coil for clamping purposes.

I claim:

1. A field member comprising the combination with an assembly of laminations having registering apertures to receive rivets, of winding guides and clamping strips having offset portions embracing the laminations and having projecting ends, the coil having its turns individually wound upon the laminations and about such ends, and having terminal leads, the ends of said strips encircling the coil as a means of positioning the turns and anchoring the leads.

2. A field member according to claim 1 in which the said strips have apertured portions registering with the apertures of the laminations, and rivets extending through the strips and the laminations and unitarily assembling said strips with said laminations.

3. A field member according to claim 1 in which the assembly of laminations has channels in which the offset portions of said strips are disposed.

4. A method of manufacturing a field member which comprises the steps of prefabricating generally conventional laminations, positioning at opposite sides of said laminations guiding and anchor strips having projecting ends, winding in situ upon said laminations a coil having turns passing about said strips and having terminal leads, and folding the ends of said strips about the turns of said coil.

5. A method according to claim 4 in which said strips are also folded about the terminal leads in a position for the anchorage thereof.

6. A method according to claim 4 including the step of fixing said strips to the laminations by extending fasteners through the strips and the laminations to effect the unitary assembly of the strips and laminations in advance of the winding of said coil.

7. A method according to claim 4 including the step of notching said laminations in registry to form channels at opposite sides of the core, forming the strips with offset central portions, seating said ofiset portions in respective channels and mechanically securing the respective strips and the laminations together in unitary assembly.

8. A method according to claim 4 including the further step of electrically insulating the assembly of the strips and the laminations by spray coating such assembly when the strips and laminations have been mechanically secured together.

9. A method according to claim 4 including the step of notching said laminations at corresponding points and assembling the laminations with the notches in registry to form channels at opposite sides of the core, forming the said guiding and anchor strips with offset central portions, providing registering apertures in said strips and said laminations, seating the offset portions of the strips in the respective channels with the said apertures in registry, mechanically securing the respective strips and laminations together in unitary assembly by passing fasten ers through the aforesaid registering apertures, and electrically insulating the unitary assembly of strips and laminations by spray coating such assembly with a dielectric coating.

References Cited UNITED STATES PATENTS 3,030,528 4/1962 Dejean 310214 X 3,145,313 8/1964 Tupper 310258 X 3,264,593 8/1966 Cole 310-2l4 FOREIGN PATENTS 1,320,580 1/1963 France.

MILTON O. HIRSHFIELD, Primary Examiner. WARREN E. RAY, Assistant Examiner.

Claims (1)

1. A FIELD MEMBER COMPRISING THE COMBINATION WITH AN ASSEMBLY OF LAMINATIONS HAVING REGISTERING APERTURES TO RECEIVE RIVETS, OF WINDING GUIDES AND CLAMPING STRIPS HAVING OFFSETS PORTS EMBRACING THE LAMINATIONS AND HAVING PROJECTING ENDS, THE COIL HAVING ITS TURNS INDIVIDUALLY WOUND UPON THE LAMINATIONS AND ABOUT SUCH ENDS, AND HAVING TERMINAL LEADS, THE ENDS OF SAID STRIPS ENCIRCLING THE COIL AS A MEANS OF POSITIONING THE TURNS AND ANCHORING THE LEADS.

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