US681295A - Dynamo-electric machine. - Google Patents

Description

No. 68l,295. Patented Aug. 27, l90l.

J. B. BLOOD.

DYNAIO ELECTRIC IAGHINE.

(Anpliwion M m. 18. 1001.

(In Iodol.)

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UNITED STATES PATENT OFFICE.

JOIIN BALCII BLOOD, OF NEWBURYPORT, MASSACHUSETTS.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 681 ,295, dated August 27, 1901.

Application filed March 18, 1901. Serial No. 51,577. (No model-J To all whom it may concern.-

Be it known that I, JOHN BALCH BLOOD, a citizen of the United States, residing at Newburyport, in the county of Essex and State of Massachusetts, have invented a new and useful Dynamo-Electric Machine, of which the following is a specification.

This invention relates to dynamo-electric machines.

The object of the invention is to simplify andimprove theconstruction of dynamo-electric machines and to render the same more elficient.

A further object is to provide means whereby the heating eifect of the current in the armature-coils is reduced to a minimum.

A further object is to provide means Whereby the inductance is reduced to a minimum.

A further object is to provide means whereby the capacity and eificiency of armaturecores are increased.

Other objects will appear more fully hereinafter.

The invention consists substantially in the construction, combination, location, and arrangement, all as will be more fully hereinafter set forth, as shown in the accompanying drawings, and finally pointed out in the appended claims.

In the designing of dynamo-electric machines and in the practical operation thereof it is exceedingly advantageous to reduce to the minimum the efiects of heating in the armature-coils, as the energy consumed in the heating of such coils is energy wasted. The general rule is that the heating is inversely proportional to the cross-sectional area of the copper in the inductor wires or limbs, and consequently the greater the cross-sectional area of the inductor sections or wires the less will be the resistance and the less will be the loss or waste of energy consumed in heating up the inductor wires or sections. Therefore it is a matter of material importance in the construction of dynamo-electric machines to provide means whereby the largest possible cross-sectional area of inductor-section may be employed with given conditions of size of armature, magnetic flux, current, 4850. Again, it is also exceedingly desirable and advantageous to reduce to a minimum the inductance. The general rule is that, other things being equal, the induct ance is inversely proportional to the circumferential distance around or the perimeter of the inductor wires or limbs, and consequently the greater this circumferential distance that is, the longer the perimeter of the active limb of the inductor-sectionthe less will be the inductance. Therefore it is important and advantageous that this perimeter or circumferential distance be as great as possible. Myinvent-ion therefore contemplates increasing the cross-sectional area of the inductorcopper with a given crosssection of field and at the same time increasing the circumferential distance around the active coillimbs. These results may be accomplished in many different ways. In the accompanying drawings-l have shown one construction and the best form in which I contemplate carrying my invention into practical operation.

Figure l is an end view of an armature-core constructed in accordance with the principles of my invention. Fig. 2 is a similar view showing the inductor sections or coils applied to the core. Fig. 3 is a detached broken view in perspective of an armature coil or section.

Reference sign A designates the armaturecore, and in carrying out my invention I form in the peripheral surface of such core and in the usual or any convenient manner slots or seats 13 O to receive the inductor sections or coils. Instead, however, of forming these slots or grooves of uniform dimensions throughout each slot or groove B is one-half the width and twice the depth of the slots or grooves O, or, to state it in a diiferent way, each slot or groove 0 is twice the width and one-half the depth of a groove or slot B. The grooves or slots B O alternate with each other, and the inductor sections or coils are received therein, one leg or limb of each coil or section being received in a slot or groove B and the other leg or limb being received in a slot or groove 0, as clearly indicated in Figs. 2 and 3.

In the manner above described I am enabled to increase to a maximum the transverse or cross-sectional area of the inductor sections or coils, thereby reducing the resistance thereof, and consequently the heating effect, to a minimum. I am also enabled to increase to a maximum the circumferential distance around the active limbs of the inductor-sec- ICO tions, and hence reduce theinductancethereof to a minimum. To more clearly illustrate, suppose the armature-core to be provided with slots or seats of uniform dimensionsthat is, with a width b, a depth a, and the distance between adjacent slots at. the foot or base of the tooth 0. Then the cross-sectional area of two slots will be a X b a X b or 2 and the iron section of the core at the root of jacent slots at the foot of the tooth and in, the.

line of thebottom of the wide slot. Nowwith these relative dimensionsit will be seen that the cross-sectional area. of each-slot, which of course determines the cross-sectional area of the limb; or leg of the inductor-coil which is received therein, is. equal to /fii and for any-two slots will be 8 3 or 2.66, which isthirty-three per cent. greater than wherethe. slots are of. equal dimensions, as above.

shown, thus gaining in the same percentage in. the cross-sectional area of theinductor-sec tions, and consequently reducing the resistance'and-the heating of the-coils. Moreover, the periphery of the wide slot is a .l a 4 3 s+ 4 01-1-2 8 3 and the periphery of the deep slot is 4- -l- 4. 3., both; of which measurements are greater than the co rrespending measurements of theordi-nary con-. structions. Consequently by: my invention 1 not only, secure; a,v greater. cross-. sectional area-of inductor-section, but Ialso secure the advantage of greater. circumferential distance around the inductor-limbs, andconsequently.alessinductance.

Thecoilsemployed for the windingsmay be.

of. the detachable counterparttype, as. indi-' cat-.odat D in Fig. 3,.and Iemployone-half as manycoils as there are slots,eacl1 coil entering a .wide shallow slot at one end and a narrow and deep slot. at theother end, as clearlyindi-i cated in. dotted lines. in..Fig. 2, andin: order unit, although for the. sake of illustration of Y theprinoiple. involved the coil is shown.- in

Fig. Bas though it were madedouble orof separate. parts.

It will be understood that myinventionv is capable of being, carried intdpracticeWith any desired construction of armature-core,

whether. solid or laminated or otherwisewand whether, the armature. is fixed Qrrotatable.

From the foregoing.description it will be:

readily seen thatwith a. given magnetic flux and a given mductance. the heating efi'ect It.willbe undere would be greatly decreased, or with "a given inductance and heating a much larger magnetic flux is gained, or with a given ilux and heating effect a much less inductance is secured, and hence a much larger current can be used, thereby increasing the capacity or output of the machine. Thus advantage may be secured in employing a machine of less Weight for a given work to be accomplished or a greater output or capacity is secured with the same size or weight and less heating or less speed and greater power is developed.

My invention may be carried out in machines designed for any particular use. Thus in the case of motors for automobiles using storage batteries for source of current difficultyhas heretoforebeen. experienced on account of the highresistance of the motor,

' which prevents the flow of suflicient current at the start. to give the requisite. torque or turning movement. Moreover, energy is con.- sumed to no useful purpose in merely heat ing the. wires, which lossof energy results in diminishing the store of the batteries .without performinguseful work. By my invention these. objections are very greatly avoided anda greater mileage is secured by the same battery capacity. In the case of motorseme ployed for elevated suburban, or 'street'rail ways, where a large-acceleration at the start is desired and where there are frequent stopping. and starting, the desired accelerationis greatly retarded by reason of the initial. G111? rent being used ups-in heating the coils, and also because-ofthe burning or destruction of the armature when current sufficient to give thedesired acceleration is initially turned on. By my invention the resistance is lessened, and hence with a givendegree. of heat development greater acceleration is secured andthe dangerzof burning or destroyingthe:

. armature is avoided Again, in the caseof very small motors the space for the insulas tion on the inductor-coils islimited- Bymyinvention greater roonnfor the same. size. of motor issecured, thereby permitting. 0fi thc useofi proper size of wires, and hence-increasing the capacity ofthemotor.

Other instances of the utility ofmy in.ven-. tion might be cited, but it is believed .that.

the foregoing is. sufficient: to emphasize. its.

Having now set forthlthe object audnature of my invention. and a construction embodying-the principles thereof and having ex-. plained the same, its-purpose, function, and model of operation, what Iclaim .asnew andv useful and of my own invention, and desire to secureby Letters Patent, is-

1. An armature-core having slots to receive the inductor-sections, the slots which receive the same inductor-section varying in dimensions from each other, as and for the purpose set forth.

2. An armature-core having slots to receive the inductor-sections, adjacent slots varying in dimensions from each other, a slot of one dimension adapted to receive one limb of an inductor-section and a slot of another dimension adapted to receive the limb of the same inductor-section, as and for the purpose set forth.

3. An armature-core having slots to receive the inductor-sections, the slots which receive the same inductor-section being of the same transverse area but of differing linear dimensions, as and for the purpose set forth.

4. An armature core having slots to receive the inductor-sections, adjacent slots being of the same area but of differing linear dimensions, as and for the purpose set forth.

5. The combination with an armature-core having slots to receive the inductor-sections, alternate slots being of the same linear dimensions and the dimensions of the intermediate slots diiferin g therefrom, of inductorsections, one limb of each section being arranged in a slot of one dimension and the other limb thereof arranged to be received in a slot of a differing dimension, as and for the purpose set forth.

6. An armature-core having slots arranged in pairs, each pair of slots receiving respectively the two limbs of the same inductor-section, the slots of each pair differing from each other in linear dimensions but of the same transverse area, as and for the purpose set forth.

7. An armature-core having slots to receive the inductor-sections, each alternate slot being half the depth and double the width of the next adjacent slots, as and for the purpose set forth.

8. The combination with an armature-core having slots, each alternate slot being half the depth and double the width of the next adjacent slot, of a coil or inductor section having one of the limbs thereof received in a slot of one dimension and the other received in a slot of a different dimension, as and for the purpose set forth.

9. An armature-core having slots, each alternate slot being half the depth and double the width of the next adjacent slot, in combination with a coil or inductor section having the active limbs thereof of dimensions corresponding to adjacent slots of the core, as and for the purpose set forth.

10. An armature-coil or inductor-section having one of the limbs thereof one-half the thickness and double the width of the other limb, as and for the purpose set forth.

11. An armature coil or winding having its active limbs of the same cross-sectional area but of different linear dimensions, as and for the purpose set forth.

12. An armature coil or winding having its active limbs of diifering dimensions, as and for the purpose set forth.

In witness whereof I have hereunto set my hand, this 4th day of March, 1901, in the presence of the subscribing witnesses.

JOHN BALOH BLOOD.

Witnesses:

JOSHUA HALE, LOUIS L. Donen.

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