US587576A - Dynamo-electric machine - Google Patents

Description

(No Model.) 4 Sheet-s8heet 1. O. M. GREEN. DYNAMO ELECTRIC MACHINE.

Patented Aug. 3,1897.

(No Model.) 4 Sheets Sheet 2 C. M. GREEN. DYNAMO ELECTRIC MACHINE.

No. 587,576. Patented Aug. 3,1897.

(No Model.) 4 Sheets-Sheet 3. G. M. GREEN.

DYNAMO ELECTRIC MACHINE.

No. 587,576. Patented Aug. 3 1897.

Y C. M. GREEN. DYNAMO ELECTRIC MACHINE.

4 Sheets Sheet 4.

(No Model.)

Patented Aug. 3,1897. I

UNITED STATES PATENT Orricn.

CHARLES M. GREEN, OF CLEVELAND, OHIO.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent N 0. 587,576, dated August 3, 1897.

Application filed November 10, 1896. Serial No. 611,663. (No model.)

T 0 all whom it may concern/.-

Be it known that 1, CHARLES M. GREEN, of Cleveland, in the county of Ouyahoga and State of Ohio, have invented certain new and useful Improvements in Dynamos; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an improvement in dynamo-electric machines, and relates to an improvement in the armature and commutator connections for a multipolar machine.

In the operation of multipolar machines it has been found that whenever an attempt is made to push up the voltage much above the normal output of such machines di lliculty has been experienced in ell'ectin g satisfactory commutation. In building multipolar machines of a greater capacity than any which have been built up to the present time, onehundred-and-twenty-live-light arc-machines being the largest that have thus far gone into commercial use,it is desirable that such larger machines be rendered more stable than the one hundred and twenty-five-light arc-machines now in use, since flashing on a ma chine having a capacity of operating three hundred and sixty or more arc-lamps would be attended by much more serious conse quences than on a machine operating only one hundred and twenty -five lamps. It has been found that two thousand volts is about the maximum voltage that can be safely commutated on a single commutator ring employed with open-coil arc-machines, and in order to keep within this prescribed limit of not over two thousand volts on each commutatonring of a three-hundredand-sixty-arc-light machine nine con1mutator-rin gs would be required under the present method of commutation. Such a commutator would be so long and cumbersome as would render it most undesirable.

The objects of my invention are to so con struct an armature and comn'iutating device that the aggregate output of the armature coils will be distributed among several sets of commutatorbrushes, to reduce the num ber of commutatonrings to a minimum for a multipolar machine having an armature OOD1 prising a large number of bobbins, and .to

employ more than two brush-studs around the commutator.

lVith these objects in view the invention consists in certain novel features of-eonstruction and combinations and arrangements of parts, as will be hereinafter set forth, and pointed out in the claims.

In the accompanying drawings, Figure 1 is a diagrammatical view illustrating one embodiment of my invention. Fig. 2 is a view showing the groups of armature bobbins cross-connected. Fig. 3 is a diagram showing a method of reducing potential. Fig. 4 is a view'showing the sets of armature-bobbins and field-coils connected in parallel with each other. Fig. 5 is an enlarged detail view of a portion of the machine.

I have illustrated my invention as applied to an eight-pole dynamo having an armature with thirty-two bobbins, the ends of the various bobbins being connected with commu tater-segments located directly in line with said bobbins and the brush-studs and brushes disposed practically at right angles to the various pole-pieces, so that the ends of a bobbin or bobbins generating current at a given time are connected with brushes and studs opposite one pole of the field-magnets instead of with opposite brushes or studs, as in some bipolar machines. The brushes are rocked forward as the load in the working circuit is .de creased, as practiced in arcmachines of today.

In the drawings I have designated the fieldmagnets poles N as north poles and S as south poles, there being eight poles, four north and four south, which alternate with each other as usual in a multipolar machine.

For sake of convenience in explaining my improvements the armature-coils will be divided into eight sets of four bobbins each and are designated A '3 C D A &c., and so on, ending with D Each commutator-ring comprises two annular series of segments spaced apart, the. segments of one set alternating with thoseof I the other set. These commutator-rings are commutator brushes are employed, four brushes being carried by each stud, and are indicated by a b c d &c., to

In tracing the circuit through the armature we may for convenience start with the plus brush A, which in the drawings is shown bearin on se ment e of commntatorrin D D D Lil R, with which segment one end of the bobbin A is connected. From bobbin A the circuit may be traced to segment 6 of com mutator-ring R on which brush Z) bears, thence,

by conductor u to brush 0', which bears on segment 6 and i of ring R thence from segment 6 of ring B through bobbin D to brush (1, which bears on segment e and t of ring R, the circuit extending, therefore, also through bobbin 15 Thus bobbin A will be connected in series and bobbins D and B in parallel.

The brush (Z is connected by a conductor 01? with brush (Z of the next set of brushes. The circuit can now be readily traced through the bobbins B and D in parallel and bobbin A in series, thence by conductor it to brush (t thence through bobbins A in series and B and D in parallel, thence by conductor a from brush (1 to brush (Z of the next set, thence through B and D" in parallel and A in series, thence by conductor "U5 to brush a of the next set, thence through bobbins A in series and DD in parallel, thence by conductor it to brush (Z6 of the next series, thence through bobbins B and D in parallel and A in series, thence by conductor a to brush (L7 of the next set, and thence through bobbins A in series and B and D in parallel, thence by conductor lb to brush (Z of the next set, thence through bobbins B and D in parallel and A in series and to minus brush a Thus it will be seen that two of each set of tour armature-bobbins will be connected in parallel, one bobbin of each set will be connected in series, and the remaining bobbin of each set will be cut out, the ends of the fourth bobbin being connected with commutatorsegments on which no brush bears for the time being. Vith the armature in the position shown in the drawings and the circuits arranged for the time being in the manner above explained the bobbins C, 0 C 0', C, 0, C and C are in the weakest part of the iield and open-circuited.

From the above it will be observed that the current generated in the various sets of coils or bobbins will be commutated simultaneously by a corresponding number of sets of commutator-brushes and that the various sets of brushes are in effect connecl ed in series with each other.

By my improvements Iain enabled to take off currents of high voltage from a large multipolar dynamo capable of operating three hundred and sixty arc-lamps without employing a large number of com mutator-rings with only two brush-studs. I am also enabled to and in practice would divide the output of the machine and utilize the current generated in several lamp-circuits, thereby reducing the difference of potential between dil't'erent parts of the machine and circuits. For instance, the conductors 14 14 n can be extended, as shown in Fig. 3, to form several external circuits, in which lamps or other translatii'ig devices may be included. The conductors it it to u might also be extended or drawn out to constitute external circuits. Thus several external circuits may be taken from the machine and all of said circuits be in series with each other.

It has heretofore been proposed to independently commutate the current generated in each pair of armature-coils in a bipolar machine and with an armature composed of a comparatively small number of coils, but it would not be practical to adopt this method of commutation with amnltipolar machine employing an armature with a large number of coils, (thirty-two coils, for instance,) because a commutator of excessive length would be necessary. By my improvements I am enabled to in effect independently eominutatc the current generated in several series of the armature-coils and produce results equal in efliciency to those accomplished by using a commutator with a sufficient number of rings to independently com mutate each pair of coils without the necessity fora long commutater.

By the construction and arrangement of the apparatus as above described I am enabled to regulate the amperage of the machine by merely altering the relations of the sets of bobbins to each other. For instance, when a large voltage and low amperage is desired the several sets of coils would be connected in series, as above explained, but when it is desired to raise the amperage the several sets of coils may be connected in parallel, as shown in Fig. 1, thereby doubling or quadrupling the amperage and reducing the vol tage in the same proportion. This can readily be accomplished by changing the exterior connections on the machine and without disturbing any of the internal connections.

In the form of the invention shown in Fig. 2 only four sets of commutator-brushes are employed and each two groups of armaturebobbins are cross-connected On account of the cross connection of the bobbins some of the commutater-segments must also be crossconnected. It will be remembered that the ends of the bobbins in the form of the invention shown in Fig. 1 are connected, respectively, with segments of two adjacent commutator-rings and that there are eight sets of bobbins and eight sets of commutator-brushes. Now with the form of the invention shown in Fig. 2, which shows the same number of bobbins as in Fig.1, there is just one-half the number of sets of commutator-brushes, and the groups of bobbins are erossconnected, as above stated. Hence the commutator-segm cuts with which one set or group of bobbins is connected must be cross-connected with the commutator-segments with which the adjacent set of bobbins is connected. Thus in Fig. 1 one end of bobbin A is connected with a segment of commutator-ringR and the other end of this bobbin is connected with a segment of the adjacent com 111 utator-rin g Rfiand comm utater-brushes bear on both of these segments, while in Fig. 2 the outside end of bobbin A is connected with a segment of commutatorring R, and the inside end of said bobbin is cross-connected with the bobbin A The outside end of the bobbin A is connected with another segment of the commutatorring R, but as no brush is 110w bearing on this segment the latter must be cross-connected with the segment of riu g R with which the bobbin A would have been connected had it not been cross-connected with the bobbin A.

My improvements are comparatively simple in construction and effectual in all respects in the performance of their functions.

Slight changes in details might be resorted to without departing from the spirit of my invention or limiting its scope, and hence I do not wish to limit myself to the precise details herein set forth.

In this case I do not broadly claim a system of electric generation and distribution consisting of generating electromotive force in two or more sets or groups of armaturecoils and distributing the electromotive force so generated in separate external circuits and connected between and included in series with such separate groups of armatureconductors, such invention being covered, broadly, by claims in my pending application filed April 18, 1896, Serial No. 588,108, and is reserved to be protected by the patent granted thereon.

Having t ull y described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a multipolar dynamomachine, the combination with a series of comm utatorrings, of armature-coils connected with commutator-segments at the same side of the ar mature fi f'f f'lcll the coils are located, and several sets of commutater-brushes to engage said commutator-rings.

2. In a multipolar dynamo-machine, the combination with an armature comprising several sets o'fcoils, of a commutator consisting of several segmental rings, and several sets of commutator-brushes, the brushes of each set being located on the same side of the commutator and arranged alternately positive and negative, substantially as set forth.

3. In a multipolar dynamo-machine, the combination with an armature and a commutator comprising several segmental commutator-rings and sevcral sets of commutator: brushes, the brushes of each set being alternately positive and negative and the intermediate positive and negative brushes of each set being electrically connected together,sub- Stantially as set forth.

4. In a multipolar dynamounachine, the combination with an open-coil armature comprising several sets of coils, of several segmental commutator-rings,several sets of commutator-brushes and external circuits between each two sets of brushes.

5. In a multipolar dynamo-machine, the combination with segment-a1 commutatorrings, of armature-coils, each coil having its respective ends connected with segments of two rings, said segments being in line with each other and with the coil connected to them.

6. The combination with an armature having several sets of coils, of a series of commutator-rings, each ring comprising two series of segments, the segments of one series alter nating with those of the otherseries, the segments of one ring being in line with the segments of another ring and several sets of comnmtator-brushes, the brushes of each set corresponding in number to the number of commutator-rings and each brush adapted to engage both series of segments of the respective rings, the several sets of brushes being connected in series with each other, substantially as set forth.

7. In a multipolar dynamo machine the combination with an open-coil armature comprising several sets of bobbins, of a commutator comprising several segmental rings, several sets of brushes to bear on said rings, said bobbins, commutator rings and brushes being so arranged that one bobbin of each set will be connected in series, two bobbins of each set in parallel and the remaining bobbin of each set out out, the several sets of brushes being connected in series and translating devices between the sets of brushes, substantially as set forth.

8. In a dynamo-electric machine, the combination with a multiplicity of field-magnet poles, of an armature having several times as many bobbins as there are field-magnet poles, a series of segmental commutator-rings equal to the total number of bobbins divided by the number of field-magnet poles, sets of brushes corresponding in number to the fieldmagnet poles, the brushes of each set corresponding to the number of commutator-rings and the various sets of brushes being connected together in series, substantially as set;

bination with a series of field-magnet poles and several segmental commutator-rings, of an armature having several sets of bobbins, both ends of the various bobbins being connected to commutator-segments in line with them, on the same side of the commutator, and several sets of brushes bearing against said commutator-rings, substantially as set forth.

10. In a multipolar machine, the combination with a commutator consisting of aseries of rings, each ring being composed of two sets of segments arranged side by side, the se ments of one set alternating with the segments of the other set, and armaturebobbins,

the opposite terminals of which are connected 1?. The combination with a multipolar ma chine havinp' several commutator-rings, a corresponding number of sets of commutatorbrushes, and flllllfttlll'OdJObblllS having their opposite terminals connected to the same side of the commutator, of several circuits, each of which is interposed between the coininuta-tor-rings, substantially as set forth.

In testimony whereof I have signed this specification in the presence of two subscribingwitnesses.

CllARLES M. GREEK.

\Vitnesses:

S. M. IIAMILL, C. J. L'EEPHART.

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