US284999A - Dynamo-electric machine - Google Patents

Description

(No Model.) 3 Sheets-Sheet 1.

A. BERNSTEIN.

DYNAMO ELECTRIG MACHINE.

No. 284,999. I Patented Sept. 18, 1883.

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(No Model.) 3 Sheets-Sheet 2.

A. BERNSTEIN.

DYNAMO ELECTRIC MACHINE. No. 284,999. Patented Sept. 18, 1883.

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UNITED STATES PATENT Orricn.

ALEXANDER BERNSTEIN, OF BOSTON, MASSACHUSETTS.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 284,999, dated September 18, 1883.

Application filed April 24,1883. (Xomodel) T0 aZZ whom it may concern Be it known that I, ALEX. Bnuxsrnrn, of Boston, in the county of Suffolk and State of lllassachusetts, have invented certain Improvements in Dynamo-Electric Machines, of which the following is a specification.

My invention relates to that class of machines in which mechanical is transformed into electrical energy, and which are commonly known and designated as dynamo-electric machines. It especially relates to devices for establishing a very intense magnetic field of force, in which the armatures of said 1nachines are to rotate, for allowing the development of currents of any desired eleetroanotive force, and for regulating the strength of the magnetic field, and consequently the production-of electricity, by the character and amount of work to be done in the external circuit. My invention is applicable to such machines, whether they are employed for converting mechanical power into electricity, which may be used for electric lighting or plating or other purposes, or whether they are employed, conversely, for converting an electric current into mechanical power, as in the transmission of power to a distance.

The object of my invention, broadly stated, is the construction of a dynamo-electric ma chine in which the generation or development of electric currents is accomplished efiicientl y yet economically, and which will present certain practical advantages by allowing the production of currents of definite electro-motive "force, which may be of any required degree of strength or intensity. I aim also at the construction of a machine which shall be selfregulating with reference to the varying requirements of the external circuit. I attain these objects by produeingavery intense magnetic field, and using in the production of the same as much effective surface of the fieldmagnets as possible. Ialso prevent all undue heating of the armature-wires and other work ing parts of the machine by exposing as much of the wire as possible to the cooling influence of the air. The armature being made in several. parts, and formed in a manner. well adapted to expose much of its surface to the atmosphere, is also kept cool, and, furthermore, allows a rapid change of polarity in its cores or throughout its substance, and the selfregulation of the machine and its producing power results from the novel and peculiar method of charging the fieldanagnets and arranging the several connections of the helices thereof, which will be more particularly dc scribed hereinafter, reference being made to the aceom 'ianying drawings.

Figure 1 is a perspective view of the complete machine; Fig. 2, asimilar view of two of the fieldmagnets with channeled pole-pieces common to both. Figs. 3 and i are horizontal sections taken through or near the center of the pole-pieces, the ring-armature in Fig. 3 being represented as entire. Fig. 3 also is shown as being provided with but one commutator. In Fig. l the ring-armature is shown in section, and the machine has two commutators. Fig. 5 is a face view of one of the armature rings. Fig. 6 is a vertical section of the ring with generating-coils attached; and Fig. 7 is also a vertical section, as it appears before winding. .Figs. 8, S), 10, 11, 12, and 13 are diagrams which graphically represent the various methods of connecting the armaturecoils and field-magnet helices with reference to the external circuit.

The machine, as constructed on my improved plan and as delineated in perspective in Fig. 1, may be described as follows:

A A are the field-magnets, consisting, as usual, ofiron cores surrounded by convolutions of insulated wire. These are provided at the center with pole-pieces D, the peculiar form of which will be hereinafter specifically described. A crown-plate, B, of iron, unites the cores of the two magnets at the top, while a base-plate, 0, Similarly unites them at the bot tom. This may either be the plate upon which the machine stands or may consist of a plate supported on a suitable base.

Between the pole-pieces D, and suitably supported by the pedestal or bracket E and journal I, (a similar journal being also provided at the opposite side,) is a shaft, F, which, with the annular armature H carried thereon, is adapted to rotate when influenced by power conveyed thereto by means of the pulley G and a suitable belt actuating the said pulley from any convenient motor or source of power.

The armature may consist of any desired number of separate rings fixed upon and adapted to rotate wit-h a common shaft or spin- .dle, as more clearly shown in Figs. 3 and 4,

and in practice I have found four to answer very well for general purposes. Each ring is furnished with a series of inducing-coils, i, and

i the corresponding coils'of all the rings, after being connected in series or multiple arc with one another, according to the work to be done,

are then connected, in a manner well under stood by those skilled in the art, with the com- IO mutator d.

It will of course be understood that the present description is general and refers especially to the perspective view shown in Fig. 1, the peculiar electrical connections of the armature- I 5 coils being hereinafter described more particularly.

The coil terminals are, by means'of screwconnectors e ce, connected with commutator (Z, and by means of metal brushes 0 the ourrents are led out from the commutator to wires communicating with screw terminals 72, to which the external 'circuitwires may be "at tached. a is an adjusting-lever for the regulation of the said brushe.

I will now proceed to describe the peculiar 4 form of the field-magnets and pole-piece.

Each of the field-magnets A consists of an iron core, 75, surrounded with coils of insulated 7 wire j at its upper and lower part, while a large and heavy pole-piece, D, is fixed to the middle of the core, and projects inwardly, as shown in Fig. 2. The cores and pole-piece may be made in one piece, or the upper and lower cores and the pole-piece may be made 3 5 severally and afterward bolted together. The pole-pieces D are provided with two or more channels, Z, (in the drawings I show four,) and these channels are made just wide enough to embrace the coil edges of the armaturerings and allow the free rotation of the same, as

shown in Figs. 3 and 4. By adopting this arrangement I am enabled to bring a large mag- -neticinducing-surface to bear upon the rotating armaturecoils with the constant result of a very intense magnetic field, through which the said armature-coils must necessarily pass. The upper and lower sections of field-magnet coils j, which surround the cores, are so wound with reference to one another as to develop the same magnetic polarity in their common pole-piece, that of the other pole-piece being of the op-- posite polarity. The armature-cores, or that portion of the substance of the ring which at any moment is entering or passing through the pole-piece, channels, will acquire by induction a polarity of an opposite character to that of the pole-piece they are passing.

The construction of the armatures is shown in Figs. 5, 6, and 7 These consist of a series of iron rings, H, corresponding in number to the channels or grooves of the pole -piece.

] sides of the said channel very thin. This circular core is attached'to the spokes or radial arms 19 of a brass spider, and the central part or hub, 0, of the spider is keyed or otherwise fixed to the armature-shaft F. As shown in Figs. 5 and 6, the generating-coils i are radially wound upon the cores r of the rings in a similar way to that of the well-known Paciinto the peripheral edge of the rings, may, if

left unfilled. With respect to the several coils of each individual ring, the leading-out wire of each coil is connected with the leading-in of the coil-junctions thus formed is led to its respective commutator-bar.

The mechanical features of the machine are shown in Figs. 3 and 4.

In Fig. 3 the rings H (four in number) compose the compound rotating armature of the machine, and are keyed or otherwise attached to the shaft F, which rests in the bearings I, these being suitably supported by the brackets E and E, which are bolted to the framework of the machine. A collar, m, attached to the armature-shaft, carries anumber of binding-screws, e, which receive the wires from the armature-coils and direct them to the bars of the commutator (1. As in Fig. 1, the brushes are designated by the letter 0 and the adjusting-lever by a. The figures also show clearly the mode in which the coiled edge of the ring is embraced and adapted to be acted upon on three sides by the channeled pole-pieces of the field-magnets. One commutator is in the machine represented in Fig. 3, intended to serve all of the rings. V

The machine shown in Fig. 4 differs in no material detail from that represented by Fig. 3, with the exception that Fig. 4 is fitted with an additional commutator, one commutator being provided at each side of the machine. The purpose of this will be hereinafter explained in detail. The commutators d are at each side closely connected with the binding screw-collar on, which, by a bushing, 02, is fitted to the shaft. It is obvious that in this machine some of the rings may hewe their coils connected with the right-hand and some with the left-hand commutator. Owing to the conformation of the substance of the iron rings and the continuous groove which channels its edge, and to which the air has free access by means of the apertures or spaces between the coils, the armature and coils are maintained in a very cool condition, and currents generated by induction in the iron are effectually prevented.

The remaining figures are explanatory of the use in connection with the field-magnets, helices, and generating-coils in order to suit the widely-varying requirements of the work to be done and the character of the external circuit.

The first three diagrams, Figs. 8, 9, and 10,

notti machine. The circular channels 8, grooved desired, be filled with iron wire, or may be wire of the next, and a branch'wire from each different circuit arrangements which I may refer to the machine shown in Fig. 3, and illustrate the difierent methods of arranging the connections of the inducing-coils so as to produce with a given degree of magnetism a current of high, low, or medium electro-motive force. The second coils, i, in each of the diagrams are intended to represent the corresponding coils of the four rings. Thus if 1 is the particular coil on the ring at the extreme left which is passing a given point, 2, 3, and 4 are the coils upon the other rings,which will pass the same point at the same time. This being understood, Fig. 8 shows a case in which the corresponding coils of the four rings are connected with one another in multiple arc, the wire marked with the negative or minus sign being led to one of the commutator bars and that marked positive or plus to the adjacent connnutator-bar. In this case, after passing the commutator, the current will be divided also in multiple arc between the four field-magnet helices, the result being a strong magnetic field and a current of low electromotive force, but of considerable volume, the latter feature being due to the low internal resistance of the arrangement. In the second method of arranging the connections shown in Fig. 9 the corresponding coils of the several rings are connected in series, and the currents developed in them will have the combined electro-motive force of the entire number of coils, which in this case is four. The current,

after passing the commutator, traverses the field-magnet helies also in series, and the general result will be a working-current of high electro-motive force. This arrangement will be preferably adopted when the resistance v of the external circuit is considerable.

It is frequently convenient to produce currents of medium electro-motive force, and in such cases I connect thearmature-coils of corresponding radius, as shown in Fig. 10, in which coil 1 is connected in parallelism with coil 2 and coil 3 in parallelism with coil 4, thus making two pairs, the pairs being then connected in series with one another. The fieldmagnets would again be similarly arranged; but although in many cases the foregoing arrangements, as shown, are convenient and useful, I prefer, in order to produce the best re sults, to construct the machine with two separate commutators, as in the horizontal sec tion, Fig. 4. In this case one or more of the armature-rings are used for the exclusive purpose of charging the field-magnets, and they may either perform this office unaided, or aided by and in connection with the other rings. In the drawings I have shown but one armature as being devoted to this purpose i. 0., that at the extreme left of the machine. The object of the additional commutator is thus made manifest. The severalterminals of the coils of the left-hand ring, No. 1, all connect with the commutator at the left-hand side, and from thence the currents are, as usual, taken off by brushes and directed through the field-magnet helices or a portion thereof, to subserve the purpose of magnetizing the cores. Those of the remaining rings, combined either in series, in multiple, or in multiple series, ac- 7 cording to the character of current which is desired, and as hereinbefore described, unite in passing to the right-hand commutator, and from thence connect either with the external circuit direct, or to the external circuit ar ranged in series with a portion of the fieldmagnet helices, or to the external circuit connected in multiple arc with a portion of the said helices. The different modifications of this method of maintaining a permanent magnetic field are explained by the diagrams Figs. 11, 12, and 13, in which the arnm-tures are rep resented by the coils '1'.

Although, as hereinbefore stated, the rings composing the compound rotating armature are in practice fixed upon a shaft or spindle between the pole-pieces D, I have, for facility of explanation and for convenience in illustrating the connections, shown them apart from the said magnets and pole-pieces. In Fig. 11 the first ring of the armature is used exclusively to charge the field-magnets, and performs that work without any connection with or aid from the others, theflcorresponding coils of rings 2, 3, and 4. being connected together in any of the ways hereinbefore described,, and, through the instrumei'itality of the right-hand commutator, caused to supply the current for the external circuit. By this arrangement the field of force is maintained permanent independently of the condition of the external circuit, and its intensity is variable only by variations in the velocity ol'rotation ofthe armature. In Fig. 12 the first ri ngis utilized to charge onehalf only of the field-magnets, and, although I have represented it as charging the lower hel ices and magnetizing the lower cores only, it is obvious that I might with identical results charge the upper portion of the magnets only, it being immaterial for the purposes of this invention which portion is charged by the first coil. The remaining coresin this case the upper onesare charged by the main current generated by the coils of the remaining armatures, and their coils are connected directly in the main circuit, the entire arrangement being a combination of those shown in Figs. 8 and 11. The outer terminals of the generating-coils are united to the wire 3, and the circuit then continues through the upper field-magnet coils and out by wire ito the external circuit. Iteturning, the wire 5 leads to the inner-coil ter minals. In Fig. 13 still another method of 0011- nection is shown. The coils of the first ring, as in the immediately-preceding case, magnetize the lower fieldmagnets; but the upper helices are in a shunt from the external circuit, and are thus charged by a portion of the main current, the amount of current flowing through the shunt being dependent on the condition of the outside circuit. The actions and reactions of the foregoing dispositions of circuits are sity is establishedas soon as the rotation of the armature begins first by the electricity evolved by the armature or ring No. '1. This, as soon as the external circuit is closed, is strengthened by the current developed by the other rings by means of the shunt-circuit. A due portion of the latter current passes to the outside circuit to perform work therein. If, now, the work to be done increases in amount, or, in other words, if the external resistance increases, a larger amount of the current is transferred to the short circuit of theupper fieldmagnets and tends to increase the magnetic force developed therein, which, reacting both upon the ring 1 and also upon the rings 2, 3, and 4, increases the strength of current first in the coils of ring 1, thus still further augmenting the strength of the field of force,and,

secondly, in the coils of the other rings, whereby a stronger current is sent to the outside circuit to overcome the increased work of resistance. Conversely, if the work in the external circuit decreases in amount, a larger amount of the generated current passes in that direction and the field of force diminishes in intensity. This arrangement in each of its modifications differs materially from all other arrangements in which the field-magnets are energized from an independent source of electricity.

I have in the drawings shown but one of the armaturerings as being in circuit with and used solely to excite the whole or a portion of the field-magnets; but Imay, if I so elect, employ more than one ring for the purpose, it being evident that the work of the sever-airings maybe divided in any desirable way.

It must be understood that in describing the rotating armature I have sometimes designated entire armature, are equally complete arma tures in themselves and operate as such.

In the foregoing specification, where I have referred to a permanent field of magnetic force,

it. isto be understood as meaning a field of force which is permanent. so long as the rotation.of the armature continues,-in contradistinction to the magnetic field of a machine whose field -magnets are arranged. in series with the external circuit, and which is consequently totally dependent uponthe closing of the external circuit for the establishment and maintenance of a magnetic field of force.

Having now described my invention, I claim 1. The combination, in dynamo-electric 1nachines, of field-of-force magnets with a compound armature consisting of a numberof coil-carrying rings, the generating-coils of one or more of the said rings being in circuit with a portion of the field magnet helices, and adapted to excite V them, and the coils of the remaining rings being in circuit with another portion of the field-magnet helices and with the external circuit, substantially as and -for the purposes described.

2. The combination of field-magnets and a number of rotating armatures therefor, one or .more of the said armatures being connected in circuit with a portion of the field-magnet helices, and adapted exclusively to excite the same, and the remaining armatures being in circuit with and adapted to produce electrical currents in the external circuit, and in a shuntcircuit consisting of the remaining field-magnet helices, substantially as described.

3. A dynamo-electric machine in which the coils of some of the field-of-force magnets are placed in the circuit of one or more of a numcircuit including the generating-coils of one or more of the said armatures and a portion of the field-magnet helices, the generating-coils of the remaining armatures being included in the main or external circuit, and the remaining field-magnet helices being also included with the said remaining armature-coils in the said main circuit, or in a shunt therefrom, whereby a permanent field of force may be maintained by means of the generating-coils in the local or exciting circuit, and whereby the said field of force may be modified and regulated by the current generated by the 'remain'ing armatures and flowing in the main circuit. v

5. A dynamoelectric machine consisting of the following elements: a compound rotating armature. composed of a number of independent annular sub-armatures, field-magnets provided with pole-pieces channeled to receive I tion of the field-magnet helices, substantially and overlap the several armaturecores, for as described.

the purpose of establishing a magnetic field of In testimony whereof Ihave signed my name force, a closed exciting-circuit including one to this specificatiomin the presence of two sub- 5 or more of the sub-armatures and a portion of scribing Witnesses,this 18th day of April, 1883. r 5

the field-magnet helices a partial or incom T IT plete circuit including the remaining arma- ALEX BER} S T1513 tures, and adapted to be closed or completed \Vitnesses: through an external circuit, and a closed shuntl GEO. WVILLIs PIERCE,

10 circuit also comprising the said remaining por- THos. D. LOOKWOOD.

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