USRE9410E - Magneto-electric machine - Google Patents

Description

4 Sheets-Sheen C. F. BRUSH. Ivcgneto Electric Machine.

No. 9,410'. Rei-Ssuedcct. 12, 1880.

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\Magnet0 Electric Machine.

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C. P. BRUSH. Magneto BlectricMaohine.

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Magneto Electric Machine- No. 9,410. I Ressued Oct. I2, 1880.

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' drawings,

PATENT OFFICE.

CHARLES BRUSH, OF CLEVELAND, OHIO.

MA'GNETO-ELECTRIO MACHINE.

SPECIFICATION forming part of Reissiied Letters Patent No. 9,410, dated October-12, 1880.

Original Xo. 189,997, dated April 2'4, 1877. Application for reissue led April 16, 1880. I

To all whom it 'may concern Beit known that I, CHARLES F. BRUSH, of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Magneto-Electric Ma-V chines; and I do hereby declare the following tc be a full, clear, and exact description of the invention, such as will enable others skilled in -the art to'whichit pertains tn make and use it, reference being had to the accompanying which form part of this specification. My invention relates. to magneto-electric machines or apparatus for the conversion of mechanical into electrical energy; audit oo nsists of improvements inthe armature and in the arrangement of commutators. I

In the drawings, Figure 1 represents a vertical section, througli its axis, ot' a convenient form of apparatus embodying m y several im' proveniente. Fig. 2 shoWsa-v'ertical section,

across its axis,pot thesame. Fig. 3 represents the armature, with grooves or depressions at right angles to its axis. Figs. 4' and 5 show four modilcations of the same. Fig. 6 shows a perspective view of the comm utator-cylinder complete. 'Fig'. 7 shows the same when developed. 4 Fig. 8 shows a developed commutator provided with double the number of seg` ments shown in Fig. 7, usedwhen eachI section of wire of the armature is connected with two opposite segments, each section provided with its own pair of segments. Fig.9 represents a commutatorvwhcrein the strips ofinetal are arranged ou the cylinder in a. directionparal- 'lel with its axis. Fig. 10 represents a per.-

spective view ot' the armature and commutator-cylinder E, both on the shaft, with the sections of wire on the armature connected with the segments of metal on said cylinder, the first o r last ends of diamctrically-opposite sections joinedv together and the remaining ends only attached to opposite segments. Fig. 11 shows two diametrically-opposite sections and segments, both detached, wherein the first and last ends of each section are connected with opposite segments. Fig. 12 represents a section and two segments, all detached, showing how the first and last ends otaI section are joined to opposite segments. Fig. 13 reprerents a number of sections on an armature and acommutatoccylinder, the sections being connected together in a continuous series, and joined to the segments. Fig. 14 shows a side view of the magnetic pole-piecesin segmental form. Fig. 15 represents an annular armature without grooves wound with aseries of sec'- Ytions of wire connected together in a'continuous series. Fig. 16 is a plan view of the armature provided with sections of wire wound in grooves. (Shown in Fig. 3.) Fig. 17V shows amodied arrangement ot commntator-cylindes and brushes or plates for collecting the electric current. Fig. 18 shows stil-l another modiled arrangement of commutator-cylinder and brushes or plates for collecting the electricV current. Fig. 19 represents an armature without grooves, wherein the diametrically- 'opposite sectionswith which said armature is -f-wofnndhave their first-'or last ends connected :together andtheir remaining ends attached to diametrically-opposite segments. Fig-20 represents moditications of grooved armatures in which the grooves are placed obliqnely instead of at right angles to the circumferential length ofthe armature. Fig. 21 represents a grooved armature, in which the magnetic polepieces are presented tothe armature on three sides of its magnetic axis.

The best forms of magneto electric apparatus at present before the public are unnecessarly bulky, heavy, and expensive, and are more orless wasteful "of mechanical power.

By means of the improved vapparatus described hereinafter a given result may be obtained with a less bulk and weight and at a. smaller costv than with any other similar apparatus in use. The losser waste of mechanical force is also reduced to a minimum. These 'importantresults are obtained by means of a new' and improved form of armature, anda peculiar arrangement of commntators or conductors for collecting the electric current generated in the bobbins or sections of wire carried by the armature.

The armature A (shown in plan in Fig. 16) is of iron or other magnetic substance. It is in the form of a ring or endless band, and is attached to a hub, B, of suitable material, provided with any conveni'en'tnumber of spokesas shown. This hub is rigidly attached to the shaft C, which, when driven by the'pulley D IOO .its magnetic axis or length. These grooves are wound full of insulated copper lwire in the manner shown.

cording to the use for whicll kthe machine is designed, eight being shown inthe drawings.

The advantage of winding the wire ou the armature in grooves or depressions in thelatler is twofold: First, theprojeetiug portions of the armature between the sections of wire may be made to revolve Very close to the poles N N and S S ot' the magnets, from which the magnetic force is derived,thus utilizing the inductive force of thc latter to a mnch greater extent tha-n is possible in thc,case ot' annular armatures ordinarily used, which are entirelycovered with wire, and therefore cannot be brought very near the magnets; second, ow-

ing to the exposure ot' a very considerable portion of the armature to the atmosphere., the heat, which is always developed by the rapidly-succeeding magnetizations and demaguetizations of armatures iu'motion, is rapidly dissipated by radiation and convection. I u the caseof armatures entirely coveredwith wire the escape of heat is very slow, so that they must be run at a comparatively low rate of speed with corresponding elfect in order to prevent injurious heating. v

lt is obvious that the depressions orgrooves in the armature in which the wirel is wound may extend entirely around its section, or may be made only on the outer side, parallel with the axis of rotation. In this last case the poles of the magnets would be presented to this part-ot the armature. It is yequally obviousthat the cross-section of the armature may be of other forms than the parallelogram shown.

. The armature may be of a uniform ring or baud of iron, or a bundle of iron wire or ribbon, or series of parallel disks with the iron projections between the sections of copper wire, fastened ou by any-suitable means, or it may be Iliade of a single piece ot' soft castiron, which is the most practicable lnethod.

In Fig. 10 diametrically-oppositc sections have their lirst (or can have their last) ends joined together, and their remaining ends connected with two segments of metal of the commutator-cylinderlE, which is carried by theshaft C, and is of insulating material.

.lhe two metal segments are placed diametrically opposite each other on the cylinder, and are each of a length less than half the circumference of the latter, thus exposing the insnlating-cylimler in two places diamctrically opposite each other, and alternating with the metal segments. The two segments-say, S3

The sections of wirethus formed may be of any suitable number, ac`

and S"-corrcsponding to sections 3 and 7 .of wire, hold a position on the cylinder in advance ot' those of the precedingr sections S2 and S6, to the same angular-extent that the sections 3 and 7 in question are in'advance of sections 2 and 6. (Sections'2 and Gare not illustrated in the drawings; but they are situated respcctively between sections 3 and 7, as suliciently suggested in Fig. 10.) In this arrangement the number ot' segments is equal to the number of sections, each segment being connected with but one section. The lirst and last ends of each section can, however, be attached to two,diametrically-opposite segments, the commutator-cylinderiu that case beingconstructed with double the number of segments as in the former case, thus making the number of segments double the number of sections, as show-n 'in Figs. 12 and 8.

Fig. 7 shows the commutator developed, showing the arrangement of metal segments on the same. and the manner in which they are connected with the sections ot' wire.

Each segment S, is insulated from its neighbors, and has a wire soldered tffitsunder side a-ntl extending under, but insulatedl from, any

segments which may be in front ot' it. Evidently the segments belonging to any one sec tion of 'wireoccupy the same position on the cylinder circumfereutially as those of the section diametrically opposite the given section, as shown in Fig. 8. l Hence each pair of segments may be made common to two opposite sections of wire, thus making the number of segments the salue as the number ot sections, instead of double, as in the former case'. This simplied arrangement is shown in Fig. l11.

'Thus the wires 1, 2, 3, &c., vrepresent the different segmcnts, and appear at equal distances IOO around the cylinder. All the sections or bobbins o t` wire on the armature being wound in the same, direction, one section' will havel its first and last end connected,respectively, with wires 2 and 6, while the opposite section will be similarly connected with 6and 2.

Two metallic plates or brushes, F, Fig. 2, insulated trom each other, press lightly upon the cylinder E at opposite points, so selected that, while each section of wire ou the armature is passing from one neutral point to the other, the corresponding,r segments on the cylinder will be iu contact with them. These plates or brushes collect the currents of electricity generated bythe revolution of the armature, one being positive and the other negative. When the section of wire is passing the neutral points on the armature the plates F are in contact with the insulating material of y.

the cylinder -betweeu the corresponding segf ments, thuscuttingthe section, whichis at the time useless, outtlof the circuit altogether.

The necessity of thus iusulatin g each section from the brushes or '.'plates F during the time Vit is inactive becoties obvious when we consider that if this was' notdone the idle section would afford a passage for the current generated in the active sections and divert; it from its proper channel. During the time a section or bobbin is passing from one neutral point ot the armature to the next one, an electrical iin-- pulse, constant in direction but varying in electro-motive force, is' induced in it. This electromotive force, starting from nothing at the neu-U sulating-space is too short, so as to keep orI bring a section in the circuit while its electromotive force is low, then the current from the other sections, being of superior electro-motive force, will overcome this weak current and d ischargea portion ot' itself (an amount expressed :s

by the di'erence of the electro-motive forces) through this sction. It' the insulating-spaces are a little longer than necessary no material inconvenience results. A suitable length for practical purposes is easily determined experimentally.

It is found in practice that the neutral points of the armature in motion are considerably in advance, ot' their theoretical position, this circumstance heilig doubtless due to the fact that some timejs required to saturate any point of the armature with magnetism, so that it is really carried beyond the point otl greatest magnetic intensity of the field before receiving its maximum charge.

.` It is necessary to adjust the commutatorcylinder on the revolving .shat't ot the machine with special reference to the neutral points of the armature when in motion, in order that its insulating-spaces muy correspond with said neutral points. This adjustment is made experimentally as follows: The commutator-cylinder having been placed approximately in the proper position, the machine is started and the presence or absence ot' sparks at the points of contact between the brushes or pla-tes Fand commutator-cylinder is noted. It' sparks oc cur the cominntator-cylimler is turned slightly forward or backwark on its axis, as experiment may indicate, until the sparks nearly or quite' disappear.

The presence of sparks when the. columntntor is even slightly outof its proper position is easily explained. lf the break between a pair ot' segments and the brushes F occurs while `the corresponding section ot wire on the arm aturc is still active, a spark is produced bythe interruption ofthe current, while, if the break occurs too late, the section in question will have become neutral and then commenced to conduct the current from the -active sections, and the interruption of this passage causes a spark in this instance.

If the commutator is unich removed i'rom its proper position in either direction, the sparks are so great as to very rapidly destroy both the commutator and the brushes, while the external current from the m-.ichiue is correspondingly diminished.

lt will be seen that with the arrangement above described, where the first and last ends ot' each of two diametrically-opposite sections are attached to two opposite segments, the intensity ot' the induced electric current will be that due to the length ot' wire in a single section only, while the quantity will be directly as the number ot' sections. By doublin g the size of each hohhin and diminishing their number one-halt' a current of double the iiitensity and one-halt' the quantity ot' the former will be obtained. -This eti'ect can, however, he secured in another manner by connecting thel first or last ends ot' the two opposite sections together, and joining the remaining ends only to two` opposite segments, as illustrated in Fig. 10. .This arrangement I tind most convenient in practice.. y

It is obvious where I employ nu armature either with or without grooves and wind that armature with the sections of wire, the wires ot' each section or pair ot' sections combined with the commutator, that these sections form, in fact, a series ot' separate and distinct bobbilis or pairs of bobbins, that are not connected into a single or continuous bobbin.

The arrangement of the cylinder E with segments S maybe replaced by another, as -follows: The last end ot one section and the trst end of the'succeeding onemay be connected with a strip ot' metal attached to the cylinder E parallel with its axis.V Thesemetallic strips or conductors are equal in vnumber to the sections ot' wire on the armature, and are insulated t'rom ca ch other.A The plates F press upon the cylinder, in this case, at points corresponding to the neutral points ot' the arnn'itnre, thus being at right angles with their position in the first-arrangement. This plan, which is the one commonly used with annular armatures, gives fair results, but is subject to a seri ons disadvantage from which the tirst is tree.

The difficulty is this: The sections ot' wire,

when at or near the neutral points ot' the armature, contribute little or no nset'ul etfcct, but

the current from the other sections must pass through these lin order to rea-cli the plates F, thus experiencing a .considerable Iand entirely useless resistance, and, owing to the oppositel directions of the currents through the active sections on opposite sides ot' the neutral points, these currents, bypassing through the idle sections, tend strongly to produce consequent.

points in the armature where the neutral points should be, thus interfering seriously with the theoretical distiibution ot' the armatnres mug netisiu.

' The tirst described arrangement ot` commututors on thccylinder-l] may be employedwith marked advantage over the other t'orm, in combination with annular armatures ol' thc Vstill ordinarykind-L e., those not provided with groovesor depressions for the reception of the sections of wire.

In Fig. 17 the strips of the commutator-cylinder are arranged on the same in a. direction parallel with its axis, and the-currentis taken o by a series ot' plates or brushesequal in number to the strips ot' metal,`said vplates or brushes attached to two curved plates arranged dia-metrically opposite each other. A,

ln Fig. 1S the segments ot' the commutatorcylinder are arranged on t'he same in pairs, placed dametricallyopposite each other, each pair occupying a different position longitudinally, but the. same position circumferentially, and the current is taken oft' by an arrangement of brushes or plates similar to that shown in Fig. 17, each pair ot' oppositely-plaeed brushes or plates, however, necessarily occupying a dit'- ferent position longitudinally with regai'd to the cylinder.

The two arrangements just described, and

illustrated in Figs. 17 and 1S, may be substi-4 tuted for the arrangement shown in Fig. vit of the drawings.

rlhe commntator-cylinder may be turned ninety degrees on its axis, while the armature remains stationar so that the sections would stand at right angles with regard to the segments. The position of the brushes would have to be changed accordingly in that case.

The electro-magnets H are excited by the whole or aportion of the electric current derived from the revolving arluature, as is usual in apparatus ot' this kind, the novel feature ot' this partof the machine" consisting ot' the manner in which the magnetic poles are pre sented to the armature. This arrangement is such that a very large proportion of the entire surface ot' the armature is constantly presented to the poles of the magnets,v thus securingunitormity of magnetization as well as maximum amount. t

The iron segments N S (shown in `Fig. 14) constitute the poles ofthe magnets H, and are arranged on both sidesot the armature, as shown in Fig. 1, thus securing the advantages enumerated above,

Obviously the pieces N Nor S S may be coilnected together at their outer edges, thus forming one piece and inclosingthe armature more. adopted by the inventor for small machines, inasmuch as one electro-magnet may thus be used instead ot' two, the effect being the same, only less in degree, while the construction ot' the machine is simplitied. Of course, perinanent steel magnets may be employed in these machines instead ot' electro-magnets, and this substitution is advisable in small hand-ma.- chines.

The arrangement of magnetic poles aboW described may also be applied to annular aimatures having no depressions or grooves, but consisting ota plain uniform ring ofiro'n o1' bundle'ot iron wire with its greatest length ot" cross-section parallel with its plane of ro- This arrangement is, in fact,`

tation. This form of apparatus givesxcellent results as compared with old forms.

What I claim as my invention, and desire 7o to secure by Letters Patent, is l 1. In a magneto-electric machine, an armature 'of iron or other magnetic substance in the form ot' a ring or endless band, of any convenient form ot'cross-section, provided with a 75 series of grooves or depressions ou the sides only at right angles with the axis of rotation ot' the armature, and with its circumferential length or magnetic axis for the reception ot" the insulated wire with which armatures are 8oY wound, substa-ntiallyas described.

2. In a magnctoelectric machine, an armature ot iron or-otherY magnetic substance in the form ot' a ring or endless band of any convenient form ot cross-section,provided with a series ot' groot-'es or depressions upon its sides only at right angles with the axis of rotation of the' armature and with its ciicumferential lengthor magnetic axis, with sections or bobbins of wire wound in said grooves around qo the armature, substantially as described.

3. ln a magneto-electric niachinefan arma: ture ot' iron or other magnetic substance in the form ot' a ring or endless band of any convenient form of crosssection, provided with a 95 serie's of grooves or depressions-at right angles with its magneticaxis,`and with sections or bobbins ot' wire wound in said grooves around the armature, the tirst or last ends ot' diametrically-opposite sections joined together, and 10o their remaining ends to diametricallyopposite con'nnutator-segments, substantially as described. x

4. In a magneto-electric machine, the bobbins or sections ot' wire upon the armature, in 105 combination with a commutator (or series of conductors) so constructed and arranged with relation to each other that the said bobbins or sections are opeu-eircuited at and fora suitable period immediately' 'before and after the 11o timer when the current in said bobbins orvsections is about to reverse-that is,at a time when said bobbins are passing a neutral point-the remaining bobbins or sections upon the armature heilig maintained in closed circuit.l

5. In a magneto-electric machine, the combination ofthe following i'nstrnmentalit-ies, t0

wit: an armature carrying bobbins or sections ot' insulated conductor, a commutator or series 12o of conductors, and brushes F, or their equivalent, all arranged and electrically connected so that each of said armature bobbins or sections, while passing a neutral point, (and for a suitable time before and after,) shall be opencircuited, the remaining bobbins or sections upon the armature being maintained in closed circuit.

6. In a magneto electric machine, a commutator-cylinder consisting of a cylinder of insu- 13o lating material provided with metal strips or segments constitutin g a series of ommntators or conductors arranged in pairs, each ofsaid pairs having its'members diametrically opposite each other, und each pair occupying aditferent position longitudinally on the cylinder from an)v other pair, their ends separa-ted a suiicient distance to prevent the current of an active bobbin or bobbins from escaping throughan idic bobbin or bobbins while the latter are at or near the neutral or current-reversing points, substantially as described.

7. As an article ot' manufacture, a-n electriccurrcntgenerating machine constructed to have the bobbins or sections of Wire upon its armature that are passing a neutral or currentreversing point open-circuited, the remaining bobbins or sections being maintained in closed circuit. i

8. As an article of manufacture, an electric currentgenerating machine constructed to .have the bobbins or sections of wire upon its armature successively open-circuited as they pass neutral or current-reversing points.

0. In a magneto-electric machine, an armature of iron or other magnetic substance in the form of a ring or endless band,with or without grooves,and provided with bobbins or sections of wire, in combination with a commutator and brushes or conductors, the latter so placed with regard to the strips or segments of said commutator and their respective hobbins on said armature as to take oli' the current continuously, except when the said bobbins or sections of wire are at and near the neutral points l of the armature, substantially as described.

10. In amagneto-electric machine, an armature of iron or other magnetic substance in the form of a ring or endless band ot' any convenient form of cross-section, and lprovided with sections or-bobbins of wire Wound around the armature at right angles to-its circumferential axis, one end of the wire of euch bobbin being connected to the dia1netrically)pposite segment ot' the com mutator-eylinder through the coils ofthe dianietrically-opposite section, substantially as described.

11. In a magneto-electric machine, a grooved armature provided with sections of Wire, the first or last ends ot diametrieally-opposite sections connected togetlier, in combination with the commutator-cylinder E, to diametrically opposite segments of which the remaining ends of said sections are attached, substantially as described.

12. In a magneto-electric machine, an armat-ure ot' iron or other magnetic substance in the form of a ring or endless band, of any convenient form of cross-section, and provided with sections or bobbins of Wire wound around the armature at right angles toits circumferential axis, the ends oteach sect-ion connected to diametrically-opposite segments of the commutator-cylinder, substantially as described 13. In a magneto-electric machine, a groovcd armature of iron or other magnetic substanceY ot' any convenient form of cross-section, provided with sections ot' insulated wire, in conibination with the magnetic pole-pieces N N and S S, so arranged as to present a magnetic surface simultaneously to two sides of its inagnetic axis, substantially as described.

In testimon7 whereof I have signed my name to this specication in the presence of two subscribin g Witnesses.

CHARLES F. BRUSH.

Witnesses: L. L. LEGGETT,

JNO. GuoWELL, Jr.

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