US1074338A - Dynamo-electric machine. - Google Patents

Description

C. RF. AHLM. DYNAMO ELECTRIC MACHINE. APPLICATION FILED JAN. 2s. 1.911.

Patented sept. 30,1913.

3 SHEETS-SHEET 1.

l 70 NYM C. E. P. AHLM.. DYNAMO ELECTRIC MACHINE. APPLICATION FILED 11111.23, 1911.

Patented Sept. 30, 1913.

3 SHEETS-SHEET 2.

.0. E. F. AHLM. DYNAMO ELECTRIC MACHINE.

APPLICATION FILED JAN. 23, 1911.

Patented Sept. 30, 1913.

i 3 SHEETS-SHEETS.

o f 4' 4M f N if i alam Y CHARLES: E. F, AHLMfor c'LEyELaND, OHIO.

DYNAMo-ELEc'r-Rio MACHINE.

,T a'ZZ cham t may-Lconcem.' j l Be it known'that I, CHARLES E. AHUM, a' citizen of the United States, lresiding at Cleveland Vin the 'county of 'Cuyahoga and` State'of- 1hie,` haya inventedl azcertain new and usci-ful Improvement in-'Dynamb-ElectricMachin'es, ef which the following is ,a full, clear, and exact description, reference 4 being had' to thezaccompa'nyin drawings,

My applicationJN0. 543,7 6, .filed February 3.4; 11910 (of-'whioh-this is a division) showsfandfdesoribes aldynamo electric machine-operating withl afconsta-nt potential' fori'arying speedsv-al'machineas a genera.- -tor'giviiig a current of--Sconste'int otential for varying speeds, though receivingcurrent 'of constant potential. A characteris-r tic-of the machine is that there is a single armature under the linfluence of two magnet lields, onelof which is constantand'the other of i which Aincreases -in-"sti'engtli with the speed.'l The windings, circuits and conneci' tions byiwhich this .isi accomplishedor, what maybe called'v the electric features of Ithe machine are claimed in the parent applica tion referred to. 1

" The presentvv application relates to the mechaiiicalfeatures by `which vsuch dynamo electric machine may be constructed as van,I

elicient pieceof mechanism.

'lhedrawing-s showa dynamo electric inachiiie ofthe two jpole type embodying this invention,

i `Figure l `isa vertical-longitudinal section through the machine; Fig. Q, is a transverse vertical section of the same; Fig. is Va horizontal 'longitudinal section, omitting the f armature with itsshaft and` comiinitator and bearings; Fig. 4 is a vertical transverse section through the machine adj'ac-ent to the cominut'atoi' brushes; Fig. 5 is an end -view on a reduced scale Fig.- 6 is a diagram illustrating the electromagnetic operation.

The mainframe of tlierinachine, desigu :cated 40, consist-s of a hollow, barrel-like,

iron casting extending above and below the armature and forming also a portion of the ends ofthe inachineythese end -portio-ns'be ing annular, as shown! at 41' Aand 42. The` annu-lar portion 42de connected with-the main portion 40by a sleeve-like'portion 43 nearer'- the axisand an outwardly extending' annular portion 4. Centrally mounted on the endv portions 441;,fiifid 42 arediskelike members@ and 46,-preferab1y ofsome non- Specicaton of Lettinrsflatent.

Original-application led February 14,191.0, Serial No. 54353326. Iviied and this 23, 1911. Serial No.' 604,120.

y balls (S2, and an outer ring coies, becker fields, the

-magnetsy ythe ironie lilbutyinfthei embodiment shown,

Patenten sepeeo, 1913- opplieation filed January magnetic niateriah'as brass or aluminum, and shown as removably secured byscrews 52. In these end disks 45 and 46, is mounted the armature shaft insuitableball bearings, as shown.' The 47, the mounting being frame openingsfwhich the disks occupy 'are large enough so that the removal of either disk allows the armature to be drawn out' of that end of the machine. The casting 40 may be flattened on its outside, above and .below the armature, as shown, thereby providing suitable bases on either of which the frame may stand. Figs. 1 and 2- omit the armature winding but show the shaft 47 and the core 48, which maybe allan'iinated strii,oA

ture of disks, or otherwise constructed, as'

desired. It is shown as composed of mem-` bers surroundinfr the shaft and-held lin-place shaft, The wintlingsvas will be understood, occupy notches 5l in the core.

, 53 designates the comnriutatorbars'insu-A latingly carried by a` commutator core 54 on th'e shaft and locked in'place by a nut ,screwing on to that core 'against a collar 5.6 thereon. Beyond the commutator core on one end and beyond 'the flange 50 on the other, are suitable distancesleeifes 58 and '59 ball bearings reand 'beyond these are thev ferr-ed to." The ball "bearing, .in the -forin shown, consists of a ring (30 surrounding the shaft and abutting the distance. sleeve, G3 seated-iii ,the disk member 45 and 4.6,.there being a dis- Atance sleeve Glontlie shaft for holding the ring 60viii place. A suitable dust-cap is-provided by the disk G5 threaded in place and.

vby suitable flanged fittings 49 and 50 on the held by a pin 67":iswill be well understood.. I

64 indicates ya cap-plate atthe cominiitator end ofthe shaft., the other end beingV connected witligthe driving or driven mechanism, not shown.

Carried bythe main body portion 40 of the frame are two magnet cores 70 which have the usual pole faces 71 and suitable windingsfQ, illustratedby dotted lines in Fins. l and 2. These ma'net cores 70 are shown as held in place by screws 73. These with their windings, .constitute operationtof which will be hereinafter'.described. The frame'40' constitu-tes a ring over the' ends of armature magnetically connecting the poles 70. The Aofsthe main field are supported by cross-section so are out of any substantial magnetic con-' nection therewith. rihe cores of these magnets are designated 75. They have flared pole faces 76 and. lare 'connected at their outer ends to the iron connecting bar Z 7 by screws 78. `This connecting bar Z7 is shown as carried byl screw bolts .794 on a cap-plate 80 which 'may ,bev made et aluminum' or other nonmagnetic material. It desired, the cap-plate may be made separately and the connecting bai` 77 secured to the main frame, either through interposed non-mag netic material or material of smal-l enough that the magnetic flux will not be suicientto intert'ere with the opera tion. y

Outside of the reduced portion 43 I mount the support for the commutator brushes, consisting of brackets 85 supported on suitable insulation. 86 and carrying pivot pins 7 on which are mounted arms 88 carrying the two pairs ot'brushes, designated S20, Q1, and 23, 24. Coiled springs 89 surrounding the pivotlpins 87 tend to keep the brushes on the commutator. rlhe brushes projecting freely through openings 84 in the traine portion 43. The brushes are covered by a removable sleeve-like cover plate 90 resting on the main frame and secured to the :traine portion 42 by screws 91. This makes a vvery simple construction and one allowing easy access to the brushes. For lthe sake of completeness, I will now describe the electromagnetic operation of the machine, as illustrated more particularly in the diagram of F ig. (3. In this diagram the windings J and F are main-field windings corresponding to the winding 82 of Fig. 2, while the double bucker field windings L, H and M D on the poles 70 correspond to the winding 72 of Fig. l. The armature illustrated is i wound as for an ordinary two-pole machine,

tilt

being connected to successive commutator bars, on the closed circuit principle, as is well understood. The t'wo poles 70 are, of course, of opposite polarity and the horseshoes T5 are so placed that thoseof their poles which are adjacent to the poles have a polarity opposite thereto respectively. Thus, asshown in the drawings, the upper pole 70, for example, inthe operation of the machine, is a north pole; the upper pole of the right hand horse-shoe Z5 a south pole, and so 0in-this polarity being indicated by the designating letters N and S on the diagram. 20 and 2l indicate twocoininutator brushes related to themain field, and 23 and 2e indicate commutator brushes related to the bucker iield. The shunt winding of the main field, shown, is in series with a small coil, indicated byD and H, constituting a portion of the bucker iield and acting as a teaser therefor, the principal bucker ltield windings being independent of the main tield windings, as hereinafter described.

. Starting from the .mutator brush 21, the main ladal'ited, when attracted, to

:terasse Referring to the circuits shown i' ft. the letters 1A and B indicate the Aii y lead A, or from the come field wind' and the teaser winding may be tracer" followss-vizt the line C to a fst/*turn (teaser coil) around the core 79, n n the line E to a winding F (main tieid) 'on the cores 75, thence via the line Gto thel teasercoil H on the other core T0, thence 7i 'via the line l to the main ieid-winding el,

thence via the line l to the brush 20. it willbe observed that the relative directiono the main coils and teaser' coils .is such that ir a current be flowing to give the main poles the polarity designated, the .teasen coils will give the bucker poles a polarity? opposite to the adjacentmain poles, as also" designated. The winding of the main pory tion of the bucker ield starts from the brush. 35 23 through the coil L to the line@ and' through the coil' M to the brush 24, and-I, these coils are of high resistance, and are wound in the same direction as the teaser coils. The lines ot torce ot the two .fields are illustrated by the conventional broken lines with arrow heads thereon.

As shown in Fig. 6, T represents a batg tery in a shunt across the main leads A and B. U represents an automatic switch adaptg5 ed to control the main line and having a compound winding; one winding of this switch being in a shu-nt V across the leads A and B, and the other winding W' in series in one of the'leads, as the lead A. Y in dicates an armature under the influence ot this compound winding W and X` which is close the break in the lead A between the switch'and hat tery.

Let us assume that the machine is a. generator and that the armature is connected with an axle ofthe car, for example, andv that the switch is wound to pick up its armature when a certain' current. is generated, say that resulting from a train speed of fifteen miles per hour. Now, as the train starts, the armatures rotate slowly and the main line is open at the switch .Y so that the voltage builds up in the shunt V through tile the winding U of the switch. Duringthis j period, before the switch picks up, the main field and the bucker eld (due to the direction given by the teaser) are operating to give currents of such direction as to cause iae the successive poles to have opposite signs. The actual direction of this current depends on the residual magnetism, but their relan tive direction is thus fixed. The bucker i'ield current (due to the high resistance oit-its 1% winding) is so small in the early stage'o'i rotation as to be negligible. As soon, however, as the switch picks up its armature, thereby throwing the battery on to the line,

the counter-electroznotive torce of the batist# 50 y lies, said frame being open on the sides of tery establishes a definite direction for the current suitable to 'the battery, and this current acting ,on the Winding of the main field and the teaser windings of the bucker'ield while it may reservetheir original polarities (if necessary) will continue their relative polarities. ow, as the speed increases,

the main field voltage rises proportional' to.

the speed, inasmuch-as this iield has a constant excitation, initially, at least, due to the battery, while the voltageof the local bucker field also rises proportional to the speed, be-

ing connected solely in series with the arma ture andthus having an excitation varying with the speed (the constant excitation b the teaserbeing negligible), and as the e fects of these two fields are opposite, the main line current, given out by the machine, is the difference bet-Ween the main field voltage and the bucker field voltage, which is a constant irrespective of the speed. With the generator, connected as described, when lthe battery has been full vcharged, the

-tator brushes, and the removable caps over such holders all contribute to the etiiciency` .of the machine. p in this'application. When associated with the windings and circuits .claimed in my parent application referred to, a simple and eiective constant potential generator or motor is provided.

Having thus described my invention, what I clairn'is y p l. In a dynamo electric machine, the combination,w1th an armature, of a frame forming a magnetic ring in planes parallel with the plane in whichvthe axis of the armature the armature, pole pieces carried by such main longitudinal ring, additional pole pieces at the open sides with a different inagnetic circuit from the pole pieces first mentioned, and means for supporting the additional pole pieces.

2. In a dynamo electric machine, the coinbination, with an armature and field magnets, cfa magnetic ring connecting the lfield lmagnets and carrying the magnetic flux through the frame of the machine longitudinally of the armature and having sidel openings, at least one of the ends of the frame having an opening sufficient for the These features are covered removal of the armature, a bearing carried by such endv at such end opening, independent'magnets at the sides, and means vcarried by the magnetic ring for supporting., such` magnets at the sides. l

3. The combination of a barrel-like fram formed with open sides and ends with central openings in them, an armature mounted Within said? barrel and having its shaft occupying said openings, removable end membersin which the v"armature shaft is journaled and which are mounted on tlie'frame at said openings, pole pieces carried by said frame, additional pole pieces at the open sides and independent of the full influence of magnetic luX throughthe barrel-like frame, and means forsu'pporting the additional pole pieces.

4. The combination of a barrel-like framev formed with open sides, an armature Vmountedaxially within said frame, removable end members in which I the armature shaft is journaled, pole pieces carried by 'said frame,

other pole pieces carried at such open sides,-

and means for supporting the last mentioned pole pieces and removably vclosing the sides.

5. In a dynamo electric machine,the combination of a main frame, a shaftjournaled therein, an armature on the shaft, pole pieces carried by the frame coperating with the armaturesaid pole pieces being magneti#v cally connected through the end portions of the frame, a plurality of pairs of additional pole pieces, each pair having a connecting bar of magneticmaterial independent the magnetic members carryingsaid additional pole pieces and forming caps for the sides of the frame. i

6. The combination, with an armature, of pole pieces, a frame for the machine extending beyond theends of the armature and supporting the armature shaft, said frame carrying the magnetic flux ofthe pole pieces mentioned, additional pole pieces coperatingwiththe armature, and removable side i main magnetic flux of said frame, and nonmembers carrying such. additional pole pieces and `mounted on the frame.

7. In a dynamo electric machine, the combination, with an armature, its.shaft and commutator, of an integral frame adapted to contain the armature and commutatorv and having' annular` end portions beyond the armature and commutator ends, a pair of central end members .carried'by the' frame, the shaft for the armature bein journaled in said end members, the frame ge duced diameter around the commutator,

brush Aholders comprising bracket's'mounted on the outer sides of such ieducd portion and arms pivoted to the brackets, there 'being openings throu h Vthe reduced portion through which brus ies carried by the said arms ot the holders'are adapted to extend into Contact with the commutator, and pole ing of ref pieces cam'ed by said imm@ smit having their nmgnetc -m carried by Said angular end portions of the frame.

8. in. a, dynamo electric machine, the cornbuaton, with an aamzatlafre, of L Emme therefor carrying poe pieces, an amnut'ure slaaf@ a communimcyA chereon, said frame appmoaehmg the shaft adjacent wh@ commutator and being Subsaniall'y cylindrical :md o xreduced diametev@ about the commutatm and' Hanging outwmdflly am thel Guten end; the reduced. pc 1'1,f n,. brush1 hoder's meunted en the outer face of such reduced pmrtom of the frame, chere being @pen-ings @Hough the reduced pomten throng-i111 Whnh 15 baushes camfed by the, holders are wcmped.-

te: extend im@ cmntact with the commumtrg and? w sleeve-like cap for said bueh Mobiele?,- i'emefmbly securec t@ fname in engage meurt VWLM; che boc'y thereoi acdi Wiu szch euml-madly flanged peten. A

En estmongr wl'leeo, hereunto ax my sgmaiume in the presence of two vviinflesses;

CHARLES E. 1f; Amm'.

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