US1022255A - Dynamo-electric machinery. - Google Patents

Description

0. A. PARSONS L A. H. LAW.

DYNAMO ELECTRIC MACHINERY.

ABPLIO/ATION FILED JULY 9, 1.909.

Patented Apr. 2, 1912.

4 SHEETS-SHEET l.

C. A. PARSONS L A. H. LAW.

DYNAMO ELECTRIC MACHINERY. APPLIVOATION FILED JULY 9,1909.

Patentgd Apr. 2, 191.2.

4 SHEETS'-SIBET 2.

Arr/i A mpc. (7M "R f C. A.PARSONS a A. H. LAWe DYNAMO ELECTRIC MACHINERY. APPLICATION FILED JULY 9, 1909.

1,022,255. y Patented Apr. 2, 1912.

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DYNAMO ELECTRIC AAAAAAA Y.

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' lines of torce causing` Self induction UNITED STATES PATENT OFFICE.

CHARLES ALGER-NON PARSONS AND ALEXANDER HElRTL" LWN, GF NEWGASTLEUFON TYNE, ENGLAND; SAID LAW ASSIGNAGR T0 SAID PARSONS.

DYNAMO-ELETRIC MACHINERY. L

To all whom it may concern.' y

lle itlnioun that we, (`ii.\unns Ail-(numeri Pinson; and i-iiilicxixnici: llnniiv Luv, ,aubjects oi the lingY of Great Britain and -lreland` residing at llealon lVoiliS, Newcastleuponffyne, in the county of Northuinheiland7 llngland, have invented certain new and useful linproveinents in and Relating to Dynauio-'lllectric Machinery., of which the following is a specification.

This invention relates to dynamo electric machinery and more esliecially to the arnia-` tui-es` oi' rotatingparte carrying conductors. t is also applicable to stationary parte ot' alternatoie4 oi any electriiL-al Winding in which it is desirable to reduce the sell inn duction as much aspossihle and which at the saine time has to he Secured Strongl f against mechanical forces.

ln the direct current dynamo electric inachiiies whether generators or motora, it is well known that hettei commutation is olitained `with less sparking' at the lirullienl hy laying the armature windings on the Sin'laee ot the core rather than hy einhedilinyg; them in Slots. This is efpecially true in the ease oi high speed machines adapted lo he driven hy steam turbines and it has hitherto heen the practice in Surface wound armatures of this type to hold the windings, in position hy steel binding' wirem.

The object of thisl invention is to obtain an `arrangcnrent t'or holeinel conductors whereby the eonsilructionsil advantages of' the slot type of iviniline' a re. eonihineil with the advantages as regards commutation oiC the surface type.

- A further object is to provide means Wherehy the self induction ot' einheilded oi partially eiul'iedded conductors: may he ie duced thus reducing' the tendeney to spark at the loi'uehesy in direct current ai'niatures.

ecordin' to this invention the conductors the seit' induction o'l' the ivinding'si is not appreciahly iiicieaSed 'While in many of thev niodilications proposed the conductors are made itat and thin so that the path for the is kept a maximum and eddy currents are kept a minimum. v

-The invention consists in an arrangement for holdingconduetore in dynamo electric machinery wherein each conductor is held te Specification of Letters Patent.

YatentedApi'. 2, 1912.

the core hy lockinga portion of the condiicous iiiipreved arrangements hereinafter described..

neierring noiv to 'the aeconiianying draw- .ings Figure l shown a plain Solid conductor locked without any special means for tightening according to one foiinof the invention. liiggs. f2 to l inclusive show modified arrangements and 'lios-ins of conductor according/to thif` invention. 8 show/S an ari'aiigeineui; oifvliolding conductora* applied i to an arii ture in which tn-e iron is carried to a height approximately equal to that of the conductor. 9 and l() show in section and side elevation respectively a modilied conductor with slots for the purpose of iin-,ruining` its resistance to eddy currents.

Figs. ll and l2 are similar views of a forni of ak Stranded conductor; Figs. 13, 14 and 'l5 show a construction 'aeeording to one torni the present invention. Fig. 16

shown in part Sectional. side elevation an arnnitiiie and tield magnets and a modified 'lorni ol? conductor.

ln carrying` the iiiventioiirinto etlectI in the torni shown in Fig'. l, the conductors u are formed ot' a strip of copper7 aluminum 85 would he a core, hut in the case of armature.

end windings miglit he an end ring-With a dovelailv connection, the Slot, and the part oi the conductor tliei'eiin having suitable insulation di llilith this; formation tlic strip can he slipped into position from one end ot the core., and does not need any special tightening or lining ineanis.

According to a modified forni shown in Fig. 2 the conductor may be made in tivo parts c and f with enlarged sides, each' part 100 being-capable of radially entering` into the core slot, a separating piece or calliinrstrip g, being' inserted between them for the piirpose o1 keeping them Yfast in the Slot. The

calking Strip may he yolf copper or other 105 metal and may he foi-eed in radially or it. may he of insulatingy in atei'ial`r in which ease one can obtain tivo eoniluctors'pei Slot. In

the form shown a metal plate h is used but this is not essential. The calking piece may be soldered, brazed or calked between or to` the conductors. The conductors also may 5 have projections formed .thereon at their facing sides in order that the calking strip may be driven in longitudinally and held in place by these projections. Further if desired all parts may be tinned before asm 'sembly and afterward sweated into a solid mass.

According to a further modification for example as indicated in Figs. 3 and 4: the conductors z may be held in place by means of tapered pieces of wood 'i or other material be wrapped entirely around the conductors of any of the forms as indicated in Fig. 4 in order to prevent short circuiting by dirt or dust.

The wedge indicated in Figs. 3 and l may be in two tapered parts driven in from either end. In these forms also the slot is shown slightly tapered so that the conductors can easily be pushed in from the end of the armature, but are tight when driven up to the top of the slot.

In carrying the invention into effect a`ccording to the modification shown in Fig. 5, the split conductors w may be inserted radially into a suitable slot d and a wedge piece 85 /s or Wedge pieces forced in and held in place either by calking or burring the core plates. lAccording to the further modification shown in Fig. 6 circular slots m may be made in the core and suitable wedge pieces n inserted between a shaped conductor a acting to force it toward the sides of the slot. Fig. 7 shows a somewhat similar arrangement. in which the wedging action is obtained by forming the conductors with a small semicircular groove through which a wire 0 whichr mav be of steel or other material, is tightly drawn, thus forcing the conductors apart.

Fig. 8 shows an arrangement of holding the conductors applied to an armature in which the iron'p is carried up to a height approximately equal to the conductor a. but in which it is kept well away from the conductor so as not appreciably to increase the self induction of the windings. This construction has the advantage that the air gap reluctance in the magnetic circuit is reduced, and therefore', less magnetizing current is required, while at the same time the self induction is not appreciably increased. It

will be seen that the arrangement in Fig. 8

differs materially from the ordinary arrangement with a completely sunk conductor, since it is possible to keep the iron well away from the conductors. This has the effect as' pointed out of reducing self induce of the current.

tion, and at the same time allows of increased ventilation and more eiiicient cooling of the conductor than can be obtained with a completely embedded conductor. If preferred, the iron core may lonly be carried a short distance up as shown alternatively by the teeth' p1, p2 and p, in the figure. Of course, teeth of only one height are use'd in any ordinary case.

By dividing the strips into two ormore pieces eddy currents are reduced to a minimum and this loss may be still further reduced by means of longitudinal slits g cut in the projecting -portion of theconductor as shown by way of example in Figs. 9 and 10. These slits do not appreciably increase the resistance in a longitudinal direction.V

In the modifications described above a small portion of each conductor is embedded in the core. The conductor will therefore have a slightly larger amount of self induci tion than if-placed entirely on the surface. If desired, this extra self induction may be obviated by putting through transversely the embedded parts of the conductors atA short intervals along the core as indicated by e in Fig. 10. This will prevent any current iowing in the portion of the conductor which is embedded in the core and t-he self induction will therefore be due solely to the partof the conductor which is external to the core and .which must be made of sufficient cross sectional area to carry the Whole 'y It is found,'however, that without these transverse cuts the self induction of the conductor as a whole is increased to only atvery small extent provided there is an external portion whose self induction is small and which is either apart of or in electrical connect-ion with the embedded part. Further if it be desired to reduce the eddy currents in the conductors, instead of making the conductors of strips they may be made of a suitably constructed stranded cable, (as shown for example in Figs. 11 and l2) having an enlarged portion r, with an insulating piece d tting into suit-ably shaped slots or grooves c, in the core a' and tightly locked in any of the methods described above.

. Fig. 12.diagrammatically shows for clearness only one stranded cable y passin at regular intervals external to the core. `Iiig 11 shows a section through the same except that all the conductors are assumed to beV Vin place.' The lay of the cable should be so proportioned that each strand passes into the slot in the core at sutliciefntly frequent intervals to carrythe part external to the core and generally to preserve the stiffness of the cable.

The end windings of armatures may be constructed according to any of these modi- .fications in which case the conductors designated by a, e, or f on the drawings would be tl tl the end conductors and the grooves such as c might be termed in end rings; but it is not essential that the end windings should be held in this manner as any other suitable means may be employed.

A general construction according to one term of the present invention is illustrated in Figs. 13 to 15, the latter being ot a ,larger scale than the other two figures. This construction shows magnet poles l and an armature 2 into which conductors 3 ot the kindreferred to above are locked. The drawing also shows a manner in which conductors .of this kind can be placed in end rings; the end rings have projections 5 thereon into which the lower row ot conductors 6 is locked and above which is placed the upper row of conductors 7. The projections 5 extend upward to embrace the expanded parts at, the lower side of the conductors on the toplayer. A modified general arrangement is shown in Fig. 16 including the magnets l as inF ig. 13 together with a core w with projections as shown in Fie. 8, and conductors a. with internal wedges g, as shown in Fig.

ln armatures such as' those described above it will be seen that the conductors may be worked at very high current densiH ties owing to the great facilities for ventilation and this enables great economies in sise to be effected and much larger outputs obtained at any given speed.

Ventilating ducts may be provided at short intervals in the core so that the air entering at one or bothends of the armature can pass radially outward between the conductors and thence ont between the magnet poles. It is however preferred to line the tace ol the magnets with a suitable thin cylinder which will present a smooth sur face to the outtlowing air and allow this air -after leaving the Ventilating ducts to pass axially along the armature between the conductors thus minimizing noise and at the same time most eliiectively cooling the condoctors and the core. This cylinder may be perforated at intervals to allow a portion ot the air to escape, or the air may be supplied by tans on or external to the armature and may pass from the Center outward or from the ends inward. A construction ot this hind is also shown in Fig. 13 in which a. thin cylinder 8 is provided lining the bore ot the magnets l and presenting a smooth surface to the ontfiowing air.. Ventilating ducts 9 are formed in the core 2 and these are in communication with passages l0 ep;- tending throughout the length. otl the armatere.

Having now described our invention what we claim as new and desire to secure by Letters Patent is zf l. lIn dynamo electricalmachinery, a` core with a slot, therein, the width o the slot at the periphery of the core being less than its width nearer the conter a conductor with anenlarged side adapted at least-iin part to enter the slot; as set forth.

Y 2. In dynamo electric machinerya core with a slot therein the width of the slot at the periphery of the core being less than its width nearer the center a conductor having an enlarged side adapted loosely to en-.

ter said slot and insulating nic-ans situate between the conductor and the slot wall;

as set forth.

3. In dynamo electric'machinery a core the conductor and the slot wall and wedging means for the purpose of tightening the conductor inthe slot; as set forth.

In dynamo electric machinery a core, conductor radially in part embedded in the core with transverse cuts in the embedded part; as set forth.

(i. In dynamo electric machinery acore with slots therein together with conductos in said slots said conductors having a part. which projects radially beyond the mouth of' the slot and a part which is embedded and looked in said core; as set fort-h.

7. An armature for dynamo electric machinery comprising in combination a slotted magnetic core and conductors :in said slots of which conductors a part of each pro jects radially beyond the mouth of the slot anda part is embedded and locked in said core; as set forth.

8. ln dynamo electric machinery a core with slots therein a conductor arranged 'ith respect to the core to have two paths oit ditlcrent seit-induction electrically connected in parallel one path forme-dot a. part ot the conductor projecting radially beyond the month of a slot and the other path formed of the other part ot the conductor embedded and locked in the core;

set forth.

t). ln dynamo electric machinery a core body having a slot. therein conductors arranged radially in part in said slot and in part radially projecting therefrom together with means for separating them and wedging them in the slot; as set forth.

10.111 dynamo electric machinery a core a. conductor radially in part embedded in the core and in partextending beyond the same and projections on said core extending to the same-height as the. conductors so that the external dlameter of the core -is substantially equal to that 4of the circle circumscribed about the conductors; las set-r forth.

ll. In dynamo electric machinery a fnachine element a conductor and a locking part on said conductor said conductor in part projecting radially from said machine element and in part embedded in said element and locked'thcrein by said locking part; as set fort-h.

l2. In dynamo electric machinery a core a conductorfin part projectinv radially therefrom and in part embedded with

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