US1237459A - Armature for dynamo-electric machines. - Google Patents

Description

J. BIJUR. A ARMATURE run pvmmo ammo memes.

APPLICATION FILED DEC-6| I913- A Patented Aug. 21, 1917.

2 SHEETSSHEET 2.

' INVENTOR w/msssfs V Q UNITED STATES PATENT OFFICE I'OSELH IBIJUB, OF NEW. YORK, N. Y., ASSIGNOB TO IBIJUB MOTOR LIGHTING OOIPAJIY, OF HOBOKEN, NEW JERSEY, A CORPORATION OF NEW YORK.

aetaase.

Specification of Letters Patent.

Patented Aug. 21, 1917.

Application filed December 6, 1913. Serial No. 804,964.

To all Pwhom 'z't may concern:

Beit known that I, J osEPH-BIJUR, a. citizen of the United States, and a resident of New York, borough of Manhattan, in the county of New York and State of New York, have 'made and invented certain new and useful, Im rovements in Armatures for .Dynamo-E ectric Machines, of which the following is a specification.

My invention relates to armatures for dynamos, motors and similar machines of the type having a series of longitudinally extending teeth, with intervening grooves within which the coils or winding of the armature lie; and the object thereof is to provide an armature in which the grooves and teeth are so formed as to permit the use of a ater amount of winding, or more coils, wigi an armature of a given diameter,

than-has been possible in armatures as here tofore constructed. A further object of my invention is to provide an improved winding or arrangement of the coils or wires of an armature of the type herein referred to.

With the above and other objects in view, my invention consists in the im roved armature for dynamo-electric machines illustrated in the accompanying drawings and hereinafter described and claimed, and in such variations and modifications thereof as will be obvious to those skilled in the art to which my invention relates.

, In the drawing wherein the referred em bodiment of my invention is ustrated:

Figure 1 is a view showing a sectionof my improved armature upon a plane perpendicular to the axis of rotation thereof;

Fig. 2 is a view showing a portion there? of in plan; Fig. 3 is, a view similar to Fig. 1 but showingan old form of armature and illustrating the advantages secured by my invention; and

Fig. 4 is a diagrammatic view illustrating the scheme of winding employed.

The core of my improved armature 1s made up of a large number of thin circular disks of soft iron arranged side by side and securedtogether to forma unitary struc-' ture, as is common in armature construction, which disks are designated by thereference numeral 3, Figs. 1 and 2. The core thus.

formed is provided with a series of longitudinally extending teeth 4, whereby mtervening grooves are formed within which grooves the wire is wound which forms the colls or windin of the armature.

Flg. 1 of the irawing illustrates the form of longitudinally extending teeth and grooves employed in my improved armature, the grooves having a wider outer portion designated by the numeral 5 and a narrower inner portion 6 extending inward from the bottom of the outer groove, both said portlons being shown as having parallel side walls. The wires which form the armature winding are indicated by theshaded circles 7 ap earin within the grooves, although it will un erstood that the drawing is in-- tended to be conventional as to the winding, and that each groove will contain as wires of such a diameter as may be ntated by the particular service for which the armature is intended, these features bein matters of desi n Fig. 4 of the rawings is shown a suit able form of armature winding. In this figure each separate coil is in the form of a U-shaped loop, as is usual in armature construction, but the several loops are made of differentsize wire, and are so connected with one another and with the commutator segments as to form two superposed layers or sections, one of coarser ,wire located in the wider outer portio'nsof the ooves and the other of finer wire located in the narrower inner portions of the grooves, the two layers or sections of the winding considered as a whole being connected one another. Each la er or section is in turn or wires of the same cross sectlon. Thus, re-

in parallel with ferring to Fig. 4, theends 17, 18 of fine andcoarse wire loops 19, 20- located respectively 7 in the narrower inner and wider outer portions of the grooves are shown as connected with acommutator segment 1, while theother ends 21, 22 of theseloops areconnected with an oppositely located commutator. ment 12, the loops being thus connected m as I parallel with one another. The ends 23, 24

of othersimilar loops 25, 26 are likewise con nected with thecommutator segment 12,

while the other ends 27, 28 of these lastmentioned loops are in turn connected with an oppositely located commutator or segment 23. This scheme of winding and connection with the commutator segments will be continued around the armature several times and until all the loop ends are connected with the commutator segments, as will be understood, thus providing a winding which, considered in its entirety, is made up of two superposed layers or sections connected in parallel with one another, the individual wires. of the outer section being larger, or of greater area, than the individual wires of the innersection 1n the embodiment of my invention illustrated.

The winding may be held" in place within the grooves in any way. I have, however,

. shown the core as provided with longitudi- "curs between poles of opposite polarity throughthe armature core and either diametrically -across the same or through a portion of one side thereof, according to the arrangement of the poles, it will be seen that the maximum permissible cross-sectional area of the grooves is determined and limited by-the minimum area of the path along which the flow; of ma netic flux takes place; thatis, by the sum of the areas of the bases or roots of those of the teeth through which the flow of mu netic flux occurs, (it 'being obvious that w on the armature is in use i the flow of the lines of magnetic force will occur simultaneously through several teeth) fas the ci'oss-section of the path along which the lines of ma etic force flow is the least at the roots of t eteeth. Thus, referring to Fig. 1, the reference numeral 10 indicates e width of a toothroot, and the area of the tooth root computed by multi lying its width by its length mustobvious y be sufficient-ly great to avoid saturation of the iron by the portion of the flow of magnetic flux whichtakes place through the tooth.

It .will be appreciated that, in designing an. armature of a given diameter and assuming a certain minimum widt-hof tooth root necesary to avoid saturation, the permissi- -ble cross-sectionalarea of the grooves might be found insufiicicnt to accommodate the amolmt of armature winding necessary. In such a case the wider outer portion of the ooves cannot be made deeper to accommoate the necessary amount of winding, as to doso would reduce the area of the tooth root, as will be understood from the dottedFi 1, to'such an extent that saturation of tie iron at the tooth root would occur. It has therefore been necessary, in armatnres as heretofore constructed, to inerease the'diameter of the core in cases inner grooves an armature where the cross-sectional area of the grooves necessary to accommodate the winding would result in too great a reduction of the area of the tooth root, in order to avoid sat uration at the tooth roots.

In an armature constructed in accordance with my invention, however, in which a narrower inner groove is provided extending inward from the bottom of the widerouter groove, it is possible to materially increase the'cross-sectlonal area of the grooves without reducing the area of the tooth root to such an extent that saturation will occur, and thereby provide for an increased amount of armature winding. Thus, referring to Fig. 1, the area of the tooth at 11 is substantially the same as at 10, which latter area is assumed a'sla starting point in designing the armature, and is sutliciently great that saturation will not occur at the tooth root; and no saturation of the metal will occur although the cross-sectional area of the grooves has been materially increased by narrowing the rooves and extending them farther into the body of the core, whereby more winding" may be placed upon the armature, this resultha-ving-been attained without increasing the diameter of the armature.

Fig. 3 illustrates in another way the advantages secured in my improved armature, in which figure the armature is shown as made up ofdisks 12 having grooves of linifor'm width. If the area of the tooth root at 14, which is determined by physical characteristics of the iron of the core and the amountof magnetic flux or number of lines of force passing through the tooth, is taken as a minimum, and if the resulting area of the grooves is insufiicient to acconunodate the necessary amount ofwinding, the grooves 15 may be widened at their u per ends, as indicated in dotted lines, wit out decreasing the area of the path alon which the flow of magnetic flux occurs. us the area at 16 is as reat as the area at 14, and

..no saturation will occur, although the area of the grooves will be considerably increased. By properly proportionin the outer and havinga given predetermined diameter and amount of winding maybe so designed as to increase the area of the tooth root over the area in case; the grooves were of uniform width throughout, thus decreasing the resistance of the path of the lines of forceand increas ing the efficiency of the armature, as the core is \vorkedfa-rther below the point of saturation; and the fact that the area of the grooves is increased for a given diameter of armature and area of tooth root permits more winding to be used, and provision made for more ampere'turns upon the armature than would be the case if the grooves were of uniform width, thus materially increasing the torque when the armature is changed, because of the fact that provision is made for a greater area of armature winding which obviously reduces the resistance of the armature winding as hereinbefore explained.

Toothed armatures of thevtype heretofore in common use have been deficient in torque because of the fact that the area of the tooth root has been small because of the fact that as large an area as possible has had tobe provided in the grooves to accommodate the necessary amount of armature winding, and

saturation at the tooth root has commonly occurred. In my improved armature, however, the area at'the tooth root is increased for an armature of a given diameter, and a' greater total area for the reception of the V winding of the armature is provided, thus reducin the density of the magnetic flux at thetoot 1 root to a point at which saturation will not occur." This obviously permits the -flow of a greater amount of magnetic flux along the teeth and across the tooth root and secures a greater torque as hereinbefore explained.

Having thus described and explained my invention, I claim and desire to secure by Letters Patent:

-; 1. An armature provided with an inner winding of conductors and with an outer winding of larger conductors, each winding being complete in itself and the two windings being connected in parallel.

2. An armature provided with a slot i wider at the outer portion than at the inner their inner portions than their outer portions, each inner portion carrying a winding of one coil ineach slot and each outer-portion carrying a winding of one coil in each slot; the two windings being similarly disposed mechanically and electrically connected in arallel.

ture having a plurality of .radially disposed slots extending longitudinally thereof, said slots being narrower at their inner end portions in a directlon clrcumferentially of the,

armature than at their outer end portions, a conductor in the narrower ortion of each of'said slots, a conductor of arger diameter in the wider portion of each of said slots, and means connecting said conductors in parallel in the winding of the armature.

5. In armature construction for dynamo electric machines, in combination, an armature having a radially dis osed slot extend ing longitudinally thereo said slot being narrower at its inner end portion in a direction circumferential of the armature than at its outer end portion, a conductor round in cross section in the narrower portion of said slot, a conductor round in cross section of larger diameter in the wider portion of said slot, and means connecting said conductors in the winding of the armature.

6. In armature construction for dynamo electric machines, in combination, an armature having a radially disposed slot extending longitudinally thereof,said-slot being narrower at its inner end portion in a direction circumferential of the armature than n armature construction for dynamo electric machines, in combination, an armaat its outer end portion, a plurality of raof New York this 2nd day of December,

A. D. 1913. i

JOSEPH BIJ'UR.

\Vitnesses ANNA V. WVALsn, GEORGE E. 0001:.

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