US333573A - Dynamo-electric machine - Google Patents

Description

(No Model.) 3 SheetsSheet 1. E. THOMSON.

DYNAMO ELECTRIC MACHINE.

No. 333,573. Patented Jan. 5, 1886.

(No Model.) 3 Sheets-Sheet 2. E. THOMSON.

DYNAMO ELEGTRIG MACHINE. No. 333,573. Patented Jan. 5,1886.

I P NT I F L \ZM W MM:

(No Model.) 3 SheetsSheet 3. E. THOMSON.

DYNAMO ELEGTRIG MACHINE. N0. 333,578. Patented Jan. 5,1886.

N 'N NT UNITED STATES PATENT OFFICE.

ELIHU THOMSON, OF LYNN, MASSACHUSETTS.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 333,573, dated January 5, 1886.

Application filed August 10, 1885. Serial No. 173,960.

To all whom it may concern:

Be it known that I, ELIHU TnoMsoN, a citizen of the United States, and a resident of Lynn, in the county of Essex and State of Mas sachusetts, have invented certain new and useful Improvements in Dynamo-Electric Machines, of which the following is a specification.

The present invention relates to improvements in dynamo-electric machines and also in electric motors, since some of the constructions herein described are applicable to both.

The object of the invention is to secure a simple and efficient dynamo-electric machine adapted to furnish a constant potential, or nearly so,and an electric motor for the purpose of maintaining, when fed by a current of constant potential, a nearly constant speed.

Figure 1 represents in elevation and partly in section a machine constructed in accordance with my invention. Fig. 2 is an end elevation of the same. Fig. 3 is a diagram of the circuits. Fig. 4 is an exterior view of the ar mature-core unwound. Fig. 5 is a longitudinal section of the armature-core. Fig. 6 illns trates the winding of the armature. Fig. 7 is a diagram of the winding. Fig. 8 is a side view of the commutator-cylinder. Figs. 9, 10, 11, and 12 are diagrams illustrating the magnetic actions during operation, and Fig. 13 an adjustable arrangement sometimes employed.

In Fig. 1, F is a section of the core of one of the field-magnets, which is flanged, so as to bejoined to a corresponding flange of the fieldmagnet F at the other end by an exterior casing of iron or iron bars, 1 1. Each of these field-magnets consists, as shown, of a short cylinder, of iron, or other suitably-shaped piece, the end of which presented to the arma' ture A is hollowed out to form a concavity conforming to the spherical outline of the armature. Exteriorly to the part F, and surrounding it, as usual, are coils of copper wire, G O, constituting the coils of the field-magnet proper. The armature A, constructed as hereinafter described, is mounted on a shaft seen end onat X in Fig. 1, and seen as extending from the pulley end across the machine in Fig. 2. A suitable frame with feet G G is provided for the support of the shaft and various parts of the machine. The armature- (No model.)

core is wound with wire, which revolves along with the said core. The mode of winding will be described hereinafter. Supported so as to surround the armature-core A, but not moving with it, is a coil or coils, B B B B, placed, as shown in Fig. 1, so as to permit the free revolution of the armature internally thereto. These coils may be described as stationary hoops, of wire, preferably bent to avoid the shaft, and whose planes of position are inclined, preferably as from B to B and B to B,in such manner that the inclination is backward with reference to the direction of revolution, as indicated by the arrow. The purpose of this arrangement will be afterward described.

In Fig. 2, P is the driving-pulley. The bearings of the shaft are shown at D and E, which bearings are suitably supported on iron frame-work carrying the feet G G, and extending from the flanges on F F, being securely bolted thereto, as in prior constructions shown by me. The bearing E is on an arm or bracket, H, fastened to the frame-work connecting to the flange t of the field-magnets, which bracket serves also as a support for the yokes and attachments of the commutator-brushes. The commutator is indicated at K. The further details of these parts will be described later.

In Fig. 3 the mode of connecting is shown. The commutator brushes J J indicated as hearing on the commutator-cylinder K in a suitable position, are attached, respectively, to connections leading through the coils 0-0, as shown, while the circuit from J J is con tinued through the coils B B and B B, themselves arranged in series or in multiple arc with each other, and traversed by the current generated by the machine and supplied to the electric mains. The work, such as a number of incandescent lamps, \V IV, arranged in multiple are from the mains or conductors leading from the machine, (the number of which lights 7 \V may be varied ad libitum,) is fed by the current developed, save that portion which passesthrough O G. The coils G O are therefore in shunt to the work W W.

In Fig. 4. the armature-core A is shown mounted on a shaft ready to be wound. It consists of a portion of a sphere, or a sphere from which two segments have been taken in the polar portion, through which the shaft passes so as to leave two flattened surfaces thereat. The core is built up bodily, either ofa mass of iron wire wound around a shaft them concentrically with'said shaft. 40

between suitable guiding plates, M N, Fig. 5, or, preferably, ofa number of sheets of iron or iron disks of varying diameter, as seen in Fig. 5, piled up around a suitable form carried by theshaft and secured between such plates. Projecting pins at 1) p serve as guides in winding the armature, and are usually carried by the plate or flange at each end of the armature-core.

Ifind it of considerable advantage in the use of such an armature-core to construct it with connecting-wires L L, equal in number to the segments to be used in the commutator, or to the number of coils or divisions of a single coil on the armature. These leadingwires or connecting-wires L L pass, as shown in Fig. 5, (sectional view,) from near the periphery of the armature inwardly through a proper space provided in the armature-core itself and out through the end plate, N, along the shaft. These leading-wires are carefully insulated, and preferably inclosed between disks of insulating material,(shown in black,) allowing them to be spread out radially from near the shaft.

Other constructions permitting the carrying of the wires L L from along the shaft to a point at or near the greatest exterior circle of thearmaturc-core will suffice, but the construction shown .is simple and efficient. The plates M N may be keyed securely to the shaft, and where it is not desirable to have the sheet-iron disks extend close to the shaft an interior tube or other support may be provided to hold It is also preferable to leave small spaces 9 9 between the disks atsuitable points, blocks of any suitable material being inserted to hold them apart. These spaces permit connection-currents to circulate through the body of the armature and help to dissipate heat, though it is desirable to construct the armature of sheets of iron of such thinness that very little heat is generated during the changes of its magnetlsm.

I The mode of winding may be described as follows, and the result of the winding is exhibited at Fig. 6: Beginning at any convenient point,a suitable wire or several wires are carried around the armature in diametrically-opposite spaces between the pins 19 1), provided as guides in winding, the space for the periphery at which the pins 1) p are located is smaller "than that at the middle line, (dotted in the figure,) so that wire which follows and fills the spaces between the pins leaves open spaces between the coils at the central position; but the wires L L, through which connection is made to-the commutator-cylinder, are arranged to have one end of each open into one of these spaces and in regular succession, so that a joint from said wire is easily made with the projecting end of L and the portion of the coil passing near thereto from one coil-space to another. Thus the wire ain Fig. 6 will be connected to L one of the terminal wires projecting radially from the armature-core, and being a continuation of a corresponding wire led along the shaft, as seen in Fig. 5.

In arniatures wound as ordinarily upon cy-' lindrical cores no such facility for the con-.

nection of coils exists, and my construction therefore furnishes a simple method, differing from others, of winding a continuous wire around the armature-core, securing ample space for the production of a good joint with the commutator leading-wires, and securing simplicity and ease of winding. To complete the winding of the armature, it is only necessary to continue,half-filiing the coil-spaces with wire in regular succession around the core and making the suitable joints with the leading-wires until the core is covered with wire. At this time it will be found that one-half the leading-wires have been connected to the wire of the winding. It is now only necessary to continue the winding, filling the spaces completely, while the joints are made with the connecting-wires between what now become the exterior coils of the system. The finishing of the winding takes place in connecting the first end to the last end of the wire used in the winding.

To elucidate the winding, Fig. 7 may be referred to, where there are supposed to be eight leading-wires, L L L L, &c., and eight coils consisting of twoseries, the under series and the outer series, all constituting a single un-j broken wire. Assuming the coil 1 to have been laid on, then in passing to the adjoining space and coil 2 described the connection to aleading-wire is made, and this is repeated in passing from coil 2 to 3 and from 3 to 4:,

at which moment the armature-core has received the entire first series of coils on its exnumber of spaces provided therefor is suifi' cient. The winding, it will be seen, is similar to what is known as the Siemens winding, but the connections are taken out in an entirely novel manner, permitting the close winding of a single wire or group of wires. The wiresL running along the shaft from the coils of the armature to the commutator-segments K, re

spectively, are insulated from each other, as usual,and are shown in Fig. 8. The revolution of the armature in the magnetic field generates currents in its coils which, as in the Siemens construction, are carried out to the strips in the commutator, and are there conveyed to the circuit by the brushes bearing upon the commutator. The position at which the brushes are set on the neutral line with an enormous strength of field-magnetism, and an armaturecore whose magnetic effects are comparatively very weak, as when but little current flows in its coils, or when a few convolutions exist upon it, will be in a line almost at right angles with the magnetic line induced by the field-poles, as is well understood. It is inconvenient, however, to give to the machine such enormous field strength and to diminish'the armature convolutions to the degree required, as it limits the capacity of the machine, and makes the field expensive to produce. In consequencea lower field strength is selected and an armature of more convolutions utilized; but in this case the position of the neutral line at which the brushes should be placed is forward to a greater or less degree, depending upon the work demanded of the armature. Thus, in Fig. 9, N S represent the field-poles; A, the revolving armature; K, the commutator, and B the brushes. Vhen the current is doing little work-that is, when the current flowing through the coils is small, as for a few lamps or devices supplied in multiple arc-the brushes B B should be placed to touch the commutator on a line, as t t, nearly at right angles to a line joining the centers of the field-poles. In practicea slightinclination is found in the direction of revolution, depending on the speed of rotation of the armature and other causes. If, now, the load on the armature or the work done by it be increased, the strength of the field-magnetism remaining the same, or even being increased to a limited extent, the position at which the brushes should touch the commutator to avoid spark will move forward, as at t t, Fig. 16, owing to the reaction between the magnetism of the armature and the magnetism of the field, and the consequent distortion of the magnetic field. It is desirable, however, to avoid the necessity of constant readjustments according to the load. To secure this end, I place around the armature-core, as in Figs. 1 and 3, the coarse-wire coils B B B B, and in an angular position backward. If the coils be made movable, this position may readily be adjusted. These coils are represented in Fig. 10, and, as has been stated, Fig. 3, are traversed by the current fed to the work, which current is of varying amount. The action of the currents traversing the coils B B B B upon the armature-core is such as to develop magnetism in it in a direction at right angles to their plane, or axially to them, with the re sult of readjusting the neutral line as the current increases in the armature to a practically constant position a little forward of a linejoin ing the field-poles N S centrally. This neu tral line so established is shown in Fig. 10, t t.

To make clear the manner in which the results'are secured, I refer to Fig. 11 as exemplifying the magnetic actions when the coils B B B B are absent. The field-poles tend to establish in the armature-core a polar line or magnetic condition whose direction is seen in the line N S, while the current generated in the armature itself tends to establish a polar line in the same armature-core in the line N S. The resultant line of real magnetism existing in the armature-core will, however, be

N S, a line drawn intermediately between the line N S, due to the inductive influence of the field, and N S due to the currents flowing in the armature, but approaching more nearly the direction of N S, on account of the superiority of the magnetic effects of the field to that of the armature-currents. The direction of revolution in all these cases is indicated by a curved arrow.

In Fig. 12, N S represent, as before, the induced magnetism or axial linein the armaturecore induced by the field, while the line N S, at right angles to coils B B and B B, represents the line of magnetism induced by the action of the coils B B B B, the direction of the current sent through such coils being made such as will assist the action of the field-magnets themselves upon the armature-core, but will produce a magnetic axis not quite coinciding with that produced by the field-magnets themselves, but which will be displaced, as indicated at N S, instead of being in the direction N S, which would have been the direction had the coils B B B B, instead of being inclined, been placed with their planes at right angles to the line N S, or with their planes parallel with the plane of the fieldmagnet wire 0 C, Fig. 3, with the current unchanged in direction.

In Fig. 12 the line N S represents, as before, the direction of the magnetic axis induced by the flow of current in the armaturecoils. It will now be easily seen that should the influence of the coils B B B B exist alone with that of the armature-currents, supposing such were possible, a resultant magnetic axis would be produced, which might easily be made coincident with the line l S, or the direction in which magnetism is induced by the field-magnets themselves acting alone; hence by the construction which I have described it is easy to secure a neutral point a little forward of the line at right angles to that joining the axis of the field-poles, and which line undergoes practically no change from light load to full load, or from weak current developed by the armature to the strongest cur rents which it may yield, this feature being due to the stationary armature-encircling coils B B B B overcoming the distortion of the magnetic field by their being placed in an inclined position, as described.

I find, also, in the practice of my invention that the proportions of the coils B B B B tothe rest of the circuit may be made such as to secure a constant potential at the commutatorbrushes, and aldifference of electro-motive force at the terminals of the machine of constant amount, this second feature being alike d-ue to the effect of the said coils acting upon the armature-core inclosed by them so as to prevent a weakeningof the magnetic actions when the armature-coils are discharging heavy currents.

The position of the coils B B B B can be made adj nstable by mounting them upon a suitable support permitting their movement.

This is indicated in Fig. 13 as consisting of a stationary ring, R, and a second ring or portions of a ring bearing on the interior surface, to which second portions the coils B B B B are secured. A proper handle, H, attached to the parts upon which the said coils are mounted, may be provided to set the coils in position. When the proper position has been selected, the screw D serves merely to clamp the portions holding the coils BB to the outer ring R. This position having been selected, requires no change,unless the other portions of the apparatus are changed. It is preterable, however, to select .a fixed position for the coils and use them at all times in the best fixed position, constructing the machine so as todispense with the adj ustability of the coils B B B B, thereby securing-cheapness and greater simplicity. I do not, however, wish to limit myself to the use of coils in a fixed position merely.

-I have described my presentinvention as applicable to a dynamo-electric machine. The improvements are equally applicable to the case of motors, which are simply reversed dynamo-electric machines,and the changes which are to be made in applying my invention to convert the dynamo-electric machine into a motor are only those changes which are made usually in such cases, and Well understood by in derived circuit or shunt to the work, and an armature surrounded by stationary coils traversed by the main current of the machine.

2. In a dynamo-electric machine or motor, an armature surrounded by stationary coils applied in the manner described to correct the tendency to distortion of the magnetic field by the reaction of armature and field-magnetism.

3. In a dynamo-electric machine or motor, the combination,with the revolv-ingarmature,

of stationary coils mounted on an adj ustablev support, whereby their plane of winding may be varied with relation to theline of field-magnetism, as and for the purpose described.

4. In a dynamo-electric machine, an armature-core surrounded by coils of wire placed in an inclined position with respect to the magnetic axis of the field-magnets.

- -5. In adynamo-electric machine, stationary coils surrounding only the armature-core of the machine and set in an inclined position,

as described.

6. In a dynamo-electric machine or motor, an"armature wound with a continuous wire and having connections therefrom to the commutator, in combination with commutatorbrushes connected to a system of field-magnet coils in derived circuit around the work, and connected in series to the work through asystem of stationary coils surrounding the armatore-core.

7. In a dynamo-electric machine, an armature-core-constructed with spaces leading to the interior of said core, in combination with leading-wires passing through such spaces from the armature-coil system to the segments of the commutator.

8. In a dynamo-electric machine, leading-v Wires from the commutator passing into the:

body of the armature-core and outwardly to-' ward the greatest periphery of said core, as

described.

9. In a dynamo-electric machine or motor, leading-wires connected to the armature coils and passing inwardly through the armature-- core-itself, as and for the purpose described.

-10. In a dynamo-electric machine or motor,

an armature circular in section transverse to its axis, and having commutator leading-wires passing through openings in the armature-. core, as and for the purpose described.

11. Au armature-core composed of end plates, M N, a series of disks of varying diam-; eter, spaces 9 g, dividing the disks into groups,

and leading-wires inserted into passages made in the body of the armature-core, as described.

IIO

12. In a dynamoelectric machine, a systemfi of coils wound upon an armature Whose peellipsoid, said system of coils being'wound in two series overlying and underlying, with the ripheral surface is a portion of a sphere or-- wire of one coil in a seriespassing to the next coil in the series diagonally across the space existing between the coils at or near the place of greatest peripheral diameter-of the armature.

13. In a dynamo'electric machine or motor,

a'spherical armature wound with a series ofcoils connected to one another diagonally across the spaces at or near the greatest peripheral diameter of the armature-core.

14. In a dynamo-electric machine or motor, leading-wires passing through aportion-of the armature core and connected with the coilsystem at the places where the coils are separated bypassing over the greatest peripheral diameter of the curved armature-core, as described:

15. In a dynamo-electric machine or motor, I 17. In a dynamo-electric machine or motor, an armature wound with a continuous conthe combination of field-magnet coils, and coils 15 ductor placed in an underlying and overlyset at an angle to the magnetic axis of the field, ing series of coils or coil-sections joined to the one set of coils being in series 'with the work 5 leading-wires from the commutator at points and the other in derived circuit thereto.

where the armature conductor or coil passes Signed at Lynn, in the county of Essex and diagonally from one section or coil to the suc- State of Massachusetts, this 6th day of August, 20

ceeding section or coil, as described. A. D. 1885.

16. In a dynamo-electric machine having its IO field-magnet coils connected in derived circuit ELIHU THOMSON to the work, a set of coils inclined to the mag Witnesses: netic axis of the field-magnet and connected E. WILBUR RICE, J r., r in series with the work. J. W. GIBBoNY.

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