Nikola Tesla Patents and Documents 00382279

8/7/2019 Nikola Tesla Patents and Documents 00382279

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(No Model.) 2 Sheets-Sheet 1.N. TESLA .

ELEO TRO MAGNETIOMOTOR.

Patented M ay I, 1888.

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(No Model.) 2 Sheets-Sheet 2.N. TESLA.

ELEOTRO MAGNETIO MOTOR;

No. 382,279. ' Patented May I , 1888.

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UNITED STATES PATENT OFFICE.

NIKOLA TESLA, OF NEW YORK, N. Y., ASSIGNOR OF ONE-HALF TO OHARLES

F. PEOK, OF ENGLEWOOD, NEW JERSEY.

ELECTRO-MAGNETIC MOTOR,

SPECl:FIcATtON' forming part of !Jetters Patent No. 392,279, dated May 1, 188:a.

Appli eatlon fi led November 30, 1887. Ser ial No. 256,561. (}lo model.)

To all iohom. if; may concern: sulated sections, so as to be susceptible to rapidBe it known that I, NntoLA T.E!s1.A, a sub- variations of magnetism. This core is wound

ject of the Emperor of Austria, from Smiljan, with foul' coils, COO' 0', the diametrically-op-Lika, border country of Austria-Hungary, now posite coils being connected in the same cir- 55

5 residing at New York, in the county and State cuit, and the two free ends of each pair beingof New York, have invented certain new and brought to the terminals t and t', respectively,useful Improvements in Electro-Magnetic Mo- as shown. Within this annular field-magnettors, of which the following is a specification, A is mounted a soft-iron cylinder 01' disk, D,reference being had to the drawings aceorn- on an axis, a, in bearings b b, properly sup- 60

ro panying and forming a part of the same. ported by the frame-work of the machine.In. a former application, filed October 12, The disk carries two coils, EE', of insulated

1887, No. 252,132, I have shown and described wire, wound at Tight anglesto one another.anda mode or plan of operating electric motors by having their respective ends joined, so thatcausing a progressive shifting of the poles of each coil forms a separate closed circuit. 65

J 5 one or both of the parts or elements of a mo- In illustration of the action or mode of on-tor-that is to say, of either the field magnet eration of this apparatus.let it be assumed that01' magnets or armature, or both. I accom- the annular field-magnet A is permanentlyplish this by constrncting a motor with two or magnetized, so as to present two free poles dia-more independent energizing-circuits, on the metrically opposite. If suitable mechanical 70

20 field-magnets,forexample, and I connect these provision be now made for rotating the field-up with corresponding induced 01' generating magnet around the disk.the apparatus exem-circuits in an alternating-current generator, so plifies the conditions of an ordinary magneto-that alternating currents are caused to trav- generator,and currents would be set up in theerse the motor - circuits. By so doing the coils or closed conductors E E' on the disk D. 75

25 poles of the field-magnet of the motor are pro- Evidently these currents would be the mostgressively shifted, and by their attraction upon powerful at or near the points of thegreatesta rotary armature set up a rotation in the lat- density of the lines of force, and they would,tel' in the direction of the movement of the as in all similar cases, tend, at least theoreti-poles, In this case, tlowever, the rotation IS cally, to establish magnetic poles in the disk 80-""'---.

3c produced and maintained by the direct attrae- D at right angles to those in the annular field-tion of the magnetic elements of the motor. I magnet A. As a' result of the well-knownhavediscoveredthatadvantageol1sresultsmay reaction of these polarities upon each other, .be secured in this system by utilizing the Shift-I a more orless powerful tendency in the disking of the poles primarily to setup currents in to rotate in the same direction as tliat of the 85

35 a closed conductor located within the influence field-magnet would be established. If, on theof the field of the motor, so that the rotation I other hand, the ring or annular fleld-magnetmay result from the reaction of such cnrrents A be held stationary and its magnetic polesupon the field.. progressively shifted by passing through its

To illustrate morefully the nature of the in- coils 0 0 ' properly-alternated currents, it is 9040 vention I refer to the accompanying drawings. obvious that similar results will follow, for

Figure 1 represents in side elevation the the passage of the currents causing the shift-operative parts or elements of a motor em- ing or whirling of the poles of the field-mag-bodying the principles of my invention, and net A.induces currents in the closed circuitsin section the generator for operating the same. of the armature coils EE', with the result of 95

45 Fig. 2 isa horizontal central section of the mo- setting up a rotation of the disk D in the sametor in Fig. 1, the circuits being shown partly in direction of such shifting. Inasmuch as thediagram. Fig. 3 is a modified form of motor currents are always induced or generated inin side elevation. Fig. 4 is a central horizon- the coils E E' in the same manner, the poles

tal cross-section of Fig. 3. of the disk or cylinder follow continuously lCO50 In Figs. 1 and 2,A is an annular core of soft the poles of the annular field-magnet, main-iron, preferably laminated or formed of in- taiuing, at least theoretically, the same rela-

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Z82,279

tive positions. This results ill an even all.d r together in se.riesand their free enC.lsbroughtperfect action of the apparatus. to terminals t t', respectively. Between theIn order that the system as a whole may be poles there is mounted, in bearings in the cross-

better understood, I shall now describe the pieces G", a cylindrical iron core, D, which, 705 mode or plan devised byme for producing the in order-to prevent the formation of eddyingcurrents that effect the progressi ve shifting of currents, and the loss consequent thereon, is

the poles of the motor. ' subdivided 'in the usual way. Insulated con-In Fig. 1, B B' are the poles or pole. pieces ductors or coils are applied to the cylinder Dof an alternating-current generator. They longitudinally, and for these I niay employ 75

10 are permanently magnetized and of opposite copper plates E. E', which are secured to thepolarity. F is a cylindrical or other armature sides and ends of the cylindrical core in well-containing the independent coils G G'. These _ known ways. These plates or conductors maycoils are wound at rightangles, so that while form one or preferably several independentone is crossing the strongest portion of, the circuits around the core. In the drawings two 80

15 field of force the other is at the neutral point. of such circuits are shown, formed respecti velyThe coils G G' terminate in the two pairs of by the conductors E and. E', which are iusu-insulated collecting-rings f and f', upon which lated from each other. It is advantageous alsobear the brushes g g'. Four wires connect the to slot these plates longitudinally, to preventmotor-terminals t ani! t' with the brushes g and the formation of eddy currents and waste of 85

20 o', respectively. When the generator is 1'0- energy. .tated, the coil Gwill at the certain point shown I From what has now been given the opera-in the drawings be"generating its maximum I tion of this apparatus will be readily under-

. current, while coil G' is neutral. Let it be as- stood. Tothe binding-posts t t' are connectedsumed that this current is conveyed from the! the proper circuits from the generator to cause 90

25 rings! f to the terminals t t and through the a progressive shifting of the resultant mag-coils 0 O. Its effect will be to establish poles netic poles produced by the magnets ~I uponin the ring midway between the two coils. the armature. Thus currents are induced inBy the further rotatiou of the generator the the closed circuits on the core, which, energiz-coil G' is bronghtwithin the intluence of the ing the core strongly, maintain a powerfulat- 95

30 field and begins to produce a current.whlch traction between the same and the field, whichgrows stronger as the said coil approaches causes a rotation of the armature in the direc-the maximum points of the field, while the tion in which the resultant poles are shifted.current produced in the coil G diminishes as The particular advantage of the construe-the said eoil recedes from those points. The I tion illustrated in Figs. 3 and 4 is that a con- 100

35 current from the coil G',being conveyed to centrated and powerful field is obtained and

the terminals t' t' and through coils 0' 0', has. a remarkably powerful tendency to rotationa tendency to establish poles at -right angles in the armature secured. The same resultsto those set up by the coils 0 0; but owing may be obtained in the form illustrated into the greater effect of the current in coils 0 Figs. 1 nd 2, however, by forming polar pro- 105

40 0 the result is merely to advance the poles jections on the field and armature cores.from the position in which they would remain When these motors are not loaded, but run-if due to the magnetizing influence of coils 0 ning free, the rotation of the armature is nearlyo alone. This progression continues fora synchronous with the rotation of the poles ofquarter-revolution untll coil G G becomes the field, and under these circumstances very ItO

'4s-neutral and coilG' G' produces its maximum little current is perceptible in the coils E E'jcnrrent. The action described is then re- but if a load is added the speed tends to di-peated, the poles having been shifted throngh minish and the currents in coils E E' are aug-one-half of the field.or a half-revolution. The meuted, so that the rotary effort is increasedsecond half-revolution is accomplished in a proportiouately. I IS

50 similar way, the same polarity being main- Obviously tbe.principle o f this invention istained in the shifti ng poles by the movement capable of many modified applications, most ofof the generator - coils alternately through Iwhich follow as a matter of course from thefields of opposite polarity. . constrnctions described. For instance, theThe same principle of operation may be ap1 armature-coils,or those in which the currents 120

55 plied to motors of various forms, and I have are set up by induction, may be held stationaryshown one of such modified forms in Figs. 3_ and the alternating currents from the genera-and 4 of the drawings. In these figures, l\ f IVI' tor conducted through the rotating inducingare field-magnets secured to or forming part or field coils by means of suitable sliding con-of a frame, F', mounted on a base, P. These tacts. It is also apparent that the induced I2~

60 magnets should be laminated or composed of coils may be movable and the magnetic partsa number of electrically-insulated magnetic of the motorstatiouary, but I have illustrated

. sections, to prevent the circulation of induced these modifications fully in the application tocurrents and to render them capable of rapid which reference has herein been made.magnetic changes. These magnetic cores or In the case of motors wound with independ- 13C

65 poles are wound with insulated coils 0 0', the ent field and armature circuits and operateddiametrically-opposite coils being connected by shifting their poles, as described in my said


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382,279 3

prior application, I may by short circuiting either the generators or the motors, the systemthe armature-coils apply the present invention is capable ofa very perfect action and invol vesin order to obtain greater power on starting. but little loss.

An advantage and characteristic feature of I do not claim herein the modem' plan of5 motors constructed and operated in accordance Iproducing currents in closed conductors in a 4 0

with this invention is their capability of al- . magneticfield which is herein disclosed.exceptmost instantaneous reversal by a reversal of Iin its application to this particular purpose;one of the energizing-currents from the gen- bnt.erator. This will be understood from a con- What I claim is-

le siderationoft,heworkingconditions. Assum-I 1. The combination, with a motor contain- ~5ing the armature to .be rotating ina certain di- I ing independent inducing or energizing eir-recti on following the movement of the Shifting! cuits and closed induced circuits, of an alter-poles, then reverse the direction of the shift- nating-current generator having induced oring, which may be done by .reversing the con- \ generating circuits corresponding to and con-

15 nections of one of the two energizing-circuits. neeted with the energizing-circuits of the moo. 50If it be borne in mind tbat in a dynamo-elec- tor, as set forth.tric machine the energy developed is very I 2. An electro - magnetic motor having itsnearly proportionate to the cube of the speed, field-magnets wound with independent coilsit is evident that at such moment an extra- and its armature with independent closed coils,

20 ordinary power is brought to playin reversing 1 in combination with a source of alternating 55the motor. In addition to this the resistance currents connected to the field, coils and eapa-

of the motor is very greatly reduced at the Ible of progressively shifting the poles of themoment of reversal, so that a much greater, field-magnet, as set forth.amount of current passes through the energiz-I 3. A motor. constructed with an annular

25 ing-circuits, . field-magnet wound with independent coils 60'I'he phenomenon alluded to-e-viz., the varia- . and a cylindrical or disk armaturewound with

tion of the resistance of the motor apparently 'I closed coils, in combination with a source oflike.that in ordinary motors=-I attribute to the Ialternating currents connected with the field-variation in the amount of self-induction in magnet coils and acting to progressively shift

30 the primary or energizing circuits. I or rotate the poles of the field, as herein setThese motors present numerous ad vantages, forth.

chief among which are their simplicity, relia- NIKOLA TESLA.bility, economy in construction and mainte- Witnesses:nance, and their easy and dangerless manage- FRANK R. MURPHY,

35 ment, As no commutators are required. on FRANK E. HARTLEY.