US1389051A

US1389051A - Continuous-current dynamo

Info

Publication number: US1389051A
Application number: US388699A
Authority: US
Inventors: Kesselring Fritz
Original assignee: Individual
Current assignee: Individual
Priority date: 1916-07-17
Filing date: 1920-06-12
Publication date: 1921-08-30
Anticipated expiration: 1938-08-30

Description

F. KESSELRING.

CONTINUOUS CURRENT DYNAMO.

APPLICATION FILED IIINE I2, I92o.

1,389,051, PanIeaAug. 30,1921.

'IIIIIIIIIIIIIIIIIIIIIIIIIIIII'III'IIF a@ MIE/7% UNITED STATES PATsN'r4 OFFICE; g

FRITZ xEssELnrNG, or NEUHAUSEN, SWITZERLAND.

i CONTINUOUS-CURRENT DYNAMO.

Original application ledJ'uly 17,1916, Serial No. 109,800. Divided and. this application filed June 12,

1920. Serial No. 388,699.

To all whom t may concern:

Be it known that I, FRITZ'KEssELRING, a citizen of the Swiss Confederation, residing at Neuhausen-on-the-Rhine, Switzerland, haveinvented a new and useful Continuous- Current Dynamo, for which I have filed applications in Austria May 18, 1916; in Great Britain June 8, 1916; in Hungary June 9, 1916, -oi" which the following is a specification..

The invention relates to variable speed generators, where an approximately constant voltage is to be obtained at variable speed, without the provision of accessories, such as controlling resistances or the like.

It is an object of the invention to provide specialk means for obtaining automatic regulation of the generator during speed variations, so that at all times a constant voltage may be obtained, such as is necessary in train l illumination, wherethe eneratorV is driven bythe shaft of the running wheels. Y

To the accomplishment of the principal object and others that will ybecome apparent upon perusal yoi the specification and claims forming a part thereof, the perferred embodiments or' the invention are illustrated in the accompanying drawing, in which Figures 1 and 2 illustratethe curves of the different magnetic fluxes in the dynamo.`

Fig. 3 indicates a two pole dynamo having main and auxiliary` poles, the latter being provided with two sets of'field coils.

Fig. lindicates the dynamo provided with main and auxiliary poles, and an armature having two separate windings.

rThis invention is a division of my copending application for Letters Patent o1 the United States, for improvements in continu.-

ous current dynamos, filed July 17, 1916,

Serial No.1109,8 00 patented July 13, 1920 No. 1,346,213. e

The E. M. F. E'zClqm, wherein- E is the E. M. F. induced in theV armature of a generator, y y

q: the resultant lmagneticlux of the armature per pole Lpitch (periphery ofv the armature divided bythe number of poles),V

a. the number of revolutionsper minute, and'C, a constant.y Y y It is immaterial in what mannerthe magnetic flux qais produced, and either an electromagnet, rora permanent magnet, or a combination of both may be adopted, constituting the field poles of the machine, To obtain a constant E. M. F. when the speed Varies, it is necessary, of course, that the product Clcpa should remain constant, and in viewl of the fact that the speed varies, qv must change, such that the product will always remain the same, in other wordsfe must vary inverselyas the number of revolutions n. To'accomplish this end, the'magneticv flux e 1s produced in the present instance' l by at least two component fluxes, namely (1) aconstant main liux cpl', which is produced either by a permanent magnet, or by an approximately yconstant number of ampere Specification of Letters Patent. Patented Aug. 30, 1921.'

turns, or by a combination of both, and (2) v a variable, auxiliary flux 92 directed oppositely to the main flux cpu and produced by a number of ampere turns aww, computed according to the formula: awnzCzn-C3, wherein C203 are constants and the constant C3 may be zero. v

The ampere turns of the auxiliary field poles, constitutingthe M. M. F. C201 and producing the magnetic flux e2 `varies directly as the number of revolutions, whereas the M. M. F. C3 is approximately constant. The part C27?, directly in proportion to the speed produces in the air space a flux opposite to thedirection of the flux cpl, produced by the main lieldpoles. The portion C3 of the ampere turns provided on the auxiliary field poles isarranged to produce a magnetic flux of the same direction as the main flux. The ampere turns C3 can, of course, also ybe replaced either wholly or in `part by a permanent magnet, or, if preferred, they may be entirely dispensed with.

lf C3; were Zerothe e-curve would have the number of revolutions and would therefore not give a constant voltage. This curve would also make necessary a large and Vcostly dynamo and for this reason itis important that C3 is dilierentirom zero.'y l

The approximately constant ampere turns of the main field poles producing the main flux :phare obtained in the `known manner by one or more windings energized by an approximately constant voltage. Or theiflux is `obtained by a permanent magnet, constituting'main eld poles, or by a combination of both arrangements.Y A,The same applies to .the ,Cnstant portion C3 0f the eMail-ier; flux.

l adapted for direct current or a portion of such a winding to rotate at a speed proportional to the number of revolutions of the generator in an approximately constant magnetic field (for instance the main magnetic flux of the generator), and by applying the induced voltage of one or more exciter windings.

Another modification embodies the regulating of auxiliary poles so that they become magnetized by the armature winding or by conducting the current of the armature around the auxiliary poles, or a combination of both lmeans may be provided. In both cases the current of the armature is not constant and varies approximately proportional to the number of revolutions. 'These modifications, therefore, are of secondary importance and will only be resorted to in the case of small' type machines.

The two fiuxes P1 and 2 may iow in entirely different paths, and in this case care is to be taken that the conductors of the armature of the dynamo should cut both fluxes. Conversely, the fluxes 151 and P2 may fiow in paths a portion of which is common to both fluxes, and similarly fluxes can be set up by spaced poles to flow through the same yoke and the samel armature (Fig. t).

Referring to the drawings, Figs. 1 and 2 show the graphic curves of the different magnetic fluxes lin the dynamo. b1 is the approximately constant main magnetic flux, f/ 2 the variable auxiliary magnetic flux and fr the resulting` flux. The number of revolutions n varies between nl and n2, constituting the range of speed variations for the dy'- namo. C201 and C3 are the M. M. F.s which produce the auxiliary flux. The curve f/ 2 is no other than the magnetization curve of. the magnetic circuit of the auxiliary flux. By a suitable selection of substance (air, cast steel, gray iron, armature iron, etc.,) as well as ythe transverse section of the auxiliary magnetic flux circuit, it is possible, as known, to change the form of the curve 412. Consequently, it is always possible to obtain a curve 15 which is nearly inversely proportionate to the number of! revolutions.' In Fig. 2 it is assumed'for the sake of. example that l 1 is not exactly constant but rises slightly with an increasing number of revolutions. In this case also by choosing an appropriate characteristic for the auxiliary magnetic crcuit it is possible toobtain a good ab curve.

- In Figs. 3 and 4L the application of the invention is diagrammatically illustrated. The generator shown in Fig. 4 comprises the armature A and produces the main magnetic fiux f/l'an'd the auxiliary flux (/)2 by means of field coils El, E2, E2. The main armature winding IV, is connected with the armature brushes K1 and K2. The auxiliary winding 72 is connected to the commutator brushes K., and K4. In Fig. 3, K3 is an auxiliary brush on the main commutator. In order to simplify the diagrammatic views all switches have been omitted.

The generator indicated in Fig. 3V comprises a two pole dynamo electric machine, the main brushes K1 and K2 being in the neutral Zone. In each pole pitch a main pole producing the flux d, and an auxiliary pole producing the flux l 2 are arranged. Between the main brushes an auxiliary brush K2 is provided onthe commutator. The armature is equipped with one armature winding only. The main pole isy adapted to produce an approximately constant magnetic flux, whereas the auxiliary pole produces a variable magnetic flux flowing in a direction opposite to that of' the main flux. The main pole is equipped with they main field coil E2, connected to the brushes K1 and K2. The auxiliary pole is equipped with two field coils E2, E2, of which the former is connected with the brushes K1 and K2. As the armature coils between the brushes K1 and K2 cut only the approximately constant 'fiux d), it is evident that between K1 and K2 a voltage C27@ isproduced proportional to the` number of revolutions. The field coil E3 is connected 4to a source of approximately constant E. M. F. such as the main brushes K1 and K2 or a storage battery to produce a constant M. M. F. C3 tending to set up a flux of the same direction as el. rlhe magnetizing effect of the coil E2 being opposed to that of' the coil E1 and the magnetization curve of the auxiliary magnetic circuit being chosen as shown in Figs. 1 and 2 it is evident that between the brushes K1 and K2 an approximately constant voltage is produced. y

llhe dynamo illustrated in Fig. 4 comprises main poles and auxiliary poles admitting the main flux q21 and the auxiliary flux o2 respectively. provided with two windings, namely, the main armature winding W1 equipped with the commutator brushes K1 and K2 and an auxiliary armature winding W2 having the commutator brushes K2 and K4. The main winding is adapted to revolve within both magnetic iuxes cp1 and e2, the auxiliary The armature A is.

winding W2 is adapted to revolve only within the constant flux e, so as to produce a voltage which is proportional to the numbervof revolutions. The main pole contains a main field coil E1 connected to the main brushes K1 and K2 and producing the approximately constant magnetic flux cpl. The field coil E2 of the auxiliary `pole is impressed with the difference of voltage existing between the auxiliary armature winding and the main armature winding. The voltage of the auxiliary armature is proportional to the number of revolutions and the voltage of the main armature is approximately constant. It kis therefore evident that the M. M. F. of the auxiliary pole is Czar-C3. The magnetizing effect of the auxiliary field coils is opposed to that of the main field coils and in View of the magnetization curve ofthe auxiliary pole (Figs. 1 or 2) it is evident that the voltage produced by the main armature winding is approximately constant.

It is within the scope of the invention to provide on the auxiliary pole in addition to the field coil E2 a third field coil energized by the main armature winding, to increase the constant C3.

If a strictly constant voltage is not required, but rather a voltage which rises or falls slightly with the number of revolutions, this may be obtained by a suitable selection of the materials, etc., for the auxiliary magnetic circuit. For example, in the case of train illumination it is sometimes required that upon greater speed the lights should shine brighter, and in such cases the voltage is permitted to rise slightly with the increasing number of revolutions. It is, of course, impossible to produce a cp curve which conforms closely to the ideal cp curve, and for this reason certain deviations from the desired voltage curve must be taken into consideration.

What I claim is 1. A variable-speed continuous current dynamo having two main magnetic poles the strength of which is substantially independent of the speed variations, in alternate arrangement with said main magnetic poles, two auxiliary poles, a two-pole armature relatively movable at a variable speed within said main and auxiliary poles, two main brushes on said armature, an auxiliary brush on said armature between the main brushes, and means for producing in said auxiliary poles two magneto-motive forces, one proportionate to the number of revolutions and the other approximately constant, said means comprising two sets of field coils energizing said auxiliary poles, the first of the two sets of coils being connected to said auxiliary brush and to one of the main brushes, the armature between said auxiliary and said main brush being affected by the magnetic lines of force of the main poles only and the second of the two sets of coils being connected to said two main brushes in such a manner that the magnetizing eect of said second set of coils is opposed to the magnetizing effect of said first set of coils.

2. A variable-speed continuous current dynamo having two main magnetic poles the strength of which is substantially independent of the speed variations, in alternate arrangement with said two main magnetic poles, two auxiliary poles with coils energizing said auxiliary poles, a two-pole armature relatively movable at a variable speed within said main and auxiliary poles, two main brushes on said armature, and means for producing in said auxiliary field coils two electro-motive forces respectively, one proportionate to the number of revolutions and the other approximately constant, said means comprising an auxiliary brush between the two main brushes, one of said auxiliary field coils being connected to said auxiliary brush and to one of the two main brushes, the armature between said auxiliary and said main brush being affected by the magnetic lines of force of the main poles only, and also comprising a suitably directed approximately constant voltage source introduced into the circuit of the other of said auxiliary coils.

In witness whereof I aiiix my signature.

FRITZ xEssEnniNe.