DE207852C

DE207852C -

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Publication number: DE207852C
Application number: DENDAT207852D
Authority: DE

Description

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⁵T^ATENTSCHRIFt ⁵ T ^ IDENTIFICATION

Vr 207852 KLASSE 21 d. GRUPPEVr 207852 CLASS 21 d. GROUP

WALTER SCHÄFFER in BERLIN.WALTER SCHÄFFER in BERLIN.

Es sind bereits verschiedene elektrische Gleichstrommaschinen bekannt geworden, bei denen ein zweites unmittelbar oder durch einen Widerstand kurzgeschlossenes. Bürstenpaar verwendet wird. Zum großen Teil werden solche Maschinen als Stromerzeuger benutzt, und zwar besonders da, wo bei beiden Drehrichtungen des Ankers Strom gleicher Richtung (Zugbeleuchtungsmaschinen) und auchVarious DC electric machines have already become known in which a second one that is short-circuited either directly or through a resistor. Pair of brushes is used. For the most part, such machines are used as electricity generators, especially where both directions of rotation of the armature current in the same direction (train lighting machines) and also

ίο bei veränderlicher Drehzahl annähernd konstanter Strom oder Spannung benötigt wird. Eine solche Maschine ist in der E. T. Z. 1905, S. 393ff., ausführlich beschrieben. Auf S. 400, Spalte i, letzter Absatz, und Spalte 2, 1. undίο more or less constant when the speed changes Current or voltage is required. Such a machine is in the E. T. Z. 1905, P. 393ff., Described in detail. On p. 400, Column i, last paragraph, and Column 2, 1st and

2. Absatz, ist auch auf das Verhalten einer solchen Maschine als Motor näher eingegangen. Eine ähnliche Anordnung ist auch in der deutschen Patentschrift 179281, ' Kl. 21 d angegeben. Dort handelt es sich besonders um Motoren, bei denen die Magnetwicklung durch ein zweites kurzgeschlossenes Bürstenpaar ersetzt wird.2nd paragraph, the behavior of such a machine as a motor has also been discussed in more detail. A similar arrangement is also given in German Patent 179281, 'Kl. 21d. These are especially motors in which the magnet winding is replaced by a second short-circuited pair of brushes will.

Bei allen diesen Anordnungen wird durch den infolge des besonderen, mehr oder weniger direkt kurzgeschlossenen Bürstenpaares hervorgerufenen Strom ein vom Anker ausgehen-• des Magnetfeld erzeugt, das das sonst von den Magneten stammende ersetzt.In all of these arrangements, the result of the special, more or less current caused by a directly short-circuited pair of brushes emanating from the armature generated by the magnetic field, which replaces that otherwise coming from the magnets.

Bei der vorliegenden Erfindung, die sich ausschließlich auf Gleichstrommotoren bezieht, wird auch ein besonderes Bürstenpaar verwendet, das unmittelbar oder durch einen besonderen Widerstand oder durch einige Magnetwindungen kurzgeschlossen wird. ImIn the present invention, which relates exclusively to DC motors, a special pair of brushes is also used, directly or through a special resistance or short-circuited by a few turns of the magnet. in the

Gegensatz zu den erwähnten und bekannten Anordnungen hat das hier durch Verwendung 40 In contrast to the above-mentioned and known arrangements, this is due to the use of 40

der besonderen Bürsten entstandene Kraftlinienfeld nicht die Aufgabe, das von den Magneten ausgehende zu ersetzen, sondern es soll gerade umgekehrt diesem während des Betriebes in bestimmter Weise entgegenwirken.The force line field created by the special brushes does not do the job of the magnets to replace outgoing, but it is just the other way around to counteract this in a certain way during operation.

Dies vorausgeschickt, soll nun nachstehend das Wesen und der Zweck vorliegender Erfindung erläutert werden.That said, the essence and purpose of the present invention will now be described below explained.

Bei der Berechnung eines normalen Gleichstrommotors ergibt es sich bekanntlich, daß die Bürsten in der der Ankerdrehung entgegengesetzten Richtung verschoben werden müssen.When calculating a normal DC motor, it is known that the brushes are moved in the opposite direction to the armature rotation have to.

In Fig. ι beiliegender Zeichnung sind die bekannten normalen Verhältnisse veranschaulicht, β und f sollen die Magnetpole eines Gehäuses darstellen, die durch Hauptstrom oder Nebenschlußspulen erregt sein können. Bei dieser Anordnung ruft bekanntlich der im Anker fließende Strom ein Kraftlinienfeld hervor, das die Richtung N S hat und also mit der Neutralen A B den Winkel α bildet.In Fig. Ι the accompanying drawing, the known normal relationships are illustrated, β and f are intended to represent the magnetic poles of a housing, which can be excited by main current or shunt coils. In this arrangement, as is known, the current flowing in the armature causes a force line field which has the direction NS and thus forms the angle α with the neutral AB.

Bei vorliegender Erfindung wird nun das Bürstenpaar c d nicht aus der Neutralen A B verschoben, sondern es wird noch ein zweites Bürstenpaar senkrecht zu dem in der Neutralen A B befindlichen angeordnet, das unmittelbar oder durch einen besonderen Widerstand oder durch einige Magnetwindungen kurzgeschlossen werden soll. In Fig. 2 ist diese Anordnung dargestellt.In the present invention, the pair of brushes cd is not moved out of the neutral AB , but a second pair of brushes is arranged perpendicular to the one in the neutral AB , which is to be short-circuited directly or by a special resistor or by a few magnetic windings. This arrangement is shown in FIG.

Es seien wieder g und h beliebig erregte Magnetpole. Den Bürsten I m wird von einer Stromquelle Strom zugeführt. Die Bürsten i und k sind unmittelbar miteinander verbunden. Über ihren Ankerspulen müssen aus be-Again, let g and h be arbitrarily excited magnetic poles. The brushes I m are supplied with current from a power source. The brushes i and k are directly connected to one another. Above their armature coils must be

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Claims

known reasons the magnetic poles are cut.

If the armature is in motion, a voltage difference arises at brushes i and k as a result of the current introduced. poles formed at N ₁ and S _1. Since i and k are connected to one another, a current ik flows which aims to form the magnetic field N ₂ S _{2 in the armature.} For this and

ίο the resulting previously at N ₁ and S ₁ resulting in the corresponding armature current strength a resultant of the anchor fields N, - S _n NS to that in Figure ι corresponds..
The magnetic conditions during normal operation correspond exactly to those of an ordinary motor.

When starting up, however, the present arrangement has the advantage of a larger one Tightening torque.

The torque when starting a motor is known to be P · R = ■ C · No · i, where C is a constant and i is the armature current. No = N ₁ - N ₂ , if N _{1 is} the line of force field emanating from the magnets and N ₂ corresponds to that component of the field caused by the armature current which counteracts the magnetic field. This component represents the anchor reaction and is dependent on the product i · sin α.

Now, since a current does not flow in the arrangement in Fig. 2 at stop of the armature by the shorted pair of brushes, the resulting anchor field coincides with the neutral AB, ie α = ο, and therefore is also N ₂ at start-up is equal to 0.

On the other hand, with the arrangement in FIG. 1 iV _{2 will} assume a relatively large value, since here α is a constant variable and i is a maximum value at start-up.

From this it is clear that the torque at start-up must be greater if the arrangement is made as indicated in Fig. 2,

This of course applies to shunt, main current and compound motors, and how already mentioned, the magnetic conditions are during operation with normal load in the embodiments according to FIGS. 1 and 2 are the same.

As is well known, main current motors now have the property of reducing the load to increase their number of revolutions and to go through with complete relief. Particularly the latter is avoided if the arrangement shown in FIG. 2 is made.

When the rotational speed is increased, the short-circuit current ik flowing as a result of the pair of brushes ik resting thereon is increased and, as a result, also the armature poles AT ₂ and S ₂ generated by it at the same time. Their lines of force, however, again cause an electromotive force that is opposite to the voltage acting on the brushes Im.

This will prevent the engine from running away.

It should finally be noted that the angle a formed by the resultant of the armature field N ₁ _{-S r} and the neutral AB must have a certain size resulting from the machine calculation during normal operation.

This shift between AB and N _r S, - is naturally dependent on the level of the short-circuit current ik. It can therefore be useful not to short-circuit brushes i and k directly, but rather through a resistor or through a few magnet turns of corresponding resistors. This would of course also influence the machine characteristics in this or that sense.

Of course, the size of the angle α would also be changed if the pairs of brushes were not offset from one another at an angle of 90 °, but rather a smaller one. But that would have a less favorable effect, especially with regard to the reversibility of the motor.

Ρλτε ν τ-Α ν SPRU c η:

Electric DC motor with main current or shunt winding, thereby marked that apart from the usual ones, standing in the neutral plane Brushes one or more special pairs of brushes standing in the direction of the pole fields are arranged in pairs are connected to one another by a few turns of the magnet, a resistor or a short-circuit line.

1 sheet of drawings.