DE638929C

DE638929C - Induction motor running at several speeds

Info

Publication number: DE638929C
Application number: DEA65646D
Authority: DE
Inventors: Dipl-Ing Heinrich Mueller
Original assignee: AEG AG
Current assignee: AEG AG
Priority date: 1932-04-14
Filing date: 1932-04-14
Publication date: 1936-11-25

Description

Der Betrieb von Wechselstrominduktionsmotoren mit sehr niedrigen Drehzahlen bereitet technische Schwierigkeiten, wenn die Motoren mit einer den kleinen Drehzahlen entsprechenden Polzahl ausgeführt werden sollen. Man hat nun bereits vorgeschlagen, zur Erzielung von kleinen Drehzahlen die Ständeroberfelder zu benutzen, durch welche ein Motor bekanntlich unter bestimmten Verhältnissen mit einer sehr kleinen Drehzahl (Schleichdrehzahl) laufen kann. Die Wirkung dieser Oberfelder läßt sich einerseits durch eine geeignete Wahl der Nutenzahlen, andererseits aber auch durch eine geeignete Anordnung bzw. Unterteilung der Läuferwicklung in bekannter Weise verstärken.The operation of AC induction motors at very low speeds prepares technical difficulties when the motors are running at one of the low speeds corresponding number of poles are to be carried out. It has already been suggested to use the stator upper fields to achieve low speeds, through which a motor is known to have a very low speed under certain conditions (Slow speed) can run. The effect of these upper fields can be seen on the one hand by a suitable choice of the number of grooves, but also by a suitable one Reinforce the arrangement or subdivision of the rotor winding in a known manner.

Es sind nun zwar bereits Motoren bekannt, bei denen der Läufer entsprechend ausgebildet ist. Auch hat man bereits vorgeschlagen, den Läufer solcher Motoren mit einer zweiten Wicklung zu versehen, durch die der Motor außer der Schleichdrehzahl noch mit einer höheren, dem Hauptfeld des Ständers entsprechenden Drehzahl laufen kann. Diese zweite Läuferwicklung mußte aber, damit sie bei der Schleichdrehzahl nicht störend wirkte, als offene Wicklung ausgeführt und beim Lauf mit der hohen Drehzahl durch besondere Vorrichtungen kurzgeschlossen werden. Diese besonderen Vorrichtungen verteuern natürlich den Motor und erschweren seine Herstellung und seine Bedienung.Motors are already known in which the rotor is designed accordingly is. It has also already been proposed that the rotor of such motors with a second To provide winding, through which the motor in addition to the creep speed also with a higher speed corresponding to the main field of the stator. This second rotor winding had to be so that it did not interfere with the creep speed, designed as an open winding and with Run at the high speed can be short-circuited by special devices. These Of course, special devices make the motor more expensive and make it more difficult to manufacture and its operation.

Diese Nachteile sind dadurch vermieden, daß Motoren mit polumschaltbarer Ständerwicklung zur Anwendung gelangen, bei denen gemäß der Erfindung der Läufer zwei dauernd kurzgeschlossene Wicklungen besitzt, von denen die eine nur auf das der einen Ständerpolzahl entsprechende Grundfeld anspricht und die zweite, vorzugsweise auf Oberfelder ansprechende Wicklung, bei der anderen Ständerpolzahl die Schleiclidrehzahl. erzeugt. Die Umschaltung von der einen auf die andere Polzahl braucht dann lediglich im Ständer vorgenommen zu werden. Diese Vereinfachung des Motors und seiner Herstellung und Bedienung ist besonders für den Antrieb von Webstühlen von Bedeutung. Es besteht dort nämlich ein großes Bedürfnis, die Antriebsmotoren vorübergehend sehr langsam laufen zu lassen, um das Webgut zu prüfen, was bisher dadurch geschah, daß man den Webstuhl bei der Prüfung von Hand weiter drehte. Die Verwendung von Motoren für den letztgenannten Zweck scheiterte bisher an der oben angegebenen unzweckmäßigen Ausbildung der bekannten Motoren.These disadvantages are avoided in that motors with pole-changing stator windings come to use, in which, according to the invention, the rotor has two permanently short-circuited windings, of which one only responds to the basic field corresponding to the number of stator poles and the second winding, preferably responsive to upper fields, in the other Number of stator poles is the grinding speed. generated. Switching from one to the other number of poles then only takes place in the stator to be made. This simplification of the motor and its manufacture and operation is particular to the drive of looms of importance. There is namely a great need there, the drive motors to run very slowly temporarily to check the woven material, which was previously done by the Loom turned by hand during the test. The use of motors for the latter purpose has so far failed in the above-mentioned unsuitable design of the known engines.

Die Erfindung ist in der Zeichnung in beispielsweiser Ausführungsform veranschaulicht. The invention is illustrated in the drawing in an exemplary embodiment.

Zur Erzielung einer ausgesprochenen Schleichdrehzahl besitzt der" Läufer in bekannter Weise eine Kurzschlußwicklung, welche geeignet ist, die Wirkung der Ständer-In order to achieve a pronounced creep speed, the "rotor has a known Way, a short-circuit winding, which is suitable to reduce the effect of the stator

*) Von dem Patentsucher ist als der Erfinder angegeben worden:*) The patent seeker stated as the inventor:

Dipl.-Ing. Heinrich Müller in Berlin-Waidmannslust.Dipl.-Ing. Heinrich Müller in Berlin-Waidmannslust.

Claims

especially to support Oberfelder. For this purpose, the individual teeth or groups of teeth of the rotor are provided with closed short-circuit loops α according to Fig. division of the upper field used corresponds to a good start-up, these individual current loops can be connected to each other by conductor b with high resistances, so that the winding with the main field gives a sufficient torque. Instead of the individual, self-contained conductor loops, conductor strands c and d drawn through the grooves in a wave-like manner can also be used, which are self-contained (Fig. 2).

In addition to this short-circuit winding, a second winding e is arranged in the slots, which, however, is connected as a phase winding and designed in such a way that, together with the main field of the stator corresponding to the normal speed, it results in a torque.

In order to be able to operate the motor at two speeds, the stator winding is required Pole-changing, ζ. B. according to the Dahlander principle in a ratio of 1: 2.

As an example it is assumed that the stator can be switched from four to eight poles is. In this case, the phase winding of the rotor is carried out four-pole, so that they only comes into effect if the stator is connected to four poles. The motor then runs at a network frequency of 50 Hertz with about 1500 XJpM. Will the However, if the stator is connected eight-pole, the four-pole rotor winding has no effect, and the motor can only run at a slow speed under the influence of the upper fields, which generally results from the number of teeth. For changing the speed is so with this motor only the switching of the stator winding is necessary, while for the rotor does not require any switching device.

Switching the number of poles of the stator

can also take place in a ratio other than ι: 2, if necessary using of two windings. A main condition for the operation, however, is that the phase winding of the rotor is preferred only to the number of poles of the stator

y®does not know with which the engine is under normal '•. ^ Conditions should work.

,, = * ■ · ".-" claims:

i. Running at multiple speeds Induction motor, in which one speed is caused by the action of upper fields is conditional, with pole-changing stator winding, characterized in that the rotor has two permanently short-circuited Has windings, one of which only responds to the basic field corresponding to the number of stator poles and the second winding, which is preferably responsive to upper fields, in which other number of stator poles generates the creep speed.

2. At several speeds running induction motor according to claim 1, characterized characterized in that the rotor winding generating the slow speed is a short-circuit winding, the other rotor winding on the other hand is a permanently short-circuited phase winding.

3. Running at several speeds induction motor according to claim 1, characterized in that the rotor winding for the generation of the creep speed consists in a known manner of individual winding loops which are placed around the individual teeth or groups of teeth and optionally among each other through conductors with high resistance are connected.

4. At several speeds running induction motor according to claim 1, characterized characterized in that · the rotor winding for generating the creep speed consists of self-contained conductors drawn through the grooves in a wave-like manner.

5. At several speeds running induction motor according to claim 4, characterized characterized in that the wave-shaped conductors below or above the phase winding lying in the same slots are arranged.

1 sheet of drawings