DE956430C - Double-wound motor for single-phase AC operation - Google Patents

Description

Double circuit motor for single-phase AC operation. Single-phase shunt motors cause difficulties with regard to the phase position between the excitation field and the armature current. If the shunt winding is connected directly to the network, it leads one practically inductive current; so that armature current and excitation current are considerably out of phase are. This fact has a two-fold disadvantageous effect on the work of the engine. Once the real power is only a fraction of the apparent power, so that the engine has a very low net power. Also is the brush voltage also strongly out of phase with the counter-voltage induced in the armature, see above that very strong armature currents and excessive brush fires occur.

The reason lies in these disadvantages of the single phase shunt machine. for the fact that practically only main current machines were used. The high idle speed However, these machines have a strong limitation in their performance.

In order to obtain a single-phase shunt motor, it is already known place a capacitor in series with the shunt winding so that the inductance the winding is reduced and thus the real power of the motor is improved. It was also suggested that a such a motor with compensation windings to be provided, which are connected in series with the armature and a capacitor.

However, this design not only requires two different capacitors, but also the construction of compensation poles, which is particularly important for. small engines, is a disadvantage.

On the other hand, DC double circuit motors have been known for a long time, those on the same pronounced poles have a main and a shunt winding exhibit. These engines cannot, however, simply because of the above-mentioned. Circumstances to be used for AC operation.

The invention now aims. To overcome these circumstances and one Manufacture double circuit motor, which is suitable for single-phase AC operation is. This motor, which has a main current winding in series with the armature and a shunt winding connected in parallel to both of them in series with a capacitance has, is characterized in that the main and shunt winding on the same pronounced. Poles are arranged and the capacity in the shunt is dimensioned in such a way that it has a mains frequency with the inductance of this winding coordinated. Resonant circuit forms.

In the preferred embodiment of the subject matter of the invention the capacitor built into the engine.

The subject of the invention is explained in more detail with reference to the drawing.

Fig. I is the circuit diagram of the single phase double circuit motor of the present invention ; Fig. 2 shows a schematic embodiment of the invention.

The motor consists of the armature I and the stator 5 with the two. Poles 6 and 7. The armature i and the stator 5 are assembled from metal sheets. The main current winding 2 and the shunt winding are on poles 6 and 7 3 arranged. A capacitor 4 is connected in series with the shunt winding 3: The capacitor 4 is advantageously dimensioned so that it is with the inductance of the Shunt winding 3 has a resonant circuit tuned to the line frequency. forms. Working in the resonance area has the advantage that the shunt current is almost for every operating state is the same.

When idling, the shunt current is relative to the main current great because the resonant circuit. 3, 4 is practically in resonance. He creates the main part of the river. In contrast, the main idle current is very small. At full load predominates the main current, while the shunt current is almost constant and depending on the structure of the Machine is slightly out of phase. The phase shift between the voltage and the resulting excitation flow is very small, and the efficiency at full load is good.

The main and shunt windings are on the same magnetic Poles arranged and are therefore very strongly coupled. Flows a very high at full load strong main current, a voltage is induced in the shunt winding, which almost compensates for the voltage drop in the shunt circuit. This is with a Reason why the shunt current decreases little at full load. In a similar way an opposing voltage is induced in the main circuit winding when idling, which is a causes an additional decrease in the main current. This gives you a machine the almost pure shunt characteristic when idling, at full load or at a standstill Main closing characteristic has. The engine therefore has a very large one Tightening torque.

Another advantage of the engine according to the invention is that the commutation is very cheap in every operating state and therefore the brush fire at brushes 8 and 9 is almost insignificant.

Of course, the engine of the present invention can be used to improve the commutation can also be provided with reversing or commutation poles.

Claims (2)

PATENT CLAIMS: I. Double-wound motor for single-phase alternating current operation with the main current winding in series with the armature and the two in series with a capacitance in parallel connected shunt windings, characterized in that the main and shunt windings are arranged on the same pronounced poles and the capacitance in the shunt circuit in such a way is dimensioned so that it forms a resonant circuit tuned to the mains frequency with the inductance of this winding. 2. Double circuit motor according to claim I, characterized in that that the capacitor is built into the engine. In, considered publications: French Patent No. 941 96o; Swiss patent specification No. 156 226; Arnold-La Cour: The asynchronous alternating current machines, Part II, igi2, The alternating current commutator machines, P. 522, and section 39 at p. 177; Liws, ch.itz - Glöckner: The electrical machines, Vol. II, edition 1934 pp. 45/46