JPS5915265B2 - dc machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a DC motor equipped with commutating poles, and particularly to a DC motor suitable for operation with a pulsating current power source.

FIG. 1 schematically shows a commutating pole section of a conventional DC machine.

For a main pole consisting of a main pole iron core 2 and a field winding 2a provided in the relay 1, a commutating pole consisting of a commutating pole iron core 3 and its commutating pole winding 5 is provided in the neutral zone between the main poles. establish.

Note that 4 is an armature.

When such a DC machine is operated with a pulsating current power source, the connection is illustrated in FIG. 2.

The power source is converted into direct current by rectifying the current of an alternating current power source I with a rectifier 8 and smoothing it with a smoothing reactor 9.

This pulsating current power supply is connected to a terminal where the armature 4 and the commutator winding 5 are connected in series.

Now, in FIG. 2, rectified magnetic flux is generated in the commutator winding 5 connected in series with the armature 4 by the armature current, but the rectified magnetic flux lags behind the armature current in time.

Furthermore, the pulsation rate of the rectified magnetic flux is reduced relative to the pulsation rate of the armature current.

As illustrated in FIG. 3, this relationship is explained by the fact that the rectified magnetic flux φ is delayed in time with respect to the armature current 11 and the pulsation rate of the rectified magnetic flux φ1 is small, so that the armature winding short-circuited by the brush The rectified magnetic flux φ1 cannot sufficiently compensate for the change in the magnitude of the reactance voltage that occurs, and the short circuit current flowing through the brush increases, causing sparks and deteriorating the rectification.

In order to prevent this, conventional methods have been adopted in which the commutating magnetic circuit is constructed of laminated iron plates or by providing conductive plates on the side surfaces of the commutating pole core.

The former suppresses eddy currents in the block core, which cause a time delay in the rectified magnetic flux and a decrease in the pulsation rate, by constructing a yoke and a commutator core with laminated iron plates, thereby reducing the pulsating component of the rectified magnetic flux. This is a method to make it easier to pass.

Although this method is effective, since part or all of the yoke is made of laminated iron plates, its mechanical strength is weak and it is difficult to manufacture.

The latter method of providing a conductive plate suppresses the leakage of about half of the rectified magnetic flux passing through the yoke side of the commutator core from the side of the commutator with a plate provided on the side, and the pulsating component of the rectified magnetic flux is transferred to the armature. It is designed to pass through the gap between the

Although this method is also effective, it has the drawbacks that the eddy current flowing through the conductive plate causes loss, increases the temperature of the commutator winding, and makes it difficult to attach the conductive plate.

An object of the present invention is to provide a DC machine that does not have the above-mentioned drawbacks and can perform good rectification even when operated with a pulsating current power supply having a high pulsating rate.

According to research conducted by the present inventors, it has been found that when a DC machine is operated with a pulsating current power source, the pulsating component of the rectified magnetic flux due to the interpolation is insufficient on the air gap side, resulting in poor rectification.

Therefore, in the present invention, as a means to eliminate the shortage of the pulsating component of the rectified magnetic flux, an auxiliary winding is provided separately from the commutating pole winding on the air gap side of the commutating pole, and the auxiliary winding is connected to the armature current and the pulsating component. By flowing a current that has the same flow cycle and a phase that is ahead of the phase of the armature current, the time delay of the pulsating component of the rectified magnetic flux is reduced, and the pulsation rate is increased.

Hereinafter, embodiments of the present invention will be described in detail.

The difference between FIG. 4 and FIG. 1 is that in addition to the commutator winding 5 connected in series with the armature winding of the armature 4, the commutator core 3 is energized by an external pulsating power source. The auxiliary winding 6 is provided on the gap side with the armature 4.

In this way, since the auxiliary winding 6 is provided on the air gap side of the commutator core 3, the auxiliary winding magnetic flux generated when a pulsating current is passed through the auxiliary winding 6 passes through the air gap side of the commutator core 3 and is transferred to the armature 4. incident on the

As a result, the armature windings short-circuited by the brushes are rectified and compensated by the combined magnetic flux of the rectified magnetic flux created by the commutator winding 50 and the auxiliary winding magnetic flux created by the auxiliary winding 60.

Figure 5 shows the wiring when such a DC machine is operated with a single-phase full-wave rectified power supply.

Components that are the same as those in FIG. 2 or have the same functions are designated by the same reference numerals.

A pulsating current power source is connected to a terminal where the armature 4 and the commutator winding 5 are connected in series.

The auxiliary winding 6 is connected to a rectifier 8A1. F
- Therefore, a full-wave rectified pulsating current power source is connected via the variable resistor 10.

Here, the variable resistor 10 is used to adjust the magnitude and phase of the current flowing through the auxiliary winding 6.

As shown in FIG. 6, the rectified magnetic flux of the rectifier of the DC machine connected in this way is equal to
A composite rectified magnetic flux (φ1+φ2) is obtained by combining the rectified magnetic flux φ1 generated by the auxiliary winding 6 and the auxiliary winding magnetic flux φ2 generated by the auxiliary winding current 2 flowing in the auxiliary winding 6.

Here, the armature current (2) is delayed in time with respect to the auxiliary winding current I2.

This is because the ratio of actance to resistance of the circuit through which the armature current flows is larger than the ratio of actance to resistance of the auxiliary winding circuit.

Therefore, the auxiliary winding magnetic flux φ2 has a smaller delay with respect to the armature current than the rectified magnetic flux φ1, and the combined magnetic flux (
φ1+φp has a small delay and a large pulsation rate, and can sufficiently rectify and compensate for changes in armature winding actance voltage caused by pulsating armature current.

In other words, by providing the auxiliary winding 6, the pulsating current rate of the armature current can be set high even when performing the same rectification compensation as a conventional DC machine. The capacity of the smoothing reactor 9 can be reduced compared to the conventional one.

FIG. 1 shows another embodiment of the present invention, which differs from FIG. 4 in that an auxiliary winding 6 is provided on the side surface of the commutator winding 5 on the gap side.

This case also has the same effect as the one shown in FIG.

FIG. 8 shows another embodiment of the present invention, which differs from FIG. 5 in that the pulsating current power source of the armature circuit is shared as the pulsating current power source of the auxiliary winding 6. FIG.

In this case, there is an advantage that a special power source for the auxiliary winding 6 is not required.

As explained in detail above, the DC machine according to the present invention can improve the temporal change and magnitude of the pulsating change in the rectified magnetic flux synthesized with the pulsating change in the armature current.
This has the effect of providing good rectification compensation even when operating with a pulsating current power source with a high pulsating current rate.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a commutating pole part of a conventional DC machine, Fig. 2 is a wiring diagram showing an example of a case where a conventional DC machine is operated with pulsating current,
Fig. 3 is a waveform diagram showing the armature current and rectified magnetic flux in a conventional DC machine, Fig. 4 is a sectional view showing the commutating pole part of the DC machine according to the present invention, and Fig. 5 is a waveform diagram showing the armature current and rectified magnetic flux in a conventional DC machine. A wiring diagram showing the case of operation, FIG. 6 is a waveform diagram of the armature current, rectified magnetic flux, auxiliary winding current, auxiliary winding magnetic flux, and composite rectified magnetic flux in the DC machine of the present invention, and FIG. 1 is a waveform diagram of the DC machine of the present invention. FIG. 8 is a sectional view of a commutating pole part showing an embodiment of the present invention, and FIG. 8 is a wiring diagram during pulsating flow operation showing another embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Yoke, 2...Main pole iron core, 2a...Field winding, 3...Commuting pole iron core, 4...Armature, 5...Commuting pole winding, 6... ... Auxiliary winding, 7... AC power supply, 8... Rectifier, 9... Smooth sliding axle, 10... Resistor.

Claims (1)

[Claims] 1. In a DC machine equipped with an armature, a commutative pole, and a main pole, an auxiliary winding gold film is applied to the gap side part of the nJ commutative pole,
And this auxiliary winding has the same ripple period as the armature current,
A DC machine characterized in that the DC machine is excited by a pulsating current power supply having a phase that is advanced from the phase of the armature current.